Herbicidal inhibitors of amino acid biosynthesis and herbicide-tolerant crops.
Acetohydroxyacid synthase (AHAS) inhibitors interfere with branched-chain amino acid biosynthesis by inhibiting AHAS. Glyphosate affects aromatic amino acid biosynthesis by inhibiting 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS). Glufosinate inhibits glutamine synthetase and blocks biosynthesis of glutamine. AHAS gene variants that confer tolerance to AHAS inhibitors have been discovered in plants through selection or mutagenesis. Imidazolinone-tolerant crops have been commercialized based on these AHAS gene variants. A modified maize EPSPS gene and CP4-EPSPS gene from Agrobacterium sp. have been used to transform plants for target-based tolerance to glyphosate. A gox gene isolated from Ochrobactrum anthropi has also been employed to encode glyphosate oxidoreductase to detoxify glyphosate in plants. Glyphosate-tolerant crops with EPSPS transgene alone or both EPSPS and gox transgenes have been commercialized. Similarly, bar and pat genes isolated from Streptomyces hygroscopicus and S. viridochromogenes, respectively, have been inserted into plants to encode phosphinothricin N-acetyltransferase to detoxify glufosinate. Glufosinate-tolerant crops have been commercialized using one of these two transgenes.
T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21 T22 T23 T24 T25 T26 T27 T28 T29 T30 T31 T32 T33 T34 T35 T36 T37
CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL GENE-N GENE-N GENE-N GENE-N GENE-N GENE-N GENE-N GENE-N GENE-N GENE-N GENE-Y GENE-Y GENE-N GENE-N GENE-N GENE-N GENE-N GENE-Y GENE-Y
Acetohydroxyacid phosphinothricin N glufosinate Glufosinate Glyphosate aromatic amino acid 5-enolpyruvylshikimate-3-phosphate Glufosinate glutamine glutamine Imidazolinone branched-chain amino acid glyphosate glyphosate glyphosate Glyphosate amino acid Acetohydroxyacid synthase phosphinothricin N-acetyltransferase AHAS 5-enolpyruvylshikimate-3-phosphate synthase EPSPS glutamine synthetase AHAS AHAS AHAS AHAS maize EPSPS EPSPS gox glyphosate oxidoreductase EPSPS EPSPS gox bar pat