Chiral Pesticides Stereoselectively Stimulate N 2 O Emissions: An Overlooked Environmental Risk in Agricultural Soils

作者：Yaxin Wang, Yaxin Wang, Bidan Zhang, Ganghua Han, Mark Bartlam, Yingying Wang, Yingying Wang · 发表于：Environmental Science & Technology · 年份：2025 · DOI：10.1021/acs.est.5c09622 · 被引用次数：3 · 研究领域：Isotope Analysis in Ecology、Pesticide and Herbicide Environmental Studies、Soil Carbon and Nitrogen Dynamics

Agricultural soil is a major source of N 2 O emissions due to soil denitrification. However, the influence of pesticides, particularly chiral pesticides, on soil denitrification has often been overlooked. In this study, we investigated the effects and regulatory mechanisms of the widely used chiral pesticide cis -epoxiconazole on denitrification and N 2 O emissions. The 2R, 3S-(+)- cis -epoxiconazole ((+)-EPO) enantiomer reduced nitrate removal efficiency by 15.04%–54.49% after 3 days and increased N 2 O emissions by 109.27%–163.68% after 35 days of exposure in a microcosm system, whereas the 2S, 3R-(−)- cis -epoxiconazole ((−)-EPO) enantiomer had minimal impact. At a concentration of 0.5 mg/kg, (+)-EPO inhibited β-glucosidase activity by 34.80% and decreased electron transport system activity by 43.70%, thereby impairing electron generation and transfer during denitrification. Expression of the nosZ gene was suppressed by 53.34%, while nitric oxide reductase and nitrous oxide reductase activities were upregulated by 118.89% and downregulated by 46.70%, respectively. These key regulatory changes directly contribute to the increased N 2 O emissions observed with (+)-EPO treatment. Additionally, although (+)-EPO caused only minor changes in denitrifying microbial taxa, it increased the relative abundance of Nitrososphaerota and Euryarchaeota by 0.08%–0.10% and 0.40%–0.45%, respectively, after 35 days, enhancing nitrification and indirectly stimulating N 2 O emissions. Overall, ...