Enantioselective phytotoxicity of the herbicide imazethapyr on the response of the antioxidant system and starch metabolism in Arabidopsis thaliana.
Enantioselective phytotoxicity of the herbicide imazethapyr on the response of the antioxidant system and starch metabolism in Arabidopsis thaliana.
复制标题
除草剂咪草烟对拟南芥抗氧化系统和淀粉代谢反应的对映选择性植物毒性
DOI：
10.1371/journal.pone.0019451
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发表时间：
2011-05-06
期刊：
影响因子：
3.7
通讯作者：
Liu W
中科院分区：
文献类型：
--
作者：
Qian H;Lu T;Peng X;Han X;Fu Z;Liu W
背景手性化合物的对映体具有不同的生物活性，其中一种对映体通常表现出较高的毒性。因此，探索对映体选择性毒性的产生机理是生物化学的首要目标之一。咪草胺(IM)是一种抑制乙酰乳酸合成酶(ALS)的手性除草剂，近年来与外消旋体一起广泛使用。我们研究了R-和S-IM之间的对映体选择性，以形成活性氧物种(ROS)，并调节抗氧化基因的转录和酶活性。结果不同对映体之间存在显著差异：R-IM的对映体强烈诱导ROS的形成，但显著降低抗氧化基因转录和酶活性，从而导致氧化应激。IM影响叶绿体碳水化合物代谢的机制长期以来一直是个谜。在此，我们报告了在淀粉代谢中也存在对映体选择性的证据。R-IM的对映体导致葡萄糖、麦芽糖和蔗糖在细胞质或叶绿体中积累，扰乱了碳水化合物的利用。结论R-IM对植物生长的抑制作用强于S-IM，不仅作用于ALS，而且以对映体选择性方式引起抗氧化系统失衡和碳水化合物代谢紊乱。
Background The enantiomers of a chiral compound possess different biological activities, and one of the enantiomers usually shows a higher level of toxicity. Therefore, the exploration of the causative mechanism of enantioselective toxicity is regarded as one of primary goals of biological chemistry. Imazethapyr (IM) is an acetolactate synthase (ALS)-inhibiting chiral herbicide that has been widely used in recent years with racemate. We investigated the enantioselectivity between R- and S-IM to form reactive oxygen species (ROS) and to regulate antioxidant gene transcription and enzyme activity. Results Dramatic differences between the enantiomers were observed: the enantiomer of R-IM powerfully induced ROS formation, yet drastically reduced antioxidant gene transcription and enzyme activity, which led to an oxidative stress. The mechanism by which IM affects carbohydrate metabolism in chloroplasts has long remained a mystery. Here we report evidence that enantioselectivity also exists in starch metabolism. The enantiomer of R-IM resulted in the accumulation of glucose, maltose and sucrose in the cytoplasm or the chloroplast and disturbed carbohydrates utilization. Conclusion The study suggests that R-IM more strongly retarded plant growth than S-IM not only by acting on ALS, but also by causing an imbalance in the antioxidant system and the disturbance of carbohydrate metabolism with enantioselective manner.
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影响因子：
7.3
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Mackerness, SAH;Surplus, SL;Thomas, B
通讯作者：
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