Patent
A Sorghum seed comprising in its genome at least one polynucleotide encoding a polypeptide having an alanine to tyrosine substitution at position 93 of the Sorghum AHAS protein large subunit. The plant has increased resistance to one or more herbicides, for example from the imidazolinone group, as compared to wild-type Sorghum plants. The Sorghum plant may comprise in its genome, one, two, three or more copies of a polynucleotide encoding a mutated large subunit of Sorghum AHAS or a Sorghum AHAS polypeptide of the invention. In this context, the Sorghum plant may be tolerant to any herbicide capable of inhibiting AHAS enzyme activity. For example, the Sorghum plant may be tolerant to herbicides of the imidazolinones type, such as imazethapyr, imazapir, and imazapic or to herbicides of the sulfonylurea group.
1 . A Sorghum polynucleotide, comprising a nucleotide sequence selected from the group consisting of:
a) the nucleotide sequence set forth in SEQ ID No. 1;
b) a nucleotide sequence encoding the polypeptide set forth in SEQ ID No. 2; and
c) a nucleotide sequence fully complementary to one of nucleotide sequences a) or b),
wherein the Sorghum polynucleotide is present in a Sorghum plant and provides said Sorghum plant with increased resistance to one or more imidazolinone herbicides as compared to wild-type Sorghum plants.
2 . An expression cassette comprising the polynucleotide of claim 1 .
3 . The expression cassette according to claim 2 , further comprising at least one promoter that drives the expression of the polynucleotide.
4 . The expression cassette according to claim 3 , wherein the promoter is selected from the group comprising promoters for expression in plants, bacteria, fungi, animal cells and protozoa.
5 . A cell transformed with the expression cassette of claim 2 .
6 . The cell according to claim 5 , wherein said cell is a Sorghum cell.
7 . A transformation vector having a Sorghum polynucleotide which comprises a nucleotide sequence selected from the group consisting of:
a) the nucleotide sequence set forth in SEQ ID No. 1;
b) a nucleotide sequence encoding the polypeptide set forth in SEQ ID No. 2; and
c) a nucleotide sequence fully complementary to one of the nucleotide sequences a) or b),
wherein the Sorghum polynucleotide is present in a Sorghum plant and provides said Sorghum plant with increased resistance to one or more imidazolinone herbicides as compared to wild-type Sorghum plants, and
wherein the vector further comprises a selectable gene and at least one promoter operably linked to the nucleotide sequence capable of driving the expression of said nucleotide sequence.
8 . A method for obtaining a herbicide-resistant Sorghum plant or a Sorghum plant with increased herbicide resistance, wherein said method comprises:
i) transforming a Sorghum plant cell with an expression cassette or vector comprising a Sorghum polynucleotide having a nucleotide sequence selected from the group consisting of:
a) the nucleotide sequence set forth in SEQ ID No. 1;
b) a nucleotide sequence encoding the polypeptide set forth in SEQ ID No. 2;
c) a nucleotide sequence fully complementary to one of the nucleotide sequences a) or b),
wherein the Sorghum polynucleotide is present in a Sorghum plant and provides said Sorghum plant with increased resistance to one or more imidazolinone herbicides as compared to wild-type Sorghum plants, and
wherein the expression cassette further comprises at least one promoter operably linked to the polynucleotide, and wherein said promoter drives the expression of said Sorghum polynucleotide; and
ii) regenerating the Sorghum plant cell to obtain a herbicide-resistant Sorghum plant.