Protective efficacy of phenoxyacetyl oxazolidine derivatives as safeners against nicosulfuron toxicity in maize

BACKGROUND Herbicide safeners mitigate crop damage without reducing herbicide efficacy. Here, the protective effects of phenoxyacetyl oxazolidine derivatives as potential safeners were evaluated with a view toward reducing injury caused by sulfonylurea herbicide nicosulfuron to sensitive maize varieties. RESULTS Growth indices demonstrated that the bioactivity of compound 9 ( N -phenoxyacety-2-methyl-2,4-diethyl-1,3-oxazolidine) was superior to that of R-28725 and all other compounds tested. Compound 9 induced endogenous glutathione and upregulated glutathione- S -transferase (GST) in maize. Thus, it could enhance maize tolerance to nicosulfuron. Compared with the untreated water control group, the maximum reaction rate of GST was increased by 37.62%, while the maximum velocity of GST was decreased by 61.93% after treatment with compound 9 . Acetolactate synthase relative activity was significantly enhanced in the case of treatment with compound 9 , indicating the excellent protective effects of compound 9 against nicosulfuron in maize. CONCLUSIONS The present work demonstrates that phenoxyacetyl oxazolidine derivatives are potentially efficacious as herbicide safeners and merit further investigation.