Differential Resistance to Acetyl-CoA Carboxylase Inhibitors in Rice: Insights from Two Distinct Target-Site Mutations

• DOI: 10.1021/acs.jafc.4c01889
• Publication Date: 2024-05-16T12:35:30Z
• Authors: Zhenzhen Zhou; Qun Jiang; Zeyu Qiu; Xiaodong Hou; Xia Yang; Yuwen Yang; Tingting Hao; Dongshu Guo; Jinyan Wang; Yongfeng Li; Qing Liu; Xitie Ling; Baolong Zhang
• Keywords: Herbicides; Mutation; Plant Weeds; Oryza; Enzyme Inhibitors; Acetyl-CoA Carboxylase; Herbicide Resistance; Plant Proteins

Weeds present a significant challenge to agricultural productivity, and acetyl-CoA carboxylase (ACCase)-inhibiting herbicides have proven to be effective in managing weed populations in rice fields. To develop ACCase-inhibiting herbicide-resistant rice, we generated mutants of rice ACCase (OsACC) featuring Ile-1792-Leu or Gly-2107-Ser substitutions through ethyl methyl sulfonate (EMS) mutagenesis. The Ile-1792-Leu mutant displayed cross-resistance to aryloxyphenoxypropionate (APP) and phenylpyrazoline (DEN) herbicides, whereas the Gly-2107-Ser mutants primarily exhibited cross-resistance to APP herbicides with diminished resistance to the DEN herbicide. In vitro assays of the OsACC activity revealed an increase in resistance to haloxyfop and quizalofop, ranging from 4.84- to 29-fold in the mutants compared to that in wild-type. Structural modeling revealed that both mutations likely reduce the binding affinity between OsACC and ACCase inhibitors, thereby imparting resistance. This study offers insights into two target-site mutations, contributing to the breeding of herbicide-resistant rice and presenting alternative weed management strategies in rice cultivation.