Effect of mutagenesis at serine 653 of Arabidopsis thaliana acetohydroxyacid synthase on the sensitivity to imidazolinone and sulfonylurea herbicides

FEBS Letters

Duggleby, Ronald G¹  Lee, Yu-Ting¹  Chang, Alan K¹ 

[1] Centre for Protein Structure, Function and Engineering, Department of Biochemistry, University of Queensland, Brisbane, Qld. 4072, Australia

关键词: Acetohydroxyacid synthase;    Enzyme inhibition;    Enzyme kinetic;    Herbicide-resistance;    Site-directed mutagenesis;   

DOI  :  10.1016/S0014-5793(99)00668-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Resistance to sulfonylurea and imidazolinone herbicides can occur by mutations in acetohydroxyacid synthase (EC 4.1.3.18). Changing serine 653 to asparagine is known to cause insensitivity to imidazolinones but not to sulfonylureas. Here, S-653 of the Arabidopsis thaliana enzyme was mutated to alanine, threonine and phenylalanine. The purified mutated enzymes resemble wild-type in their enzymatic properties. The threonine and phenylalanine mutants are imidazolinone-resistant and the latter is also slightly sulfonylurea-resistant. The alanine mutant remains sensitive to both herbicides. The results suggest that the β-hydroxyl group is not required for imidazolinone binding and that the size of the side-chain determines resistance.

【 授权许可】

Unknown