STACKED HERBICIDE TOLERANCE EVENT 8264.44.06.1, RELATED TRANSGENIC SOYBEAN LINES, AND DETECTION THEREOF
This invention relates in part to soybean event pDAB8264.44.06.1 and includes a novel expression cassettes and transgenic inserts comprising multiple traits conferring resistance to glyphosate, aryloxyalkanoate, and glufosinate herbicides. This invention also relates in part to methods of controlling resistant weeds, plant breeding and herbicide tolerant plants. In some embodiments, the event sequence can be “stacked” with other traits, including, for example, other herbicide tolerance gene(s) and/or insect-inhibitory proteins. This invention further relates in part to endpoint TaqMan PCR assays for the detection of Event pDAB8264.44.06.1 in soybeans and related plant material. Some embodiments can perform high throughput zygosity analysis of plant material and other embodiments can be used to uniquely identify the zygosity of and breed soybean lines comprising the event of the subject invention. Kits and conditions useful in conducting these assays are also provided.
Glyphosate (N-phosphonomethylglycine), a broad-spectrum herbicide, inhibits 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), an enzyme in the shikimate biosynthetic pathway that produces the essential aromatic amino acids in plant cells. Inhibition of EPSPS effectively disrupts protein synthesis and thereby kills the affected plant cells. Because glyphosate is non-selective, it kills both weeds and crop plants. Thus it is useful with crop plants when one can modify the crop plants to be resistant to glyphosate, allowing the desirable plants to survive exposure to the glyphosate.
Recombinant DNA technology has been used to isolate mutant EPSP synthases that are glyphosate-resistant. Such glyphosate-resistant mutant EPSP synthases can be transformed into plants and confer glyphosate-resistance upon the transformed plants. By way of example, a glyphosate tolerance gene was isolated from Agrobacterium strain CP4 as described in U.S. Pat. No. 5,633,435. This reference and all references cited herein are hereby incorporated by reference.
Other glyphosate tolerance genes have been created through the introduction of mutations. These include the AroA gene isolated by Comai and described at U.S. Pat. Nos. 5,094,945, 4,769,061 and 4,535,060. A single mutant has been utilized, as described in U.S. Pat. No. 5,310,667, by substituting an alanine residue for a glycine residue between amino acid positions 80 and 120. Double mutants have been described in U.S. Pat. Nos. 6,225,114 and 5,866,775 in which, in addition to the above mutation, a second mutation (a threonine residue for an alanine residue between positions 170 and 210) was introduced into a wild-type EPSPS gene.
Other work resulted in the production of glyphosate resistant maize through the introduction of a modified maize EPSPS gene bearing mutations at residue 102 (changing threonine to isoleucine) and residue 106 (changing proline to serine) of the amino acid sequence encoded by GenBank Accession No. X63374. See U.S. Pat. Nos. 6,566,587 and 6,040,497.
Examples of events providing resistance to glyphosate in soybeans include soybean line GTS 40-3-2 (Padgette et al. 1995), soybean event MON89788 (U.S. Pat. No. 7,608,761), U.S. Pat. No. 7,608,761 relates to soybean event MON89788, each of which was produced by inserting the cp4 epsps gene into soybean.
The widespread adoption of the glyphosate tolerant cropping system and the increasing use of glyphosate has contributed to the prevalence of glyphosate-resistant and difficult-to-control weeds in recent years. In areas where growers are faced with glyphosate resistant weeds or a shift to more difficult-to-control weed species, growers can compensate for glyphosate's weaknesses by tank mixing or alternating with other herbicides that will control the missed weeds.
One popular and efficacious tankmix partner for controlling broadleaf escapes in many instances has been 2,4-dichlorophenoxyacetic acid (2,4-D). 2,4-D, which has been used as a herbicide for more than 60 years, provides broad spectrum, post-emergence control of many annual, biennial, and perennial broadleaf weeds including several key weeds in corn, soybeans, and cotton. Key weeds controlled by 2,4-D (560-1120 g ac/ha rates) in row crop production include Ambrosia artemisiifolia, Ambrosia triida, Xanthium strumarium, Chenopodium album, Helianthus annuus, Ipomoea sp., Abutilon theophrasti, Conyza Canadensis, and Senna obtusifolia. 2,4-D provides partial control of several key weeds including Polygonum pensylvanicum, Polygonum persicaria, Cirsium arvense, Taraxacum oficinale, and Amaranthus sp. including Amaranthus rudis, and Amaranthus palmeri.
A limitation to further use of 2,4-D is that its selectivity in dicot crops like soybean or cotton is very poor, and hence 2,4-D is not typically used on (and generally not near) sensitive dicot crops. Additionally, 2,4-D's use in grass crops is somewhat limited by the nature of crop injury that can occur. 2,4-D in combination with glyphosate has been used to provide a more robust burndown treatment prior to planting no-till soybeans and cotton; however, due to these dicot species' sensitivity to 2,4-D, these burndown treatments must occur at least 14-30 days prior to planting (Agriliance, 2005).
One organism that has been extensively researched for its ability to degrade 2,4-D is Ralstonia eutropha, which contains a gene that codes for fdA (Streber et al., 1987), an enzyme which catalyzes the first step in the mineralization pathway. (See U.S. Pat. No. 6,153,401 and GENBANK Acc. No. M16730). tfdA has been reported to degrade 2,4-D (Smejkal et al., 2001). The products that result from the degradation have little to no herbicidal activity compared to 2,4-D. tfdA has been used in transgenic plants to impart 2,4-D resistance in dicot plants (e.g., cotton and tobacco) normally sensitive to 2,4-D (Streber et al. (1989), Lyon et al. (1989), Lyon (1993), and U.S. Pat. No. 5,608,147).
A number of tfdA-type genes that encode proteins capable of degrading 2,4-D have been identified from the environment and deposited into the Genbank database. Many homologues are similar to tfdA (>85% amino acid identity). However, there are a number of polynucleotide sequences that have a significantly lower identity to tfdA (25-50%), yet have the characteristic residues associated with α-ketoglutarate dioxygenase Fe(II) dioxygenases.
An example of a 2,4-D-degrading gene with low sequence identity (<35%) to tfdA is the aad-12 gene from Delftia acidovorans (US Patent App 2011/0203017). The aad-12 gene encodes an S-enantiomer-specific α-ketoglutarate-dependent dioxygenase which has been used in plants to confer tolerance to certain phenoxy auxin herbicides, including, but not limited to: phenoxyacctic acid herbicides such as 2,4-D and MCPA; and phenoxybutanoic acid herbicides, such as 2,4-DB and MCPB) and pyridyloxyalkanoic acid herbicides (e.g., pyridyloxyacetic acid herbicides such as triclopyr and fluroxypyr), and including acid, salt, or ester forms of the active ingredient(s). (See, e.g., WO 2007/053482).
Glufosinate-ammonium (“glufosinate”) is a non-systemic, non-selective herbicide in the phosphinothricin class of herbicides. Used primarily for post-emergence control of a wide range of broadleaf and grassy weeds, L-phosphinothricin, the active ingredient in glufosinate, controls weeds through the irreversible inhibition of glutamine-synthase, an enzyme which is necessary for ammonia detoxification in plants. Glufosinate herbicides are sold commercially, for example, under the brand names Ignite®, BASTA, and Liberty®.
The enzyme phosphinothricin N-acetyl transferase (PAT), isolated from the soil bacterium Streptomyces viridochromogenes, catalyzes the conversion of L-phosphinothricin to its inactive form by acetylation. A plant-optimized form of the gene expressing PAT has been used in soybeans to confer tolerance to glufosinate herbicide. One such example of glufosinate resistant soybeans is event A5547-127. Most recently, the use of glufosinate herbicide in combination with the glufosinate-tolerance trait has been proposed as a non-selective means to effectively manage ALS- and glyphosate resistant weeds.
The expression of heterologous or foreign genes in plants is influenced by where the foreign gene is inserted in the chromosome. This could be due to chromatin structure (e.g., heterochromatin) or the proximity of transcriptional regulation elements (e.g., enhancers) close to the integration site (Weising et al., Ann. Rev. Genet 22:421-477, 1988), for example. The same gene in the same type of transgenic plant (or other organism) can exhibit a wide variation in expression level amongst different events. There may also be differences in spatial or temporal patterns of expression. For example, differences in the relative expression of a transgene in various plant tissues may not correspond to the patterns expected from transcriptional regulatory elements present in the introduced gene construct.
Thus, large numbers of events are often created and screened in order to identify an event that expresses an introduced gene of interest to a satisfactory level for a given purpose. For commercial purposes, it is common to produce hundreds to thousands of different events and to screen those events for a single event that has desired transgene expression levels and patterns. An event that has desired levels and/or patterns of transgene expression is useful for introgressing the transgene into other genetic backgrounds by sexual outcrossing using conventional breeding methods. Progeny of such crosses maintain the transgene expression characteristics of the original transformant. This strategy is used to ensure reliable gene expression in a number of varieties that are well adapted to local growing conditions.
BRIEF SUMMARY OF THE INVENTIONThe subject invention can provide, in part, effective means for managing weed resistance, which helps preserve the usefulness of herbicide-tolerant technologies. The subject invention can also provide growers with great flexibility and convenience in weed control options.
More specifically, the present invention relates in part to the soybean (Glycine max) event designated pDAB8264.44.06.1 (“Event pDA138264.44.06.1”) having representative seed deposited with American Type Culture Collection (ATCC) with Accession No. PTA-11336, and progeny derived thereof. The subject invention includes soybean plants comprising Event pDAB8264.44.06.1 (and includes soybean plants comprising a transgenic insert in a genomic segment comprising SEQ ID NO:1 and SEQ ID NO:2).
The transgenic insert present in the subject event and deposited seed comprises three herbicide tolerance genes: aad-12, 2mepsps, and a pat gene. The aad-12 gene, derived from Delftia acidovorans, encodes the aryloxyalkanoate dioxygenase (AAD-12) protein, which confers tolerance to, e.g., 2,4-dichlorophenoxyacetic acid and pyridyloxyacetate herbicides. The 2mepsps gene, a modified EPSPS sequence isolated from maize, produces a protein which confers tolerance to glyphosate herbicides. The pat gene, from the soil bacterium Streptomyces viridochromogenes, confers tolerance to the herbicide glufosinate.
Other aspects of the invention comprise progeny plants, soybeans, seeds, and/or regenerable parts of the plants and seeds and progeny comprising soybean event pDAB8264.44.06.1, as well as food or feed products made from any thereof. The invention also includes plant parts of Event pDAB8264.44.06.1 that include, but are not limited to, pollen, ovule, flowers, shoots, roots, leaves, nuclei of vegetative cells, pollen cells, and other plant cells that comprise Event pDAB8264.44.06.1. The invention further relates to soybean plants having tolerance to multiple herbicides including phenoxyacetic acid herbicides, phenoxybutanoic acid herbicides, pyridyloxyalkanoic acid herbicides, glyphosate, and/or glufosinate. Such soybean plants may also be stacked with genes that confer tolerance to various other non-selective and selective herbicides, including but not limited to dicamba, imidazolinone, and HPPD herbicides. The invention further includes novel genetic compositions Event pDAB8264.44.06.1 and aspects of agronomic performance of soybean plants comprising Event pDAB8264.44.06.1.
This invention relates in part to plant breeding and herbicide tolerant plants. This invention includes a novel transformation event in soybean plants comprising a polynucleotide, as described herein, inserted into a specific site within the genome of a soybean cell.
In some embodiments, said event/polynucleotide can be “stacked” with other traits, including, for example, agronomic traits and/or insect-inhibitory proteins. However, the subject invention includes plants having the single event, as described herein.
In some embodiments, the subject herbicide tolerance event can be combined in a breeding stack with an insect resistance event. In some of these embodiments, the insect resistance event comprises a cry1F gene and a cry1Ac gene. Some such events and stacks are specifically exemplified herein, including soybean event 9582.812.9.1 (“the 812 Event”) and soybean event 9582.814.19.1 (“the 814 Event”). Plants, plant cells, and seeds, for example, comprising any combination of the subject events are included in the subject invention. In some embodiments, the subject invention includes the Soybean Event 9582.812.9.1 ('812 Event), alone, as discussed in more detail below.
The additional traits may be stacked into the plant genome, or into the same locus as Event pDAB8264.44.06.1, for example via plant breeding, re-transformation of the transgenic plant containing Event DAS-8264.44.06.1, or addition of new traits through targeted integration via homologous recombination.
Other embodiments include the excision of a portion or all of the transgenic insert and/or flanking sequences of Event DAS-8264.44.06.1. Upon excision, another and/or additional insert can be targeted to the specific chromosomal site of Event DAS-8264.44.06.1. The exemplified insert can be replaced, or further insert(s) can be stacked, in this manner, with the exemplified insert of the subject soybean event.
In one embodiment, the present invention encompasses a soybean chromosomal target site located on chromosome 6. In some embodiments, the target site comprises a heterologous nucleic acid. In some embodiments, the soybean chromosomal target site is located between or within the genomic flanking sequences set forth in SEQ ID NO:1 and SEQ ID NO:2.
In one embodiment, the present invention encompasses a method of making a transgenic soybean plant comprising inserting a heterologous nucleic acid at a position on chromosome 6. In another embodiment, the heterologous nucleic acid is inserted on chromosome 6 near or between various exemplified polynucleotide segments as described herein.
Additionally, the subject invention provides assays for detecting the presence of the subject event in a sample (of soybeans, for example). The assays can be based on the DNA sequence of the recombinant construct, inserted into the soybean genome, and on the genomic sequences flanking the insertion site. Kits and conditions useful in conducting the assays arc also provided.
Thus, the subject invention relates in part to the cloning and analysis of the DNA sequences of the whole exemplified insert and the border regions thereof (in transgenic soybean lines). These sequences are unique. Based on these insert and border (and junction) sequences, event-specific primers can be and were generated. PCR analysis demonstrated that the events can be identified by analysis of the PCR amplicons generated with these event-specific primer sets. Thus, these and other related procedures can be used to uniquely identify soybean lines comprising the event of the subject invention.
The subject invention also relates in part to realtime or endpoint TaqMan PCR assays for the detection of event 8264.44.06.1. Some embodiments are directed to assays that are capable of high throughput zygosity analysis. The subject invention further relates, in part, to the use of a GMFL01-25-J19 (GenBank: AK286292.1) reference gene for use in determining zygosity. These and other related procedures can be used to uniquely identify the zygosity of Event pDAB8264.44.06.1 and breed soybean lines comprising the event.
SEQ ID NO:1 provides the 5′ flanking border sequence for the subject soybean Event pDAB8264.44.06.1.
SEQ ID NO:2 provides the 3′ flanking border sequence for the subject soybean Event pDAB8264.44.06.1.
SEQ ID NO:3 provides primer 4406_WF1.
SEQ ID NO:4 provides primer 4406_WF2.
SEQ ID NO:5 provides primer 4406_WF3.
SEQ ID NO:6 provides primer 4406_WF4.
SEQ ID NO:7 provides primer 4406_WR5.
SEQ ID NO:8 provides primer 4406_WR6.
SEQ ID NO:9 provides primer 4406_WR7.
SEQ ID NO:10 provides primer 4406_WR8.
SEQ ID NO:11 provides primer ED_v1_C1.
SEQ ID NO:12 provides primer PAT_12.
SEQ ID NO:13 provides sequence for plasmid pDAB8264.
SEQ ID NO:14 provides partial 5′ soybean genomic flanking and partial 5′ insert sequence.
SEQ ID NO:15 provides partial 3′ soybean genomic flanking and partial 3′ insert sequence.
SEQ ID NO:16 provides a 98 base pair sequence spanning the 5′ integration junction.
SEQ ID NO:17 provides a 131 base pair sequence spanning the 3′ integration junction.
SEQ ID NO:18 provides primer 4406_5′F.
SEQ ID NO:19 provides primer 4406_5′R.
SEQ ID NO:20 provides probe 4406_5′P.
SEQ ID NO:21 provides primer 4406_3′F.
SEQ ID NO:22 provides primer 4406_3′R.
SEQ ID NO:23 provides probe 4406_3′P.
SEQ ID NO:24 provides primer GMS116F.
SEQ ID NO:25 provides primer GMS116R.
SEQ ID NO:26 provides probe GMS116Probe
SEQ ID NO:27 provides the sequence of soybean Event pDAB8264.44.06.1, including the 5′ genomic flanking sequence, insert, and 3′ genomic flanking sequence.
SEQ ID NO:28 provides the expected sequence of Soybean Event 9582.812.9.1, including the 5′ genomic flanking sequence, pDAB9582 T-strand insert, and 3′ genomic flanking sequence.
SEQ ID NO:29 provides the expected sequence of Soybean Event 9582.814.19.1, including the 5′ genomic flanking sequence, pDAB9582 T-strand insert, and 3′ genomic flanking sequence.
DETAILED DESCRIPTION OF THE INVENTIONThe invention described herein includes novel transformation events of soybean plants (soybean) comprising a cassette for the expression of multiple herbicide tolerance genes inserted into a specific locus within the genome of a soybean cell.
The exemplified transgenic insert comprising Event pDAB8264.44.06.1 includes genetic elements for the expression of three different herbicide tolerance genes: (1) a synthetic aad-12 gene; (2) an EPSPS sequence from maize encoding a protein containing mutations, as compared to the wild-type EPSPS polypeptide: at amino acid residues 102 (from threonine to isoleucine) and 106 (from proline to serine) and which confers resistance or tolerance to glyphosate herbicides; and (3) a pat gene which confers tolerance or resistance to the glufosinate herbicides. The aad-12 gene was derived from Delftia acidovorans and encodes an aryloxyalkanoate dioxygenase (AAD-12) protein enzyme capable of deactivating herbicides having an α-ketoglutarate moiety, including phenoxyalkanoate herbicides (e.g., phenoxyacetic acid herbicides such as 2,4-D and MCPA; phenoxypropionic acid herbicides such as dichlorprop, mecoprop and their enantiomers; and phenoxybutanoic acid herbicides such as 2,4-DB and MCPB) and pyridyloxyalkanoic acid herbicides (e.g., pyridyloxyacetic acid herbicides such as triclopyr and fluroxypyr), including acid, salt, or ester forms of the active ingredient(s)
More specifically, the subject invention relates in part to transgenic soybean Event pDAB8264.44.06.1, plant lines comprising these events, and the cloning and analysis of the DNA sequences of this insert, and/or the border regions thereof. Plant lines of the subject invention can be detected using sequences disclosed and suggested herein.
This invention relates in part to plant breeding and herbicide tolerant plants. In some embodiments, said polynucleotide sequence can be “stacked” with other traits (such as other herbicide tolerance gene(s) and/or gene(s) that encode insect-inhibitory proteins or inhibitory RNA sequences, for example). However, the subject invention also includes plants having a single event, as described herein.
In some embodiments, the subject herbicide tolerance event can be combined in a breeding stack with an insect resistance event. In some embodiments, the insect resistance event is selected from the group consisting of the 812 Event and the 814 Event (as defined in greater detail below), each of which comprises a cry1F gene and a cry1Ac gene. Plants, plant cells, and seeds, for example, comprising any combination of the subject events are included in the subject invention. The subject invention also includes the novel 812 Event, alone, in certain embodiments, including plants, plant cells, and seeds, for example.
U.S. provisional application Ser. No. 61/471,845, filed Apr. 5, 2011, relates in part to soybean lines comprising Soybean Event 9582.812.9.1 (the 812 Event). Seeds comprising this event were deposited and made available to the public without restriction (but subject to patent rights), with the American Type Culture Collection (ATCC), 10801 University Boulevard, Manassas, Va., 20110. The deposit, designated as ATCC Deposit No. PTA-11602, was made on Jan. 20, 2011. This deposit was made and will be maintained in accordance with and under the terms of the Budapest Treaty with respect to seed deposits for the purposes of patent procedure.
U.S. provisional application Ser. No. 61/511,664 (filed Jul. 26, 2011) and 61/521,798 (filed Aug. 10, 2011) relates in part to soybean lines comprising soybean event 9582.814.19.1 (the 814 Event). Seeds comprising this event were deposited with the American Type Culture Collection (ATCC), 10801 University Boulevard, Manassas, Va., 20110. The deposit, ATCC Patent Deposit Designation PTA-12006, was received by the ATCC on Jul. 21, 2011. This deposit was made and will be maintained in accordance with and under the terms of the Budapest Treaty with respect to seed deposits for the purposes of patent procedure.
The subject invention also includes plants, seeds, and plant cells, for example, comprising SEQ ID NO:27 (Event pDAB8264.44.06.1; the 4406 Event), SEQ ID NO:28 (the 812 Event), and/or SEQ ID NO:29 (the 814 Event), and variants of these sequences having, for example, at least 95,%, 96%, 97%, 98%, or 99% identity with such sequences. It is not uncommon for some variation (such as deletion of some segments) to occur upon integration of an insert sequence within the plant genome. This is discussed in more detail in Example 7, for example.
The subject invention also provides assays for detecting the presence of the subject event in a sample. Aspects of the subject invention include methods of designing and/or producing any diagnostic nucleic acid molecules exemplified or suggested herein, particularly those based wholly or partially on the subject flanking sequences.
In some embodiments, a polynucleotide segment exemplified or described herein (such as SEQ ID NO:1, SEQ ID NO:2, and/or the insert therebetween, as depicted in
In some embodiments, this invention relates to herbicide-tolerant soybean lines, and the identification thereof. The subject invention relates in part to detecting the presence of the subject event in order to determine whether progeny of a sexual cross contain the event of interest. In addition, a method for detecting the event is included and is helpful, for example, for complying with regulations requiring the pre-market approval and labeling of foods derived from recombinant crop plants, for example. It is possible to detect the presence of the subject event by any well-known nucleic acid detection method such as polymerase chain reaction (PCR) or DNA hybridization using nucleic acid probes. Event-specific PCR assays are discussed herein. (See e.g. Windels et al. (Med. Fac. Landbouww, Univ. Gent 64/5b:459462, 1999) for another example.) Some of these examples relate to using a primer set spanning the junction between the insert and flanking DNA. More specifically, one primer included sequence from the insert and a second primer included sequence from flanking DNA.
Exemplified herein is soybean Event pDAB8264.44.06.1, and its selection and characterization for stability and expression in soybean plants from generation to generation. Both flanking sequences of Event pDAB8264.44.06.1 have been sequenced and are described herein as SEQ ID NO:1 and SEQ ID NO:2. Event specific assays were developed. It has also been mapped onto the soybean genome (soybean chromosome 6). Event pDAB8264.44.06.1 can be introgressed into elite cultivars where it will confer tolerance to phenoxy auxin, glyphosate and glufosinate herbicides in inbred and hybrid soybean lines.
The subject EPSPS gene encodes a mutant 5-enolpyruvyl-3-phosphoshikimic acid synthase (EPSPS). The wild-type EPSPS gene was originally isolated from Zea mays, and the sequence was deposited under GcnBank accession number X63374. See also U.S. Pat. No. 6,566,587 (in particular, SEQ ID No. 3 therein).
To obtain high expression of heterologous genes in plants, it may be preferred to reengineer said genes so that they are more efficiently expressed in plant cells. Modification of the wild-type plant EPSPS nucleotide sequence can provide such resistance when expressed in a plant cell. As described in the '587 patent, when comparing an EPSPS polypeptide to the wild-type polypeptide, modification to substitute isoleucine for threonine at residue 102 and substitute serine for proline at position 106 of the protein, the result is the double mutant EPSPS polypeptide (2mEPSPS) used in the subject insert. When expressed in a plant cell, it provides tolerance to glyphosate. The subject EPSPS gene, also referred to as the “2mepsps gene” or DMMG, can alternatively be optimized to improve expression in both dicotyledonous plants as well as monocotyledonous plants, and in particular in soybean. Codon usage can be selected based upon preferred hemicot codon usage, i.e. redesigned such that the protein is encoded by codons having a bias toward both monocot and dicot plant usage. Deleterious sequences and superfluous restriction sites can be removed to increase the efficiency of transcription/translation of the 2mepsps coding sequence and to facilitate DNA manipulation steps. A hemicot-optimized version of the subject monocot gene is further detailed in U.S. Ser. No. 13/303,502 (filed Nov. 23, 2011, claiming priority to Dec. 3, 2010) entitled, “OPTIMIZED EXPRESSION OF GLYPHOSATE RESISTANCE ENCODING NUCLEIC ACID MOLECULES IN PLANT CELLS.”
As previously referenced herein, the introduction and integration of a transgene into a plant genome involves some random events (hence the name “event” for a given insertion that is expressed). That is, with many transformation techniques such as Agrobacterium transformation, the “gene gun,” and WHISKERS, it is unpredictable where in the genome a transgene will become inserted. Thus, identifying the flanking plant genomic DNA on both sides of the insert can be important for identifying a plant that has a given insertion event. For example, PCR primers can be designed that generate a PCR amplicon across the junction region of the insert and the host genome. This PCR amplicon can be used to identify a unique or distinct type of insertion event.
During the process of introducing an insert into the genome of plant cells, it is not uncommon for some deletions or other alterations of the insert and/or genomic flanking sequences to occur. Thus, the relevant segment of the plasmid sequence provided herein might comprise some minor variations. The same is true for the flanking sequences provided herein. Thus, a plant comprising a polynucleotide having some range of identity with the subject flanking and/or insert sequences is within the scope of the subject invention. Identity to the sequence of the present invention can be a polynucleotide sequence having at least 65% sequence identity, more preferably at least 70% sequence identity, more preferably at least 75% sequence identity, more preferably at least 80% identity, and more preferably at least 85% 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% sequence identity with a sequence exemplified or described herein. Hybridization and hybridization conditions as provided herein can also be used to define such plants and polynucleotide sequences of the subject invention. The sequence which comprises the flanking sequences plus the full insert sequence can be confirmed with reference to the deposited seed.
As “events” are originally random events, as part of this disclosure at least 2500 seeds of a soybean line comprising Event pDAB8264.44.06.1 have been deposited and made available to the public without restriction (but subject to patent rights), with the American Type Culture Collection (ATCC), 10801 University Boulevard, Manassas, Va., 20110. The deposit has been designated as ATCC Deposit No. PTA-11336. 100 packets (25 seeds per packet) of Glycine max seeds (“Soybean Seed Glycine max L.: pDAB8264.44.06.1”) were deposited on behalf of Dow AgroSciences LLC and MS Technologies, LLC on Sep. 14, 2010. The deposit was tested on Oct. 4, 2010, and on that date, the seeds were viable. This deposit was made and will be maintained in accordance with and under the terms of the Budapest Treaty with respect to seed deposits for the purposes of patent procedure. The deposit will be maintained without restriction at the ATCC depository, which is a public depository, for a period of 30 years, or five years after the most recent request, or for the effective life of the patent, whichever is longer, and will be replaced if it becomes nonviable during that period.
As part of this disclosure at least 2500 seeds of a soybean line comprising Event pDAB9582.812.9.1 and Event pDAB8264.44.06.1 (the subject herbicide tolerance event and the 812 insect resistance event) have been deposited and made available to the public without restriction (but subject to patent rights), with the American Type Culture Collection (ATCC), 10801 University Boulevard, Manassas, Va., 20110. The deposit has been identified as “Designation: pDAB9582.812.9.1:: Event pDAB8264.44.06.1” by the ATCC. 100 packets (25 seeds per packet) of Glycine max seeds (“Soybean Seed Glycine max L.: pDAB8264.44.06.1”) were deposited on Nov. 18, 2011. This deposit was made and will be maintained in accordance with and under the terms of the Budapest Treaty with respect to seed deposits for the purposes of patent procedure. The deposit will be maintained without restriction at the ATCC depository, which is a public depository, for a period of 30 years, or five years after the most recent request, or for the effective life of the patent, whichever is longer, and will be replaced if it becomes nonviable during that period.
The deposited seeds are part of the subject invention. Clearly, soybean plants can be grown from these seeds, and such plants are part of the subject invention. The subject invention also relates to DNA sequences contained in these soybean plants that are useful for detecting these plants and progeny thereof. Detection methods and kits of the subject invention can be directed to identifying any one, two, or even all three of these events, depending on the ultimate purpose of the test.
Definitions and examples are provided herein to help describe the present invention and to guide those of ordinary skill in the art to practice the invention. Unless otherwise noted, terms are to be understood according to conventional usage by those of ordinary skill in the relevant art. The nomenclature for DNA bases as set forth at 37 CFR § 1.822 is used.
As used herein, the term “progeny” denotes the offspring of any generation of a parent plant which comprises soybean Event pDAB8264.44.06.1.
A transgenic “event” is produced by transformation of plant cells with heterologous DNA, i.e., a nucleic acid construct that includes a transgene of interest, regeneration of a population of plants resulting from the insertion of the transgene into the genome of the plant, and selection of a particular plant characterized by insertion into a particular genome location. The term “event” refers to the original transformant and progeny of the transformant that include the heterologous DNA. The term “event” also refers to progeny produced by a sexual outcross between the transformant and another variety that includes the genomic/transgene DNA. Even after repeated back-crossing to a recurrent parent, the inserted transgene DNA and flanking genomic DNA (genomic/transgene DNA) from the transformed parent is present in the progeny of the cross at the same chromosomal location. The term “event” also refers to DNA from the original transformant and progeny thereof comprising the inserted DNA and flanking genomic sequence immediately adjacent to the inserted DNA that would be expected to be transferred to a progeny that receives inserted DNA including the transgene of interest as the result of a sexual cross of one parental line that includes the inserted DNA (e.g., the original transformant and progeny resulting from selfing) and a parental line that does not contain the inserted DNA.
A “junction sequence” spans the point at which DNA inserted into the genome is linked to DNA from the soybean native genome flanking the insertion point, the identification or detection of one or the other junction sequences in a plant's genetic material being sufficient to be diagnostic for the event. Included are the DNA sequences that span the insertions in herein-described soybean events and similar lengths of flanking DNA. Specific examples of such diagnostic sequences are provided herein; however, other sequences that overlap the junctions of the insertions, or the junctions of the insertions and the genomic sequence, are also diagnostic and could be used according to the subject invention.
The subject invention relates in part to event identification using such flanking, junction, and insert sequences. Related PCR primers and amplicons are included in the invention. According to the subject invention, PCR analysis methods using amplicons that span across inserted DNA and its borders can be used to detect or identify commercialized transgenic soybean varieties or lines derived from the subject proprietary transgenic soybean lines.
The binary plasmid, pDAB8264 (SEQ ID NO:13) comprises the genetic elements depicted in
SEQ ID NOs: 14 and 15, respectively, are the 5′ and 3′ flanking sequences together with 5′ and 3′ portions of the insert sequence, as described in more detail below, and thus include the 5′ and 3′ “junction” or “transition” sequences of the insert and the genomic DNA. With respect to SEQ ID NO: 14, residues 1-570 are 5′ genomic flanking sequence, and residues 571-859 are residues of the 5′ end of the insert. With respect to SEQ ID NO: 15, residues 1-220 are residues of the 3′ end of the insert, and residues 221-1719 are 3′ genomic flanking sequence. The junction sequence or transition with respect to the 5′ end of the insert thus occurs at residues 570-571 of SEQ ID NO: 14. The junction sequence or transition with respect to the 3′ end of the insert thus occurs at residues 220-221 of SEQ ID NO: 15. Polynucleotides of the subject invention include those comprising, for example, 5, 10, 20, 50, 100, 150, or 200 bases, or possibly more, and any increments therebetween, on either side of the junction sequence. Thus, a primer spanning the junction sequence could comprise, for example, 5-10 bases that would hybridize with flanking sequence and 5-10 bases that would hybridize with insert sequence. Probes and amplicons could be similarly designed, although they would often be longer than primers.
The subject sequences (including the flanking sequences) are unique. Based on these insert and flanking sequences, event-specific primers were generated. PCR analysis demonstrated that these soybean lines can be identified in different soybean genotypes by analysis of the PCR amplicons generated with these event-specific primer sets. Thus, these and other related procedures can be used to uniquely identify these soybean lines. The sequences identified herein are unique.
Detection techniques of the subject invention are especially useful in conjunction with plant breeding, to determine which progeny plants comprise a given event, after a parent plant comprising an event of interest is crossed with another plant line in an effort to impart one or more additional traits of interest in the progeny. These PCR analysis methods benefit soybean breeding programs as well as quality control, especially for commercialized transgenic soybean seeds. PCR detection kits for these transgenic soybean lines can also now be made and used. This can also benefit product registration and product stewardship.
Furthermore, flanking soybean/genomic sequences can be used to specifically identify the genomic location of each insert. This information can be used to make molecular marker systems specific to each event. These can be used for accelerated breeding strategies and to establish linkage data.
Still further, the flanking sequence information can be used to study and characterize transgene integration processes, genomic integration site characteristics, event sorting, stability of transgenes and their flanking sequences, and gene expression (especially related to gene silencing, transgene methylation patterns, position effects, and potential expression-related elements such as MARS [matrix attachment regions], and the like).
In light of the subject disclosure, it should be clear that the subject invention includes seeds available under ATCC Deposit No. PTA-11336. The subject invention also includes a herbicide-tolerant soybean plant grown from a seed deposited with the ATCC under accession number PTA-11336. The subject invention further includes parts of said plant, such as leaves, tissue samples, seeds produced by said plant, pollen, and the like (wherein they comprise a transgenic insert flanked by SEQ ID NO:1 and SEQ ID NO:2).
Still further, the subject invention includes descendant and/or progeny plants of plants grown from the deposited seed, preferably a herbicide-resistant soybean plant wherein said plant has a genome comprising a detectable wild-type genomic DNA/insert DNA junction sequence as described herein. As used herein, the term “soybean” means Glycine max and includes all varieties thereof that can be bred with a soybean plant.
The invention further includes processes of making crosses using a plant of the subject invention as at least one parent. For example, the subject invention includes an F1 hybrid plant having as one or both parents any of the plants exemplified herein. Also within the subject invention is seed produced by such F1 hybrids of the subject invention. This invention includes a method for producing an F1 hybrid seed by crossing an exemplified plant with a different (e.g. in-bred parent) plant and harvesting the resultant hybrid seed. The subject invention includes an exemplified plant that is either a female parent or a male parent. Characteristics of the resulting plants may be improved by careful consideration of the parent plants.
A herbicide-tolerant soybean plant of the subject invention can be bred by first sexually crossing a first parental soybean plant consisting of a soybean plant grown from seed of any one of the lines referred to herein, and a second parental soybean plant, thereby producing a plurality of first progeny plants; then selecting a first progeny plant that is resistant to a herbicide (or that possesses at least one of the events of the subject invention); selfing the first progeny plant, thereby producing a plurality of second progeny plants; and then selecting from the second progeny plants a plant that is resistant to a herbicide (or that possesses at least one of the events of the subject invention). These steps can further include the back-crossing of the first progeny plant or the second progeny plant to the second parental soybean plant or a third parental soybean plant. A soybean crop comprising soybean seeds of the subject invention, or progeny thereof, can then be planted.
It is also to be understood that two different transgenic plants can also be mated to produce offspring that contain two independently segregating, added, exogenous genes. Selfing of appropriate progeny can produce plants that are homozygous for both added, exogenous genes. Back-crossing to a parental plant and out-crossing with a non-transgenic plant are also contemplated, as is vegetative propagation. Other breeding methods commonly used for different traits and crops are known in the art. Backcross breeding has been used to transfer genes for a simply inherited, highly heritable trait into a desirable homozygous cultivar or inbred line, which is the recurrent parent. The source of the trait to be transferred is called the donor parent. The resulting plant is expected to have the attributes of the recurrent parent (e.g., cultivar) and the desirable trait transferred from the donor parent. After the initial cross, individuals possessing the phenotype of the donor parent are selected and repeatedly crossed (backcrossed) to the recurrent parent. The resulting parent is expected to have the attributes of the recurrent parent (e.g., cultivar) and the desirable trait transferred from the donor parent.
The DNA molecules of the present invention can be used as molecular markers in a marker assisted breeding (MAB) method. DNA molecules of the present invention can be used in methods (such as, AFLP markers, RFLP markers, RAPD markers, SNPs, and SSRs) that identify genetically linked agronomically useful traits, as is known in the art. The herbicide-resistance trait can be tracked in the progeny of a cross with a soybean plant of the subject invention (or progeny thereof and any other soybean cultivar or variety) using the MAB methods. The DNA molecules are markers for this trait, and MAB methods that are well known in the art can be used to track the herbicide-resistance trait(s) in soybean plants where at least one soybean line of the subject invention, or progeny thereof, was a parent or ancestor. The methods of the present invention can be used to identify any soybean variety having the subject event.
Methods of the subject invention include a method of producing a herbicide-tolerant soybean plant wherein said method comprises introgessing Event pDAB8264.44.06.1 into a soybean cultivar. More specifically, methods of the present invention can comprise crossing two plants of the subject invention, or one plant of the subject invention and any other plant. Preferred methods further comprise selecting progeny of said cross by analyzing said progeny for an event detectable according to the subject invention. For example, the subject invention can be used to track the subject event through breeding cycles with plants comprising other desirable traits, such as agronomic traits such as those tested herein in various Examples. Plants comprising the subject event and the desired trait can be detected, identified, selected, and quickly used in further rounds of breeding, for example. The subject event/trait can also be combined through breeding, and tracked according to the subject invention, with an insect resistant trait(s) and/or with further herbicide tolerance traits. One embodiment of the latter is a plant comprising the subject event combined with a gene encoding resistance to the herbicide dicamba.
Thus, the subject invention can be combined with, for example, additional traits encoding glyphosate resistance (e.g., resistant plant or bacterial glyphosate oxidase (GOX)), glyphosate acetyl transferase (GA 7), additional traits for glufosinate resistance (e.g. bialaphos resistance (bar)), traits conferring acetolactate synthase (ALS)-inhibiting herbicide resistance (e.g., imidazolinones [such as imazethapyr], sulfonylureas, triazolopyrimidine sulfonanilide, pyrmidinylthiobenzoates, and other chemistries [Csr1, SurA, el al.]), bromoxynil resistance traits (e.g., Bxn), traits for resistance to dicamba herbicide (see, e.g., U.S. 2003/0135879), traits for resistance to inhibitors of HPPD (4-hydroxyphenyl-pyruvate-dioxygenase) enzyme, traits for resistance to inhibitors of phytoene desaturase (PDS), traits for resistance to photosystem 11 inhibiting herbicides (e.g., psbA), traits for resistance to photosystem I inhibiting herbicides, traits for resistance to protoporphyrinogen oxidase IX (PPO)-inhibiting herbicides (e.g., PPO-1), and traits for resistance to phenylurea herbicides (e.g., CYP76B1). One or more of such traits can be combined with the subject invention to provide the ability to effectively control, delay and/or prevent weed shifts and/or resistance to herbicides of multiple classes.
It will be appreciated by those of skill in the art that the aad-12 gene used in the subject invention also provides resistance to compounds that are converted to phenoxyacetate auxin herbicides (e.g., 2,4-DB, MCPB, etc.). The butyric acid moiety present in the 2,4-DB herbicide is converted through β-oxidation to the phytotoxic 2,4-dichlorophenoxyacetic acid. Likewise. MCPB is converted through β-oxidation to the phytotoxic MCPA. The butanoic acid herbicides are themselves nonherbicidal, but are converted to their respective acid from by β-oxidation within susceptible plants to produce the acetic acid form of the herbicide that is phytotoxic. Plants incapable of rapid β-oxidation are not harmed by the butanoic acid herbicides. However, plants that are capable of rapid β-oxidation and can convert the butanoic acid herbicide to the acetic form are subsequently protected by AAD-12.
Methods of applying herbicides are well known in the art. Such applications can include tank mixes of more than one herbicide. Preferred herbicides for use according to the subject invention are combinations of glyphosate, glufosinate, and a phenoxy auxin herbicide (such as 2,4-D; 2,4-DB; MCPA; MCPB). Other preferred combinations include glyphosate plus 2,4-D or glufosinate plus 2,4-D mixtures. These three types of herbicides can be used in advantageous combinations that would be apparent to one skilled in the art having the benefit of the subject disclosure. One or more of the subject herbicides can be applied to a field/area prior to planting it with seeds of the subject invention. Such applications can be within 14 days, for example, of planting seeds of the subject invention. One or more of the subject herbicides can also be applied after planting prior to emergence. One or more of the subject herbicides can also be applied to the ground (for controlling weeds) or over the top of the weeds and/or over the top of transgenic plants of the subject invention. The subject three herbicides can be rotated or used in combination to, for example, control or prevent weeds that might to tolerant to one herbicide but not another. Various application times for the subject three types of herbicides can be used in various ways as would be known in the art.
Additionally, the subject event can be stacked with one or more additional herbicide tolerance traits, one or more additional input (e.g., insect resistance (e.g., the 812 Event or the 814 Event), fungal resistance, or stress tolerance, et al.) or output (e.g., increased yield, improved oil profile, improved fiber quality, et al.) traits, both transgenic and nontransgenic. Thus, the subject invention can be used to provide a complete agronomic package of improved crop quality with the ability to flexibly and cost effectively control any number of agronomic pests.
Methods to integrate a polynucleotide sequence within a specific chromosomal site of a plant cell via homologous recombination have been described within the art. For instance, site specific integration as described in U.S. Patent Application Publication No. 2009/0111188 A1, describes the use of recombinases or integrases to mediate the introduction of a donor polynucleotide sequence into a chromosomal target. In addition, International Patent Application No. WO 2008/021207 describes zinc finger mediated-homologous recombination to integrate one or more donor polynucleotide sequences within specific locations of the genome. The use of recombinases such as FLP/FRT as described in U.S. Pat. No. 6,720,475, or CRE/LOX as described in U.S. Pat. No. 5,658,772, can be utilized to integrate a polynucleotide sequence into a specific chromosomal site. Finally the use of meganucleases for targeting donor polynucleotides into a specific chromosomal location was described in Puchta et al., PNAS USA 93 (1996) pp. 5055-5060).
Other various methods for site specific integration within plant cells are generally known and applicable (Kumar et al., Trends in Plant Sci. 6(4) (2001) pp. 155-159). Furthermore, site-specific recombination systems which have been identified in several prokaryotic and lower eukaryotic organisms may be applied to use in plants. Examples of such systems include, but are not limited too; the R/RS recombinase system from the pSR1 plasmid of the yeast Zygosaccharomyces rouxii (Araki et al. (1985) J. Mol. Biol. 182: 191-203), and the Gin/gix system of phage Mu (Maeser and Kahlmann (1991) Mol. Gen. Genet. 230: 170-176).
In some embodiments of the present invention, it can be desirable to integrate or stack a new transgene(s) in proximity to an existing transgenic event. The transgenic event can be considered a preferred genomic locus which was selected based on unique characteristics such as single insertion site, normal Mendelian segregation and stable expression, and a superior combination of efficacy, including herbicide tolerance and agronomic performance in and across multiple environmental locations. The newly integrated transgenes should maintain the transgene expression characteristics of the existing transformants. Moreover, the development of assays for the detection and confirmation of the newly integrated event would be overcome as the genomic flanking sequences and chromosomal location of the newly integrated event are already identified. Finally, the integration of a new transgene into a specific chromosomal location which is linked to an existing transgene would expedite the introgression of the transgenes into other genetic backgrounds by sexual out-crossing using conventional breeding methods.
In some embodiments of the present invention, it can be desirable to excise polynucleotide sequences from a transgenic event. For instance transgene excision as described in U.S. patent application Ser. No. 13/011,666, describes the use of zinc finger nucleases to remove a polynucleotide sequence, consisting of a gene expression cassette, from a chromosomally integrated transgenic event. The polynucleotide sequence which is removed can be a selectable marker. Upon excision and removal of a polynucleotide sequence the modified transgenic event can be retargeted by the insertion of a polynucleotide sequence. The excision of a polynucleotide sequence and subsequent retargeting of the modified transgenic event provides advantages such as re-use of a selectable marker or the ability to overcome unintended changes to the plant transcriptome which results from the expression of specific genes.
The subject invention discloses herein a specific site on chromosome 6 in the soybean genome that is excellent for insertion of heterologous nucleic acids. Also disclosed is a 5′ flanking sequence and a 3′ flanking sequence, which can also be useful in identifying and/or targeting the location of the insertion/targeting site on chromosome 6. Thus, the subject invention provides methods to introduce heterologous nucleic acids of interest into this pre-established target site or in the vicinity of this target site. The subject invention also encompasses a soybean seed and/or a soybean plant comprising any heterologous nucleotide sequence inserted at the disclosed target site or in the general vicinity of such site. One option to accomplish such targeted integration is to excise and/or substitute a different insert in place of the pat expression cassette exemplified herein. In this general regard, targeted homologous recombination, for example and without limitation, can be used according to the subject invention.
As used herein gene, event or trait “stacking” is combining desired traits into one transgenic line. Plant breeders stack transgenic traits by making crosses between parents that each have a desired trait and then identifying offspring that have both of these desired traits. Another way to stack genes is by transferring two or more genes into the cell nucleus of a plant at the same time during transformation. Another way to stack genes is by re-transforming a transgenic plant with another gene of interest. For example, gene stacking can be used to combine two or more different traits, including for example, two or more different insect traits, insect resistance trait(s) and disease resistance trait(s), two or more herbicide resistance traits, and/or insect resistance trait(s) and herbicide resistant trait(s). The use of a selectable marker in addition to a gene of interest can also be considered gene stacking.
“Homologous recombination” refers to a reaction between any pair of nucleotide sequences having corresponding sites containing a similar nucleotide sequence though which the two nucleotide sequences can interact (recombine) to form a new, recombinant DNA sequence. The sites of similar nucleotide sequence are each referred to herein as a “homology sequence.” Generally, the frequency of homologous recombination increases as the length of the homology sequence increases. Thus, while homologous recombination can occur between two nucleotide sequences that are less than identical, the recombination frequency (or efficiency) declines as the divergence between the two sequences increases. Recombination may be accomplished using one homology sequence on each of the donor and target molecules, thereby generating a “single-crossover” recombination product. Alternatively, two homology sequences may be placed on each of the target and donor nucleotide sequences. Recombination between two homology sequences on the donor with two homology sequences on the target generates a “double-crossover” recombination product. If the homology sequences on the donor molecule flank a sequence that is to be manipulated (e.g., a sequence of interest), the double-crossover recombination with the target molecule will result in a recombination product wherein the sequence of interest replaces a DNA sequence that was originally between the homology sequences on the target molecule. The exchange of DNA sequence between the target and donor through a double-crossover recombination event is termed “sequence replacement.”
The subject event enables transgenic expression of three different herbicide tolerance proteins resulting in tolerance to combinations of herbicides that would control nearly all broadleaf and grass weeds. This multi-herbicide tolerance trait expression cassette/transgenic insert can be stacked with other herbicide tolerance traits (e.g., glyphosate resistance, glufosinate resistance, imidazolinone resistance, dicamba resistance, HPPD resistance, bromoxynil resistance, et al.), and insect resistance traits (such as Cry1F, Cry1Ab, Cry1Ac, Cry 34/45, Cry1Be, Cry1Ca, Cry1 Da, Cry1Ea, Cry1Fa, vegetative insecticidal proteins (“VIPS”)—including VIP3A, and the like), for example. Additionally, the herbicide tolerance proteins in the expression cassette/transgenic insert of the subject invention can serve as one or more selectable marker sto aid in selection of primary transformants of plants genetically engineered with a second gene or group of genes.
These combinations of traits give rise to novel methods of controlling weeds (and like) species, due to the newly acquired resistance or inherent tolerance to herbicides (e.g., glyphosate). Thus, novel methods for controlling weeds using Event pDAB8264.44.06.1 are within the scope of the invention.
The use of the subject transgenic traits, stacked or transformed individually into crops, provides a tool for controlling other herbicide tolerant volunteer crops that do not contain genes for conferring tolerance to phenoxy, pyridyloxy, glyphosate and/or glufosinate herbicides.
A preferred plant, or a seed, of the subject invention comprises in its genome the insert sequences, as identified herein, together with at least 20-500 or more contiguous flanking nucleotides on both sides of the insert, as described herein. Unless indicated otherwise, reference to flanking sequences refers to those identified with respect to SEQ ID NO:1 and SEQ ID NO:2. Again, the subject events include heterologous DNA inserted between the subject flanking genomic sequences immediately adjacent to the inserted DNA. All or part of these flanking sequences could be expected to be transferred to progeny that receives the inserted DNA as a result of a sexual cross of a parental line that includes the event.
The subject invention includes tissue cultures of regenerable cells of a plant of the subject invention. Also included is a plant regenerated from such tissue culture, particularly where said plant is capable of expressing all the morphological and physiological properties of an exemplified variety. Preferred plants of the subject invention have all the physiological and morphological characteristics of a plant grown from the deposited seed. This invention further comprises progeny of such seed and seed possessing the quality traits of interest.
Manipulations (such as mutation, further transfection, and further breeding) of plants or seeds, or parts thereof, may lead to the creation of what may be termed “essentially derived” varieties. The International Union for the Protection of New Varieties of Plants (UPOV) has provided the following guideline for determining if a variety has been essentially derived from a protected variety:
[A] variety shall be deemed to be essentially derived from another variety (“the initial variety”) when
(i) it is predominantly derived from the initial variety, or from a variety that is itself predominantly derived from the initial variety, while retaining the expression of the essential characteristics that result from the genotype or combination of genotypes of the initial variety;
(ii) it is clearly distinguishable from the initial variety; and
(iii) except for the differences which result from the act of derivation, it conforms to the initial variety in the expression of the essential characteristics that result from the genotype or combination of genotypes of the initial variety.
UPOV, Sixth Meeting with International Organizations, Geneva, Oct. 30, 1992; document prepared by the Office of the Union.
As used herein, a “line” is a group of plants that display little or no genetic variation between individuals for at least one trait. Such lines may be created by several generations of self-pollination and selection, or vegetative propagation from a single parent using tissue or cell culture techniques.
As used herein, the terms “cultivar” and “variety” are synonymous and refer to a line which is used for commercial production.
“Stability” or “stable” means that with respect to the given component, the component is maintained from generation to generation and, preferably, at least three generations at substantially the same level, e.g., preferably ±15%, more preferably ±10%, most preferably ±5%. The stability may be affected by temperature, location, stress and the time of planting. Comparison of subsequent generations under field conditions should produce the component in a similar manner.
“Commercial Utility” is defined as having good plant vigor and high fertility, such that the crop can be produced by farmers using conventional farming equipment, and the oil with the described components can be extracted from the seed using conventional crushing and extraction equipment. To be commercially useful, the yield, as measured by seed weight, oil content, and total oil produced per acre, is within 15% of the average yield of an otherwise comparable commercial canola variety without the premium value traits grown in the same region.
“Agronomically elite” means that a line has desirable agronomic characteristics such as yield, maturity, disease resistance, and the like, in addition to the herbicide tolerance due to the subject event(s). Agronomic traits, taken individually or in any combination, as set forth in Examples, below, in a plant comprising an event of the subject invention, are within the scope of the subject invention. Any and all of these agronomic characteristics and data points can be used to identify such plants, cither as a point or at cither end or both ends of a range of characteristics used to define such plants.
As one skilled in the art will recognize in light of this disclosure, preferred embodiments of detection kits, for example, can include probes and/or primers directed to and/or comprising “junction sequences” or “transition sequences” (where the soybean genomic flanking sequence meets the insert sequence). For example, this includes a polynucleotide probes, primers, and/or amplicons designed to identify one or both junction sequences (where the insert meets the flanking sequence), as indicated in the Table 1. One common design is to have one primer that hybridizes in the flanking region, and one primer that hybridizes in the insert. Such primers are often each about at least 15 residues in length. With this arrangement, the primers can be used to generate/amplify a detectable amplicon that indicates the presence of an event of the subject invention. These primers can be used to generate an amplicon that spans (and includes) a junction sequence as indicated above.
The primer(s) “touching down” in the flanking sequence is typically not designed to hybridize beyond about 200 bases or so beyond the junction. Thus, typical flanking primers would be designed to comprise at least 15 residues of either strand within 200 bases into the flanking sequences from the beginning of the insert. That is, primers comprising a sequence of an appropriate size from (or hybridizing to) residues within 100 to 200-500 or so bases from either or both junction sequences identified above are within the scope of the subject invention. Insert primers can likewise be designed anywhere on the insert, but residues on the insert (including the complement) within 100 to 200-500 or so bases in from the junction sequence(s) identified above, can be used, for example, non-exclusively for such primer design.
One skilled in the art will also recognize that primers and probes can be designed to hybridize, under a range of standard hybridization and/or PCR conditions, to segments of sequences exemplified herein (or complements thereof), wherein the primer or probe is not perfectly complementary to the exemplified sequence. That is, some degree of mismatch can be tolerated. For an approximately 20 nucleotide primer, for example, typically one or two or so nucleotides do not need to bind with the opposite strand if the mismatched base is internal or on the end of the primer that is opposite the amplicon. Various appropriate hybridization conditions are provided below. Synthetic nucleotide analogs, such as inosine, can also be used in probes. Peptide nucleic acid (PNA) probes, as well as DNA and RNA probes, can also be used. What is important is that such probes and primers are diagnostic for (able to uniquely identify and distinguish) the presence of an event of the subject invention.
It should be noted that errors in PCR amplification can occur which might result in minor sequencing errors, for example. That is, unless otherwise indicated, the sequences listed herein were determined by generating long amplicons from soybean genomic DNAs, and then cloning and sequencing the amplicons. It is not unusual to find slight differences and minor discrepancies in sequences generated and determined in this manner, given the many rounds of amplification that are necessary to generate enough amplicon for sequencing from genomic DNAs. One skilled in the art should recognize and be put on notice that any adjustments needed due to these types of common sequencing errors or discrepancies are within the scope of the subject invention.
It should also be noted that it is not uncommon for some genomic sequence to be deleted, for example, when a sequence is inserted during the creation of an event. Thus, some differences can also appear between the subject flanking sequences and genomic sequences listed in GENBANK, for example.
Components of the “insert” are illustrated in the Figures and are discussed in more detail below in the Examples. The DNA polynucleotide sequences of these components, or fragments thereof, can be used as DNA primers or probes in the methods of the present invention.
In some embodiments of the invention, compositions and methods are provided for detecting the presence of the transgene/genomic insertion region, in plants and seeds and the like, from a soybean plant. DNA sequences are provided that comprise the subject transgene/genomic insertion region junction sequence provided herein, segments comprising a junction sequence identified herein, and complements of any such exemplified sequences and any segments thereof. The insertion region junction sequence spans the junction between heterologous DNA inserted into the genome and the DNA from the soybean cell flanking the insertion site. Such sequences can be diagnostic for the given event.
Based on these insert and border sequences, event-specific primers can be generated. PCR analysis demonstrated that soybean lines of the subject invention can be identified in different soybean genotypes by analysis of the PCR amplicons generated with these event-specific primer sets. These and other related procedures can be used to uniquely identify these soybean lines. Thus, PCR amplicons derived from such primer pairs are unique and can be used to identify these soybean lines.
In some embodiments, DNA sequences that comprise a contiguous fragment of the novel transgene/genomic insertion region are an aspect of this invention. Included are DNA sequences that comprise a sufficient length of polynucleotides of transgene insert sequence and a sufficient length of polynucleotides of soybean genomic sequence from one or more of the aforementioned soybean plants and/or sequences that are useful as primer sequences for the production of an amplicon product diagnostic for one or more of these soybean plants.
Related embodiments pertain to DNA sequences that comprise at least 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, or more contiguous nucleotides of a transgene portion of a DNA sequence identified herein, or complements thereof, and a similar length of flanking soybean DNA sequence (such as SEQ ID NO:1 and SEQ ID NO:2 and segments thereof) from these sequences, or complements thereof. Such sequences are useful as DNA primers in DNA amplification methods. The amplicons produced using these primers are diagnostic for any of the soybean events referred to herein. Therefore, the invention also includes the amplicons produced by such DNA primers and homologous primers.
This invention also includes methods of detecting the presence of DNA, in a sample, that corresponds to the soybean event referred to herein. Such methods can comprise: (a) contacting the sample comprising DNA with a primer set that, when used in a nucleic acid amplification reaction with DNA from at least one of these soybean events, produces an amplicon that is diagnostic for said event(s); (b) performing a nucleic acid amplification reaction, thereby producing the amplicon; and (c) detecting the amplicon.
Further detection methods of the subject invention include a method of detecting the presence of a DNA, in a sample, corresponding to said event, wherein said method comprises: (a) contacting the sample comprising DNA with a probe that hybridizes under stringent hybridization conditions with DNA from at least one of said soybean events and which does not hybridize under the stringent hybridization conditions with a control soybean plant (non-event-of-interest DNA); (b) subjecting the sample and probe to stringent hybridization conditions; and (c) detecting hybridization of the probe to the DNA.
In still further embodiments, the subject invention includes methods of producing a soybean plant comprising Event pDAB8264.44.06.1, wherein said method comprises the steps of: (a) sexually crossing a first parental soybean line (comprising an expression cassettes of the present invention, which confers said herbicide resistance trait to plants of said line) and a second parental soybean line (that lacks this herbicide tolerance trait) thereby producing a plurality of progeny plants; and (b) selecting a progeny plant by the use of molecular markers. Such methods may optionally comprise the further step of back-crossing the progeny plant to the second parental soybean line to producing a true-breeding soybean plant that comprises said herbicide tolerance trait.
According to another aspect of the invention, methods of determining the zygosity of progeny of a cross with said event is provided. Said methods can comprise contacting a sample, comprising soybean DNA, with a primer set of the subject invention. Said primers, when used in a nucleic-acid amplification reaction with genomic DNA from at least one of said soybean events, produces a first amplicon that is diagnostic for at least one of said soybean events. Such methods further comprise performing a nucleic acid amplification reaction, thereby producing the first amplicon; detecting the first amplicon; and contacting the sample comprising soybean DNA with said primer set (said primer set, when used in a nucleic-acid amplification reaction with genomic DNA from soybean plants, produces a second amplicon comprising the native soybean genomic DNA homologous to the soybean genomic region; and performing a nucleic acid amplification reaction, thereby producing the second amplicon. The methods further comprise detecting the second amplicon, and comparing the first and second amplicons in a sample, wherein the presence of both amplicons indicates that the sample is heterozygous for the transgene insertion.
DNA detection kits can be developed using the compositions disclosed herein and methods well known in the art of DNA detection. The kits are useful for identification of the subject soybean event DNA in a sample and can be applied to methods for breeding soybean plants containing this DNA. The kits contain DNA sequences homologous or complementary to the amplicons, for example, disclosed herein, or to DNA sequences homologous or complementary to DNA contained in the transgene genetic elements of the subject events. These DNA sequences can be used in DNA amplification reactions or as probes in a DNA hybridization method. The kits may also contain the reagents and materials necessary for the performance of the detection method.
A “probe” is an isolated nucleic acid molecule to which is attached a conventional detectable label or reporter molecule (such as a radioactive isotope, ligand, chemiluminescent agent, or enzyme). Such a probe is complementary to a strand of a target nucleic acid, in the case of the present invention, to a strand of genomic DNA from one of said soybean events, whether from a soybean plant or from a sample that includes DNA from the event. Probes according to the present invention include not only deoxyribonucleic or ribonucleic acids but also polyamides and other probe materials that bind specifically to a target DNA sequence and can be used to detect the presence of that target DNA sequence. An “isolated” polynucleotide connotes that the polynucleotide is in a non-natural state—operably linked to a heterologous promoter, for example. A “purified” protein likewise connotes that the protein is in a non-natural state.
“Primers” are isolated/synthesized nucleic acids that are annealed to a complementary target DNA strand by nucleic acid hybridization to form a hybrid between the primer and the target DNA strand, then extended along the target DNA strand by a polymerase, e.g., a DNA polymerase. Primer pairs of the present invention refer to their use for amplification of a target nucleic acid sequence, e.g., by the polymerase chain reaction (PCR) or other conventional nucleic-acid amplification methods.
Probes and primers are generally 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246,247, 248, 249, 250, 251, 252, 253, 254, 255, 256, 257, 258, 259, 260, 261, 262, 263, 264, 265, 266, 267, 268, 269, 270, 271, 272, 273, 274, 275, 276, 277, 278, 279, 280, 281, 282, 283, 284, 285, 286, 287, 288, 289, 290, 291, 292, 293, 294, 295, 296, 297, 298, 299, 300, 301, 302, 303, 304, 305, 306, 307, 308, 309, 310, 311, 312, 313, 314, 315, 316, 317, 318, 319, 320, 321, 322, 323, 324, 325, 326, 327, 328, 329, 330, 331, 332, 333, 334, 335, 336, 337, 338, 339, 340, 341, 342, 343, 344, 345, 346, 347, 348, 349, 350, 351, 352, 353, 354, 355, 356, 357, 358, 359, 360, 361, 362, 363, 364, 365, 366, 367, 368, 369, 370, 371, 372, 373, 374, 375, 376, 377, 378, 379, 380, 381, 382, 383, 384, 385, 386, 387, 388, 389, 390, 391, 392, 393, 394, 395, 396, 397, 398, 399, 400, 401, 402, 403, 404, 405, 406, 407, 408, 409, 410, 411, 412, 413, 414, 415, 416, 417, 418, 419, 420, 421, 422, 423, 424, 425, 426, 427, 428, 429, 430, 431, 432, 433, 434, 435, 436, 437, 438, 439, 440, 441, 442, 443, 444, 445, 446, 447, 448, 449, 450, 451, 452, 453, 454, 455, 456, 457, 458, 459, 460, 461, 462, 463, 464, 465, 466, 467, 468, 469, 470, 471, 472, 473, 474, 475, 476, 477, 478, 479, 480, 481, 482, 483, 484, 485, 486, 487, 488, 489, 490, 491, 492, 493, 494, 495, 496, 497, 498, 499, or 500 polynucleotides or more in length. Such probes and primers hybridize specifically to a target sequence under high stringency hybridization conditions. Preferably, probes and primers according to the present invention have complete sequence similarity with the target sequence, although probes differing from the target sequence and that retain the ability to hybridize to target sequences may be designed by conventional methods.
Methods for preparing and using probes and primers are described, for example, in Molecular Cloning: A Laboratory Manual, 2nd ed., vol. 1-3, ed. Sambrook et al., Cold Spring Harbor Laboratory Press, Cold Spring Harbor. N.Y., 1989. PCR-primer pairs can be derived from a known sequence, for example, by using computer programs intended for that purpose.
Primers and probes based on the flanking DNA and insert sequences disclosed herein can be used to confirm (and, if necessary, to correct) the disclosed sequences by conventional methods, e.g., by re-cloning and sequencing such sequences.
The nucleic acid probes and primers of the present invention hybridize under stringent conditions to a target DNA sequence. Any conventional nucleic acid hybridization or amplification method can be used to identify the presence of DNA from a transgenic event in a sample. Nucleic acid molecules or fragments thereof are capable of specifically hybridizing to other nucleic acid molecules under certain circumstances. As used herein, two nucleic acid molecules are said to be capable of specifically hybridizing to one another if the two molecules are capable of forming an anti-parallel, double-stranded nucleic acid structure. A nucleic acid molecule is said to be the “complement” of another nucleic acid molecule if they exhibit complete complementarity. As used herein, molecules are said to exhibit “complete complementarity” when every nucleotide of one of the molecules is complementary to a nucleotide of the other. Two molecules are said to be “minimally complementary” if they can hybridize to one another with sufficient stability to permit them to remain annealed to one another under at least conventional “low-stringency” conditions. Similarly, the molecules are said to be “complementary” if they can hybridize to one another with sufficient stability to permit them to remain annealed to one another under conventional “high-stringency” conditions. Conventional stringency conditions are described by Sambrook et al., 1989. Departures from complete complementarity are therefore permissible, as long as such departures do not completely preclude the capacity of the molecules to form a double-stranded structure. In order for a nucleic acid molecule to serve as a primer or probe it need only be sufficiently complementary in sequence to be able to form a stable double-stranded structure under the particular solvent and salt concentrations employed.
As used herein, a substantially homologous sequence is a nucleic acid sequence that will specifically hybridize to the complement of the nucleic acid sequence to which it is being compared under high stringency conditions. The term “stringent conditions” is functionally defined with regard to the hybridization of a nucleic-acid probe to a target nucleic acid (i.e., to a particular nucleic-acid sequence of interest) by the specific hybridization procedure discussed in Sambrook et al., 1989, at 9.52-9.55. See also, Sambrook et al., 1989 at 9.47-9.52 and 9.56-9.58. Accordingly, the nucleotide sequences of the invention may be used for their ability to selectively form duplex molecules with complementary stretches of DNA fragments.
Depending on the application envisioned, one can use varying conditions of hybridization to achieve varying degrees of selectivity of probe towards target sequence. For applications requiring high selectivity, one will typically employ relatively stringent conditions to form the hybrids, e.g., with regards to endpoint TaqMan and real-time PCR applications, one will select 1.5 mM to about 4.0 mM MgCl2 at temperature of about 60° C. to about 75° C. and may vary hold times, as described herein, for increasing stringency. For other hybridization techniques one will typically employ relatively low salt and/or high temperature conditions, such as provided by about 0.02 M to about 0.15 M NaCl at temperatures of about 50° C. to about 70° C. Stringent conditions, for example, could involve washing the hybridization filter at least twice with high-stringency wash buffer (0.2×SSC, 0.1% SDS, 65° C.). Appropriate stringency conditions which promote DNA hybridization, for example, 6.0× sodium chloride/sodium citrate (SSC) at about 45° C., followed by a wash of 2.0×SSC at 50° C. are known to those skilled in the art. For example, the salt concentration in the wash step can be selected from a low stringency of about 2.0×SSC at 50° C. to a high stringency of about 0.2×SSC at 50° C. In addition, the temperature in the wash step can be increased from low stringency conditions at room temperature, about 22° C., to high stringency conditions at about 65° C. Both temperature and salt may be varied, or either the temperature or the salt concentration may be held constant while the other variable is changed. Such selective conditions tolerate little, if any, mismatch between the probe and the template or target strand. Detection of DNA sequences via hybridization is well-known to those of skill in the art, and the teachings of U.S. Pat. Nos. 4,965,188 and 5,176,995 are exemplary of the methods of hybridization analyses.
In a particularly preferred embodiment, a nucleic acid of the present invention will specifically hybridize to one or more of the primers (or amplicons or other sequences) exemplified or suggested herein, including complements and fragments thereof, under high stringency conditions. In one aspect of the present invention, a marker nucleic acid molecule of the present invention has the nucleic acid sequence as set forth herein in one of the exemplified sequences, or complements and/or fragments thereof.
In another aspect of the present invention, a marker nucleic acid molecule of the present invention shares between 80% and 100% or 90% and 100% sequence identity with such nucleic acid sequences. In a further aspect of the present invention, a marker nucleic acid molecule of the present invention shares between 95% and 100% sequence identity with such sequence. Such sequences may be used as markers in plant breeding methods to identify the progeny of genetic crosses. The hybridization of the probe to the target DNA molecule can be detected by any number of methods known to those skilled in the art, these can include, but are not limited to, fluorescent tags, radioactive tags, antibody based tags, and chemiluminescent tags.
Regarding the amplification of a target nucleic acid sequence (e.g., by PCR) using a particular amplification primer pair, “stringent conditions” are conditions that permit the primer pair to hybridize only to the target nucleic-acid sequence to which a primer having the corresponding wild-type sequence (or its complement) would bind and preferably to produce a unique amplification product, the amplicon.
The term “specific for (a target sequence)” indicates that a probe or primer hybridizes under stringent hybridization conditions only to the target sequence in a sample comprising the target sequence.
As used herein, “amplified DNA” or “amplicon” refers to the product of nucleic-acid amplification of a target nucleic acid sequence that is part of a nucleic acid template. For example, to determine whether the soybean plant resulting from a sexual cross contains transgenic event genomic DNA from the soybean plant of the present invention, DNA extracted from a soybean plant tissue sample may be subjected to nucleic acid amplification method using a primer pair that includes a primer derived from flanking sequence in the genome of the plant adjacent to the insertion site of inserted heterologous DNA, and a second primer derived from the inserted heterologous DNA to produce an amplicon that is diagnostic for the presence of the event DNA. The amplicon is of a length and has a sequence that is also diagnostic for the event. The amplicon may range in length from the combined length of the primer pairs plus one nucleotide base pair, and/or the combined length of the primer pairs plus about 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204,205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255, 256,257, 258, 259, 260, 261, 262, 263, 264, 265, 266, 267, 268, 269, 270, 271, 272, 273, 274, 275, 276, 277, 278, 279, 280, 281, 282, 283, 284, 285, 286, 287, 288, 289, 290, 291, 292, 293, 294, 295, 296, 297, 298, 299, 300, 301, 302, 303, 304, 305, 306, 307, 308, 309, 310, 311, 312, 313, 314, 315, 316, 317, 318, 319, 320, 321, 322, 323, 324, 325, 326, 327, 328, 329, 330, 331, 332, 333, 334, 335, 336, 337, 338, 339, 340, 341, 342, 343, 344, 345, 346, 347, 348, 349, 350, 351, 352, 353, 354, 355, 356, 357, 358, 359, 360, 361, 362, 363, 364, 365, 366, 367, 368, 369, 370, 371, 372, 373, 374, 375, 376, 377, 378, 379, 380, 381, 382, 383, 384, 385, 386, 387, 388, 389, 390, 391, 392, 393, 394, 395, 396, 397, 398, 399, 400, 401, 402, 403, 404, 405, 406, 407, 408, 409, 410, 411, 412, 413, 414, 415, 416, 417, 418, 419, 420, 421, 422, 423, 424, 425, 426, 427, 428, 429, 430, 431, 432, 433, 434, 435, 436, 437, 438, 439, 440, 441, 442, 443, 444, 445, 446, 447, 448, 449, 450, 451, 452, 453, 454, 455, 456, 457, 458, 459, 460, 461, 462, 463, 464, 465, 466, 467, 468, 469, 470, 471, 472, 473, 474, 475, 476, 477, 478, 479, 480, 481, 482, 483, 484, 485, 486, 487, 488, 489, 490, 491, 492, 493, 494, 495, 496, 497, 498, 499, or 500, 750, 1000, 1250, 1500, 1750, 2000, or more nucleotide base pairs (plus or minus any of the increments listed above). Alternatively, a primer pair can be derived from flanking sequence on both sides of the inserted DNA so as to produce an amplicon that includes the entire insert nucleotide sequence. A member of a primer pair derived from the plant genomic sequence may be located a distance from the inserted DNA sequence. This distance can range from one nucleotide base pair up to about twenty thousand nucleotide base pairs. The use of the term “amplicon” specifically excludes primer dimers that may be formed in the DNA thermal amplification reaction.
Nucleic-acid amplification can be accomplished by any of the various nucleic-acid amplification methods known in the art, including the polymerase chain reaction (PCR). A variety of amplification methods are known in the art and are described, inter alia, in U.S. Pat. Nos. 4,683,195 and 4,683,202. PCR amplification methods have been developed to amplify up to 22 kb of genomic DNA. These methods as well as other methods known in the art of DNA amplification may be used in the practice of the present invention. The sequence of the heterologous transgene DNA insert or flanking genomic sequence from a subject soybean event can be verified (and corrected if necessary) by amplifying such sequences from the event using primers derived from the sequences provided herein followed by standard DNA sequencing of the PCR amplicon or of the cloned DNA.
The amplicon produced by these methods may be detected by a plurality of techniques. Agarose gel electrophoresis and staining with ethidium bromide is a common well known method of detecting DNA amplicons. Another such method is Genetic Bit Analysis where an DNA oligonucleotide is designed which overlaps both the adjacent flanking genomic DNA sequence and the inserted DNA sequence. The oligonucleotide is immobilized in wells of a microwell plate. Following PCR of the region of interest (using one primer in the inserted sequence and one in the adjacent flanking genomic sequence), a single-stranded PCR product can be hybridized to the immobilized oligonucleotide and serve as a template for a single base extension reaction using a DNA polymerase and labeled ddNTPs specific for the expected next base. Readout may be fluorescent or ELISA-based. A signal indicates presence of the insert/flanking sequence due to successful amplification, hybridization, and single base extension.
Another method is the Pyrosequencing technique as described by Winge (Innov. Pharma. Tech. 00:18-24, 2000). In this method an oligonucleotide is designed that overlaps the adjacent genomic DNA and insert DNA junction. The oligonucleotide is hybridized to single-stranded PCR product from the region of interest (one primer in the inserted sequence and one in the flanking genomic sequence) and incubated in the presence of a DNA polymerase, ATP, sulfurylase, luciferase, apyrase, adenosine 5′ phosphosulfate and luciferin. DNTPs are added individually and the incorporation results in a light signal that is measured. A light signal indicates the presence of the transgene insert/flanking sequence due to successful amplification, hybridization, and single or multi-base extension.
Fluorescence Polarization is another method that can be used to detect an amplicon of the present invention. Following this method, an oligonucleotide is designed which overlaps the genomic flanking and inserted DNA junction. The oligonucleotide is hybridized to single-stranded PCR product from the region of interest (one primer in the inserted DNA and one in the flanking genomic DNA sequence) and incubated in the presence of a DNA polymerase and a fluorescent-labeled ddNTP. Single base extension results in incorporation of the ddNTP. Incorporation can be measured as a change in polarization using a fluorometer. A change in polarization indicates the presence of the transgene insert/flanking sequence due to successful amplification, hybridization, and single base extension.
TAQMAN (PE Applied Biosystems, Foster City, Calif.) is a method of detecting and quantifying the presence of a DNA sequence. Briefly, a FRET oligonucleotide probe is designed that overlaps the genomic flanking and insert DNA junction. The FRET probe and PCR primers (one primer in the insert DNA sequence and one in the flanking genomic sequence) are cycled in the presence of a thermostable polymerase and dNTPs. During specific amplification, Taq DNA polymerase cleans and releases the fluorescent moiety away from the quenching moiety on the FRET probe. A fluorescent signal indicates the presence of the flanking/transgene insert sequence due to successful amplification and hybridization.
Molecular Beacons have been described for use in sequence detection. Briefly, a FRET oligonucleotide probe is designed that overlaps the flanking genomic and insert DNA junction. The unique structure of the FRET probe results in it containing secondary structure that keeps the fluorescent and quenching moieties in close proximity. The FRET probe and PCR primers (one primer in the insert DNA sequence and one in the flanking genomic sequence) are cycled in the presence of a thermostable polymerase and dNTPs. Following successful PCR amplification, hybridization of the FRET probe to the target sequence results in the removal of the probe secondary structure and spatial separation of the fluorescent and quenching moieties. A fluorescent signal results. A fluorescent signal indicates the presence of the flanking genomic/transgene insert sequence due to successful amplification and hybridization.
Having disclosed a location in the soybean genome that is excellent for an insertion, the subject invention also includes a soybean seed and/or a soybean plant comprising at least one non-aad12/pat/2mepsps coding sequence in or around the general vicinity of this genomic location. One option is to substitute a different insert in place of the insert exemplified herein. In these general regards, targeted homologous recombination, for example, can be used according to the subject invention. This type of technology is the subject of, for example, WO 03/080809 A2 and the corresponding published U.S. application (U.S. 2003/0232410). Thus, the subject invention includes plants and plant cells comprising a heterologous insert (in place of or with multi-copies of the exemplified insert), flanked by all or a recognizable part of the flanking sequences identified herein as SEQ ID NO:1 and SEQ ID NO:2. An additional copy (or additional copies) of the exemplified insert or any of its components could also be targeted for insertion in this/these manner(s).
All patents, patent applications, provisional applications, and publications referred to or cited herein are incorporated by reference in their entirety to the extent they are not inconsistent with the explicit teachings of this specification.
The following examples are included to illustrate procedures for practicing the invention and to demonstrate certain preferred embodiments of the invention. These examples should not be construed as limiting. It should be appreciated by those of skill in the art that the techniques disclosed in the following examples represent specific approaches used to illustrate preferred modes for its practice. However, those of skill in the art should, in light of the present disclosure, appreciate that many changes can be made in these specific embodiments while still obtaining like or similar results without departing from the spirit and scope of the invention. Unless otherwise indicated, all percentages are by weight and all solvent mixture proportions are by volume unless otherwise noted.
The following abbreviations are used unless otherwise indicated.
-
- bp base pair
- ° C. degrees Celcius
- DNA deoxyribonucleic acid
- DIG digoxigenin
- EDTA ethylenediaminetetraacetic acid
- kb kilobase
- μg microgram
- μL microliter
- mL milliliter
- M molar mass
- OLP overlapping probe
- PCR polymerase chain reaction
- PTU plant transcription unit
- SDS sodium dodecyl sulfate
- SOP standard operating procedure
- SSC a buffer solution containing a mixture of sodium chloride and sodium citrate, pH 7.0
- TBE a buffer solution containing a mixture of Tris base, boric acid and EDTA, pH 8.3
- V volts
Transgenic soybean (Glycine max) containing the Soybean Event 8264.44.06.1 was generated through Agrobacterium-mediated transformation of soybean cotyledonary node explants. The disarmed Agrobacterium strain EHA101 (Hood et al., 2006), carrying the binary vector pDAB8264 (
Agrobacterium-mediated transformation was carried out using a modified procedure of Zeng et al. (2004). Briefly, soybean seeds (cv Maverick) were germinated on basal media and cotyledonary nodes were isolated and infected with Agrobacterium. Shoot initiation, shoot elongation, and rooting media were supplemented with cefotaxime, timentin and vancomycin for removal of Agrobacterium. Glufosinate selection was employed to inhibit the growth of non-transformed shoots. Selected shoots were transferred to rooting medium for root development and then transferred to soil mix for acclimatization of plantlets.
Terminal leaflets of selected plantlets were leaf painted with glufosinate to screen for putative transformants. The screened plantlets were transferred to the greenhouse, allowed to acclimate and then leaf-painted with glufosinate to reconfirm tolerance and deemed to be putative transformants. The screened plants were sampled and molecular analyses for the confirmation of the selectable marker gene and/or the gene of interest were carried out. T0 plants were allowed to self fertilize in the greenhouse to give rise to T, seed.
This event, Soybcan Event 8264.44.06.1, was generated from an independent transformed isolate. The T1 plants were backcrossed and introgressed into elite varieties over subsequent generations. The event was selected based on its unique characteristics such as single insertion site, normal Mendelian segregation and stable expression, and a superior combination of efficacy, including herbicide tolerance and agronomic performance. The following examples contain the data which were used to characterize Soybean Event 8264.44.06.1.
Example 2: Characterization of AAD-12, 2mEPSPS and PAT Protein in Soybean Event 8264.44.06.1The biochemical properties of the recombinant AAD-12, 2mEPSPS and PAT protein derived from the transgenic soybean event pDAB8264.44.06.1 were characterized. Quantitative enzyme-linked immunosorbent assay (ELISA) was used to characterize the biochemical properties of the protein and confirm expression of AAD-12, PAT and 2mEPSPS protein.
Example 2.1: Expression of the AAD-12 Protein in Plant TissuesLevels of AAD-12 protein were determined in soybean event 8264.44.06.1. The soluble, extractable AAD-12 protein was measured using a quantitative enzyme-linked immunosorbent assay (ELISA) method from soybean leaf tissue.
Samples of soybean tissues were isolated from the test plants and prepared for expression analysis. The AAD-12 protein was extracted from soybean plant tissues with a phosphate buffered saline solution containing the detergent Tween-20 (PBST) containing 0.5% Bovine Serum Albumin (BSA). The plant tissue was centrifuged; the aqueous supernatant was collected, diluted with appropriate buffer as necessary, and analyzed using an AAD-12 ELISA kit in a sandwich format. The kit was used following the manufacturer's suggested protocol.
Detection analysis was performed to investigate the expression stability and heritability both vertically (between generations) and horizontally (between lineages of the same generation) in soybean event 8264.44.06.1. At the T4 generation soybean event 8264.44.06.1 expression was stable (not segregating) and consistent across all lineages. Field expression level studies were performed on soybean event; average expression across all lineages was approximately 200-400 ng/cm2.
Example 2.2: Expression of the 2mEPSPS Protein in Plant TissuesLevels of 2mEPSPS protein were determined in soybean event 8264.44.06.1. The soluble, extractable 2mEPSPS protein was measured using a quantitative enzyme-linked immunosorbent assay (ELISA) method from soybean leaf tissue.
Samples of soybean tissues were isolated from the test plants and prepared for expression analysis. The 2mEPSPS protein was extracted from soybean plant tissues with a phosphate buffered saline solution containing the detergent Tween-20 (PBST) containing 0.5% Bovine Serum Albumin (BSA). The plant tissue was centrifuged; the aqueous supernatant was collected, diluted with appropriate buffer as necessary, and analyzed using a 2mEPSPS ELISA kit in a sandwich format. The kit was used following the manufacturer's suggested protocol.
Detection analysis was performed to investigate the expression stability and heritability both vertically (between generations) and horizontally (between lineages of the same generation) in soybean event 8264.44.06.1. At the T4 generation soybean event 8264.44.06.1 expression was stable (not segregating) and consistent across all lineages. Field expression level studies were performed on soybean event 8264.44.06.1. Average expression across all lineages was approximately 5,000-17,500 ng/cm2. These expression levels were higher than the positive control which expressed the 2mEPSPS protein.
Example 2.3: Expression of the PAT Protein in Plant TissuesLevels of PAT protein were determined in soybean event 8264.44.06.1. The soluble, extractable PAT protein was measured using a quantitative enzyme-linked immunosorbent assay (ELISA) method from soybean leaf tissue.
Samples of soybean tissues were isolated from the test plants and prepared for expression analysis. The PAT protein was extracted from soybean plant tissues with a phosphate buffered saline solution containing the detergent Tween-20 (PBST) containing 0.5% Bovine Serum Albumin (BSA). The plant tissue was centrifuged; the aqueous supernatant was collected, diluted with appropriate buffer as necessary, and analyzed using a PAT ELISA kit in a sandwich format. The kit was used following the manufacturer's suggested protocol.
Detection analysis was performed to investigate the expression stability and heritability both vertically (between generations) and horizontally (between lineages of the same generation) in soybean event 8264.44.06.1. At the T4 generation soybean event 8264.44.06.1 expression was stable (not segregating) and consistent across all lineages. Field expression level studies were performed on soybean event 8264.44.06.1. Average expression across all lineages was approximately 15-25 ng/cm2.
Example 3: Cloning and Characterization of DNA Sequence in the Insert and the Flanking Border Regions of Soybean Event pDAB8264.44.06.1To characterize and describe the genomic insertion site, the sequence of the flanking genomic T-DNA border regions of soybean event pDAB8264.44.06.1 were determined. In total, 2,578 bp of soybean event pDAB8264.44.06.1 genomic sequence was confirmed, comprising 570 bp of 5′ flanking border sequence (SEQ ID NO:1), 1,499 bp of 3′ flanking border sequence (SEQ ID NO:2). PCR amplification based on the soybean Event pDAB8264.44.06.1 border sequences validated that the border regions were of soybean origin and that the junction regions are unique sequences for event pDAB8264.44.06.1. The junction regions could be used for event-specific identification of soybean event pDAB8264.44.06.1. In addition, the T-strand insertion site was characterized by amplifying a genomic fragment corresponding to the region of the identified flanking border sequences from the genome of wild type soybean. Comparison of soybean event pDAB8264.44.06.1 with the wild type genomic sequence revealed about 4,357 bp deletion from the original locus. Overall, the characterization of the insert and border sequence of soybean event pDAB8264.44.06.1 indicated that an intact copy of the T-strand was present in the soybean genome.
The 5′ and 3′ flanking borders aligned to a Glycine max whole genome shotgun sequence from chromosome 6, indicating that the transgene of soybean event pDAB8264.44.06.1 was inserted in soybean genome chromosome 6. To confirm the insertion site of soybean event pDAB8264.44.06.1 transgene from the soybean genome, PCR was carried out with different pairs of primers (
To further confirm the DNA insertion in the soybean genome, a PCR amplification spanning the two soybean sequences was completed. Two primers designed according to the 5′ end border sequence, 4406-WF1 (SEQ ID NO:3) and 4406-WF3 (SEQ ID NO:5), and two primers for the 3′ end border sequence, 4406-WR5 (SEQ ID NO:7) and 4406-WR7 (SEQ ID NO:9), were used to amplify DNA segments which contained the entire transgene, the 5′ end border sequence, and the 3′ border sequence. As expected, PCR amplification with the primer pair of 4406-WF1 (SEQ ID NO:3) and 4406-WR5 (SEQ ID NO:7) amplified an approximately 12 kb DNA fragment from the genomic DNA of soybean event pDAB8264.44.06.1 and a 6 kb DNA fragment from the non-transgenic soybean controls and other soybean transgenic lines. Similarly, PCR reactions completed with the primer pair of 4406-WF3 (SEQ ID NO:5) and 4406-WR7 (SEQ ID NO:9) produced an approximately 12 kb DNA fragment from the sample of soybean event pDAB8264.44.06.1 and a 6 kb DNA fragment from all the other soybean control lines, correspondingly. These results demonstrated that the transgene of soybean event pDAB8264.44.06.1 was inserted into the site of soybean genome chromosome 6. Aligning the identified 5′ and 3′ border sequences of soybean event pDAB8264.44.06.1 with a Glycine max whole genome shotgun sequence from chromosome 6 revealed about 4.4 kb deletion from the original locus. (
Southern blot analysis was used to establish the integration pattern of soybean event pDAB8264.44.06.1. These experiments generated data which demonstrated the integration and integrity of the aad-12, pat and 2mepsps v1 transgenes within the soybean genome. Soybean event pDAB8264.44.06.1 was characterized as a full length, simple integration event containing a single copy of the aad-12, pat and 2mepsps v1 PTU from plasmid pDAB8264.
Southern blot data suggested that a T-strand fragment inserted into the genome of soybean event pDAB8264.44.06.1. Detailed Southern blot analysis was conducted using a probe specific to the aad-12, pat and 2mepsps v1 insert, contained in the T-strand integration region of pDAB8264, and descriptive restriction enzymes that have cleavage sites located within the plasmid and produce hybridizing fragments internal to the plasmid or fragments that span the junction of the plasmid with soybean genomic DNA (border fragments). The molecular weights indicated from the Southern hybridization for the combination of the restriction enzyme and the probe were unique for the event, and established its identification patterns. These analyses also showed that the plasmid fragment had been inserted into soybean genomic DNA without rearrangements of the aad-12, pat and 2mepsps v1 PTU.
Example 4.1: Soybean Leaf Sample Collection and Genomic DNA (rDNA) IsolationGenomic DNA was extracted from leaf tissue harvested from individual soybean plants containing soybean event pDAB8264.44.06.1. In addition, gDNA was isolated from a conventional soybean plant, Maverick, which contains the genetic background that is representative of the substance line, absent the aad-12 and 2mepsps v0 genes. Individual genomic DNA was extracted from lyophilized leaf tissue following the standard cetyltrimethylammonium bromide CTAB method. Following extraction, the DNA was quantified spectrofluorometrically using Pico Green reagent (Invitrogen, Carlsbad, Calif.). The DNA was then visualized on an agarose gel to confirm values from the Pico Green analysis and to determine the DNA quality.
Example 4.2: DNA Digestion and SeparationFor Southern blot molecular characterization of soybean event pDAB8264.44.06.1, ten micrograms (10 μg) of genomic DNA was digested. Genomic DNA from the soybean pDAB8264.44.06.1 and non-transgenic soybean line Maverick was digested by adding approximately five units of selected restriction enzyme per μg of DNA and the corresponding reaction buffer to each DNA sample. Each sample was incubated at approximately 37° C. overnight. The restriction enzymes BstZ17I, HinDIII, NcoI, NsiI, and PacI were used individually for the digests (New England Biolabs, Ipswich, Mass.). In addition, a positive hybridization control sample was prepared by combining plasmid DNA, pDAB8264 with genomic DNA from the non-transgenic soybean variety, Maverick. The plasmid DNA/genomic DNA cocktail was digested using the same procedures and restriction enzyme as the test samples. After the digestions were incubated overnight, NaCl was added to a final concentration of 0.1M and the digested DNA samples were precipitated with isopropanol. The precipitated DNA pellet was resuspended in 20 μl of 1× loading buffer (0.01% bromophenol blue, 10.0 mM EDTA, 5.0% glycerol, 1.0 mM Tris pH 7.5). The DNA samples and molecular size markers were then electrophoresed through 0.85% agarose gels with 0.4×TAE buffer (Fisher Scientific, Pittsburgh, Pa.) at 35 volts for approximately 18-22 hours to achieve fragment separation. The gels were stained with ethidium bromide (Invitrogen, Carlsbad, Calif.) and the DNA was visualized under ultraviolet (UV) light
Example 4.3: Southern Transfer and Membrane TreatmentSouthern blot analysis was performed essentially as described by, Memelink, J.; Swords, K.; Harry J.; Hoge, C.; (1994) Southern, Northern, and Western Blot Analysis. Plant Mol. Biol. Manual F1:1-23. Briefly, following electrophoretic separation and visualization of the DNA fragments, the gels were depurinated with 0.25M HCl for approximately 20 minutes, and then exposed to a denaturing solution (0.4 M NaOH, 1.5 M NaCl) for approximately 30 minutes followed by neutralizing solution (1.5 M NaCl, 0.5 M Tris pH 7.5) for at least 30 minutes. Southern transfer was performed overnight onto nylon membranes using a wicking system with 10×SSC. After transfer the DNA was bound to the membrane by UV crosslinking following by briefly washing membrane with a 2×SSC solution. This process produced Southern blot membranes ready for hybridization.
Example 4.4: DNA Probe Labeling and HybridizationThe DNA fragments bound to the nylon membrane were detected using a labeled probe. Probes were generated by a PCR-based incorporation of a digoxigenin (DIG) labeled nucleotide, [DIG-11]-dUTP, into the DNA fragment amplified from plasmid pDAB8264 using primers specific to gene elements. Generation of DNA probes by PCR synthesis was carried out using a PCR DIG Probe Synthesis Kit (Roche Diagnostics, Indianapolis, Ind.) following the manufacturer's recommended procedures.
Labeled probes were analyzed by agarose gel electrophoresis to determine their quality and quantity. A desired amount of labeled probe was then used for hybridization to the target DNA on the nylon membranes for detection of the specific fragments using the procedures essentially as described for DIG Easy Hyb Solution (Roche Diagnostics, Indianapolis, Ind.). Briefly, nylon membrane blots containing fixed DNA were briefly washed with 2×SSC and pre-hybridized with 20-25 mL of pre-warmed DIG Easy Hyb solution in hybridization bottles at approximately 45-55° C. for about 2 hours in a hybridization oven. The pre-hybridization solution was then decanted and replaced with approximately 15 mL of pre-warmed DIG Easy Hyb solution containing a desired amount of specific probes denatured by boiling in a water bath for approximately five minutes. The hybridization step was then conducted at approximately 45-55° C. overnight in the hybridization oven.
At the end of the probe hybridization, DIG Easy Hyb solutions containing the probes were decanted into clean tubes and stored at approximately −20° C. These probes could be reused for twice according to the manufacturer's recommended procedure. The membrane blots were rinsed briefly and washed twice in clean plastic containers with low stringency wash buffer (2×SSC, 0.1% SDS) for approximately five minutes at room temperature, followed by washing twice with high stringency wash buffer (0.1×SSC, 0.1% SDS) for 15 minutes each at approximately 65° C. The membrane blots briefly washed with 1×Malcic acid buffer from the DIG Wash and Block Buffer Set (Roche Diagnostics, Indianapolis, Ind.) for approximately 5 minutes. This was followed by blocking in a 1× blocking buffer for 2 hours and an incubation with anti-DIG-AP (alkaline phosphatase) antibody (Roche Diagnostics, Indianapolis. Ind.) in 1× blocking buffer also for a minimum of 30 minutes. After 2-3 washes with 1× washing buffer, specific DNA probes remain bound to the membrane blots and DIG-labeled DNA standards were visualized using CDP-Star Chemiluminescent Nucleic Acid Detection System (Roche Diagnostics, Indianapolis, Ind.) following the manufacturer's recommendation. Blots were exposed to chemiluminescent film for one or more time points to detect hybridizing fragments and to visualize molecular size standards. Films were developed with an All-Pro 100 Plus film developer (Konica Minolta, Osaka, Japan) and images were scanned. The number and sizes of detected bands were documented for each probe (Table 5). DIG-labeled DNA Molecular Weight Marker II (DIG MWM II) and DIG-labeled DNA Molecular Weight Marker VII (DIG MWM VII), visible after DIG detection as described, were used to determine hybridizing fragment size on the Southern blots.
Expected and observed fragment sizes with a particular digest and probe, based on the known restriction enzyme sites of the aad-12 and 2mepsps PTU, are given in Table 6. Expected fragment sizes are based on the plasmid map of pDAB8264 and observed fragment sizes arc approximate results from these analyses and are based on the indicated sizes of the DIG-labeled DNA Molecular Weight Marker II and Mark VII fragments.
Two types of fragments were identified from these digests and hybridizations: internal fragments where known enzyme sites flank the probe region and are completely contained within the insertion region of the aad-12 and 2mepsps PTU PTU, and border fragments where a known enzyme site is located at one end of the probe region and a second site is expected in the soybean genome. Border fragment sizes vary by event because, in most cases, DNA fragment integration sites are unique for each event. The border fragments provide a means to locate a restriction enzyme site relative to the integrated DNA and to evaluate the number of DNA insertions. Southern blot analyses completed on multiple generations of soybean containing event pDAB8264.44.06.1 produced data which suggested that a low copy, intact aad-12 and 2mepsps PTU from plasmid pDAB8264 was inserted into the soybean genome of soybean event pDAB8264.44.06.1.
The restriction enzymes NcoI and HinD III bind and cleave unique restriction sites in plasmid pDAB8264. Subsequently, these enzymes were selected to characterize the aad-12 gene insert in soybean event pDAB8264.44.06.1. Border fragments of greater than 4,078 bp or greater than 3,690 bp were predicted to hybridize with the probe following HinD III and NcoI digests, respectively (Table 6). Single aad-12 hybridization bands of approximately 7,400 bp and approximately 3,800 bp were observed when HinDIII and NcoI were used, respectively. The hybridization of the probe to bands of this size suggests the presence of a single site of insertion for the aad-12 gene in the soybean genome of soybean event pDAB8264.44.06.1. Restriction enzymes BstZ17I, NsiI and PacI was selected to release a fragment which contains the aad-12 plant transcription unit (PTU; promoter/gene/terminator) (Table 6). The predicted approximately 5,000, approximately 5,000, and approximately 6,800 bp fragments were observed with the probe following BstZ17I, NsiI and PacI digestions, respectively. Results obtained with the enzyme digestion of the pDAB8264.44.06.1 samples followed by probe hybridization indicated that an intact aad-12 PTU from plasmid pDAB8264 was inserted into the soybean genome of soybean event pDAB8264.44.06.1. In addition, the molecular weight sizes of the hybridization bands produced for the HinDIII, NcoI, NsiI, and BstZ17I restriction fragments indicate that the aad-12 PTU also contained the linked pat PTU.
The restriction enzymes BstZ17I, NcoI and NsiI bind and cleave restriction sites in plasmid pDAB8264. Subsequently, these enzymes were selected to characterize the 2mepsps gene insert in soybean event pDAB8264.44.06.1. Border fragments of greater than 4,858 bp, greater than 3,756, or greater than 5,199 bp were predicted to hybridize with the probe following the BstZ17I, NcoI and NsiI digests respectively (Table 6). Single 2mepsps hybridization bands of approximately 16,000 bp, approximately 6,100 bp and approximately 5,300 bp were observed when BstZ17I, NcoI and NsiI were used, respectively. The hybridization of the probe to bands of this size suggests the presence of a single site of insertion for the 2mepsps gene in the soybean genome of soybean event pDAB8264.44.06.1. Restriction enzyme PacI was selected to release a fragment which contains the 2mepsps plant transcription unit (PTU; promoter/gene/terminator) (Table 6). The predicted approximately 6,800 bp fragment was observed with the probe following the PacI digestions. Results obtained with the enzyme digestion of the pDAB8264.44.06.1 sample followed by probe hybridization indicated that an intact 2mepsps PTU from plasmid pDAB8264 was inserted into the soybean genome of soybean event pDAB8264.44.06.1.
Example 4.6: Absence of Backbone SequencesSouthern blot analysis was also conducted to verify the absence of the spectinomycin resistance gene (specR), Ori Rep element and replication initiation protein trfA (trf A element) in soybean event pDAB8264.44.06.1. No specific hybridization to spectinomycin resistance, Ori Rep element or trf A element is expected when appropriate positive (pDAB8264 plus Maverick) and negative (Maverick) controls are included for Southern analysis. Following Hind III digestion and hybridization with specR specific probe, one expected size band of approximately 9,300 bp was observed in the positive control sample (pDAB8264 plus maverick) but absent from samples of the negative control and soybean event pDAB8264.44.06.1. Similarly, one expected size band of approximately 9,200 bp was detected in the positive control sample (pDAB8264 plus maverick) but absent from the samples of the negative control and soybean event pDAB8264.44.06.1 after Pac I digestion and hybridization with mixture of OriRep specific probe and trfA specific probe. These data indicate the absence of spectinomycin resistance gene, Ori Rep element and replication initiation protein trfA in soybean event pDAB8264.44.06.1.
Example 5: Agronomic, Yield and Herbicide Tolerance EvaluationThe agronomic characteristics and herbicide tolerance of soybean Event pDAB8264.44.06.1 were studied in yield trials at multiple geographical locales during a single growing season. No agronomically meaningful unintended differences were observed between soybean Event pDAB8264.44.06.1 and the Maverick control plants. The results of the study demonstrated that soybean Event pDAB8264.44.06.1 was agronomically equivalent to the Maverick control plants. In addition, soybean Event pDAB8264.44.06.1 provided robust herbicide tolerance when sprayed with a tankmix of glyphosate and 2,4-D.
The following agronomic characteristics were measured and recorded for all test entries at each location.
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- 1.) Emergence: Calculated by dividing Stand count by number of seeds planted in a one meter section and multiplying by 100.
- 2.) Seedling Vigor at V1: Vigor is an overall estimate of the health of the plot. Results were rated on a scale of 0-100% with 0% representing a plot with all dead plants and 100% representing plots that look very healthy.
- 3.) Rated overall visual crop injury, chlorosis and necrosis at 1 day, 7 days, and 14 days after V3 chemical application. Observations were made for any signs of epinasty which is typical of 2,4-D injury. Epinasty is exhibited as twisting or drooping of leaves and stems. All crop injuries used a 0 to 100% scale, where 0% indicates no injury and 100% indicates complete plant death.
- 4.) Flowering date: This measurement records the date when 50% of the plants in the plot begin to flower. The number of days from planting to when 50% of the plants in each plot were flowering was recorded.
- 5.) Stand count at R2 or R1: Is a visual estimate of the average vigor of plants in each plot, determined by counting the number of plants in a representative one meter section of one row per plot, and taking note at the R2 or R1 growth stage.
- 6.) Rated overall visual crop injury, chlorosis and necrosis at 1 day, 7 days, and 14 days after R2 chemical application. Observations were made for any signs of epinasty which is typical of 2,4-D injury. Epinasty is exhibited as twisting or drooping of leaves and stems. All crop injuries used a 0 to 100% scale where 0% indicates no injury and 100% indicates complete plant death.
- 7.) Disease incidence at R6 growth stage: Is a visual estimate of disease incidence used to record the severity of disease in the plot. Rated on a scale of 0-100%. Where 0% indicates no disease present and 100% indicates all plants in plot had disease.
- 8.) Insect damage at R6 growth stage: Is a visual estimate of insect damage used to record the severity of insect damage in the plot. Recorded the percentage of plant tissue in the plot damaged by insects using a 0-100% scale. Where 0% indicates no insect damage present and 100% indicates all plants in plot had insect damage.
- 9.) Plant height at senescence: The average height of the plants in each plot was recorded. Plants were measured from the soil surface to the tip after the leaves had fallen. Measurements were recorded in centimeters. If the plot was lodged, a representative group of plants were stood-up to obtain a measurement.
- 10.) Days to maturity. Recorded date when 95% of the pods in a plot reached physiological maturity and the plants were a dry down color. The numbers of days to elapse since planting were calculated.
- 11.) Lodging: Recorded a visual estimate of lodging severity at harvest time. Recorded on a 0 to 100% scale, where 0% indicates no lodging and 100% indicates all plants in a plot flat on the ground.
- 12.) Shattering: Recorded a visual estimate of pod shattering at harvest time. Recorded as an estimate of percentage of pods shattered per plot. 0-100% scale with 0% indicating no shattering and 100% indicating all pods shattered.
- 13.) Yield: Recorded the weight of grain harvested from each plot. Harvested the entire 2 row plot and recorded seed weight and moisture. Calculations of bu/acre were made by adjusting to 13% moisture.
- 14.) 100 seed weight: For each plot 100 seeds were counted out and the weight was recorded in grams.
Herbicide tolerance of soybean Event pDAB8264.44.06.1 was assessed following the application of a tankmix of 2,4-D and glyphosate at 2,185 g ae/ha mixed with 2% weight per weight ammonium sulfate (AMS). The herbicides were sprayed as a V3/R2 sequential herbicide treatment. This herbicide treatment was completed by spraying soybean plants at the V3 growth stage of development followed by a second sequential application at the R2 growth stage of development. The V3 growth stage is characterized when the unifoliolate and first three trifoliolate leaves are fully developed. The R2 growth stage is characterized by a single open flower at one of the two uppermost nodes on the main stem with a fully developed leaf.
These trials were set up using a randomized complete block design with four replications for every treatment. Each plot was 2 rows wide and rows were spaced 30 inches apart. Plots were planted to a total length of 12.5 ft with a 2.5 to 3.0 ft alley between plots. Maverick control plants were expected to die from herbicide applications so they were grown in a separate plot; away from the transgenic soybean plant rows.
The results of soybean Event pDAB8264.44.06.1 sprayed with the 2,4-D and glyphosate herbicide tank mix as compared to unsprayed soybean Event pDAB8264.44.06.1 are summarized. Table 7 presents the means from an analysis comparing soybean Event pDAB8264.44.06.1 sprayed with a tankmix of 2,4-D and glyphosate to unsprayed soybean Event pDAB8264.44.06.1. The herbicide application did not damage soybean Event pDAB8264.44.06.1, these plants performed equivalently as compared to unsprayed soybean Event pDAB8264.44.06.1 plants for the reported agronomic characteristics listed in Table 7. With the exception of some early transient injury 1 and 7 daa (days after application) at the V3 stage of development and at 1, 7 and 14 daa at the R2 stage of development, soybean Event pDAB8264.44.06.1 showed robust tolerance to the 2,4-D and glyphosate tank mix. In contrast none of the Maverick plants were surviving after being sprayed with the herbicide treatment.
Agronomic equivalence of soybean Event pDAB8264.44.06.1 as compared to the control line, Maverick, was assessed. These trials were set up using a block design with two replications. Each plot was 2 rows wide and rows were spaced 30 inches apart. Plots were planted to a total length of 12.5 ft with a 2.5 to 3.0 foot alley between plots.
Table 8 presents the means from the analysis comparing the agronomic equivalence of soybean Event pDAB8264.44.06.1 with the control line, Maverick. The agronomic data is indicative that soybean Event pDAB8264.44.06.1 performs equivalently to Maverick plants, and does not result in agronomically meaningful unintended differences.
Two event specific TAQMAN assays were developed to detect the presence of soybean event pDAB8264.44.06.1 and to determine zygosity status of plants in breeding populations. Soybean event pDAB8264.44.06.1 contains the T-strand of the binary vector pDAB8264 (
gDNA samples of 11 different soybean events and non-transgenic soybean varieties were tested in this study. Genomic DNA was extracted using modified Qiagen MagAttract plant DNA kit (Qiagen, Valencia, Calif.). Fresh soybean leaf discs, 8 per sample, were used for gDNA extraction. The gDNA was quantified with the Pico Green method according to vendor's instructions (Molecular Probes, Eugene, Oreg.). Samples were diluted with DNase-free water resulting in a concentration of 10 ng/μL for the purpose of this study.
Example 6.2: Taqman Assay and ResultsSpecific Taqman primers and probes were designed for a soybean event pDAB8264.44.06.1 specific Taqman assay. These reagents can be used with the conditions listed below to detect the transgene within soybean event pDAB8264.44.06.1. Table 9 lists the primer and probe sequences that were developed specifically for the detection of soybean event pDAB8264.44.06.1.
The multiplex PCR conditions for amplification are as follows: 1× Roche PCR Buffer, 0.4 μM event specific forward primer, 0.4 μM event specific reverse primer, 0.4 μM Primer GMS116 F, 0.4 μM Primer GMS116 R, 0.2 μM Event specific probe, 0.2 μM GMS116 Probe, 0.1% PVP, 20 ng gDNA in a total reaction of 10 μl. The cocktail was amplified using the following conditions: i) 95° C. for 10 min., ii) 95° C. for 10 sec, iii) 60′C for 30 sec. iv) 72° C. for 1 sec v) repeat step ii-iv for 35 cycles, v) 40° C. hold. The Real time PCR was carried out on the Roche LightCycler 480. Data analysis was based on measurement of the crossing point (Cp value) determined by LightCycler 480 software, which is the PCR cycle number when the rate of change in fluorescence reaches its maximum.
The Taqman detection method for soybean event pDAB8264.44.06.1 was tested against 11 different events which contain the 2mEPSPS and aad-12 PTUs and non-transgenic soybean varieties in duplex format with soybean specific endogenous reference gene, GMFL01-25-J19 (GenBank: AK286292. 1). The assays specifically detected the soybean event pDAB8264.44.06.1 and did not produce or amplify any false-positive results from the controls (i.e. the 11 different events which contain the 2mEPSPS and aad-12 PTUs and non-transgenic soybean varieties). The event specific primers and probes can be used for the detection of the soybean event pDAB8264.44.06.1 and these conditions and reagents are applicable for zygosity assays.
Example 7: Full Length Sequence of Soybean Event pDAB8264.44.06.1SEQ ID NO:27 provides the full length sequence of soybean Event pDAB8264.44.06.1. This sequence contains the 5′ genomic flanking sequence, the integrated T-strand insert from pDAB8264 and the 3′ genomic flanking sequence. With respect to SEQ ID NO:27, residues 1-1494 are 5′ genomic flanking sequence, residues 1495-1497 are a three base pair insertion, residues 1498-11,774 are the pDAB8264 T-strand insert, and residues 11,775-13,659 are 3′ flanking sequence. The junction sequence or transition with respect to the 5′ end of the insert thus occurs at residues 1494-1495 of SEQ ID NO:27. The junction sequence or transition with respect to the 3′ end of the insert thus occurs at residues 11,774-11,775 of SEQ ID NO:27. SEQ ID NO:27 is the polynucleotide sequence of soybean Event pDAB8264.44.06.1 and was assembled from an alignment of multiple PCR contigs which were produced via PCR amplification reactions and sequenced using the ABI Big Dye® Terminator sequencing reaction kit (Applied Biosystems, Foster City, Calif.).
Example 8: Breeding Stack of Soybean Event pDAB8264.44.06.1 and Soybean Insect Tolerant Event pDA89582.812.9.1 Example 8.1: Sexual Crossing of Soybean Event pDAB8264.44.06.1 and Soybean Insect Tolerant Event pDAB9582.812.9.1Soybean event pDAB8264.44.06.1 was sexually crossed with soybean event pDAB9582.812.9.1. The anthers of soybean event pDAB8264.44.06.1 were manually rubbed across the stigma of soybean event pDAB9582.812.9.1, thereby fertilizing soybean event pDAB9582.812.9.1. The resulting F1 progeny which contained integration events from both soybean event pDAB9582.812.9.1 and soybean event pDAB8264.44.06.1 were screened for tolerance to 2,4-D and glyphosate herbicides to identify progeny plants which contained both integration events. Next, the F1 progeny plants were self-fertilized to produce an F2 offspring which was confirmed to segregate independently for both events. The F2 plants were sprayed with a single herbicide application containing both 2,4-D (1120 g ae/ha) and glyphosate (1120 g ac/ha). The resulting F2 plants were screened using a Taqman zygosity based assay to identify plants that were homozygous for both events. Selfing of these F2 homozygous plants produced an F3 offspring that were homozygous for both soybean event pDAB9582.812.9.1 and soybean event pDAB8264.44.06.1. The resulting event was labeled as soybean event pDAB9582.812.9.1::pDAB8264.44.06.1.
Example 8.2: Determination of the Zygosity Status of Soybean Event pDAB9582.812.9.1::pDA88264.44.06.1To determine the zygosity status of plants produced from the breeding cross of soybean event pDAB8264.44.06.1 and soybean event pDAB9582.812.9.1, separate event specific TAQMAN® assays were developed to detect the presence of either the pDAB9582.812.9.1 or pDAB8264.44.06.1 integration events. Segregating F2 plants, produced from the self fertilization of a breeding cross of soybean event pDAB9582.812.9.1 and soybean event pDAB8264.44.06.1, were tested with these event specific TAQMAN® assays to identify individual plants which contained both soybean event pDAB9582.812.9.1 and soybean event pDAB8264.44.06.1, and were homozygous for both events.
gDNA Isolation
gDNA samples from segregating F2 plants of the breeding stack of soybean event pDAB9582.812.9.1::pDAB8264.44.06.1 were tested in this study. Fresh soybean leaf discs, 4 per plant, were collected from 3,187 segregating F2 plants of the breeding stack of soybean event pDAB9582.812.9.1::pDAB8264.44.06.1. Genomic DNA was extracted from these samples using a modified Qiagen MagAttract Plant DNA Kit® (Qiagen, Valencia, Calif.).
TAQMAN® Assay and ResultsTAQMAN® primers and probes as previously described were designed for the use of individual event specific assays for soybean events pDAB9582.812.9.1 (U.S. Provisional Application No. 61/471,845) and pDAB8264.44.06.1 (described above). These reagents were used with the conditions listed below to determine the zygosity of each integration event contained within the breeding stack of soybean event pDAB9582.812.9.1::pDAB8264.44.06.1.
The multiplex PCR conditions for amplification are as follows: 1× Roche PCR Buffer, 0.4 μM event pDAB8264.44.06.1 specific forward primer, 0.4 μM event pDAB8264.44.06.1 specific reverse primer 0.4 μM event pDAB9582.812.9.1 specific forward primer, 0.4 μM event pDAB9582.812.9.1 specific reverse primer, 0.4 μM Primer GMS116 F, 0.4 μM Primer GMS116 R, 0.2 μM Event pDAB9582.812.9.1 specific probe, 0.2 μM Event pDAB8264.44.06.1 specific probe, 0.2 μM GMS116 Probe, 0.1% PVP, 20 ng gDNA in a total reaction of 10 μl. The cocktail was amplified using the following conditions: i) 95° C. for 10 min., ii) 95° C. for 10 sec, iii) 60° C. for 30 sec, iv) 72° C. for 1 sec v) repeat step ii-iv for 35 cycles, v) 40° C. hold. The Real time PCR was carried out on the Roche LightCycler® 480. Data analysis was based on measurement of the crossing point (Cp value) determined by LightCycler® 480 software, which is the PCR cycle number when the rate of change in fluorescence reaches its maximum.
A total of 3,187 segregating F2 plants, produced from the breeding cross of soybean event pDAB9582.812.9.1 and soybean event pDAB8264.44.06.1 were tested with the event specific TAQMAN® assays to determine the zygosity of individual plants for both soybean event pDAB9582.812.9.1 and soybean event pDAB8264.44.06.1. The results from these assays indicated that soybean event pDAB9582.812.9.1 and soybean event pDAB8264.44.06.1 were both present and detected in 2,360 plants. The zygosity status (also described as ploidy level) of each integration event is indicated in Table 9b. Of the 2,360 identified plants, 237 were determined to contain two copies of soybean event pDAB9582.812.9.1 and soybean event pDAB8264.44.06.1.
The biochemical properties of the recombinant Cry1F, Cry1Ac, AAD12, 2mEPSPS, and PAT proteins expressed in the breeding stack of soybean event pDAB9582.812.9.1::pDAB8264.44.06.1 were characterized. An Enzyme Linked Immunosorbent Assay (ELISA) was used to quantify the expression of PAT. Comparatively, Cry1Ac/Cry1F and AAD12/2mEPSPS proteins were quantified by multiplexed immunoassays utilizing electrochemiluminescent technology from Meso-Scale Discovery (MSD, Gaithersburg. Md.). Collectively, these assays were used to characterize the biochemical properties and confirm the robust expression of these proteins in the breeding stack of soybean event pDAB9582.812.9.1::pDAB8264.44.06.1.
Expression of the PAT Protein in Plant TissuesLevels of PAT protein were determined in the breeding stack of F3 soybean event pDAB9582.812.9.1::pDAB8264.44.06.1 which were identified to be homozygous for both event pDAB9582.812.9.1 and event pDAB8264.44.06.1 integrations. The levels of PAT protein expressed from soybean event pDAB9582.812.9.1::pDAB8264.44.06.1 was compared to the parental events, soybean event pDAB9582.812.9.1 and soybean event pDAB8264.44.06.1.
The soluble, extractable PAT protein was obtained from soybean leaf tissue and measured using a quantitative ELISA method (APS 014, Envirologix, Portland, Me.). Samples of soybean leaf tissues were isolated from greenhouse grown test plants at the unifoliate to V1 stage and prepared for expression analysis. The PAT protein was extracted from soybean plant tissues with a phosphate buffered saline solution containing the detergent Tween-20 (PBST) and 1% polyvinylpyrrolidone 40 (PVP-40). The samples were then extracted using a GenoGrinder® at 1500 rpm for 5 minutes. The plant extract was centrifuged; the aqueous supernatant was collected, diluted with appropriate buffer as necessary, and analyzed using the PAT ELISA kit in a sandwich format. The kit was used following the manufacturer's suggested protocol (Envirologix, Portland, Me.).
Detection analysis was performed to investigate the expression and heritability of soybean event pDAB9582.812.9.1::pDAB8264.44.06.1. The F3 generation of the breeding stack, soybean event pDAB9582.812.9.1::pDAB8264.44.06.1 expressed PAT at higher concentrations than either the parental events, pDAB9582.812.9.1 and pDAB8264.44.06.1. The increased concentration of PAT in soybean event pDAB9582.812.9.1::pDAB8264.44.06.1 breeding stack was expected. The higher concentrations of PAT are a result of soybean event pDAB9582.812.9.1::pDAB8264.44.06.1 containing twice as many copies of the pat coding sequence as compared to either of the parental events (Table 10).
Levels of Cry1F and Cry1Ac protein were determined in the breeding stack of F3 soybean event pDAB9582.812.9.1::pDAB8264.44.06.1 which were identified to be homozygous for both event pDAB9582.812.9.1 and event pDAB8264.44.06.1 integrations. The levels of Cry1F and Cry1Ac protein expressed from soybean event pDAB9582.812.9.1::pDAB8264.44.06.1 was compared to the parental event, soybean event pDAB9582.812.9.1.
The soluble, extractable Cry1F and Cry1Ac protein was obtained from soybean leaf tissue and measured using a multiplexed electrochemiluminescent MSD assay. Samples of soybean leaf tissue were isolated from greenhouse grown plants at the unifoliate to V1 stage and prepared for expression analysis. The Cry1F and Cry1Ac protein was extracted from soybean plant tissues with a phosphate buffered saline solution containing the detergent Tween-20 (PBST) and 1% polyvinylpyrrolidone 40 (PVP-40). The samples were then extracted using a GenoGrinder® at 1500 rpm for 5 minutes. The plant extract was centrifuged; the aqueous supernatant was collected, diluted with appropriate buffer as necessary, and analyzed using a Cry1F/Cry1Ac multiplex MSD assay from Meso-Scale Discovery. The kit was used following the manufacturer's suggested protocol.
Detection analysis was performed to investigate the expression and heritability of soybean event pDAB9582.812.9.1::pDAB8264.44.06.1. The F3 generation of the breeding stack of soybean event pDAB9582.812.9.1::pDAB8264.44.06.1 expressed Cry1F and Cry1Ac proteins at concentrations higher than the parental soybean event pDAB9582.812.9.1. (Table 11). These results indicate that soybean event pDAB9582.812.9.1::pDAB8264.44.06.1 plants contained a functionally expressing copy of the cry1F and cry1Ac coding sequences which were inherited from the parental line, soybean event pDAB9582.812.9.1.
Expression of the AAD12 and 2mEPSPS Proteins in Plant Tissues
Levels of AAD12 and 2mEPSPS protein were determined in the breeding stack of F3 soybean event pDAB9582.812.9.1::pDAB8264.44.06.1 which were identified to be homozygous for both event pDAB9582.812.9.1 and event pDAB8264.44.06.1 integrations. The levels of AAD12 and 2mEPSPS protein expressed from soybean event pDAB9582.812.9.1::pDAB8264.44.06.1 was compared to the parental event, Soybean Event pDAB8264.44.06.1.
The soluble, extractable AAD12 and 2mEPSPS protein was obtained from soybean leaf tissue and measured using a multiplexed electrochemiluminescent MSD assay. Samples of soybean leaf tissue were isolated from greenhouse grown plants at the unifoliate to V1 stage and prepared for expression analysis. The AAD12 and 2mEPSPS protein was extracted from soybean plant tissues with a phosphate buffered saline solution containing the detergent Tween-(PBST) and 1% polyvinylpyrrolidone 40 (PVP-40). The samples were then extracted using a GenoGrinder® at 1500 rpm for 5 minutes. The plant extract was centrifuged; the aqueous supernatant was collected, diluted with appropriate buffer as necessary, and analyzed using a AAD12 and 2mEPSPS multiplex MSD assay from Meso-Scale Discovery. The kit was used following the manufacturer's suggested protocol.
Detection analysis was performed to investigate the expression and heritability of soybean event pDAB9582.812.9.1::pDAB8264.44.06.1. The F3 generation of the breeding stack of soybean event pDAB9582.812.9.1::pDAB8264.44.06.1 expressed AAD12 and 2mEPSPS proteins at concentrations higher than the parental soybean event pDAB8264.44.06.1. (Table 12). These results indicated that soybean event pDAB9582.812.9.1::pDAB8264.44.06.1 plants contained a functionally expressing copy of the aad-12 and 2mEPSPS coding sequences which were inherited from the parental line, soybean event pDAB8264.44.06.1.
Herbicide tolerance of the breeding stack, soybean event pDAB9582.812.9.1::pDAB8264.44.06.1 was assayed during two growing seasons. Soybean event pDAB9582.812.9.1::pDAB8264.44.06.1 seed were planted and grown to maturity.
Mature plants were sprayed with a single herbicide application which consisted of a combination of 2,4-D and glyphosate. The resulting tolerance to these herbicides was measured by counting the number of surviving plants. Comparatively, control plants which did not contain the aad-12 and 2mEPSPS genes and were expected to be susceptible to the application of the 2,4-D and glyphosate herbicides were included in the study.
During the first season, herbicide tolerance was assessed in 120 field grown plots of F2 segregating lineages of the breeding stack of soybean event pDAB9582.812.9.1::pDAB8264.44.06.1. Each plot was 1 row wide and rows were spaced 30 inches apart. Plots were planted on 12 foot centers (total planted length 7.5 feet) with a 4.5 foot alley between plots. A total of 4.364 plants from F2 segregating lineages of the breeding stack of soybean event pDAB9582.812.9.1::pDAB8264.44.06.1 were sprayed with a mixture of 2,4-D and glyphosate (1120 g ae/ha). A single spray application of the glyphosate/2,4-D herbicides was made between V3 and V4 growth stages. The V3 growth stage is characterized by the unifoliate and first three trifoliate leaves being fully developed and the V4 growth stage is characterized by the unifoliate and first four trifoliate leaves being fully developed. After the herbicide treatment was completed, the plots were observed and 3,234 plants were identified as being tolerant to the application of the herbicides. The soybean event pDAB9582.812.9.1::pDAB8264.44.06.1 plants which were susceptible to the herbicide application did not contain copies of the aad-12 and 2mEPSPS as a result of Mendelian segregation of the pDAB8264.44.06.1 integration event.
During the second season, herbicide tolerance was assessed in greenhouse grown F3 homozygous plants of soybean event pDAB9582.812.9.1::pDAB8264.44.06.1. The soybean plants were grown in 4 inch pots which contained one plant per pot. A total of 15, F3 homozygous plants were sprayed with a single application of 2,4-D and glyphosate (840 ae/ha). All 15 plants survived after being sprayed with the herbicides, indicating that the soybean event pDAB9582.812.9.1::pDAB8264.44.06.1 plants were tolerant to the application of the herbicides, glyphosate and 2,4-D.
In summary, the aad-12 and 2mEPSPS genes which were present in the soybean event pDAB8264.44.06.1 parental line conferred tolerance to 2,4-D and glyphosate herbicides. These traits were passed and inherited in soybean event pDAB9582.812.9.1::pDAB8264.44.06.1, thereby providing herbicidal tolerance to soybean event pDAB9582.812.9.1::pDAB8264.44.06.1. Comparatively, control plants which did not contain the aad-12 and 2mEPSPS genes were susceptible to the application of the 2,4-D and glyphosate herbicides.
Example 8.5: Characterization of Insecticidal Activity of Soybean Event pDAB9582.812.9.1::pDAB8264.44.06.1Greenhouse evaluations were conducted to characterize the insecticidal tolerance of the breeding stack of soybean event pDAB9582.812.9.1::pDAB8264.44.06.1 which resulted from the expression of the cry1Ac and cry1F transgenes. Soybean event pDAB9582.812.9.1::pDAB8264.44.06.1 was tested against lab reared soybean pests including Anticarsia gemmatalis (velvetbean caterpillar) and Pseudoplusia includens (soybean looper). The breeding stack of soybean event pDAB9582.812.9.1::pDAB8264.44.06.1 was compared against the parental soybean events (soybean event pDAB9582.812.9.1 and soybean event pDAB8264.44.06.1) in addition to the non-transformed soybean variety Maverick. This comparison was made to determine whether the level of plant protection provided by the Cry1F and Cry1Ac proteins would be present in the breeding stack which introduced additional transgenes into the genome of the soybean plant. In addition, the breeding stack of soybean event pDAB9582.812.9.1::pDAB8264.44.06.1 and soybean event pDAB8264.44.06.1 were both sprayed with a single herbicide application containing 2,4-D and glyphosate (840 g ae/ha) prior to the insect bioassay to determine whether the spraying of the herbicides had any effect on the plant protection from insects provided by the Cry1F and Cry1Ac proteins.
Greenhouse trials were conducted on approximately three week old plants. Ten plants each were used to evaluate the breeding stack of soybean event pDAB9582.812.9.1::pDAB8264.44.06.1, soybean event pDAB9582.812.9.1, and the negative controls; herbicide sprayed soybean event pDAB8264.44.06.1 and Maverick. For each insect species tested (Anticarsia gemmatalis and Chrysodeixis (formerly Pseudoplusia) includens), 3 leaf punches were made from each plant for a total of 30 leaf discs/plant/insect species. The 1.4 cm diameter (or 1.54 cm2) leaf punches were placed in a test arena on top of 2% water agar, infested with one neonate larvae and sealed with a perforated plastic lid. Mortality and leaf consumption were rated four days after infestation. Larvae that were not responsive to gentle probing were considered dead. Leaf damage was assessed by visually scoring the percentage of leaf punch consumed by the insect. Statistical analysis was performed on the data using JMP® Pro 9.0.1 (2010 SAS Institute Inc., Cary, N.C.).
The results (Table 13) obtained from these replicated experiments indicated that the level of insect protection and mortality provided by the Cry1F and Cry1Ac proteins of the breeding stack of soybean event pDAB9582.812.9.1::pDAB8264.44.06.1 were consistent with the parental soybean event pDAB9582.812.9.1. As expected, soybean event pDAB9582.812.9.1::pDAB8264.44.06.1 sustained significantly lower insect damage (0.10-0.15%) than soybean event pDAB8264.44.06.1 (58-76%) and the Maverick (79-91%) control plants for all insects tested. Additionally, high insect mortality (100%) was recorded for all soybean events which contained the cry1F and cry1Ac coding sequences, while the negative controls, Maverick and soybean event pDAB8264.44.06.1 resulted in <10% insect mortality. Thus, the soybean event pDAB9582.812.9.1::pDAB8264.44.06.1 provided protection from insecticidal activity at levels comparable to the parental soybean event pDAB9582.812.9.1.
Soybean event pDAB8264.44.06.1 was sexually crossed with soybean event pDAB9582.814.19.1. The anthers of soybean event pDAB8264.44.06.1 were manually rubbed across the stigma of soybean event pDAB9582.814.19.1, thereby fertilizing soybean event pDAB9582.814.19.1. The resulting F1 progeny which contained integration events from both soybean event pDAB9582.814.19.1 and soybean event pDAB8264.44.06.1 were screened for tolerance to 2,4-D and glyphosate herbicides to identify progeny plants which contained both integration events. Next, the F1 progeny plants were self-fertilized to produce an F2 offspring which was confirmed to segregate independently for both events. The F2 plants were sprayed with a single herbicide application containing both 2,4-D (840 g ac/ha) and glyphosate (840 g ae/ha). The resulting F2 plants were screened using a Taqman zygosity based assay to identify plants that were homozygous for both events. Selfing of these F2 homozygous plants produced an F3 offspring that were homozygous for both soybean event pDAB9582.814.19.1 and soybean event pDAB8264.44.06.1. The resulting event was labeled as soybean event pDAB9582.814.19.1::pDAB8264.44.06.1.
Example 9.2: Determination of the Zygosity Status of Soybean Event pDAB9582.814.19.1::pDAB8264.44.06.1To determine the zygosity status of plants produced from the breeding cross of soybean event pDAB8264.44.06.1 and soybean event pDAB9582.814.19.1, separate event specific TAQMAN® assays were developed to detect the presence of either the pDAB9582.814.19.1 or pDAB8264.44.06.1 integration events. Segregating F2 plants, produced from the self fertilization of a breeding cross of soybean event pDAB9582.814.19.1 and soybean event pDAB8264.44.06.1, were tested with these event specific TAQMAN® assays to identify individual plants which contained both soybean event pDAB9582.814.19.1 and soybean event pDAB8264.44.06.1, and were homozygous for both events.
gDNA Isolation
gDNA samples from segregating F2 plants of the breeding stack of soybean event pDAB9582.814.19.1::pDAB8264.44.06.1 were tested in this study. Fresh soybean leaf discs, 4 per plant, were collected from 37 segregating F2 plants of the breeding stack of soybean event pDAB9582.814.19.1::pDAB8264.44.06.1. Genomic DNA was extracted from these samples using a modified Qiagen MagAttract Plant DNA Kit® (Qiagen, Valencia, Calif.).
TAQMAN® Assay and ResultsTAQMAN® primers and probes as previously described were designed for the use of individual event specific assays for soybean events pDAB9582.814.19.1 (U.S. Provisional Application No. 61/471,845) and pDAB8264.44.06.1 (described above). These reagents were used with the conditions listed below to determine the zygosity of each integration event contained within the breeding stack of soybean event pDAB9582.814.19.1::pDAB8264.44.06.1.
The multiplex PCR conditions for amplification are as follows: 1× Roche PCR Buffer, 0.4 μM event pDAB8264.44.06.1 specific forward primer, 0.4 μM event pDAB8264.44.06.1 specific reverse primer 0.4 μM event pDAB9582.814.19.1 specific forward primer, 0.4 μM event pDAB9582.814.19.1 specific reverse primer, 0.4 μM Primer GMS116 F, 0.4 μM Primer GMS116 R, 0.2 μM Event pDAB9582.814.19.1 specific probe, 0.2 μM Event pDAB8264.44.06.1 specific probe, 0.2 μM GMS116 Probe, 0.1% PVP, 20 ng gDNA in a total reaction of 10 μl. The cocktail was amplified using the following conditions: i) 95° C. for 10 min., ii) 95° C. for 10 sec, iii) 60° C. for 30 sec, iv) 72° C. for 1 sec v) repeat step ii-iv for 35 cycles, v) 40° C. hold. The Real time PCR was carried out on the Roche LightCycler® 480. Data analysis was based on measurement of the crossing point (Cp value) determined by LightCycler® 480 software, which is the PCR cycle number when the rate of change in fluorescence reaches its maximum.
A total of 37 segregating F2 plants, produced from the breeding cross of soybean event pDAB9582.814.19.1 and soybean event pDAB8264.44.06.1 were tested with the event specific TAQMAN® assays to determine the zygosity of individual plants for both soybean event pDAB9582.814.19.1 and soybean event pDAB8264.44.06.1. The results from these assays indicated that soybean event pDAB9582.814.19.1 and soybean event pDAB8264.44.06.1 were both present and detected in 23 plants. The zygosity status (also described as ploidy level) of each integration event is indicated in Table 14. Of the 23 identified plants, 1 plant was identified which contained two copies of soybean event pDAB9582.814.19.1 and soybean event pDAB8264.44.06.1.
The biochemical properties of the recombinant Cry1F, Cry1Ac, AAD12, 2mEPSPS, and PAT proteins expressed in the breeding stack of soybean event pDAB9582.814.19.1::pDAB8264.44.06.1 were characterized. An Enzyme Linked Immunosorbent Assay (ELISA) was used to quantify the expression of PAT. Comparatively, Cry1Ac/Cry1F and AAD12/2mEPSPS proteins were quantified by multiplexed immunoassays utilizing electrochemiluminescent technology from Meso-Scale Discovery (MSD, Gaithersburg, Md.). Collectively, these assays were used to characterize the biochemical properties and confirm the robust expression of these proteins in the breeding stack of soybean event pDAB9582.814.19.1::pDAB8264.44.06.1.
Expression of the PAT Protein in Plant TissuesLevels of PAT protein were determined in the breeding stack of F3 soybean event pDAB9582.814.19.1::pDAB8264.44.06.1 which were identified to be homozygous for both event pDAB9582.814.19.1 and event pDAB8264.44.06.1 integrations. The levels of PAT protein expressed from soybean event pDAB9582.814.19.1::pDAB8264.44.06.1 was compared to the parental events, soybean event pDAB9582.814.19.1 and soybean event pDAB8264.44.06.1.
The soluble, extractable PAT protein was obtained from soybean leaf tissue and measured using a quantitative ELISA method (APS 014, Envirologix, Portland, Me.). Samples of soybean leaf tissues were isolated from greenhouse grown test plants at the unifoliate to V1 stage and prepared for expression analysis. The PAT protein was extracted from soybean plant tissues with a phosphate buffered saline solution containing the detergent Tween-20 (PBST) and 1% polyvinylpyrrolidone 40 (PVP-40). The samples were then extracted using a GenoGrinder® at 1500 rpm for 5 minutes. The plant extract was centrifuged; the aqueous supernatant was collected, diluted with appropriate buffer as necessary, and analyzed using the PAT ELISA kit in a sandwich format. The kit was used following the manufacturer's suggested protocol (Envirologix, Portland, Me.).
Detection analysis was performed to investigate the expression and heritability of soybean event pDAB9582.814.19.1::pDAB8264.44.06.1. The F3 generation of the breeding stack, soybean event pDAB9582.814.19.1::pDAB8264.44.06.1 expressed PAT at higher concentrations than either the parental events, pDAB9582.814.19.1 and pDAB8264.44.06.1. The increased concentration of PAT in soybean event pDAB9582.814.19.1::pDAB8264.44.06.1 breeding stack was expected. The higher concentrations of PAT are a result of soybean event pDAB9582.814.19.1::pDAB8264.44.06.1 containing twice as many copies of the pat coding sequence as compared to either of the parental events (Table 15).
Levels of Cry1F and Cry1Ac protein were determined in the breeding stack of F3 soybean event pDAB9582.814.19.1::pDAB8264.44.06.1 which were identified to be homozygous for both event pDAB9582.814.19.1 and event pDAB8264.44.06.1 integrations. The levels of Cry1F and Cry1Ac protein expressed from soybean event pDAB9582.814.19.1::pDAB8264.44.06.1 was compared to the parental event, soybean event pDAB9582.814.19.1.
The soluble, extractable Cry1F and Cry1 Ac protein was obtained from soybean leaf tissue and measured using a multiplexed electrochemiluminescent MSD assay. Samples of soybean leaf tissue were isolated from greenhouse grown plants at the unifoliate to V1 stage and prepared for expression analysis. The Cry1F and Cry1Ac protein was extracted from soybean plant tissues with a phosphate buffered saline solution containing the detergent Tween-20 (PBST) and 1% polyvinylpyrrolidone 40 (PVP-40). The samples were then extracted using a GenoGrinder® at 1500 rpm for 5 minutes. The plant extract was centrifuged; the aqueous supernatant was collected, diluted with appropriate buffer as necessary, and analyzed using a Cry1F/Cry1Ac multiplex MSD assay from Meso-Scale Discovery. The kit was used following the manufacturer's suggested protocol.
Detection analysis was performed to investigate the expression and heritability of soybean event pDAB9582.814.19.1::pDAB8264.44.06.1. The F3 generation of the breeding stack of soybean event pDAB9582.814.19.1::pDAB8264.44.06.1 expressed Cry1Ac protein at concentrations higher than the parental soybean event pDAB9582.814.19.1. The F3 generation of the breeding stack of soybean event pDAB9582.814.19.1::pDAB8264.44.06.1 expressed Cry1F protein at concentrations lower than the parental soybean event pDAB9582.814.19.1. (Table 16). Despite the variability in expression levels, these results indicate that soybean event pDAB9582.814.19.1::pDAB8264.44.06.1 plants contained a functionally expressing copy of the cry1F and cry1Ac coding sequences which were inherited from the parental line, soybean event pDAB9582.814.19.1.
Expression of the AAD12 and 2mEPSPS Proteins in Plant Tissues
Levels of AAD12 and 2mEPSPS protein were determined in the breeding stack of F3 soybean event pDAB9582.814.19.1::pDAB8264.44.06.1 which were identified to be homozygous for both event pDAB9582.814.19.1 and event pDAB8264.44.06.1 integrations. The levels of AAD12 and 2mEPSPS protein expressed from soybean event pDAB9582.814.19.1::pDAB8264.44.06.1 was compared to the parental event, Soybean Event pDAB8264.44.06.1.
The soluble, extractable AAD12 and 2mEPSPS protein was obtained from soybean leaf tissue and measured using a multiplexed electrochemiluminescent MSD assay. Samples of soybean leaf tissue were isolated from greenhouse grown plants at the unifoliate to V1 stage and prepared for expression analysis. The AAD12 and 2mEPSPS protein was extracted from soybean plant tissues with a phosphate buffered saline solution containing the detergent Tween-20 (PBST) and 1% polyvinylpyrrolidone 40 (PVP-40). The samples were then extracted using a GenoGrinder® at 1500 rpm for 5 minutes. The plant extract was centrifuged; the aqueous supernatant was collected, diluted with appropriate buffer as necessary, and analyzed using a AAD12 and 2mEPSPS multiplex MSD assay from Meso-Scale Discovery. The kit was used following the manufacturer's suggested protocol.
Detection analysis was performed to investigate the expression and heritability of soybean event pDAB9582.814.19.1::pDAB38264.44.06.1. The F3 generation of the breeding stack of soybean event pDAB9582.814.19.1::pDAB8264.44.06.1 expressed AAD12 and 2mEPSPS proteins at concentrations lower than the parental soybean event pDAB8264.44.06.1. (Table 17). Despite the variability in expression levels, these results indicated that soybean event pDAB9582.814.19.1::pDAB8264.44.06.1 plants contained a functionally expressing copy of the aad-12 and 2mEPSPS coding sequences which were inherited from the parental line, soybean event pDAB8264.44.06.1.
Herbicide tolerance of the breeding stack, soybean event pDAB9582.814.19.1::pDAB8264.44.06.1 was assayed. Soybean event pDAB9582.814.19.1::pDAB8264.44.06.1 seed were planted in a greenhouse study and mature plants were sprayed with a single herbicide application which consisted of a combination of 2,4-D and glyphosate. The resulting tolerance to these herbicides was measured by counting the number of surviving plants. Comparatively, control plants which did not contain the aad-12 and 2mEPSPS genes and were expected to be susceptible to the application of the 2,4-D and glyphosate herbicides were included in the study.
Herbicide tolerance was assessed in greenhouse grown F2 plants of soybean event pDAB9582.814.19.1::pDAB8264.44.06.1. The soybean plants were grown in 4 inch pots which contained one plant per pot. A total of 37, F3 homozygous plants were sprayed with a single application of 2,4-D and glyphosate (840 ae/ha) at the unfoliate growth stage. All 25 plants survived after being sprayed with the herbicides, indicating that the soybean event pDAB9582.814.19.1::pDAB8264.44.06.1 plants were tolerant to the application of the herbicides, glyphosate and 2,4-D.
In summary, the aad-12 and 2mEPSPS genes which were present in the soybean event pDAB8264.44.06.1 parental line conferred tolerance to 2,4-D and glyphosate herbicides. These traits were passed and inherited in soybean event pDAB9582.814.19.1::pDAB8264.44.06.1, thereby providing herbicidal tolerance to soybean event pDAB9582.814.19.1::pDAB8264.44.06.1. The soybean event pDAB9582.812.9.1::pDAB8264.44.06.1 plants which were susceptible to the herbicide application did not contain copies of the aad-12 and 2mEPSPS as a result of Mendelian segregation of the pDAB8264.44.06.1 integration event. Additionally, control plants which did not contain the aad-12 and 2mEPSPS genes were susceptible to the application of the 2,4-D and glyphosate herbicides.
Example 9.5: Characterization of Insecticidal Activity of Soybean Event pDAB9582.814.19.1::pDAB8264.44.06.1Greenhouse evaluations were conducted to characterize the insecticidal tolerance activity of soybean event pDAB9582.814.19.1::pDAB8264.44.06.1 which resulted from the expression of the Cry1Ac and Cry1F transgenes. Soybean event pDAB9582.814.19.1::pDAB8264.44.06.1 was tested against lab reared soybean pests including Anticarsia gemmatalis (velvetbean caterpillar) and Pseudoplusia includens (soybean looper). The breeding stack of soybean event pDAB9582.814.19.1::pDAB8264.44.06.1 was compared against the parental soybean events (soybean event pDAB9582.814.19.1 and soybean event pDAB8264.44.06.1) in addition to the non-transformed soybean variety Maverick. This comparison was made to determine whether the level of plant protection to insect damage provided by the Cry1F and Cry1Ac proteins would be present in the breeding stack which introduced additional transgenes into the genome of the soybean plant. In addition, the breeding stack of soybean event pDA139582.814.19.1::pDAB8264.44.06.1 and soybean event pDAB8264.44.06.1 were both sprayed with a single herbicide application containing 2,4-D and glyphosate (840 g ae/ha) prior to the insect bioassay to determine whether the spraying of the herbicides had any effect on the plant protection from insects provided by the Cry1F and Cry1Ac proteins.
Greenhouse trials were conducted on approximately three week old plants. Ten plants each were used to evaluate the breeding stack of soybean event pDAB9582.814.19.1::pDAB8264.44.06.1, soybean event pDAB9582.814.19.1, and the negative controls; herbicide sprayed soybean event pDAB8264.44.06.1 and Maverick. For each insect species tested (Anticarsia gemmatalis and Pseudoplusia includens), 3 leaf punches were made from each plant for a total of 30 leaf discs/plant/insect species. The 1.4 cm diameter (or 1.54 cm2) leaf punches were placed in a test arena on top of 2% water agar, infested with one neonate larvae and sealed with a perforated plastic lid. Mortality and leaf consumption were rated 4 days after infestation. Larvae that were not responsive to gentle probing were considered dead. Leaf damage was assessed by visually scoring the percentage of leaf punch consumed by the insect. Statistical analysis was performed on the data using JMP® Pro 9.0.1 (2010 SAS Institute Inc., Cary, N.C.).
The results (Table 18) obtained from these replicated experiments indicated that the level of insect damage and mortality provided by the Cry1F and Cry1Ac proteins of the breeding stack of soybean event pDAB9582.814.19.1::pDAB8264.44.06.1 were consistent with the parental soybean event pDAB9582.814.19.1. As expected soybean event pDAB9582.814.19.1::pDAB8264.44.06.1 sustained significantly lower insect damage (0.10-0.12%) than soybean event pDAB8264.44.06.1 (58-76%) and the Maverick (79-91%) control plants for all insects tested. Additionally, high insect mortality (100%) was recorded for all soybean events which contained the cry1F and cry1Ac coding sequences, while the negative controls, maverick and soybean event pDAB8264.44.06.1, resulted in <10% insect mortality. Thus, the soybean event pDAB9582.814.19.1::pDAB8264.44.06.1 provided protection from insecticidal activity at levels comparable to the parental soybean event pDAB9582.814.19.1.
Claims
1.-69. (canceled)
70. A method of protecting a soybean plant from weeds, the soybean plant comprising a genome comprising Event pDAB8264.44.06.1 as present in representative seeds deposited with American Type Culture Collection (ATCC) under Accession No. PTA-11336, the method comprising applying a herbicide selected from the group consisting of a phenoxyacetic acid herbicide, a glyphosate herbicide, and a glufosinate herbicide to a field, the field comprising the weeds and the soybean plant comprising the genome comprising Event pDAB8264.44.06.1.
71. The method of claim 70, wherein the herbicide is a phenoxyacetic acid herbicide.
72. The method of claim 71, wherein the phenoxyacetic acid herbicide is 2,4-D.
73. The method of claim 70, wherein the method comprises applying at least two of the herbicides simultaneously.
74. The method of claim 70, wherein the method comprises applying at least two of the herbicides sequentially.
75. The method of claim 70, wherein the phenoxyacetic acid herbicide is selected from the group consisting of 2,4-D and 2,4-DB.
76. The method of claim 70, wherein the herbicide is applied over the top of the plant.
77. The method of claim 70, wherein the herbicide is a glyphosate herbicide.
78. The method of claim 70, wherein the herbicide is a glufosinate herbicide.
79. A method of protecting a soybean plant from injury, the soybean plant comprising a genome comprising Event pDAB8264.44.06.1 as present in representative seeds deposited with American Type Culture Collection (ATCC) under Accession No. PTA-11336, the method comprising applying a herbicide selected from the group consisting of a phenoxyacetic acid herbicide, a glyphosate herbicide, and a glufosinate herbicide to a field, the field comprising the soybean plant comprising the genome comprising Event pDAB8264.44.06.1 which protects the plant from injury by the herbicide.
80. The method of claim 79, wherein the herbicide is a phenoxyacetic acid herbicide.
81. The method of claim 80, wherein the phenoxyacetic acid herbicide is 2,4-D.
82. The method of claim 79, wherein the method comprises applying at least two of the herbicides simultaneously.
83. The method of claim 79, wherein the method comprises applying at least two of the herbicides sequentially.
84. The method of claim 79, wherein the phenoxyacetic acid herbicide is selected from the group consisting of 2,4-D and 2,4-DB.
85. The method of claim 79, wherein the herbicide is applied over the top of the plant.
86. The method of claim 79, wherein the herbicide is a glyphosate herbicide.
87. The method of claim 79, wherein the herbicide is a glufosinate herbicide.
88. A method of protecting a soybean plant from weeds in a field, the method comprising applying a herbicide selected from the group consisting of a phenoxyacetic acid herbicide, a glyphosate herbicide, and a glufosinate herbicide to the field, and planting a soybean seed in the field within 14 days of applying the herbicide wherein the soybean seed comprises a genome comprising Event pDAB8264.44.06.1 as present in representative seeds deposited with American Type Culture Collection (ATCC) under Accession No. PTA-11336, and wherein the soybean plant is produced from the soybean seed.
Type: Application
Filed: Jul 28, 2022
Publication Date: Feb 23, 2023
Inventors: Yunxing C. Cui (Carmel, IN), Thomas Hoffman (Zionsville, IN), Ning Zhou (Zionsville, IN), Stephen N. Novak (Westfield, IN), Julissa Colon (Cidra, PR), Dawn M. Parkhurst (Avon, IN), Sandra G. Toledo (West Lafayette, IN), Terry R. Wright (Westfield, IN), Sean M. Russell (Carmel, IN), Bruce Held (Ames, IA), Vaithilingam Sekar (Ames, IA)
Application Number: 17/876,172
