Patent
Plants, plant parts and plant seeds that are resistant to imidazolinone herbicides are provided. Plants are disclosed that contain a mutation in an AHAS gene. Specifically, plants are disclosed that contain a mutant AHAS gene allele of the Brassica juncea B genome. Two B. juncea AHAS gene sequences (BjAHAS-a and BjAHAS-b) and one B. nigra AHAS gene sequence (BngrAHAS) are disclosed. The sequence of the mutant allele, BjAHAS-bR, is also disclosed. Various methods are disclosed that include creation of mutant B. juncea lines, selection for herbicide resistant lines and determining the presence of the BjAHAS-bR mutant allele after crosses.
1. A Brassica juncea plant obtained by a process comprising crossing a plant of line J04E-0044, a representative sample of seed of the line having been deposited under ATCC Accession No. PTA-6324, with another Brassica variety,
wherein the plant comprises a B-genome having a Brassica juncea acetohydroxyacid synthase (AHAS) nucleic acid at the AHAS-b locus thereof, the nucleic acid encoding an herbicide resistant AHAS polypeptide comprising amino acid residues 114 to 655 of SEQ ID NO:15, said plant exhibiting increased tolerance to an AHAS-inhibiting herbicide as compared to that of a corresponding wild-type plant.
2. The Brassica juncea plant of claim 1 , wherein the AHAS-inhibiting herbicide is an imidazolinone herbicide.
3. A method of producing Brassica juncea plant lines wherein the method comprises:
a) making a cross involving a first parent and a second parent plant, wherein the first plant is a plant of line J04E-0044, a representative sample of seed of the line having been deposited under ATCC Accession No. PTA-6324 and comprises a B-genome having a Brassica juncea acetohydroxyacid synthase (AHAS) nucleic acid at the AHAS-b locus thereof, the nucleic acid encoding an herbicide resistant AHAS a polypeptide comprising amino acid residues 114 to 655 of SEQ ID NO:15;
b) obtaining seeds from the cross of step (a);
c) growing fertile plants from such seeds;
d) identifying progeny plants that are herbicide resistant and that comprise a polynucleotide encoding a polypeptide comprising amino acid residues 114 to 655 of SEQ ID NO:15; and
e) obtaining progeny seeds from plants identified in step (d), wherein the Brassica juncea plant lines are commercial Brassica juncea plant lines.
4. The method of claim 3 , wherein said herbicide resistant plant is resistant to an imidazolinone herbicide.
5. The plant of claim 1 , wherein the AHAS nucleic acid comprises nucleotides 396 to 2024 of SEQ ID NO:14.
6. A seed of the Brassica juncea plant of claim 1 .
7. The seed of claim 6 , wherein the seed is untreated.
8. The seed of claim 6 , wherein the seed is sprayed with imidazolinone herbicide.
9. A method to control weeds in a Brassica crop comprising applying an herbicide to weeds in said crop, wherein the Brassica crop comprises the plant of claim 1 .
10. The method of claim 9 , wherein the herbicide comprises an imidazolinone herbicide.
11. The method of claim 9 , wherein the herbicide comprises imazamox.
12. The method of claim 9 , wherein said method comprises applying the herbicide to a seed from which the plant is grown.
13. The plant of claim 1 , wherein the AHAS nucleic acid sequence has been obtained by ethyl methyl sulfonate (EMS) mutagenesis.
14. The plant of claim 1 , wherein the AHAS nucleic acid sequence is non-recombinant.
15. The plant of claim 1 , wherein the plant is a commercial Brassica juncea plant.
16. A plant part or plant cell of the plant of claim 1 comprising the AHAS nucleic acid.
17. The method of claim 3 , wherein the AHAS nucleic acid sequence has been obtained by ethyl methyl sulfonate (EMS) mutagenesis.
18. The method of claim 3 , wherein the AHAS nucleic acid sequence is non-recombinant.