SYNTHETIC GENES
The invention provides synthetic nucleic acid sequences encoding proteins of interest that are particularly adapted to express well in plants. The claimed synthetic sequences utilize plant-optimized codons roughly in the same frequency at which they are utilized, on average, in genes naturally occurring in the plant species. The invention further includes synthetic DNA sequence for herbicide tolerance, water and/or heat stress tolerance, healthy oil modifications and for transformation marker genes and selectable marker genes are used. DNA construct and transgenic plants containing the synthetic sequences are taught as are methods and compositions for using the plants in agriculture.
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This application claims priority to provisional application Ser. No. 61/475,921 filed Apr. 15, 2011, the disclosure of which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTIONTo achieve desired expression levels of heterologous proteins in transgenic plants it has been found beneficial to alter the native, sometimes referred to as wild-type or original, DNA coding sequence in various ways, e.g. so that codon usage more closely matches the codon usage of the host plant species, and/or so the G+C content of the coding sequence more closely matches the G+C level typically found in coding sequences of the host plant species, and/or so that certain sequences that destabilize mRNA are removed. Expression in plants of Bacillus thuringiensis (B.t.) crystal protein insect toxins, for example, has been improved using one or more of these approaches. See, for example, U.S. Pat. Nos. 5,380,301, 5,625,136, 6,218,188, 6,340,593, 6,673,990, 7,741,118. Codon degeneracy allows one to make synthetic DNA sequences that encode a protein of interest using codons that differ from those used in the original DNA coding sequence.
In regard to removing sequences that may destabilize mRNA, U.S. Pat. No. 7,741,118 discloses a list of 16 polyadenylation signal sequences (column 15, Table II) and calls for reducing the number of such sequences in synthetic coding sequences that are intended for expression in plants. The polyadenylation signal sequences listed in U.S. Pat. No. 7,741,118, Table II are listed below in Table 1:
U.S. Pat. No. 7,741,118 also calls for preferably removing the sequence ATTTA (known as the Shaw-Kamen sequence), because it has been identified as potentially destabilizing mRNA.
Contrary to the teaching of U.S. Pat. No. 7,741,118, we have found that reduction in the number of the polyadenylation signal sequences identified in Table 1 above is neither necessary nor sufficient to enable enhanced expression of synthetic genes in plants.
SUMMARY OF THE INVENTIONTable 2 below identifies 20 potential polyadenylation signal sequences that occur frequently in maize genes.
Table 3 below identifies 20 potential polyadenylation signal sequences that occur frequently in soybean genes.
The present invention provides a synthetic DNA sequence for expressing a protein of interest in maize cells which comprises:
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- a) a codon-optimized DNA sequence encoding the protein of interest,
- b) at least one polyadenylation signal sequence chosen from the group consisting of Class I and Class II wherein;
- Class 1 is chosen from the group consisting of AATAAA, AATAAT, AACCAA, ATATAA, AATCAA, ATACTA, ATAAAA, ATGAAA, AAGCAT, ATTAAT, ATACAT, AAAATA, ATTAAA, AATTAA. AATACA, and CATAAA; and
- Class II is chosen from the group consisting of ATATAT, TTGTTT, TTTTGT, TGTTTT, TATATA, TATTTT, TTTTTT, ATTTTT, TTATTT, TTTATT, TAATAA, ATTTAT, TATATT, TTTTAT, ATATTT, TATTAT, TGTTTG, TTATAT, TGTAAT, and AAATAA; and
wherein said codon-optimized DNA sequence contains-at least one polyadenylation signal sequence from Class II and wherein said synthetic DNA sequence contains fewer Class II polyadenylation signal sequences than the protein's native DNA sequence and contains the same number of Class I polyadenylation signal sequences compared to the native DNA sequence.
The present invention also provides a synthetic DNA sequence for expressing a protein of interest in soybean cells which comprises:
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- a) a codon-optimized DNA sequence encoding the protein of interest,
- b) at least one polyadenylation signal sequence chosen from the group consisting of Class I and Class III wherein:
- Class I is chosen from the group consisting of AATAAA, AATAAT, AACCAA, ATATAA, AATCAA, ATACTA, ATAAAA, ATGAAA, AAGCAT, ATTAAT, ATACAT, AAAATA, ATTAAA, AATTAA. AATACA, and CATAAA; and
- Class III is chosen from the group consisting of ATTTTT, TATTTT, TTATTT, TTTATT, TTTTT, TTTTAT, AATTTT, TTTTTA, ATATAT, TAATTT, TTAATT, AAATTT, AAATAA, ATATTT, TTTGTT TTGTTT, ATTATT, ATTTTA, TTTAAT, and TITTAA, and
wherein said codon-optimized DNA sequence contains at least one polyadenylation signal sequence from Class III and wherein said synthetic DNA sequence contains fewer Class III polyadenylation signal sequences than the protein's native DNA sequence and contains the same number of Class I polyadenylation signal sequences compared to the native DNA sequence.
The invention also provides a method of making a synthetic DNA sequence that encodes a protein of interest which comprises (a) starting with an amino acid sequence of a protein of interest derived from naturally occurring polypeptide(s) encoded by native sequence(s) that comprise at least one polyadenylation signal sequence listed in Table 2, and (b) making a synthetic DNA sequence that encodes said amino acid sequence and contains fewer polyadenylation signal sequences listed in Table 2 compared to the corresponding coding sequence of the native sequence(s) and contains the same number of polyadenylation signal sequences listed in Table 1.
In another embodiment the invention provides a method of making a synthetic DNA sequence that encodes a protein of interest which comprises (a) starting with an amino acid sequence of a protein of interest derived from naturally occurring polypeptide(s) encoded by native sequence(s) that comprise at least one polyadenylation signal sequence-listed in Table 3, and (b) making a synthetic DNA sequence that encodes said amino acid sequence and contains fewer polyadenylation signal sequences listed in Table 3 compared to the corresponding coding sequence of the native sequence(s) and contains the same number of polyadenylation signal sequences listed in Table 1.
In some embodiments the synthetic DNA sequences provided by the invention are devoid of the polyadenylation signal sequences listed in Table 2 and/or Table 3, or the number of polyadenylation signal sequences identified in Table 2 and/or Table 3 is reduced as much as possible consistent with maintaining the same number of polyadenylation signal sequences identified in Table 1 and maintaining the Table 1 sequences in their original positions in the sequence.
In some embodiments the synthetic DNA sequences provided by the invention encode an insecticidal protein, optionally derived from Bacillus thuringiensis, as well as DNA sequences useful for herbicide tolerance, water and/or heat stress tolerance, healthy oil modifications and for transformation marker genes and selectable marker genes.
The synthetic DNA sequences of the invention may be used in a DNA construct for expression of a protein of interest, where the construct comprises a 5′ non-translated sequence, a synthetic DNA sequence of the invention, and a 3′ non-translated region, and said 5′ non-translated sequence contains a promoter that functions in plants, and said 3′ non-translated sequence comprises a transcription termination and polyadenylation signal.
The invention also provides a transgenic plant containing the synthetic DNA sequences of the invention.
Also provided is a method of controlling pests in a plant which comprises expressing a synthetic DNA sequence of the invention in the plant where the synthetic DNA sequence encodes an insect toxin, for example a Bacillus thuringiensis Cry protein.
Also provided is a method for herbicide tolerance in a plant which comprises expressing a synthetic DNA sequence of the invention in the plant where the synthetic DNA sequence encodes a known herbicide tolerance enzyme, for example the ryloxykanoate gioxygenase (AADI) see WO/2005/107437, or phosphinothricin acetytransferase, or 5-enolpyruvylshikimate-3-phosphate synthase enzymes.
Also provided is a method for modifying oil profiles in a plant which comprises expressing one or more synthetic DNA sequences of the invention in the plant where the synthetic DNA sequence encodes one or more known enzymes for modifying oil profiles in plants, for example fatty acid desaturase.
Also provided is a method for stress tolerance in a plant which comprises expressing a synthetic DNA sequence of the invention in the plant where the synthetic DNA sequence encodes known stress tolerance genes for water and/or heat stress, for example the stress associated protein (SAPI); US Patent Publication No: 2010/0275327, and 1-Cys peroxiredoxin (Perl) proteins (Mowla, et al., 2002, Planta 215:716-726).
Also provided is a method adding reporter genes in a plant which comprises expressing a synthetic DNA sequence of the invention in the plant where the synthetic DNA sequence encodes a known transformation marker protein functional in plants, for example green fluorescence protein (GFP) or beta glucuronidase enzyme.
Also provided is a method of controlling pests in grain or seed which comprises obtaining said grain or seed from plants containing a synthetic gene of the invention that expresses an insect toxin, and a method of controlling pests in meal or flour which comprises obtaining said meal or flour from grain containing a synthetic gene of the invention that expresses an insect toxin.
Also provided is a composition derived from transgenic plants containing synthetic DNA of the invention wherein said composition is a commodity product selected from the group consisting of meal, flour, protein concentrate, or oil.
In some cases the number of polyadenylation signals listed in Table 1 can be maintained in synthetic DNA sequences of the invention by deleting occurrences of AATAAA and substituting another polyadenylation signal sequence listed in Table 1. This is exemplified in Example 1, SEQ ID NO:5.
DESCRIPTION OF THE SEQUENCESSEQ ID NO:1 is the native DNA sequence encoding Bacillus thuringiensis Cry1Fa core toxin.
SEQ ID NO:2 is Bacillus thuringiensis Cry1Fa core toxin sequence.
SEQ ID NO:3 is a synthetic DNA sequence encoding Bacillus thuringiensis Cry1Fa core toxin using codons optimized for maize and Table 1 sequences are maintained.
SEQ ID NO:4 is Bacillus thuringiensis Cry1Fa core toxin sequence.
SEQ ID NO:5 is a synthetic DNA sequence in accordance with the invention encoding-Bacillus thuringiensis Cry1Fa core toxin using codons optimized for maize and with sequences identified in Table 2 removed and Table 1 sequences are maintained.
SEQ ID NO 6 is Bacillus thuringiensis Cry1Fa core toxin sequence.
SEQ ID NO:7 is the native DNA sequence encoding Bacillus thuringiensis Cry34Ab1 toxin.
SEQ ID NO:8 is Bacillus thuringiensis Cry34Ab1 toxin sequence.
SEQ ID NO:9 is a synthetic DNA sequence encoding Bacillus thuringiensis Cry34Ab1 toxin using codons optimized for maize and Table 1 sequences are maintained.
SEQ ID NO:10 is Bacillus thuringiensis Cry34Ab1 toxin sequence.
SEQ ID NO:11 is a synthetic DNA sequence in accordance with the invention encoding Bacillus thuringiensis Cry34Ab1 toxin using codons optimized for maize and with sequences identified in Table 2 removed and Table 1 sequences are maintained.
SEQ ID NO:12 is Bacillus thuringiensis Cry34Ab1 toxin sequence.
SEQ ID NO: 13 is the native DNA sequence encoding Bacillus thuringiensis Cry35Ab1 toxin.
SEQ ID NO:14 is Bacillus thuringiensis Cry35Ab1 toxin sequence.
SEQ ID NO:15 is a synthetic DNA sequence encoding Bacillus thuringiensis Cry35Ab1 toxin using codons optimized for maize and Table 1 sequences are maintained
SEQ ID NO:16 is Bacillus thuringiensis Cry35Ab1 toxin sequence.
SEQ ID NO:17 is a synthetic DNA sequence in accordance with the invention encoding Bacillus thuringiensis Cry35Ab1 toxin using codons optimized for maize and with sequences identified in Table 2 removed and Table 1 sequences are maintained.
SEQ ID NO:18 is Bacillus thuringiensis Cry35Ab1 toxin sequence.
SEQ ID NO:19 is the native DNA sequence encoding Bacillus thuringiensis Cry1Ab1 core toxin.
SEQ ID NO:20 is Bacillus thuringiensis Cry1Ab1 core toxin sequence.
SEQ ID NO:21 is a synthetic DNA sequence encoding Bacillus thuringiensis Cry1Ab1 core toxin using codons optimized for maize and Table 1 sequences are maintained.
SEQ ID NO:22 is Bacillus thuringiensis Cry1Ab1 core toxin sequence.
SEQ ID NO:23 is a synthetic DNA sequence in accordance with the invention encoding-Bacillus thuringiensis Cry1Ab1 core toxin using codons optimized for maize and with sequences identified in Table 2 removed and Table 1 sequences are maintained.
SEQ ID NO:24 is Bacillus thuringiensis Cry1Ab1 core toxin sequence.
SEQ ID NO:25 is the native DNA sequence encoding Bacillus thuringiensis Cry1Ca core toxin.
SEQ ID NO:26 is encoding Bacillus thuringiensis Cry1Ca core toxin sequence.
SEQ ID NO:27 is a synthetic DNA sequence encoding Bacillus thuringiensis Cry1Ca core toxin using codons optimized for maize and Table 1 sequences are maintained.
SEQ ID NO:28 is encoding Bacillus thuringiensis Cry1Ca core toxin sequence.
SEQ ID NO:29 is a synthetic DNA sequence in accordance with the invention encoding Bacillus thuringiensis Cry1Ca core toxin using codons optimized for maize and with sequences identified in Table 2 removed and Table 1 sequences are maintained.
SEQ ID NO:30 is encoding Bacillus thuringiensis Cry1Ca core toxin sequence.
SEQ ID NO:31 is the native DNA sequence encoding Bacillus thuringiensis Cry6Aa toxin.
SEQ ID NO:32 is Bacillus thuringiensis Cry6Aa toxin sequence.
SEQ ID NO:33 is a synthetic DNA sequence encoding Bacillus thuringiensis Cry6Aa toxin using codons optimized for maize and Table 1 sequences are maintained.
SEQ ID NO:34 is Bacillus thuringiensis Cry6Aa toxin sequence.
SEQ ID NO:35 is a synthetic DNA sequence in accordance with the invention encoding Bacillus thuringiensis Cry6Aa toxin using codons optimized for maize and with sequences identified in Table 2 removed and Table 1 sequences are maintained.
SEQ ID NO:36 is Bacillus thuringiensis Cry6Aa toxin sequence.
SEQ ID NO:37 is the native DNA sequence encoding Sphingobiurn herbicidovorans AAD1 protein.
SEQ ID NO:38 is Sphingobiurn herbicidovorans AADI protein sequence.
SEQ ID NO:39 is a synthetic DNA sequence encoding Sphingobiurn herbicidovorans AAD1 protein using codons optimized for maize and Table 1 & Table 2 sequences are maintained.
SEQ ID NO:40 is Sphingobiurn herbicidovorans AADI protein sequence.
SEQ ID NO:41 is a synthetic DNA sequence in accordance with the invention encoding Sphingobiurn herbicidovorans AAD1 protein using codons optimized for maize and with sequences identified in Table 2 removed and Table 1 sequences are maintained.
SEQ ID NO:42 is Sphingobiurn herbicidovorans AADI protein sequence.
SEQ ID NO:43 is the native DNA sequence encoding Aspergillus nidulans delta-9 fatty acid desaturase protein.
SEQ ID NO:44 is Aspergillus nidulans delta-9 fatty acid desaturase protein sequence.
SEQ ID NO:45 is a synthetic DNA sequence encoding Aspergillus nidulans delta-9 fatty acid desaturase protein using codons optimized for maize and Table 1 & Table 2 sequences are maintained.
SEQ ID NO:46 is Aspergillus nidulans delta-9 fatty acid desaturase protein sequence.
SEQ ID NO:47 is a synthetic DNA sequence in accordance with the invention encoding Aspergillus nidulans delta-9 fatty acid desaturase protein using codons optimized for maize and with sequences identified in Table 2 removed and Table 1 sequences are maintained.
SEQ ID NO:48 is Aspergillus nidulans delta-9 fatty acid desaturase protein.
SEQ ID NO:49 is the native DNA sequence encoding Xerophyta viscosa SAPI protein.
SEQ ID NO:50 is Xerophyta viscosa SAPI protein sequence.
SEQ ID NO:51 is a synthetic DNA sequence encoding Xerophyta viscosa SAPI protein using codons optimized for maize and Table 1 & Table 2 sequences are maintained
SEQ ID NO:52 is Xerophyta viscosa SAPI protein sequence.
SEQ ID NO:53 is a synthetic DNA sequence in accordance with the invention encoding Xerophyta viscosa SAP1 protein using codons optimized for maize and with sequences identified in Table 2 removed and Table 1 sequences are maintained
SEQ ID NO:54 is Xerophyta viscosa SAPI protein sequence.
SEQ ID NO:55 is the native DNA sequence encoding Aequorea victoria GFPI protein.
SEQ ID NO:56 is Aequorea victoria GFPI protein sequence.
SEQ ID NO:57 is a synthetic DNA sequence encoding Aequorea victoria GFPI protein using codons optimized for maize and Table 1 & Table 2 sequences are maintained.
SEQ ID NO:58 is Aequorea victoria GFPI protein sequence.
SEQ ID NO:59 is a synthetic DNA sequence in accordance with the invention encoding Aequorea victoria GFPI protein using codons optimized for maize and with sequences identified in Table 2 removed and Table 1 sequences are maintained.
SEQ ID NO:60 is Aequorea victoria GFPI protein sequence.
SEQ ID NO:61 is the native DNA sequence encoding Leptosphaeria nodorum delta-9 fatty acid desaturase protein.
SEQ ID NO:62 is Leptosphaeria nodorum delta-9 fatty acid desaturase protein sequence.
SEQ ID NO:63 is a synthetic DNA sequence encoding Leptosphaeria nodorum delta-9 fatty acid desaturase protein using codons optimized for maize and Table 1 & Table 2 sequences are maintained
SEQ ID NO:64 is Leptosphaeria nodorum delta-9 fatty acid desaturase protein sequence.
SEQ ID NO:65 is a synthetic DNA sequence in accordance with the invention encoding Leptosphaeria nodorum delta-9 fatty acid desaturase protein using codons optimized for maize and with sequences identified in Table 2 removed and Table 1 sequences are maintained
SEQ ID NO:66 is Leptosphaeria nodorum delta-9 fatty acid desaturase protein sequence.
SEQ ID NO:67 is the native DNA sequence encoding Xerophyta viscosa PERI protein.
SEQ ID NO:68 is Xerophyta viscosa PERI protein sequence.
SEQ ID NO:69 is a synthetic DNA sequence encoding Xerophyta viscosa PERI protein using codons optimized for maize and Table 1 & Table 2 sequences are maintained.
SEQ ID NO:70 is Xerophyta viscosa PERI protein sequence.
SEQ ID NO:71 is a synthetic DNA sequence in accordance with the invention encoding-Xerophyta viscosa PERI protein using codons optimized for maize and with sequences identified in Table 2 removed and Table 1 sequences are maintained.
SEQ ID NO:72 is Xerophyta viscosa PERI protein sequence.
DETAILED DESCRIPTION OF THE INVENTIONThe invention provides synthetic nucleic acid sequences encoding proteins of interest. The synthetic coding sequences are particularly adapted for use in expressing the proteins of interest in transgenic plants.
A protein of interest is any protein or polypeptide that occurs in nature, or any naturally occurring variant including but not limited to processed forms of such proteins. The protein of interest also may be a protein formed by combining portions or fragments of more than one naturally occurring protein such as by mixing and matching functional protein domains.
A preferred group of proteins of interest is one in which the resulting phenotype is an agronomic trait or reporter protein useful for creating agronomic traits. These include but are not limited to resistance to insects, tolerance to herbicides, tolerance to water and/or heat stress, and oil profile modification.
A more preferred group of proteins of interest is one in which the resulting phenotype is an agronomic trait. Another preferred group is one in which the resulting phenotype provides herbicide tolerance. Another preferred group is one in which the resulting phenotype provides stress tolerance. Another preferred group is one in which the resulting phenotype provides a modified oil profile for healthier food. A more highly preferred group is one in which the protein of interest is a Cry protein that provides insect resistance.
The native/wild-type DNA sequences encoding the protein of interest must be identified and analyzed to determine whether polyadenylation signal sequences listed in Tables 1 and 2 and/or 3 are present. In accordance with the invention, for coding sequences intended for use in maize, the number of polyadenylation signal sequences listed in Table 2 is reduced compared to the number present in the native sequence. For coding sequences intended for use in soybean, the number of polyadenylation signal sequences listed in Table 3 is reduced. It is vey important to remove the polyadenylation signal sequences listed in Tables 2 and 3, particularly where they occur in nested multimeric form.
In addition to removing polyadenylation signal sequences listed in Tables 2 and 3, it may be desirable to remove occurrences of the Shaw-Kamen sequence, ATTTA.
In addition to removing polyadenylation signal sequences and Shaw-Kamen sequences, we prefer to build synthetic DNA coding sequences that utilize codons roughly in the same frequency at which they are utilized, on average, in genes naturally occurring in the plant species in which the synthetic DNA sequence will be used. Table 4 gives suitable target percentages for codon usage in synthetic genes intended for use in various specific crops as well as for use in dicots generally or plants generally.
A preferred embodiment of the subject invention is the transformation of plants with genes encoding insect toxins. The transformed plants that express insect toxin genes are resistant to attack by an insect target pest by virtue of the presence of controlling amounts of the subject insecticidal protein or its variants in the cells of the transformed plant. By incorporating genetic material that encodes the insecticidal properties of the B.t. insecticidal toxins into the genome of a plant eaten by a particular insect pest, the adult or larvae die after consuming the food plant. Numerous members of the monocotyledonous and dicotyledonous classifications have been transformed. Transgenic agronomic crops as well as fruits and vegetables are of commercial interest. Such crops include but are not limited to maize, rice, soybeans, canola, sunflower, alfalfa, sorghum, wheat, cotton, peanuts, tomatoes, potatoes, and the like. Several techniques exist for introducing foreign genetic material into plant cells, and for obtaining plants that stably maintain and express the introduced gene. Such techniques include acceleration of genetic material coated onto microparticles directly into cells (U.S. Pat. Nos. 4,945,050 and 5,141,131). Plants may be transformed using Agrobacterium technology, see U.S. Pat. No. 5,177,010, European Patent No. EP131624B1, European Patent No. EP159418B1, European Patent No. EP17611281, U.S. Pat. No. 5,149,645, EP120516B1, U.S. Pat. Nos. 5,464,763, 4,693,976, European Patent No. EP116718B1, European Patent No. EP290799B1, European Patent No. EP320500B1, European Patent No. EP604662B1, U.S. Pat. Nos. 7,060,876, 6,037,526, 6,376,234, European Patent No. EP292435B1, U.S. Pat. Nos. 5,231,019, 5,463,174, 4,762,785, 5,608,142, and 5,159,135. Other transformation technology includes WHISKERS™ technology, see U.S. Pat. Nos. 5,302,523 and 5,464,765. Electroporation technology has also been used to transform plants, see WO1987006614, U.S. Pat. Nos. 5,472,869, 5,384,253, WO199209696, U.S. Pat. No. 6,074,877, WO1993021335, and U.S. Pat. No. 5,679,558. In addition to numerous technologies for transforming plants, the type of tissue which is contacted with the foreign genes may vary as well. Such tissue would include but would not be limited to embryogenic tissue, callus tissue type I and type II, hypocotyl, meristem, and the like. Almost all plant tissues may be transformed during dedifferentiation using appropriate techniques within the skill of an artisan.
Known techniques of inserting DNA into plants include transformation with T-DNA delivered by Agrobacterium tumefaciens or Agrobacterium rhizogenes as the transformation agent. The use of T-DNA-containing vectors for the transformation of plant cells has been intensively researched and sufficiently described in European Patent No. EP12051681; Lee and Gelvin (2008) Plant Physiol. 146:325-332; Fraley et al (1986) Crit. Rev. Plant Sci. 4:1-46; and An et al. (1985) EMBO J. 4:277-284; and is well established in the field. Additionally, fusion of plant protoplasts with liposomes containing the DNA to be delivered, direct injection of the DNA, biolistics transformation (microparticle bombardment), or electroporation, as well as other possible methods, may be employed.
Once the inserted DNA has been integrated into the plant genome, it is relatively stable throughout subsequent generations. The vector used to transform the plant cell normally contains a selectable marker gene encoding a protein that confers on the transformed plant cells resistance to a herbicide or an antibiotic, such as Bialaphos, Kanamycin. G418, Bleomycin, or Hygromycin, inter alia. The individually employed selectable marker gene should accordingly permit the selection of transformed cells while the growth of cells that do not contain the inserted DNA is suppressed by the selective compound.
In a preferred embodiment of the subject invention, plants are transformed with genes wherein the codon usage of the protein coding region has been optimized for plants. See, for example, U.S. Pat. No. 5,380,831. Also, advantageously, plants encoding a truncated toxin, e.g. a functional protein domain, maybe used. The truncated toxin typically encodes about 55% to about 80% of the native full length toxin. Methods for creating synthetic B.t. genes for use in plants are known in the art (Stewart 2007, Frontiers in Drug Design and Discovery 1297-341).
Regardless of transformation technique, the gene is preferably incorporated into a gene transfer vector adapted to express the protein of interest in the plant cell by including in the vector a plant promoter. In addition to plant promoters, promoters from a variety of sources can be used efficiently in plant cells to express foreign genes. For example, promoters of bacterial origin, such as the octopine synthase promoter, the nopaline synthase promoter, the mannopine synthase promoter; promoters of viral origin, such as the 35S and 19S promoters of cauliflower mosaic virus (CaMV), and the like may be used. Plant-derived promoters include, but are not limited to ribulose-1,6-bisphosphate (RUBP) carboxylase small subunit (ssu), beta-conglycinin promoter, phaseolin promoter, ADH (alcohol dehydrogenase) promoter, heat-shock promoters, ADF (actin depolymerization factor) promoter, and tissue specific promoters. Promoters may also contain certain enhancer sequence elements that may improve the transcription efficiency. Typical enhancers include but are not limited to ADHI-intron 1 and ADHI-intron 6. Constitutive promoters may be used. Constitutive promoters direct continuous gene expression in nearly all cells types and at nearly all times (e.g. actin, ubiquitin, CaMV 35S). Tissue specific promoters are responsible for gene expression in specific cell or tissue types, such as the leaves or seeds (e.g. zein, oleosin, napin, ACP (Acyl Carrier Protein)), and these promoters may also be used. Promoters may also be used that are active during a certain stage of the plants' development as well as active in specific plant tissues and organs. Examples of such promoters include but are not limited to promoters that are root specific, pollen-specific, embryo specific, corn silk specific, cotton fiber specific, seed endosperm specific, phloem specific, and the like.
Under certain circumstances it may be desirable to use an inducible promoter. An inducible promoter is responsible for expression of genes in response to a specific signal, such as: physical stimulus (e.g. heat shock genes); light (e.g. RUBP carboxylase); hormone (e.g. glucocorticoid); antibiotic (e.g. tetracycline); metabolites; and stress (e.g. drought). Other desirable transcription and translation elements that function in plants may be used, such as 5′ untranslated leader sequences, RNA transcription termination sequences and poly-adenylate addition signal sequences. Numerous plant-specific gene transfer vectors are known to the art.
Transgenic crops containing insect resistance (IR) traits are prevalent in corn and cotton plants throughout North America, and usage of these traits is expanding globally. Commercial transgenic crops combining IR and herbicide tolerance (HT) traits have been developed by numerous seed companies. These include combinations of IR traits conferred by B.I. insecticidal proteins and HT traits such as tolerance to Acetolactate Synthase (ALS) inhibitors such as sulfonylureas, imidazolinones, triazolopyrimidine, sulfonanilides, and the like, Glutamine Synthetase (GS) inhibitors such as Bialaphos, glufosinate, and the like, 4-HydroxyPhenylPyruvate Dioxygenase (HPPD) inhibitors such as mesotrione, isoxaflutole, and the like, 5-EnolPyruvylShikimate-3-Phosphate Synthase (EPSPS) inhibitors such as glyphosate and the like, and Acetyl-Coenzyme A Carboxylase (ACCase) inhibitors such as haloxyfop, quizalofop, diclofop, and the like. Other examples are known in which transgenically provided proteins provide plant tolerance to herbicide chemical classes such as phenoxy acids herbicides and pyridyloxyacetates auxin herbicides (see WO2007053482), or phenoxy acids herbicides and aryloxyphenoxypropionates herbicides (see US Patent Application No. 20090093366). The ability to control multiple pest problems through IR traits is a valuable commercial product concept, and the convenience of this product concept is enhanced if insect control traits and weed control traits are combined in the same plant. Further, improved value may be obtained via single plant combinations of IR traits conferred by a B. t. insecticidal protein such as that of the subject invention with one or more additional HT traits such as those mentioned above, plus one or more additional input traits (e.g. other insect resistance conferred by B.t.-derived or other insecticidal proteins, insect resistance conferred by mechanisms such as RNAi and the like, nematode resistance, disease resistance, stress tolerance, improved nitrogen utilization, and the like), or output traits (e.g. high oils content, healthy oil composition, nutritional improvement, and the like). Such combinations may be obtained either through conventional breeding (breeding stack) or jointly as a novel transformation event involving the simultaneous introduction of multiple genes (molecular stack or co-transformation). Benefits include the ability to manage insect pests and improved weed control in a crop plant that provides secondary benefits to the producer and/or the consumer. Thus, the subject invention can be used in connection with a variety of traits to provide a complete agronomic package of improved crop quality with the ability to flexibly and cost effectively control any number of agronomic issues.
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. Unless specifically indicated or implied, the terms “a”, “an”, and “the” signify “at least one” as used herein. By “isolated” applicants mean that the nucleotide or polypeptide molecules have been removed from their native environment and have been placed in a different environment by the hand of man.
Embodiments of the present invention are further defined in the following Examples. It should be understood that these Examples are given by way of illustration only. From the above discussion and these Examples, one skilled in the art can ascertain the essential characteristics of this invention, and without departing from the spirit and scope thereof can make various changes and modifications of the embodiments of the invention to adapt it to various usages and conditions. Thus, various modifications of the embodiments of the invention, in addition to those shown and described herein, will be apparent to those skilled in the art from the foregoing description. Such modifications are also intended to fall within the scope of the appended claims.
All percentages are by weight and all solvent mixture proportions are by volume unless otherwise noted. All temperatures are in degrees Celsius.
Example 1 Synthetic Coding Region Encoding Bacillus thuringiensis Cry1Fa Core ToxinComparative Sequence. The native DNA sequence encoding the Cry1Fa core toxin is given in SEQ ID NO:1. This sequence was analyzed to determine which sequences identified in Table 1 are present in SEQ ID NO:1 and their locations. The amino acid sequence encoded by SEQ ID NO:1 was then reverse translated using the target codon frequencies given in the column of Table 4 for synthetic genes to be used in maize. The resulting DNA sequence was analyzed and codons were changed where necessary to remove unwanted open reading frames and remove unwanted restriction sites, and restore sequences identified in Table 1. The amino acid sequence encoded by SEQ ID NO:1 was preserved. The resulting DNA sequence is given in SEQ ID NO:3.
SEQ ID NO:3 was analyzed and codons were changed to remove potential polyadenylation signal sequences identified in Table 2, while maintaining the same number of sequences identified in Table 1. The resulting sequence, which embodies the present invention, is given in SEQ ID NO:5. Table 5 shows that the number and locations of polyadenylation signal sequences identified in Table 1 are maintained in SEQ ID NO:5, with the exception that the two occurrences of AATAAA, one at nt 426 and one at nt 582, in SEQ ID NO:1 were replaced with AATCAA, which maintains the number and location of polyadenylation signal sequences identified in Table 1, but substitutes a less problematic sequence for each of the two AATAAA sequences. Table 6 shows that the number of polyadenylation signal sequences identified in Table 2 are reduced in SEQ ID NO:5. Because there is overlap in the sequences identified in Tables 2 and 3 (sequences 1, 2, 6, 7, 8, 9, 10, 14, 13, and 20 in Table 2 correspond to sequences 16, 15, 2, 5, 1, 3, 4, 6, 13, and 12, respectively, in Table 3) it is also true that the number of polyadenylation signal sequences identified in Table 3 are reduced in SEQ ID NO:5.
The synthetic coding region of SEQ ID NO:5 was optimized for expression in maize.
A construct for use in expressing the synthetic coding region of SEQ ID NO:5 is made by combining the synthetic coding region of SEQ ID NO:5 with a 5′ non-translated region comprising a promoter that functions in plant cells and a 3′ non-translated region comprising a transcription termination and polyadenylation sequence.
In one embodiment of such a construct, production of the primary mRNA transcript comprising SEQ ID NO:5 was driven by a copy of a maize ubiquitin1 promoter with its native intron1 (U.S. Pat. No. 5,510,474). A fragment comprising a 3′ untranslated region from a maize peroxidase 5 gene (ZmPer5 3′UTR v2; U.S. Pat. No. 6,699,984) was used to terminate transcription. A binary plant transformation plasmid, pDAB1 11440, containing the aforementioned gene expression cassette, was constructed and utilized in the production of transgenic maize plants. Plasmid pDAB111440 further comprises a herbicide resistance gene comprising a coding region for aryloxyalknoate dioxygenase (AAD-1 v3; U.S. Pat. No. 7,838,733(82), and Wright et al. (2010) Proc. Nat. Acad. Sci. U.S.A. 107:20240-5) under the transcriptional control of a sugarcane bacilliform badnavirus (ScBV) promoter (Schenk e al. (1999) Plant Molec. Biol. 39:1221-30). A fragment comprising a 3′ untranslated region from a maize lipase gene (ZmLip 3′UTR; U.S. Pat. No. 7,179,902) was used to terminate transcription.
Comparative Sequences. The native DNA sequence encoding the Cry34A toxin is given in SEQ ID NO:7. This sequence was analyzed to determine which sequences identified in Table 1 are present in SEQ ID NO:7 and their locations. The native DNA sequence was translated into the corresponding amino acid sequence using the standard genetic code. The amino acid sequence encoded by SEQ ID NO:7 was then reverse translated using the target codon frequencies given in the column of Table 7 for synthetic genes to be used in maize. The resulting DNA sequence was analyzed and codons were changed where necessary to remove unwanted open reading frames and remove unwanted restriction sites, and restore all sequences identified in Table 1. The amino acid sequence encoded by SEQ ID NO:7 was preserved. The resulting DNA sequence is given in SEQ ID NO:9. DNA having the sequence of SEQ ID NO:9 is synthesized.
SEQ ID NO:9 was analyzed and codons were changed to remove potential polyadenylation signal sequences identified in Table 2, while maintaining the same number of sequences identified in Table 1. The resulting sequence, which embodies the present invention, is given in SEQ ID NO:11. Table 7 shows that the number and locations of polyadenylation signals sequences identified in Table 1 are maintained in SEQ ID NO:11. Table 8 shows that the number of polyadenylation signal sequences identified in Tables 2 and 3 are reduced in SEQ ID NO:5.
DNA of SEQ ID NO:5 is synthesized, and expression levels observed in plant cells transformed to express this sequence are compared with expression levels observed in plant cells transformed to express SEQ ID NO:1 and SEQ ID NO:3.
The synthetic coding region of SEQ ID NO:5 was optimized for expression in maize.
A construct for use in expressing the synthetic coding region of SEQ ID NO:5 is made by combining the synthetic coding region of SEQ ID NO:5 with a 5′ non-translated region comprising a promoter that functions in plant cells and a 3′ non-translated region comprising a transcription termination and polyadenylation sequence.
Comparative Sequences. The native DNA sequence encoding the Cry35Ab1 toxin is given in SEQ ID NO:13. This sequence was analyzed to determine which sequences identified in Table 1 are present in SEQ ID NO: 13 and their locations. The amino acid sequence encoded by SEQ ID NO: 13 was then reverse translated using the target codon frequencies given in the column of Table 4 for synthetic genes to be used in maize. The resulting DNA sequence was analyzed and codons were changed where necessary to remove unwanted open reading frames and remove unwanted restriction enzyme recognition sites, while maintaining all sequences identified in Table 1. The amino acid sequence encoded by SEQ ID NO: 13 was preserved. The resulting DNA sequence is given in SEQ ID NO:15. This sequence will be synthesized and used for comparison with a synthetic coding region designed in accordance with the invention.
SEQ ID NO:15 was analyzed and codons were changed to remove potential polyadenylation signal sequences identified in Table 2, while maintaining the same number of sequences identified in Table 1, except that two of the occurrences of AATAAA, one at nt 228 and one at nt 276 of SEQ ID NO:8 were changed to AATCAA. The resulting sequence, which embodies the present invention, is given in SEQ ID NO: 17. Table 9 shows that the number and location of polyadenylation signal sequences identified in Table are maintained in SEQ ID NO:17. Table 10 shows that the number of polyadenylation signal sequences identified in Tables 2 and 3 are reduced in SEQ ID NO: 17 compared to SEQ ID NO:13.
DNA of SEQ ID NO: 17 is synthesized, and expression levels observed in plant cells transformed to express this sequence are compared with expression levels observed in plant cells transformed to express SEQ ID NO:13 and SEQ ID NO:15.
The synthetic coding region of SEQ ID NO:17 was optimized for expression in maize.
A construct for use in expressing the synthetic coding region of SEQ ID NO: 17 is made by combining the synthetic coding region of SEQ ID NO: 17 with a 5′ non-translated region comprising a promoter that functions in plant cells and a 3′ non-translated region comprising a transcription termination and polyadenylation sequence.
Comparative Sequences. The native DNA sequence encoding Cry1Ab core toxin is given in SEQ ID NO:19. This sequence was analyzed to determine which sequences identified in Table 1 are present in SEQ ID NO:19 and their locations. The amino acid sequence encoded by SEQ ID NO:19 was then reverse translated using the target codon frequencies given in the column of Table 4 for synthetic genes to be used in maize. The resulting DNA sequence was analyzed and codons were changed where necessary to remove unwanted open reading frames and remove unwanted restriction enzyme recognition sites, while maintaining all sequences identified in Table 1. The amino acid sequence encoded by SEQ ID NO:19 was preserved. The resulting DNA sequence is given in SEQ ID NO:21.
SEQ ID NO:21 was analyzed and codons were changed to remove potential polyadenylation signal sequences identified in Table 2, while maintaining the same number of sequences identified in Table 1. The resulting sequence, which embodies the present invention, is given in SEQ ID NO:23. Table 11 shows that the number and location of polyadenylation signal sequences identified in Table 1 are maintained in SEQ ID NO:23. Table 12 shows that the number of polyadenylation signal sequences identified in Tables 2 and 3 are reduced in SEQ ID NO:23 compared to SEQ ID NO:19.
The synthetic coding region of SEQ ID NO:23 was optimized for expression in maize.
A construct for use in expressing the synthetic coding region of SEQ ID NO:23 was made by combining the synthetic coding region of SEQ ID NO:23 with a 5′ non-translated region comprising a promoter that functions in plant cells and a 3′ non-translated region comprising a transcription termination and polyadenylation sequence.
In one embodiment of such a construct, production of the primary mRNA transcript comprising SEQ ID NO:23 was driven by a copy of a maize ubiquitin1 promoter with its native intron1 (U.S. Pat. No. 5,510,474). A fragment comprising a 3′ untranslated region from a maize peroxidase 5 gene (ZmPer5 3′UTR v2; U.S. Pat. No. 6,699,984) was used to terminate transcription. A binary plant transformation plasmid, pDAB11449, containing the aforementioned gene expression cassette, was constructed and utilized in the production of transgenic maize plants. Plasmid pDABI 11449 further comprises a herbicide resistance gene comprising a coding region for aryloxyalknoate dioxygenase (AAD-1 v3, U.S. Pat. No. 7,838,733(82), and Wright et al. (2010) Proc. Natl. Acad. Sci. U.S.A. 107:20240-5) under the transcriptional control of a sugarcane bacilliform badnavirus (ScBV) promoter (Schenk et al. (1999) Plant Molec. Biol. 39:1221-30). A fragment comprising a 3′ untranslated region from a maize lipase gene (ZmLip 3′UTR, U.S. Pat. No. 7,179,902) was used to terminate transcription.
Comparative Sequences. The native DNA sequence encoding the Cry35A core toxin is given in SEQ ID NO:25. This sequence was analyzed to determine which sequences identified in Table 1 are present in SEQ ID NO:25 and their locations. The amino acid sequence encoded by SEQ ID NO:25 was then reverse translated using the target codon frequencies given in the column of Table 4 for synthetic genes to be used in maize. The resulting DNA sequence was analyzed and codons were changed where necessary to remove unwanted open reading frames, and remove unwanted restriction enzyme recognition sites, while maintaining all sequences identified in Table 1. The amino acid sequence encoded by SEQ ID NO:25 was preserved. The resulting DNA sequence is given in SEQ ID NO:27. This sequence will be synthesized and used for comparison with a synthetic gene designed in accordance with the invention.
SEQ ID NO:27 was analyzed and codons were changed to remove potential polyadenylation signal sequences identified in Table 2, while maintaining the same number of sequences identified in Table 1. The resulting sequence, which embodies the present invention, is given in SEQ ID NO:29. Table 13 shows that the number and location of polyadenylation signal sequences identified in Table 1 are maintained in SEQ ID NO:29. Table 14 shows that the number of polyadenylation signal sequences identified in Tables 2 and 3 are reduced in SEQ ID NO:29 compared to SEQ ID NO:25.
DNA of SEQ ID NO:29 is synthesized, and expression levels observed in plant cells transformed to express this sequence are compared with expression levels observed in plant cells transformed to express SEQ ID NO:25 and SEQ ID NO:27.
The synthetic gene of SEQ ID NO:29 was optimized for expression in maize.
A construct for use in expressing the synthetic gene of SEQ ID NO:29 is made by combining the synthetic gene of SEQ ID NO:29 with a 5′ non-translated region comprising a promoter that functions in plant cells and a 3′ non-translated region comprising a transcription terminator and polyadenylation sequence.
Comparative Sequences. The native DNA sequence encoding the Cry6Aa toxin is given in SEQ ID NO:31. This sequence was analyzed to determine which sequences identified in Table 1 are present in SEQ ID NO:31 and their locations. The amino acid sequence encoded by SEQ ID NO:31 was then reverse translated using the target codon frequencies given in the column of Table 4 for synthetic genes to be used in maize. The resulting DNA sequence was analyzed and codons were changed where necessary to remove unwanted open reading frames, and remove unwanted restriction enzyme recognition sites, while maintaining all sequences identified in Table 1. The amino acid sequence encoded by SEQ ID NO:31 was preserved. The resulting DNA sequence is given in SEQ ID NO:33. This sequence will be synthesized and used for comparison with a synthetic gene designed in accordance with the invention.
SEQ ID NO:33 was analyzed and codons were changed to remove potential polyadenylation signal sequences identified in Table 2, while maintaining the number of sequences identified in Table 1. The resulting sequence, which embodies the present invention, is given in SEQ ID NO:35. Table 15 shows that the number and location of polyadenylation signal sequences identified in Table 1 are maintained in SEQ ID NO:35. Table 16 shows that the number of polyadenylation signal sequences identified in Tables 2 and 3 are reduced in SEQ ID NO:35 compared to SEQ ID NO:31.
DNA of SEQ ID NO:35 is synthesized, and expression levels observed in plant cells transformed to express this sequence are compared with expression levels observed in plant cells transformed to express SEQ ID NO:31 and SEQ ID NO:33.
The synthetic coding region of SEQ ID NO:35 was optimized for expression in maize.
A construct for use in expressing the synthetic coding region of SEQ ID NO:35 is made by combining the synthetic coding region of SEQ ID NO:35 with a 5′ non-translated region comprising a promoter that functions in plant cells and a 3′ non-translated region comprising a transcription terminator and polyadenylation sequence.
Comparative Sequences. The native DNA sequence encoding the AAD1 protein is given in SEQ ID NO:37. This sequence was analyzed to determine which sequences identified in Table 1 are present in SEQ ID NO:37 and their locations. The amino acid sequence encoded by SEQ ID NO:37 was then reverse translated using the target codon frequencies given in the column of Table 4 for synthetic genes to be used in maize. The resulting DNA sequence was analyzed and codons were changed where necessary to remove unwanted open reading frames, and remove unwanted restriction enzyme recognition sites, while maintaining all sequences identified in Table 1. The amino acid sequence encoded by SEQ ID NO:37 was preserved. The resulting DNA sequence is given in SEQ ID NO:39. This sequence will be synthesized and used for comparison with a synthetic gene designed in accordance with the invention.
SEQ ID NO:39 was analyzed and codons were changed to remove potential polyadenylation signal sequences identified in Table 2, while maintaining the number of sequences identified in Table 1. The resulting sequence, which embodies the present invention, is given in SEQ ID NO:41. Table 17 shows that the number and location of polyadenylation signal sequences identified in Table are maintained in SEQ ID NO:41. Table 18 shows that the number of polyadenylation signal sequences identified in Tables 2 and 3 are reduced in SEQ ID NO:41 compared to SEQ ID NO:37.
DNA of SEQ ID NO:41 is synthesized, and expression levels observed in plant cells transformed to express this sequence are compared with expression levels observed in plant cells transformed to express SEQ ID NO:37 and SEQ ID NO:39.
The synthetic coding region of SEQ ID NO:41 was optimized for expression in maize.
A construct for use in expressing the synthetic coding region of SEQ ID NO:41 is made by combining the synthetic coding region of SEQ ID NO:41 with a 5′ non-translated region comprising a promoter that functions in plant cells and a 3′ non-translated region comprising a transcription terminator and polyadenylation sequence.
Comparative Sequences. The native DNA sequence encoding the Aspergillus nidulans Delta-9 Desaturase protein is given in SEQ ID NO:43. This sequence was analyzed to determine which sequences identified in Table 1 are present in SEQ ID NO:43 and their locations. The amino acid sequence encoded by SEQ ID NO:43 was then reverse translated using the target codon frequencies given in the column of Table 4 for synthetic genes to be used in maize. The resulting DNA sequence was analyzed and codons were changed where necessary to remove unwanted open reading frames and remove unwanted restriction enzyme recognition sites, while maintaining all sequences identified in Table 1. The amino acid sequence encoded by SEQ ID NO:43 was preserved. The resulting DNA sequence is given in SEQ ID NO:45. This sequence will be synthesized and used for comparison with a synthetic gene designed in accordance with the invention.
SEQ ID NO:45 was analyzed and codons were changed to remove potential polyadenylation signal sequences identified in Table 2, while maintaining the number of sequences identified in Table 1. The resulting sequence, which embodies the present invention, is given in SEQ ID NO:47. Table 1 shows that the number and location of polyadenylation signal sequences identified in Table 1 are maintained in SEQ ID NO:47. Table 20 shows that the number of polyadenylation signal sequences identified in Tables 2 and 3 are reduced in SEQ ID NO:47 compared to SEQ ID NO:43.
DNA of SEQ ID NO:47 is synthesized, and expression levels observed in plant cells transformed to express this sequence are compared with expression levels observed in plant cells transformed to express SEQ ID NO:43 and SEQ ID NO:45.
The synthetic coding region of SEQ ID NO:47 was optimized for expression in maize.
A construct for use in expressing the synthetic coding region of SEQ ID NO:47 is made by combining the synthetic coding region of SEQ ID NO:47 with a 5′ non-translated region comprising a promoter that functions in plant cells and a 3′ non-translated region comprising a transcription termination and polyadenylation sequence.
Comparative Sequences. The native DNA sequence encoding the Xerophyta viscosa SAPI protein is given in SEQ ID NO:49. This sequence was analyzed to determine which sequences identified in Table 1 are present in SEQ ID NO:49 and their locations. The amino acid sequence encoded by SEQ ID NO:49 was then reverse translated using the target codon frequencies given in the column of Table 4 for synthetic genes to be used in maize. The resulting DNA sequence was analyzed and codons were changed where necessary to remove unwanted open reading frames and remove unwanted restriction enzyme recognition sites, while maintaining all sequences identified in Table 1. The amino acid sequence encoded by SEQ ID NO:49 was preserved. The resulting DNA sequence is given in SEQ ID NO:51. This sequence will be synthesized and used for comparison with a synthetic gene designed in accordance with the invention.
SEQ ID NO:52 was analyzed and codons were changed to remove potential polyadenylation signal sequences identified in Table 2, while maintaining the number of sequences identified in Table 1. The resulting sequence, which embodies the present invention, is given in SEQ ID NO:53. Table 1 shows that the number and location of polyadenylation signal sequences identified in Table 1 are maintained in SEQ ID NO:53. Table 21 shows that the number of polyadenylation signal sequences identified in Tables 2 and 3 are reduced in SEQ ID NO:53 compared to SEQ ID NO:49.
DNA of SEQ ID NO:53 is synthesized, and expression levels observed in plant cells transformed to express this sequence are compared with expression levels observed in plant cells transformed to express SEQ ID NO:49 and SEQ ID NO:51.
The synthetic coding region of SEQ ID NO:53 was optimized for expression in maize.
A construct for use in expressing the synthetic coding region of SEQ ID NO:53 is made by combining the synthetic coding region of SEQ ID NO:53 with a 5′ non-translated region comprising a promoter that functions in plant cells and a 3′ non-translated region comprising a transcription terminator and polyadenylation sequence.
Comparative Sequences. The native DNA sequence encoding the Aequorea victoria GFPI is given in SEQ ID NO:55. This sequence was analyzed to determine which sequences identified in Table 1 are present in SEQ ID NO:55 and their locations. The amino acid sequence encoded by SEQ ID NO:55 was then reverse translated using the target codon frequencies given in the column of Table 4 for synthetic genes to be used in maize. The resulting DNA sequence was analyzed and codon were changed where necessary to remove unwanted open reading frames and remove unwanted restriction enzyme recognition sites, while maintaining all sequences identified in Table 1. The amino acid sequence encoded by SEQ ID NO:55 was preserved. The resulting DNA sequence is given in SEQ ID NO:57. This sequence will be synthesized and used for comparison with a synthetic gene designed in accordance with the invention.
SEQ ID NO:57 was analyzed and codons were changed to remove potential polyadenylation signal sequences identified in Table 2, while maintaining the number of sequences identified in Table 1. The resulting sequence, which embodies the present invention, is given in SEQ ID NO:59. Table 1 shows that the number and location of polyadenylation signal sequences identified in Table 1 are maintained in SEQ ID NO:59. Table 23 shows that the number of polyadenylation signal sequences identified in Tables 2 and 3 are reduced in SEQ ID NO:59 compared to SEQ ID NO:55.
DNA of SEQ ID NO:59 is synthesized, and expression levels observed in plant cells transformed to express this sequence are compared with expression levels observed in plant cells transformed to express SEQ ID NO:55 and SEQ ID NO:57.
The synthetic coding region of SEQ ID NO:59 was optimized for expression in maize.
A construct for use in expressing the synthetic coding region of SEQ ID NO:59 is made by combining the synthetic coding region of SEQ ID NO:59 with a 5′ non-translated region comprising a promoter that functions in plant cells and a 3′ non-translated region comprising a transcription terminator and polyadenylation sequence.
Comparative Sequences. The native DNA sequence encoding the Leptosphaeria nodorum FAD9 protein is given in SEQ ID NO:61. This sequence was analyzed to determine which sequences identified in Table 1 are present in SEQ ID NO:61 and their locations. The amino acid sequence encoded by SEQ ID NO:61 was then reverse translated using the target codon frequencies given in the column of Table 4 for synthetic genes to be used in maize. The resulting DNA sequence was analyzed and codons were changed where necessary to remove unwanted open reading frames and remove unwanted restriction enzyme recognition sites, while maintaining all sequences identified in Table 1. The amino acid sequence encoded by SEQ ID NO:61 was preserved. The resulting DNA sequence is given in SEQ ID NO:63. This sequence will be synthesized and used for comparison with a synthetic gene designed in accordance with the invention.
SEQ ID NO:63 was analyzed and codons were changed to remove potential polyadenylation signal sequences identified in Table 2, while maintaining the number of sequences identified in Table 1. The resulting sequence, which embodies the present invention, is given in SEQ ID NO:65. Table 1 shows that the number and location of polyadenylation signal sequences identified in Table 1 are maintained in SEQ ID NO:65. Table 25 shows that the number of polyadenylation signal sequences identified in Tables 2 and 3 are reduced in SEQ ID NO:65 compared to SEQ ID NO:61.
DNA of SEQ ID NO:65 is synthesized, and expression levels observed in plant cells transformed to express this sequence are compared with expression levels observed in plant cells transformed to express SEQ ID NO:61 and SEQ ID NO:63.
The synthetic coding region of SEQ ID NO:65 was optimized for expression in maize.
A construct for use in expressing the synthetic coding region of SEQ ID NO:65 is made by combining the synthetic coding region of SEQ ID NO:65 with a 5′ non-translated region comprising a promoter that functions in plant cells and a 3′ non-translated region comprising a transcription terminator and polyadenylation sequence.
Comparative Sequences. The native DNA sequence encoding the Xerophyta viscosa PERI protein is given in SEQ ID NO:67. This sequence was analyzed to determine which sequences identified in Table 1 are present in SEQ ID NO:67 and their locations. The amino acid sequence encoded by SEQ ID NO:67 was then reverse translated using the target codon frequencies given in the column of Table 4 for synthetic genes to be used in maize. The resulting DNA sequence was analyzed and codons were changed where necessary to remove unwanted open reading frames and remove unwanted restriction enzyme recognition sites, while maintaining all sequences identified in Table 1. The amino acid sequence encoded by SEQ ID NO:67 was preserved. The resulting DNA sequence is given in SEQ ID NO:69. This sequence will be synthesized and used for comparison with a synthetic gene designed in accordance with the invention.
SEQ ID NO:69 was analyzed and codons were changed to remove potential polyadenylation signal sequences identified in Table 2, while maintaining the number of sequences identified in Table 1. The resulting sequence, which embodies the present invention, is given in SEQ ID NO:71. Table 1 shows that the number and location of polyadenylation signal sequences identified in Table 1 are maintained in SEQ ID NO:71. Table 27 shows that the number of polyadenylation signal sequences identified in Tables 2 and 3 are reduced in SEQ ID NO:71 compared to SEQ ID NO:67.
DNA of SEQ ID NO:71 is synthesized, and expression levels observed in plant cells transformed to express this sequence are compared with expression levels observed in plant cells transformed to express SEQ ID NO:67 and SEQ ID NO:69.
The synthetic coding region of SEQ ID NO:71 was optimized for expression in maize.
A construct for use in expressing the synthetic coding region of SEQ ID NO:71 is made by combining the synthetic coding region of SEQ ID NO:71 with a 5′ non-translated region comprising a promoter that functions in plant cells and a 3′ non-translated region comprising a transcription terminator and polyadenylation sequence.
A standard WHISKERS transformation vector was constructed in which the Arabidopsis thaliana promoter, Rd29A, was placed 5′ to the XvSAP1 redesigned coding region sequence of the invention (SEQ ID NO:53). These sequences were flanked by Zea maize PERS, 3′ and 5′ untranslated regions to stabilize expression of the redesigned coding region. A pat selection cassette (See, for example, U.S. Pat. No. 5,648,477) driven by the rice actin1 promoter was placed 3′ to the XvSAP1 expression cassette.
Vector DNA was digested with appropriate restriction enzymes to release a fragment containing the bacterial ampicillin resistance gene present in the vector backbone, and to produce a linear DNA fragment suitable for WHISKERS™-mediated transformation. Purification of the linear fragment containing the XvSAP1 and pat expression cassettes was accomplished on a preparative scale by high pressure liquid chromatography (HPLC). This plant transformation DNA was delivered into maize Hi-II suspension cell cultures via WHISKERS™-mediated transformation (essentially as described in U.S. Pat. Nos. 5,302,523 and 5,464,765; US Patent Publication No. 2008/0182332; and Petolino and Arnold (2009) (Methods Molec. Biol. 526:59-67).
Transformants were placed in selective medium after which transformed isolates were obtained over the course of approximately 8 weeks. The selection medium was an LS based medium (LS Basal medium, N6 vitamins, 1.5 mg/L 2,4-D, 0.5 gm/L MES (2-(N-morpholino)ethanesulfonic acid monohydrate; PhytoTechnologies Labr.), 30.0 gm/L sucrose, 6 mM L-proline, 1.0 mg/L AgNO3, 250 mg/L cefotaxime, 2.5 gm/L Gellan gum, pH 5.7) containing Bialaphos (Gold BioTechnology). The embryos were transferred to selection media containing 3 mg/L Bialaphos until embryogenic isolates were obtained. Recovered isolates were bulked up by transferring to fresh selection medium at 2-week intervals for regeneration and further analysis.
For regeneration, the cultures were transferred to “28” induction medium (MS salts and vitamins, 30 gm/L sucrose, 5 mg/L Benzylaminopurine, 0.25 mg/L 2, 4-D, 3 mg/L Bialaphos, 250 mg/L cefotaxime, 2.5 gm/L Gellan gum. pH 5.7) for 1 week under low-light conditions (14 μEm-2s-1) then 1 week under high-light conditions (approximately 89 μEm-2s-1) Tissues were subsequently transferred to “36” regeneration medium (same as induction medium except lacking plant growth regulators). When plantlets reached 3-5 cm in length, they were transferred to glass culture tubes containing SHGA medium (Schenk and Hildebrandt salts and vitamins (1972); PhytoTechnologies Labr.), 1.0 gm/L myo-inositol, 10 gm/L sucrose and 2.0 gm/L Gellan gum, pH 5.8) to allow for further growth and development of the shoot and roots. Plants were transplanted to the same soil mixture as described earlier herein and grown to flowering in the greenhouse. Controlled pollinations for seed production were conducted.
Example 14 Agrobacterium TransformationStandard cloning methods are used in the construction of binary plant transformation and expression plasmids. Restriction endonucleases and T4 DNA Ligase are obtained from NEB. Plasmid preparations are performed using the NucleoSpin® Plasmid Preparation kit or the NucleoBond® AX Xtra Midi kit (both from Macherey-Nagel), following the instructions of the manufacturers. DNA fragments are purified using the QIAquick® PCR Purification Kit or the QIAEX II® Gel Extraction Kit (both from Qiagen) after gel isolation.
Synthetic genes in accordance with the invention may be synthesized by a commercial vendor (e.g. DNA2.0, Menlo Park, Calif.) and supplied as cloned fragments in standard plasmid vectors, or may be obtained by standard molecular biology manipulation of other constructs containing appropriate nucleotide sequences.
In a non-limiting example, a basic cloning strategy may be to subclone full length coding sequences (CDS) into a plant expression plasmid at Neal and Sac!restriction sites. The resulting plant expression cassettes containing the appropriate coding region under the control of plant expression elements, (e.g., plant expressible promoters, 3′ terminal transcription termination and polyadenylate addition determinants, and the like) are subcloned into a binary vector plasmid, utilizing, for example, Gateway® technology or standard restriction enzyme fragment cloning procedures. LR Clonase™ (Invitrogen) for example, may be used to recombine the full length and modified gene plant expression cassettes into a binary plant transformation plasmid if the Gateway® technology is utilized. It is convenient to employ a binary plant transformation vector that harbors a bacterial gene that confers resistance to the antibiotic spectinomycin when the plasmid is present in E. coli and Agrobacterium cells. It is also convenient to employ a binary vector plasmid that contains a plant-expressible selectable marker gene that is functional in the desired host plants. Examples of plant-expressible selectable marker genes include but are not limited those that encode the aminoglycoside phosphotransferase gene (aph!) of transposon Tn5, which confers resistance to the antibiotics kanamycin, neomycin and G418, as well as those genes which code for resistance or tolerance to glyphosate; hygromycin; methotrexate; phosphinothricin (bialaphos), imidazolinones, sulfonylureas and triazolopyrimidine herbicides, such as chlorosulfuron, bromoxynil, dalapon and the like.
Electro-competent cells of Agrobacterium tumeficiens strain Z707S (a streptomycin-resistant derivative of Z707; Hepburn et al., 1985, J. Gen. Microbiol. 131:2961-2969.) are prepared and transformed using electroporation (Weigel and Glazebrook, 2002, Arabidopsis: A Laboratory Manual). After electroporation, 1 mL of YEP broth (gm/L: yeast extract, 10 peptone, 10; NaCl, 5) are added to the cuvette and the cell-YEP suspension is transferred to a 15 mL culture tube for incubation at 280 in a water bath with constant agitation for 4 hours. The cells are plated on YEP plus agar (25 gm/L) with spectinomycin (200 μg/mL) and streptomycin (250 μg/mL) and the plates are incubated for 2-4 days at 28°. Well separated single colonies are selected and streaked onto fresh YEP+agar plates with spectinomycin and streptomycin as before, and incubated at 280 for 1-3 days.
The presence of the synthetic gene insert in the binary plant transformation vector is performed by PCR analysis using vector-specific primers with template plasmid DNA prepared from selected Agrobacterium colonies. The cell pellet from a 4 mL aliquot of a 15 mL overnight culture grown in YEP with spectinomycin and streptomycin as before is extracted using Qiagen Spin® Mini Preps, performed per manufacturer's instructions. Plasmid DNA from the binary vector used in the Agrobacterium electroporation transformation is included as a control. The PCR reaction is completed using Taq DNA polymerase from Invitrogen per manufacture's instructions at 0.5× concentrations. PCR reactions are carried out in a MJ Research Peltier Thermal Cycler programmed with the following conditions: Step 1) 94° for 3 minutes; Step 2) 94° for 45 seconds; Step 3) 550 for 30 seconds; Step 4) 72° for 1 minute per kb of expected product length; Step 5) 29 times to Step 2; Step 6) 72 for 10 minutes. The reaction is maintained at 4 after cycling. The amplification products are analyzed by agarose gel electrophoresis (e.g. 0.7% to 1% agarose, w/v) and visualized by ethidium bromide staining. A colony is selected whose PCR product is identical to the plasmid control.
Alternatively, the plasmid structure of the binary plant transformation vector containing the synthetic gene insert is performed by restriction digest fingerprint mapping of plasmid DNA prepared from candidate Agrobacterium isolates by standard molecular biology methods well known to those skilled in the art of Agrobacterium manipulation.
Those skilled in the art of obtaining transformed plants via Agrobacterium-mediated transformation methods will understand that other Agrobacterium strains besides Z707S may be used to advantage, and the choice of strain may depend upon the identity of the host plant species to be transformed.
Example 15 Production of Insecticidal Proteins in Dicot PlantsArabidopsis Transformation. Arabidopsis thaliana Col-01 is transformed using the floral dip method (Weigel and Glazebrook, supra). The selected Agrobacterium colony is used to inoculate 1 mL to 15 mL cultures of YEP broth containing appropriate antibiotics for selection. The culture is incubated overnight at 280 with constant agitation at 220 rpm. Each culture is used to inoculate two 500 mL cultures of YEP broth containing appropriate antibiotics for selection and the new cultures are incubated overnight at 28° with constant agitation. The cells are pelleted at approximately 8700×g for 10 minutes at room temperature, and the resulting supernatant is discarded. The cell pellet is gently resuspended in 500 mL of infiltration media containing: ½× Murashige and Skoog salts (Sigma-Aldrich)/Gamborg's BS vitamins (Gold BioTechnology. St. Louis, Mo.), 10% (w/v) sucrose, 0.044 μM benzylaminopurine (10 μL/liter of 1 mg/mL stock in DMSO) and 300 μL/liter Silwet L-77. Plants approximately 1 month old are dipped into the media for 15 seconds, with care taken to assure submergence of the newest inflorescence. The plants are then laid on their sides and covered (transparent or opaque) for 24 hours, washed with water, and placed upright. The plants are grown at 22°, with a 16-hour light/8-hour dark photoperiod. Approximately 4 weeks after dipping, the seeds are harvested.
Arabidopsis Growth and Selection. Freshly harvested Ti seed is allowed to dry for at least 7 days at room temperature in the presence of desiccant. Seed is suspended in a 0.1% agar/water (Sigma-Aldrich) solution and then stratified at 4° for 2 days. To prepare for planting, Sunshine Mix LP5 (Sun Gro Horticulture Inc., Bellevue, Wash.) in 10.5 inch×21 inch germination trays (T.O. Plastics Inc., Clearwater. Minn.) is covered with fine vermiculite, sub-irrigated with Hoagland's solution (Hoagland and Amon, 1950) until wet, then allowed to drain for 24 hours. Stratified seed is sown onto the vermiculite and covered with humidity domes (KORD Products, Bramalea, Ontario, Canada) for 7 days. Seeds are germinated and plants are grown in a Conviron (Models CMP4030 or CMP3244; Controlled Environments Limited, Winnipeg, Manitoba, Canada) under long day conditions (16 hours light/8 hours dark) at a light intensity of 120-150 μmol/ sec under constant temperature (22°) and humidity (40-50%). Plants are initially watered with Hoagland's solution and subsequently with deionized water to keep the soil moist but not wet.
The domes are removed 5-6 days post sowing and plants are sprayed with a chemical selection agent to kill plants germinated from nontransformed seeds. For example, if the plant expressible selectable marker gene provided by the binary plant transformation vector is a pat or bar gene (Wehrmann et al., 1996, Nat. Biotech. 14:1274-1278), transformed plants may be selected by spraying with a 1000× solution of Finale (5.78% glufosinate ammonium, Farnam Companies Inc., Phoenix, Ariz.). Two subsequent sprays are performed at 5-7 day intervals. Survivors (plants actively growing) are identified 7-10 days after the final spraying and transplanted into pots prepared with Sunshine Mix LP5. Transplanted plants are covered with a humidity dome for 3-4 days and placed in a Conviron under the above-mentioned growth conditions.
Those skilled in the art of dicot plant transformation will understand that other methods of selection of transformed plants are available when other plant expressible selectable marker genes (e.g. herbicide tolerance genes) are used.
Insect Bioassays of transgenic Arabidopsis. Transgenic Arabidopsis lines expressing Cry proteins are demonstrated to be active against sensitive insect species in artificial diet overlay assays. Protein extracted from transgenic and non-transgenic Arabidopsis lines is quantified by appropriate methods and sample volumes are adjusted to normalize protein concentration. Bioassays are conducted on artificial diet as described above. Non-transgenic Arabidopsis and/or buffer and water are included in assays as background check treatments.
Example 16 Agrobacterium Transformation for Generation of Superbinary VectorsThe Agrobacterium superbinary system is conveniently used for transformation of monocot plant hosts. Methodologies for constructing and validating superbinary vectors are well disclosed and incorporated herein by reference (Operating Manual for Plasmid pSB1, Version 3.1, available from Japan Tobacco, Inc., Tokyo, Japan). Standard molecular biological and microbiological methods are used to generate superbinary plasmids. Verification/validation of the structure of the superbinary plasmid is done using methodologies as described above for binary vectors, and may be modified as suggested in the Operating Manual for Plasmid pSB1.
Example 17 Production of Insecticidal Proteins in Monocot PlantsAgrobacterium-Mediated Transformation of Maize. Seeds from a High II F1 cross (Armstrong et al., 1991, Maize Genet. Coop. Newsletter 65:92-93) are planted into 5-gallon-pots containing a mixture of 95% Metro-Mix 360 soilless growing medium (Sun Gro Horticulture, Bellevue, Wash.) and 5% clay/loam soil. The plants are grown in a greenhouse using a combination of high pressure sodium and metal halide lamps with a 16:8 hour Light:Dark photoperiod. For obtaining immature F2 embryos for transformation, controlled sib-pollinations are performed. Immature embryos are isolated at 8-10 days post-pollination when embryos are approximately 1.0 to 2.0 mm in size.
Infection and co-cultivation. Maize ears are surface sterilized by scrubbing with liquid soap, immersing in 70% ethanol for 2 minutes, and then immersing in 20% commercial bleach (0.1% sodium hypochlorite) for 30 minutes before being rinsed with sterile water. A suspension of Agrobacterium cells containing a superbinary vector is prepared by transferring 1-2 loops of bacteria grown on YEP solid medium containing 100 mg/L spectinomycin, 10 mg/L tetracycline, and 250 mg/L streptomycin at 28 for 2-3 days into 5 mL of liquid infection medium (LS Basal Medium (Linsmaier and Skoog, 1965, Physiol. Plant. 18:100-127), N6 vitamins (Chu et al., 1975, Scientia Sinica 18:659-668), 1.5 mg/L 2,4-Dichlorophenoxyacetic acid (2,4-D), 68.5 gm/L sucrose, 36.0 gm/L glucose, 6 mM L-proline, pH 5.2) containing 100 μM acetosyringone. The solution was vortexed until a uniform suspension was achieved, and the concentration is adjusted to a final density of about 200 Klett units, using a Klett-Summerson colorimeter with a purple filter, or an optical density of approximately 0.4 at 550 nm. Immature embryos are isolated directly into a micro centrifuge tube containing 2 mL of the infection medium. The medium is removed and replaced with 1 mL of the Agrobacterium solution with a density of 200 Klett units, and the Agrobacterium and embryo solution is incubated for 5 minutes at room temperature and then transferred to co-cultivation medium (LS Basal Medium, N6 vitamins, 1.5 mg/L 2,4-D, 30.0 gm/L sucrose, 6 mM L-proline, 0.85 mg/L AgNO3, 100 μM acetosyringone, 3.0 gm/L Gellan gum (PhytoTechnology Laboratories, Lenexa, Kans.), pH 5.8) for 5 days at 250 under dark conditions.
After co-cultivation, the embryos are transferred to selective medium after which transformed isolates are obtained over the course of approximately 8 weeks. For selection of maize tissues transformed with a superbinary plasmid containing a plant expressible pat or bar selectable marker gene, an LS based medium (LS Basal medium, N6 vitamins, 1.5 mg/L 2,4-D, 0.5 gm/L MES (2-(N-morpholino)ethanesulfonic acid monohydrate; PhytoTechnologies Labr.), 30.0 gm/L sucrose, 6 mM L-proline, 1.0 mg/L AgNO3. 250 mg/L cefotaxime, 2.5 gm/L Gellan gum, pH 5.7) is used with Bialaphos (Gold BioTechnology). The embryos are transferred to selection media containing 3 mg/L Bialaphos until embryogenic isolates were obtained. Recovered isolates are bulked up by transferring to fresh selection medium at 2-week intervals for regeneration and further analysis.
Those skilled in the art of maize transformation will understand that other methods of selection of transformed plants are available when other plant expressible selectable marker genes (e.g. herbicide tolerance genes) are used.
Regeneration and seed production. For regeneration, the cultures are transferred to “28” induction medium (MS salts and vitamins, 30 gm/L sucrose, 5 mg/L Benzylaminopurine, 0.25 mg/L 2, 4-D, 3 mg/L Bialaphos, 250 mg/L cefotaxime, 2.5 gm/L Gellan gum, pH 5.7) for 1 week under low-light conditions (14 μEm-2s-1) then 1 week under high-light conditions (approximately 89 μEm-2s-1) Tissues are subsequently transferred to “36” regeneration medium (same as induction medium except lacking plant growth regulators). When plantlets grow to 3-5 cm in length, they were transferred to glass culture tubes containing SHGA medium (Schenk and Hildebrandt salts and vitamins (1972); PhytoTechnologies Labr.), 1.0 gm/L myo-inositol, 10 gm/L sucrose and 2.0 gm/L Gellan gum. pH 5.8) to allow for further growth and development of the shoot and roots. Plants are transplanted to the same soil mixture as described earlier herein and grown to flowering in the greenhouse. Controlled pollinations for seed production are conducted.
Alternatively, binary vectors may be used to produce transgenic maize plants that contain one or more chimeric genes stably-integrated into the plant genome and comprising a coding region disclosed herein. For example, plants comprising at least one coding region of SEQ ID NOs:5, 11, 17, 23, 29, 35, 41, 47, 53, 59, 65, or 71 are produced following Agrobacterium-mediated transformation. Maize transformation methods employing binary transformation vectors are known in the art. In one embodiment, transformed tissues are selected by their ability to grow on haloxyfop-containing medium and are screened for protein production, as appropriate.
Ear sterilization and embryo isolation. Maize immature embryos were obtained from plants of Zea mays inbred line B104 grown in the greenhouse and self or sib-pollinated to produce ears. The ears were harvested approximately 9 to 12 days post-pollination. On the experimental day, de-husked ears were surface-sterilized by immersion in a 20% solution of sodium hypochlorite (6.15%) and shaken for 20 to 30 min, followed by three rinses in sterile water. After sterilization, immature zygotic embryos (1.5 to 2.4 mm) were aseptically dissected from each ear and randomly distributed into microcentrifuge tubes containing liquid Inoculation Medium. Inoculation Medium contains: 2.2 gm/L MS salts (Frame et al., 2011, Genetic Transformation Using Maize Immature Zygotic Embryos. IN Plant Embryo Culture Methods and Protocols: Methods in Molecular Biology. T. A. Thorpe and E. C. Yeung, (Eds), SPRINGER SCIENCE AND BUSINESS MEDIA, LLC. pp 327-341); IX ISU Modified MS Vitamins (Frame et al, 2011 supra); 68.4 gm/L sucrose; 36 gm/L glucose; 115 mg/L L-proline; 100 mg/L myo-inositol; and 200 μM acetosyringone (prepared in DMSO); at pH 5.4. For a given set of experiments, embryos from pooled ears were used for each transformation.
Agrobacterium Culture Initiation. Glycerol stocks of Agrobacterium strain DAt13192 (International PCT Publication No. WO2012016222(A2)) containing the binary transformation vector pDAB111440 (Example 1) were streaked on AB minimal medium plates (Watson, et al., (1975) J. Bacteriol. 123:255-264) containing appropriate antibiotics and were grown at 20° C. for 3 to 4 days. A single colony was picked and streaked onto YEP plates (gm/L: yeast extract, 10; Peptone, 10; NaCl 5) containing the same antibiotics and was incubated at 20° C. for 1-2 days.
Agrobacterium culture and Co-cultivation. Agrobacterium colonies were taken from a YEP plate, suspended in 10 mL of inoculation Medium in a 50 mL disposable tube, and the cell density was adjusted to an OO550 of 0.2 to 0.4 (Optical Density measured at 550 nm; a measure of cell growth) using a spectrophotometer. The Agrobacterium cultures were incubated on a rotary shaker at 125 rpm (room temperature) while embryo dissection was performed. Immature zygotic embryos (previously isolated from the sterilized maize kernels and placed in 1 mL of Inoculation Medium) were washed once in the same medium. Two ml of the Agrobacterium suspension was added to each tube of embryos and the tubes were placed on a shaker platform for 10 to 15 minutes. The embryos were transferred onto Co-cultivation Medium, oriented with the scutellum facing up, and incubated at 25° C., under 24-hour light at 50 μEm-2 sec″ light intensity for 3 days. Co-cultivation Medium, contains 4.33 gm/L MS salts; IX ISU Modified MS Vitamins; 30 gm/L sucrose; 700 mg/L L-proline; 3.3 mg/L Dicamba in KOH (3,6-dichloro-o-anisic acid or 3,6-dichloro-2-methoxybenzoic acid); 100 mg/L myo-inositol; 100 mg/L Casein Enzymatic Hydrolysate; 15 mg/L AgNO3; 100 μM acetosyringone in DMSO; and 3 gm/L GELZAN™ (SIGMA-ALDRICH); at pH 5.8.
Callus Selection and Regeneration of Putative Events. Following the co-cultivation period, embryos were transferred to Resting Medium and incubated under 24-hour light at 50 μEm-2 sec-1 light intensity and at 25° C. for 3 days. Resting Medium contains 4.33 gm/L MS salts; IX ISU Modified MS Vitamins; 30 gm/L sucrose; 700 mg/L L-proline; 3.3 mg/L Dicamba in KOH; 100 mg/L myo-inositol; 100 mg/L Casein Enzymatic Hydrolysate; 15 mg/L AgNO3; 0.5 gm/L MES (2-(N-morpholino)ethanesulfonic acid monohydrate: PHYTOTECHNOLOGIES LABR.; Lenexa, Kans.); 250 mg/L Carbenicillin; and 2.3 gm/L GELZAN™; at pH 5.8. Embryos were transferred onto Selection Medium 1 (which consists of the Resting Medium (above) with 100 nM R-Haloxyfop acid (0.0362 mg/L)), and incubated in either dark and/or under 24-hour light at 50 μEm-2sec-1 light intensity for 7 to 14 days at 28° C. Proliferating embryogenic calli were transferred onto Selection Medium 2 (which consists of Resting Medium (above), with 500 nM R-Haloxyfop acid (0.1810 mg/L)), and were incubated in 24-hour light at 50 μEm-2 sec-1 light intensity for 14 to 21 days at 28° C. This selection step allowed transgenic callus to further proliferate and differentiate.
Proliferating, embryogenic calli were transferred onto PreRegeneration Medium and cultured under 24-hour light at 50 μEm-2 sec-1 light intensity for 7 days at 28° C. PreRegeneration Medium contains 4.33 gm/L MS salts; IX ISU Modified MS Vitamins; 45 gm/L sucrose; 350 mg/L L-proline; 100 mg/L myo-inositol; 50 mg/L Casein Enzymatic Hydrolysate; 1.0 mg/L AgNO3; 0.25 gm/L MES; 0.5 mg/L naphthaleneacetic acid in NaOH; 2.5 mg/L abscisic acid in ethanol; 1 mg/L 6-benzylaminopurine; 250 mg/L Carbenicillin; 2.5 gm/L GELZAN™; and 500 nM R-Haloxyfop acid; at pH 5.8. Embryogenic calli with shoot-like buds were transferred onto Regeneration Medium and cultured under 24-hour light at 50 μEm-2 sec″ light intensity for 7 days. Regeneration Medium 1 contains 4.33 gm/L MS salts; IX ISU Modified MS Vitamins; 60 gm/L sucrose; 100 mg/L myo-inositol; 125 mg/L Carbenicillin; 3.0 gm/L GELZAN™; and 500 nM R-Haloxyfop acid; at pH 5.8. Small shoots with primary roots were transferred to Shoot/Root medium in PHYTATRAYS (PHYTOTECHNOLOGIES LABR; Lenexa, Kans.) and were incubated under 16:8 hr. light:dark at 140 to 190 μEm-2 sec″ light intensity for 7 days at 27° C. Shoot/Root Medium contains 4.33 gm/L MS salts; IX ISU Modified MS Vitamins; 30 gm/L sucrose; 100 mg/L myo-inositol; 3.5 gm/L GELZAN™; at pH 5.8. Putative transgenic plantlets were analyzed for transgene copy number by quantitative real-time PCR or other standard molecular analysis techniques, and were transferred to soil.
Transfer and establishment of T0 plants in the greenhouse for seed production. Transformed plant tissues selected by their ability to grow on medium containing 500 nM R-Haloxyfop acid were transplanted into METRO-MIX 360 soilless growing medium (SUN GRO HORTICULTURE) and hardened-off in a growth room. Plants were then transplanted into SUNSHINE CUSTOM BLEND 160 soil mixture and grown to flowering in the greenhouse. Controlled pollinations for seed production are conducted.
Leaf tissues of selected T0 plants were sampled at the V-3 to V-5 stage. Two 6 mm diameter leaf samples were stored in a 96 well cluster tube rack at −80° C. until the day of analysis. Two DAISY™ steel BB's and 200 μL of extraction buffer (PBS solution containing 0.05% of Tween 20 and 5 μL/ml of SIGMA protease inhibitor cocktail (catalog number 9599)) were added to each tube. The samples were milled in a KLECO bead mill (Visalia, Calif.) for 3 minutes, on maximum setting. Samples were centrifuged at 3,000×g for 5 minutes, then 100 μL of the supernatant were transferred to an empty sample tube. Another 100 μL of extraction buffer was added to the plant sample and bead-milled an 3 additional minutes. After centrifuging again, 100 μL of this extract was combined with the first 100 μL. The combined supernatants were mixed and analyzed on the same day as the extraction.
Proteins extracted from measured areas of leaf tissue were analyzed for expression of Cry1Fa protein and AAD-1 protein by standard ELISA (Enzyme-Linked Immunosorbant Assay) or protein immunoblots (western blots). For Cry1Fa ELISA detection, reagents from an ENVIROLOGIX ELISA kit (Cat. No. AP 016 NW VlO; Portland, Me.) were used according to the manufacturer's instructions. AAD-1 detection was performed by standard ELISA methodologies (for example, as taught in Ausubel et al. (1995 and updates) Current Protocols in Molecular Biology, John Wiley and Sons, New York) using rabbit antibodies prepared against purified AAD-1 protein.
The ELISA results obtained from extracts of pDAB111440-transformed plants are disclosed in Table 29. Protein levels are expressed as ng of the subject protein detected per square centimeter of leaf area harvested.
Protein extracts of the five pDAB1 11440-transformed plants listed in Table 29 (as well as extract from a non-transformed negative control plant) were prepared as above and probed with Cry1Fa antibody on immunoblots (western blots). Immunoblot procedures were essentially as described by Gallagher et al. (2008; Immunoblotting and Immunodetection. Current Protocols in Immunology 8.10.1-8.10.28). Protein samples (80 μL) were mixed with 20 μL of INVITROGEN NuPAGE LDS Sample Buffer, heated at >90° C. for five min, loaded on an INVITROGEN NuPAGE 4-12% Bis-Tris gel, and run in MOPS SDS Running Buffer (200 Volts for 45 minutes). BIORAD PRECISION PLUS Dual Color Standards were loaded in a separate lane. Proteins were transferred to 0.2 μM nitrocellulose membrane by means of an INVITROGEN iBLOT Gel Transfer system according to the manufacturer's instructions. The membrane was blocked with INVITROGEN WESTERN BREEZE BLOCKING MIX, then reacted with Primary antibody (anti-Cry1F Purified Rabbit Antibody No. D0609RA07-A0; Strategic Diagnostics Inc., Newark, Del.), followed by Secondary antibody (INVITROGEN Biotinylated goat anti-rabbit antibody.) This was followed by INVITROGEN HRP-Streptavidin conjugate and reacted bands were detected by PIERCE SUPERSIGNAL WEST PICO LUMINOL ENHANCER AND STABLE PEROXIDE (No. 34080).
Positive control lanes contained 0.5 ng or 1.0 ng of purified Cry1Fa core toxin protein produced by expression of a full length Cry1Fa coding region in a Pseudomonas jluorescens expression system (See, for example, US Patent Application No. 20100269223A1). The full-length Cry1Fa protein was trypsin treated to release the Cry1Fa core toxin segment of calculated molecular size 68 kDa, which was used as the positive control standard on the immunoblot. No antibody-reacting bands were detected in the extract from the negative control plant, while all five transgenic plant extracts contained a single predominant band (roughly equal in intensity to the control Cry1Fa proteins) of estimated size somewhat larger than 75 kDa.
Methods of controlling insect pests. When an insect comes into contact with an effective amount of toxin delivered via transgenic plant expression the results are typically death of the insect, or the insects do not feed upon the source which makes the toxins available to the insects.
Claims
1. A synthetic DNA sequence for expressing a protein of interest in maize cells which comprises:
- a) a codon-optimized DNA sequence encoding the protein of interest,
- b) at least one polyadenylation signal sequence chosen from the group consisting of Class I and Class II wherein;
- Class I is chosen from the group consisting of AATAAA, AATAAT, AACCAA, ATATAA, AATCAA, ATACTA, ATAAAA, ATGAAA, AAGCAT, ATTAAT, ATACAT, AAAATA, ATTAAA, AATTAA, AATACA, and CATAAA; and
- Class II is chosen from the group consisting of ATATAT, TTGTTT, TTTTGT, TGTTTT, TATATA, TATTT, TrTTT, ATTTr, TTATTT, TTTATT, TAATAA, ATTTAT, TATATT, TrTTAT, ATATTT, TATTAT, TGTTTG, TTATAT, TGTAAT, and AAATAA; and
- wherein said codon-optimized DNA sequence contains at least one polyadenylation signal sequence from Class II and wherein said synthetic DNA sequence contains fewer Class II polyadenylation signal sequences than the protein's native DNA sequence and contains the same number of class I polyadenylation signal sequences compared to said native DNA sequence.
2. The synthetic DNA sequence of claim 1 that is substantially devoid of class II polyadenylation signal sequences.
3. The synthetic DNA sequence of claim 1 that is devoid of class II polyadenylation signal sequences.
4. The synthetic DNA sequence of claim 1 wherein said synthetic DNA sequence encodes a native protein selected from the group consisting of insecticidal proteins, herbicide tolerance proteins, stress tolerance-related proteins, and oil profile modification proteins.
5. The synthetic DNA sequence of claim 4 wherein said synthetic DNA sequence encodes an insecticidal protein.
6. The synthetic DNA sequence of claim 4 wherein said synthetic DNA sequence encodes aryloxyalkanoate dioxygenase 1 protein.
7-12. (canceled)
13. A synthetic DNA sequence chosen from the group consisting of SEQ ID NO:5, SEQ ID NO:11, SEQ ID NO:17, SEQ ID NO:23, SEQ ID NO:29, SEQ ID NO:35, SEQ ID NO:41, SEQ ID NO:47, SEQ ID NO:53, SEQ ID NO:59, SEQ ID NO:65, and SEQ ID NO:71.
14. A DNA construct for expression of a protein of interest comprising a 5′ non-translated sequence, a coding sequence for a protein of interest, and a 3′ non-translated region, wherein said 5′ nontranslated sequence contains a promoter functional in a plant cell, said coding sequence is the synthetic DNA coding sequence of claim 1, and wherein said 3′ nontranslated sequence comprises a transcription termination sequence and a polyadenylation signal.
15. (canceled)
16. A transgenic plant containing the synthetic DNA sequence of claim 1.
17. (canceled)
18. A method of controlling pests in grain or seed which comprises obtaining said grain or seed from plants containing the synthetic DNA of claim 5.
19. (canceled)
20. A method of controlling pests in grain or seed which comprises obtaining said grain or seed from plants containing the synthetic DNA of claim 5.
21. A method of controlling pests in meal or flour which comprises obtaining said meal or flour from the grain containing the synthetic DNA of claim 5.
22. A composition derived from the transgenic plant of claim 16 wherein said composition is a commodity product selected from the group consisting of meal, flour, protein concentrate, or oil.
23. (canceled)
Type: Application
Filed: Mar 25, 2021
Publication Date: Jul 15, 2021
Applicant: CORTEVA AGRISCIENCE LLC (INDIANAPOLIS, IN)
Inventors: IGNACIO MARIO LARRINUA (INDIANAPOLIS, IN), DONALD MERLO (CARMEL, IN), AVUTU SAMBI REDDY (CARMEL, IN), ARVIND KUMAR THIRUMALAISWAMYSEKHAR (JOHNSTON, IA), AARON TODD WOOSLEY (FISHERS, IN)
Application Number: 17/212,795
