Abstract: A method for enhancing the expression of a tomato phytoene synthese gene in a plant while avoiding or reducing co-suppression involves the synthesis of a DNA which is altered in nucleotide sequence (SEQ ID NO:1) and is capable of expression of a protein, ideally identical to that of a protein already expressed by a DNA already present in the plant. This method ensures that sequence similarity between the two genes is reduced enough to eliminate the phenomenon of co-suppression, allowing the over-expression of a specific phytoene synthese protein.

Abstract: Male sterility is imparted to a plant by a cascade of gene sequences which expresses a protein which disrupts the biosynthesis of viable pollen. Expression of the disrupter protein is restricted to male parts of the plant by an upstream promoter sequence which is specific to male flowers, the male specific promoter being under control of an operator sequence. The cascade also includes a gene encoding a repressor protein specific for that operator. Expression of the repressor protein is under control of a chemically inducible promoter which is inducible by the application to the plant by, spraying or like process, of an exogenous chemical. In the absence of the exogenous chemical inducer, no repressor protein is expressed, resulting in expression of the disrupter protein and, consequently, male sterility.

Abstract: The chemically-inducible 27 kD subunit of the enzyme glutathione-S-transferase, isoform II (GST-II-27) and sequences encoding it are provided. In particular, a genomic DNA sequence encoding the gene promoter for the GST-II-27 subunit is provided. Then linked to an exogenous gene and introduced into a plant by transformation, and GST-II-27 promoter provides a means for the external regulation of expression of that exogenous gene. Transformation with DNA encoding glutathione-S-transferase polypeptides produces herbicide resistance transgenic plants.

Abstract: The synthesis of lignin by plants is controlled by transformation of the plant genome with a recombinant gene construct which contains the gene specifying an enzyme critical to the synthesis of a lignin precursor, which gene may be in antisense orientation so that it is transcribed to mRNA having a sequence complementary to the equivalent mRNA transcribed from the endogenous gene thus leading to suppression of lignin synthesis. If the recombinant gene has the lignin enzyme gene in normal, or "sense" orientation, increased production of the enzyme may occur when the insert is the full length DNA but suppression may occur it only a partial sequence is employed.

Abstract: Pseudo-operator sequences may be located in (or inserted into) plant genomes and utilized to drive expression of foreign genes. These pseudo-operator sequences are nucleotide sequences which are present at a suitable location in a gene at which repressor binding will lead to inhibitation or enhancement of gene expression. The disclosed technique permits the design of altered specificity repressors, which bind the pseudo-operators.

Abstract: Process for the inhibition of two or more target genes which comprises introducing into the plant a single control gene which has distinct DNA regions homologous to each of the target genes and a promoter operative in plants adapted to transcribe from such distinct regions RNA that inhibits expression of each of the target genes. Constructs suitable for use in the process, as well as cells and plants containing such constructs are disclosed. Specific examples relate to the pectinesterse and polygalacturonase genes.

Abstract: The chemically-inducible 27 kD subunit of the enzyme glutathione-S-transferase, isoform II (GST-II-27) and sequences encoding it are provided. In particular, a genomic DNA sequence encoding the gene promoter for the GST-II-27 subunit is provided. Then linked to an exogenous gene and introduced into a plant by transformation, and GST-II-27 promoter provides a means for the external regulation of expression of that exogenous gene. Transformation with DNA encoding glutathione-S-transferase polypeptides produces herbicide resistance transgenic plants.

Abstract: The invention provides DNA homologous to a disclosed sequence which encodes a galactosidase/galactanase enzyme. Such DNA is incorporated into DNA constructs which are transformed into plants to increase or decrease expression of the related gene. This provides a method for modifying cell wall metabolism and fruit-ripening characteristics.

Abstract: A DNA which has the sequence shown in FIG. 5 and which defines a gene promoter region has been isolated from maize roots. The promoter may be used for driving expression of foreign genes in the roots of plants. This is particularly useful for expressing an insecticidal toxin, such as a delta-endotoxin of Bacillus thuringiensis, to impart resistance to insect attack on the roots of plants by Coleopteran insects.

Abstract: The present invention provides a method for modifying fruit ripening characteristics in plants and is particularly suitable for modification of tomato plants. The DNA expressing an enzyme involved in fruit ripening has been identified and characterized. The DNA is useful in genetically modifying plants to improve shelf life, flavor, resistance to post-harvest pathogens and improved processing characteristics.

Abstract: Male sterility is imparted to a plant by a cascade of gene sequences which expresses a protein which disrupts the biosynthesis of viable pollen. Expression of the disrupter protein is restricted to male parts of the plant by an upstream promoter sequence which is specific to male flowers, the male specific promoter being under control of an operator sequence. The cascade also includes a gene encoding a repressor protein specific for that operator. Expression of the repressor protein is under control of a chemically inducible promoter which is inducible by the application to the plant by, spraying or like process, of an exogenous chemical. In the absence of the exogenous chemical inducer, no repressor protein is expressed, resulting in expression of the disrupter protein and, consequently, male sterility.

Abstract: Plants, particularly cereal plants, which have altered ability to synthesise starch are produced by inserting into the genome of the plant a gene encoding an enzyme of the starch biosynthetic pathway such that capacity to produce starch is improved or reduced. The gene encoding the enzyme ADP-glucose pyrophosphorylase has been isolated from wheat leaf and wheat endosperm tissue. The enzyme is essential to the biosynthesis of starch in plants. Addition of extra copies of the gene to a plant by transformation enhances starch production, increasing the food value of the crop. Conversely, insertion of a gene encoding mRNA antisense to the mRNA encoded by the endogenous ADP-glucose pyrophosphorylase gene will reduce starch production. cDNA sequences are provided which may be used to identify homologous sequences in other tissue and in other plants. The ADP-glucose pyrophosphorylase gene promoter may be used in the genetic manipulation of plants to alter their starch-synthesising ability.

Abstract: The gene of the construct pTOM5 is involved in the carotenoid pathway, which produces carotenes, lutein, xanthophylls, and pigments such as lycopene. The invention proposes to modify (inhibit or promote) the synthesis of such compounds in plants using novel DNA contructs comprising a DNA sequence homologous to some or all of the gene encoded by the clone pTOM5, preceded by a plant promoter. In particular, colour of plant parts, especially fruit, may be modified. Yellow tomatoes are disclosed.

Abstract: The invention relates to the clone pTOM36, comprising a gene encoding an enzyme involved in ripening related processes in tomato. Also described are DNA constructs comprising pTOM36 and a transcriptional intiation region operative in plants such that pTOM36 RNA is generated in plant cells, and tomato cells transformed with the DNA constructs.