Guangxi key laboratory of Agric-Environment and Agric-products Safety, National Demonstration Center for Experimental Plant Science Education, College of Agriculture, Guangxi University, Nanning, Guangxi 530004, People's Republic of China.
Guangxi key laboratory of Agric-Environment and Agric-products Safety, National Demonstration Center for Experimental Plant Science Education, College of Agriculture, Guangxi University, Nanning, Guangxi 530004, People's Republic of China.
J Hazard Mater. 2022 Mar 5;425:127818. doi: 10.1016/j.jhazmat.2021.127818. Epub 2021 Nov 22.
Imazamox (IM) is a chiral pesticide that has been widely used in agriculture. Currently, few studies have investigated the toxicity mechanisms of imazamox to aquatic macrophyte from the enantiomer level. In this study, the enantioselective effects of IM on the toxicity and physiological and biochemical system of aquatic macrophyte Lemna minor were systematically investigated. Metabolomic and transcriptomic for Lemna minor were used to identify potential mechanisms of toxicity. 7 d ECs for racemic-, R-, and S-IM were 0.036, 0.035, and 0.203 mg/L, respectively, showing enantioselective toxicity. In addition, IM caused Lemna minor lipid peroxidation and antioxidant damage, and inhibited the activities of the target enzymes. Metabolomic and transcriptomic data indicated that R-IM interferenced differentially expressed genes and metabolites of Lemna minor which were enriched in carbon fixation during photosynthesis, glutathione metabolic pathway, pentose phosphate pathway, zeatin biosynthesis, and porphyrin and chlorophyll metabolism. S-IM affected phenylalanine metabolism, phenylpropanoid biosynthesis, zeatin biosynthesis and secondary metabolite biosynthesis. Racemic-IM influenced carbon fixation during operation, glutathione metabolic pathway, zeatin biosynthesis and pentose phosphate pathway. The results provide new insights into the enantioselective toxicity mechanisms of IM to Lemna minor, and lay the foundation for conducting environmental risk assessments.
异恶草松（IM）是一种手性农药，已广泛应用于农业。目前，很少有研究从对映体水平研究异恶草松对水生大型植物的毒性机制。在这项研究中，系统研究了 IM 对水生大型植物浮萍的毒性和生理生化系统的对映体选择性效应。浮萍的代谢组学和转录组学用于鉴定潜在的毒性机制。外消旋体、R- 和 S-IM 的 7dEC50 分别为 0.036、0.035 和 0.203mg/L，表现出对映体选择性毒性。此外，IM 导致浮萍脂质过氧化和抗氧化损伤，并抑制靶酶的活性。代谢组学和转录组学数据表明，R-IM 干扰了浮萍中光合作用碳固定、谷胱甘肽代谢途径、戊糖磷酸途径、玉米素生物合成、卟啉和叶绿素代谢等差异表达基因和代谢物。S-IM 影响苯丙氨酸代谢、苯丙烷生物合成、玉米素生物合成和次生代谢物生物合成。外消旋体 IM 影响光合作用碳固定、谷胱甘肽代谢途径、玉米素生物合成和戊糖磷酸途径。结果为深入了解 IM 对浮萍的对映体选择性毒性机制提供了新的见解，并为进行环境风险评估奠定了基础。
