Enantioselective damage of diclofop acid mediated by oxidative stress and acetyl-CoA carboxylase in nontarget plant Arabidopsis thaliana.
Enantioselective damage of diclofop acid mediated by oxidative stress and acetyl-CoA carboxylase in nontarget plant Arabidopsis thaliana.
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DOI：
10.1021/es300049q
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发表时间：
2012-07
影响因子：
11.4
通讯作者：
Qiong Zhang;Mei-rong Zhao;H. Qian;Tao Lu;Quan Zhang;Weiping Liu
中科院分区：
文献类型：
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作者：
Qiong Zhang;Mei-rong Zhao;H. Qian;Tao Lu;Quan Zhang;Weiping Liu
烯草灵（DM）是一种广泛使用的手性除草剂，施用后迅速水解为其主要代谢物烯草灵酸（DC）。 DC具有碳手性中心，不仅是除草活性的重要成分，而且在土壤中半衰期长。迄今为止的研究仅考虑了外消旋DM在靶标生物体中的活性，DM和DC在非靶标植物中的对映选择性毒性仍有待探索。本研究研究了氧化应激和脂肪酸合成系统中关键酶ACCase介导的DC对模式植物拟南芥的对映选择性植物毒性。两种对映体在植物毒性方面存在显着差异，包括生长抑制、氧化损伤和ACCase关键基因表达的改变，其中R-DC对拟南芥的毒性高于S-DC。分子对接结果表明，R-DC与ACCase的靶酶羧基转移酶结构域之间存在较强的亲和力，可能导致DC的对映选择性植物毒性。这项研究表明，应考虑母体化合物和代谢物的手性，以提高我们对手性农药的环境命运和风险的理解。
Diclofop-methyl (DM) is a widely used chiral herbicide, which rapidly hydrolyzes to its major metabolite diclofop acid (DC) after application. With a carbon chiral center, DC not only is an important ingredient of herbicidal activity, but also has a long half-life in soil. Studies so far have only considered the activity of racemic DM in target organisms, and the enantioselective toxicity in nontarget plants of DM and DC has yet to be explored. In this study, the enantioselective phytotoxicity of DC mediated by oxidative stress and the key enzyme ACCase in the fatty acid synthesis system on the model plant Arabidopsis thaliana was investigated. Significant differences between the two enantiomers were observed in phytotoxicity including growth inhibition, oxidative damage and alteration of key genes expression of ACCase, with R-DC showing greater toxicity to Arabidopsis thaliana than S-DC. The results of molecular docking showed that there was a stronger affinity between R-DC and the target enzyme carboxyltransferase domain of ACCase, likely leading to the enantioselective phytotoxicity of DC. This study suggested that chirality of both parent compounds and metabolites should be considered to improve our understanding of the environmental fate and risks of chiral pesticides.