A122S , A205V , D376E , W574L and S653N substitutions in acetolactate synthase ( ALS ) from Amaranthus palmeri show different functional impacts on herbicide resistance

ALVAREZ, CLARISA E.; PALMIERI, VALERIA E.; PEROTTI, VALERIA E.; PERMINGEAT, HUGO R.

PEST MANAGEMENT SCIENCE

JOHN WILEY & SONS LTD

Lugar: LOndres; Año: 2021

1526-498X

Amaranthus palmeri S. Watson, a problematic weed infesting summer crops in Argentina, has developed multiple herbicide resistance. Resistance to acetolactate synthase (ALS)-inhibiting herbicides is particularly common, with high-level resistance mostly caused by different mutations in the ALS enzyme. Six versions of the enzyme were identified from a resistant A. palmeri population, carrying substitutions D376E, A205V, A122S, A282D, W574L and S653N. This work aims to provide a comparative analysis of these mutants and the wild-type (WT) enzyme to fully understand the herbicide resistance. Thus, all the versions of the ALS gene from A. palmeri were heterologously expressed and purified to evaluate their kinetics and inhibitory response against imazethapyr, diclosulam, chlorimuron-ethyl, flucarbazone-sodium and bispyribac-sodium.