Agronomy (Sep 2022)

Molecular Basis of Resistance to Mesosulfuron-Methyl in a Black-Grass (<i>Alopecurus myosuroides</i> Huds.) Population from China

  • Xiangyang Qin,
  • Cheng Yang,
  • Mengmeng Hu,
  • Yunxia Duan,
  • Na Zhang,
  • Jinxin Wang,
  • Hengzhi Wang,
  • Weitang Liu

DOI
https://doi.org/10.3390/agronomy12092203
Journal volume & issue
Vol. 12, no. 9
p. 2203

Abstract

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Black-grass (Alopecurus myosuroides Huds.) is a common weed in Chinese wheat fields, and has become troublesome due to its evolution of herbicide resistance. One black-grass population (HN-14) collected from a wheat field where herbicides were applied was suspected to be resistant (R) to mesosulfuron-methyl. This study aims to establish a cross-resistance pattern and explore potential resistance mechanisms. The results of a whole-plant dose response assay showed that the resistant (R) population had a high of resistance to mesosulfuron-methyl (33-fold); meanwhile, no synergism of P450s activity inhibitor malathion was observed. The sequencing results revealed that ALS resistance mutation Trp-574-Leu occurred in R plants. The results of in vitro ALS enzyme activity assays also supported that the extractable ALS from R plants were 23.22-fold resistant to mesosulfuron-methyl. In the light of the “R” resistance rating system, HN-14 has evolved RRR and RR resistance to fenoxaprop-P-ethyl, clodinafop-propargyl, haloxyfop-methyl, and fluazifop-P-butyl and R? (resistance may be developing) to pinoxaden, however remains sensitive to imazethapyr, quizalofop-P-ethyl, tralkoxydim, and isoproturon. These results indicated that the mesosulfuron-methyl resistance in the black-grass population HN-14 was driven by a target-site mechanism rather than a nontarget (at least P450s-mediated) mechanism.

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