Effects of the fungicide trifloxystrobin on the structure and function of soil bacterial community

Trifloxystrobin has been widely applied to prevent fungal diseases because of its high efficiency and desirable safety characteristics. In the present study, the effects of trifloxystrobin on soil microorganisms were integrally investigated. The results showed that trifloxystrobin inhibited urease activity, promoted dehydrogenase activity. Downregulated expressions of the nitrifying gene (amoA), denitrifying genes (nirK and nirS), and carbon fixation gene (cbbL) were also observed. Soil bacterial community structure analysis showed that trifloxystrobin changed the abundance of bacteria genera related to nitrogen and carbon cycle in soil. Through the comprehensive analysis of soil enzymes, functional gene abundance, and soil bacterial community structure, we concluded that trifloxystrobin inhibited both nitrification and denitrification of soil microorganisms, and also diminished the carbon-sequestration ability. Integrated biomarker response analysis showed that dehydrogenase and nifH were the most sensitive indicators of trifloxystrobin exposure. It provides new insights about trifloxystrobin envi-ronmental pollution and its influence on soil ecosystem.