MOE Key Laboratory of Environmental Remediation & Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
College of Science and Technology, Ningbo University, Ningbo 315211, China.
Sci Total Environ. 2021 Feb 25;757:143759. doi: 10.1016/j.scitotenv.2020.143759. Epub 2020 Nov 25.
The secondary metabolism of plants is key for mediating responses to environmental stress, but few studies have examined how the relationship between secondary metabolism and the stress response of plants is affected by exposure to chiral herbicides. Here, we studied the enantioselective disturbance of the chiral herbicide imazethapyr (IM) on the secondary metabolism and nutrient levels of wheat seedlings. The bioactive enantiomer R-IM significantly increased the contents of major secondary metabolites, including phenolic acids, flavonoids, and carotenoids but greatly inhibited the production of benzoxazine. The antioxidant system also responded strongly to R-IM; specifically, the activities of SOD, CAT, and GPX enzymes were all significantly induced, and the GSH content initially increased but then decreased. Furthermore, the nutrient levels of wheat seedlings were also affected; dietary fiber content decreased, while the contents of the microelements Fe, Mn, and Zn increased. In sum, this study provides new insight into the phytotoxic effects of IM and raises new questions on the role of secondary metabolites and nutrients in mediating enantioselective effects.
植物的次生代谢对于介导对环境胁迫的响应至关重要，但很少有研究探讨暴露于手性除草剂如何影响次生代谢和植物胁迫响应之间的关系。在这里，我们研究了手性除草剂咪草烟（IM）对小麦幼苗次生代谢和养分水平的对映体选择性干扰。生物活性对映体 R-IM 显著增加了主要次生代谢物的含量，包括酚酸、类黄酮和类胡萝卜素，但大大抑制了苯并恶嗪的产生。抗氧化系统也对手性 R-IM 有强烈的响应；具体来说，SOD、CAT 和 GPX 酶的活性均显著诱导，GSH 含量最初增加但随后下降。此外，小麦幼苗的养分水平也受到影响；膳食纤维含量下降，而微量元素 Fe、Mn 和 Zn 的含量增加。总之，本研究为 IM 的植物毒性作用提供了新的见解，并对手性代谢物和养分在介导对映体选择性效应中的作用提出了新的问题。
