Cross-resistance pattern to four AHAS-inhibiting herbicides of tribenuron-methyl-resistant flixweed(Descurainia sophia) conferred by Asp-376-Glu mutation in AHAS  

作　　者：DENG Wei YANG Qian JIAO Hong-tao ZHANG Yong-zhi LI Xue-feng ZHENG Ming-qi 

机构地区：[1]Department of applied Chemistry, China Agricultural University, Beijing 1000193, P.R.China

出　　处：《Journal of Integrative Agriculture》2016年第11期2563-2570,共8页农业科学学报（英文版）

基　　金：sponsored by the Special Fund for Agro-scientific Research in the Public Interest,China(201303031)

摘　　要：Flixweed（Descurainia sophia L.） is a problematic and widespread weed in winter wheat fields and has been controlled by tribenuron-methyl for more than twenty years in China. In this study, a flixweed accession（Hebei 25, HB25） with an Asp-376-Glu mutation in acetohydroxy acid synthase（AHAS） was identified and purified. The purified HB25 accession（p HB25） developed 758.1-fold resistance to tribenuron-methyl and exhibited obvious cross-resistance to four AHAS-inhibiting herbicides. The resistant/susceptible（R/S） ratios of 50% plant growth reduction（GR_（50）） to herbicides of halosulfuron-methyl, flumetsulam, imazethapyr and pyribenzoxim were 346.1, 15.7, 8.1 and 7.1, respectively. The reduced AHAS sensitivities to four different AHAS-inhibiting herbicides, which were caused by the Asp-376-Glu mutation, were responsible for the resistance and cross-resistance to AHAS-inhibiting herbicides. The R/S ratios of 50% inhibition of AHAS activity（I50） to tribenuron-methyl, halosulfuron-methyl, flumetsulam, imazethapyr and pyribenzoxim were 844.5, 532.9, 74.5, 13.3 and 5.5, respectively. The results of AHAS activity in vitro were highly correlated with that of whole-plant response experiments.Flixweed（Descurainia sophia L.） is a problematic and widespread weed in winter wheat fields and has been controlled by tribenuron-methyl for more than twenty years in China. In this study, a flixweed accession（Hebei 25, HB25） with an Asp-376-Glu mutation in acetohydroxy acid synthase（AHAS） was identified and purified. The purified HB25 accession（p HB25） developed 758.1-fold resistance to tribenuron-methyl and exhibited obvious cross-resistance to four AHAS-inhibiting herbicides. The resistant/susceptible（R/S） ratios of 50% plant growth reduction（GR_（50）） to herbicides of halosulfuron-methyl, flumetsulam, imazethapyr and pyribenzoxim were 346.1, 15.7, 8.1 and 7.1, respectively. The reduced AHAS sensitivities to four different AHAS-inhibiting herbicides, which were caused by the Asp-376-Glu mutation, were responsible for the resistance and cross-resistance to AHAS-inhibiting herbicides. The R/S ratios of 50% inhibition of AHAS activity（I50） to tribenuron-methyl, halosulfuron-methyl, flumetsulam, imazethapyr and pyribenzoxim were 844.5, 532.9, 74.5, 13.3 and 5.5, respectively. The results of AHAS activity in vitro were highly correlated with that of whole-plant response experiments.

关 键 词：flixweed AHAS CROSS-RESISTANCE Asp-376-Glu mutation 

分 类 号：S451.2[农业科学—植物保护]