College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China; MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China.
Sci Total Environ. 2019 Mar 15;656:1365-1372. doi: 10.1016/j.scitotenv.2018.11.355. Epub 2018 Nov 24.
Echinochloa crus-galli is one of the most noxious weeds in the world and causes yield losses in a variety of different field crops. Napropamide and acetochlor are herbicides commonly employed to control this weed. Both compounds are chiral, with enantiomers displaying different activities. However, it is unclear how the enantiomers of these two chiral herbicides act on different tissues of E. crus-galli. The objective of this paper is to investigate the action mechanism of napropamide and acetochlor in the roots and shoots of E. crus-galli. R‑enantiomers were found to be more active than either the racemates or S-enantiomers on the weed. The content of chlorophyll was not significantly affected by treatment with either enantiomer. The impacts on the activity for the oxidative stress enzymes, except catalase (CAT), showed that both napropamide and acetochlor enantiomers could induce oxidative stress. Furthermore, R‑enantiomers caused greater oxidative damage. Enhanced glutathione-S-transferase (GST) activity and expression of GST genes suggested both EcGSTF1 and EcGSTZ1 were present in the roots and shoots, and this will be helpful for detoxification. The changes in both the roots and shoots revealed the two herbicides displayed tissue selectivity in E. crus-galli. These results enable a better understanding on the mechanism of action for napropamide and acetochlor enantiomers on different tissues, including the shoots and roots in E. crus-galli.
稗草是世界上最有害的杂草之一，会导致多种不同大田作物减产。萘丙胺和乙草胺是常用于防治这种杂草的除草剂。这两种化合物都是手性的，对映异构体显示出不同的活性。然而，目前尚不清楚这两种手性除草剂的对映异构体如何作用于稗草的不同组织。本文的目的是研究萘丙胺和乙草胺在稗草根和茎叶中的作用机制。结果表明，在杂草中，R-对映异构体比外消旋体或 S-对映异构体的活性更高。处理后，叶绿素含量没有明显变化。对氧化应激酶活性的影响（除了过氧化氢酶 (CAT)）表明，萘丙胺和乙草胺对映异构体都能诱导氧化应激。此外，R-对映异构体引起更大的氧化损伤。增强谷胱甘肽-S-转移酶 (GST) 活性和 GST 基因的表达表明，EcGSTF1 和 EcGSTZ1 存在于稗草根和茎叶中，这有助于解毒。根和茎叶的变化表明，这两种除草剂在稗草中表现出组织选择性。这些结果使我们能够更好地理解萘丙胺和乙草胺对映异构体在稗草根和茎叶等不同组织中的作用机制。
