Inducing Glutathione S-Transferase Expression and Activity using an Herbicide Safener against Metolachlor in Maize

摘要

The effect of three potential herbicide safeners including N-Dichloroacetyl-2, 2 and 5-trimethyl-1and 3-oxazolidine (R-29148) and its two optical isomers on preventing maize (Zea mays L.) injury by herbicide metolachlor were determined. Treatment on maize with chiral safeners caused a progressive increase in glutathione-s-transferase activity in roots and reduced chloroacetanilide herbicide phytotoxicity in maize seedlings. After pretreating with the R-enantiomer in vivo and in vitro glutathione S-transferases activities in roots were increased by 107 and 17%, respectively. Compared with an untreated control the glutathione S-transferase kinetic parameter V max of the maize after treatment with the R-enantiomer and racemic R-29148 increased by 60 and 18% respectively, while the K M decreased by 24 and 7%. The R-enantiomer of R-29148 could induce glutathione expression glutathione S-transferase activity and affinity for the substrate 1-chloro-2 and 4-dinitrobenzene in maize, which meant the compound could protect maize against injury from chloroacetanilide herbicides. Catalase and peroxidase activities were higher when the plants responsed in the presence of a stressor agent like herbicides. We also observed that two antioxidant enzyme activities in maize were significantly changed due to the presence of the safener.