Abstract:
Alopecurus aequalis Sobol. is a predominant grass weed in Chinese winter wheat fields, posing a substantial threat to crop production owing to its escalating herbicide resistance. This study documented the initial instance of an A. aequalis population (AHFT-3) manifesting resistance to multiple herbicides targeting four distinct sites: acetyl-CoA carboxylase (ACCase), acetolactate synthase, photosystem II, and 1-deoxy-d-xylulose-5-phosphate synthase. AHFT-3 carried an Asp-to-Gly mutation at codon 2078 of ACCase, with no mutations in the remaining three herbicide target genes, and exhibited no overexpression of any target gene. Compared with the susceptible population AHFY-3, AHFT-3 metabolized mesosulfuron-methyl, isoproturon, and bixlozone faster. The inhibition and comparison of herbicide-detoxifying enzyme activities indicated the participation of cytochrome P450s in the resistance to all four herbicides, with glutathione S-transferases specifically linked to mesosulfuron-methyl. Three CYP72As and a Tau class glutathione S-transferase, markedly upregulated in resistant plants, potentially played pivotal roles in the multiple-herbicide-resistance phenotype.
摘要:
aequalisSobol。是中国冬麦田中主要的草杂草,由于其不断升级的除草剂抗性,对作物生产构成了重大威胁。这项研究记录了A.aequalis种群(AHFT-3)的最初实例,表明对针对四个不同位点的多种除草剂具有抗性:乙酰辅酶A羧化酶(ACCase),乙酰乳酸合酶,光系统II,和1-脱氧-d-木酮糖-5-磷酸合酶。AHFT-3在ACCase的2078密码子携带Asp到Gly突变,其余三个除草剂靶基因没有突变,并且没有表现出任何靶基因的过表达。与易感人群AHFY-3相比,AHFT-3代谢了甲基甲磺隆,异丙隆,和Bixlozone更快。除草剂解毒酶活性的抑制和比较表明细胞色素P450参与了对所有四种除草剂的抗性,与特异性连接到甲基甲磺隆的谷胱甘肽S-转移酶。三个CYP72As和一个Tau类谷胱甘肽S-转移酶,在抗性植物中显著上调,在多种除草剂抗性表型中可能发挥关键作用。