Methods and compositions for weed control

A composition comprising a polynucleotide and a transfer agent, wherein said polynucleotide is essentially identical or essentially complementary to a GS gene sequence, or to an RNA transcript of said GS gene sequence, wherein said GS gene sequence is selected from the group consisting of SEQ ID NO:1-59 or a polynucleotide fragment thereof, and whereby a plant treated with said composition has its growth or development or reproductive ability regulated, suppressed or delayed or said plant is more sensitive to a GS inhibitor herbicide as a result of said polynucleotide containing composition relative to a plant not treated with said composition.

A method of reducing expression of a GS gene in a plant comprising:

• external application to a plant of a composition comprising a polynucleotide and a transfer agent, wherein said polynucleotide is essentially identical or essentially complementary to a GS gene sequence or fragment thereof, or to the RNA transcript of said GS gene sequence or fragment thereof, wherein said GS gene sequence is selected from the group consisting of SEQ ID NO:1-59 or a polynucleotide fragment thereof, whereby said expression of said GS gene is reduced relative to a plant in which the composition was not applied.

The method as claimed in 17, wherein said polynucleotide molecule is selected from the group consisting of sense or anti-sense ssDNA or ssRNA, dsRNA, or dsDNA, or dsDNA/RNA hybrids.

A microbial expression cassette comprising a polynucleotide fragment of 18 contiguous, 19 contiguous nucleotides, 20 contiguous nucleotides or at least 21 contiguous nucleotides in length and at least 85 percent identical to a GS gene sequence selected from the group consisting of SEQ ID NO:1-59.

A method of identifying polynucleotides useful in modulating GS gene expression when externally treating a plant comprising:

• a) providing a plurality of polynucleotides that comprise a region essentially identical or essentially complementary to a polynucleotide fragment of 18 contiguous, 19 contiguous nucleotides, 20 contiguous nucleotides or at least 21 contiguous nucleotides in length and at least 85 percent identical to a GS gene sequence selected from the group consisting of SEQ ID NO:1-59;
• b) externally treating said plant with one or more of said polynucleotides and a transfer agent;
• c) analyzing said plant or extract for modulation of GS gene expression, and whereby a plant treated with said composition has its growth or development or reproductive ability regulated, suppressed or delayed or said plant is more sensitive to a GS inhibitor herbicide as a result of said polynucleotide containing composition relative to a plant not treated with said composition.

The method as claimed in 23, wherein said plant is selected from the group consisting of Abutilon theophrasti, Amaranthus albus, Amaranthus chlorostachys, Amaranthus graecizans, Amaranthus hybridus, Amaranthus lividus, Amaranthus palmeri, Amaranthus rudis, Amaranthus spinosus, Amaranthus thunbergii, Ambrosia trifida, Ambrosia artemisiifolia, Chenopodium album, Commelina diffusa, Convulvulus arvensis, Conyza candensis, Lolium multiflorum, Euphorbia heterophylla, Kochia scoparia, Sorghum halepense and Digitaria sanguinalis

The method as claimed in 23, wherein said GS gene expression is reduced relative to a plant not treated with said polynucleotide fragment and a transfer agent.

The method as claimed in 23, wherein said transfer agent is an organosilicone compound.

An agricultural chemical composition comprising an admixture of a polynucleotide and a GS inhibitor and a co-herbicide, wherein said polynucleotide is essentially identical or essentially complementary to a portion of a GS gene sequence, or to a portion of an RNA transcript of said GS gene sequence, wherein said GS gene sequence is selected from the group consisting of SEQ ID NO:1-78 or a polynucleotide fragment thereof, and whereby a plant treated with said composition has its growth or development or reproductive ability regulated, suppressed or delayed or said plant is more sensitive to a GS inhibitor herbicide as a result of said polynucleotide containing composition relative to a plant not treated with said composition.

An agricultural chemical composition comprising an admixture of a polynucleotide and a GS inhibitor herbicide and a pesticide, wherein said polynucleotide is essentially identical or essentially complementary to a portion of a GS gene sequence, or to a portion of an RNA transcript of said GS gene sequence, wherein said GS gene sequence is selected from the group consisting of SEQ ID NO:1-78 or a polynucleotide fragment thereof, whereby a field of crop plants in need of weed and pest control are treated with said composition, and whereby a plant treated with said composition has its growth or development or reproductive ability regulated, suppressed or delayed or said plant is more sensitive to a GS inhibitor herbicide as a result of said polynucleotide containing composition relative to a plant not treated with said composition.

A composition comprising a polynucleotide and a transfer agent, wherein said polynucleotide is essentially identical or essentially complementary to a GS gene sequence, wherein said polynucleotide is selected from the group consisting of SEQ ID NO:2046-2056 or a complement or polynucleotide fragment thereof, and whereby a plant treated with said composition has its growth or development or reproductive ability regulated, suppressed or delayed or said plant is more sensitive to a GS inhibitor herbicide as a result of said polynucleotide containing composition relative to a plant not treated with said composition.