Keya Laboratory of Pesticide Toxicology and Application Technique, College of Plant Protection, Shandong Agricultural University, Tai'an, Shandong 271018, PR China.
Taian Academy of Agricultural Sciences, Tai'an, Shandong 271000, PR China.
Pestic Biochem Physiol. 2017 Nov;143:239-245. doi: 10.1016/j.pestbp.2017.05.007. Epub 2017 May 11.
Shepherd's purse is a troublesome dicot weed that occurs in the major wheat-producing areas in China. Twenty-eight shepherd's purse populations were collected from winter wheat-planting areas in Henan Province and used to evaluate tribenuron-methyl resistance and acetohydroxyacid synthase (AHAS) gene-mutation diversity. The results indicate that all 28 shepherd's purse populations were resistant to tribenuron-methyl at different levels compared with the susceptible population. Mutation of the 197 codon (CCT) changed proline (Pro) into tyrosine (Tyr), histidine (His), leucine (Leu), serine (Ser), arginine (Arg), alanine (Ala) and threonine (Thr), whereas mutation of the 574 codon (TGG) changed tryptophan (Trp) into leucine (Leu). Among these amino acid changes, a co-concurrence of Pro197Leu and Trp574Leu substitutions was identified for the first time in resistant weed species. Furthermore, Pro197Tyr, Pro197Arg and Pro197Ala substitutions have not been previously reported in shepherd's purse. The results of the in vitro AHAS assay suggest that an insensitive AHAS is likely involved in the resistance to tribenuron-methyl in the R populations with AHAS gene mutations, and the non-target-site based resistance might exist in some populations.
荠菜是一种常见的阔叶杂草，在中国主要的小麦产区均有发生。本研究从河南省冬小麦种植区采集了 28 个荠菜种群，用以评估啶磺草胺抗药性和乙酰羟酸合成酶（AHAS）基因突变多样性。结果表明，与敏感种群相比，28 个荠菜种群均对啶磺草胺表现出不同水平的抗药性。第 197 密码子（CCT）的突变将脯氨酸（Pro）突变为酪氨酸（Tyr）、组氨酸（His）、亮氨酸（Leu）、丝氨酸（Ser）、精氨酸（Arg）、丙氨酸（Ala）和苏氨酸（Thr），而第 574 密码子（TGG）的突变将色氨酸（Trp）突变为亮氨酸（Leu）。在这些氨基酸变化中，首次在抗药性杂草物种中发现了 Pro197Leu 和 Trp574Leu 取代的共同出现。此外，Pro197Tyr、Pro197Arg 和 Pro197Ala 取代在荠菜中尚未有报道。体外 AHAS 测定结果表明，在具有 AHAS 基因突变的 R 种群中，对啶磺草胺的抗药性可能与 AHAS 不敏感有关，并且在一些种群中可能存在非靶标位点的抗性。
