Structural Effect of Pesticides on Rhizosphere Microbiome

Pesticide residues in the field pose significant risks to nontarget organisms, and their structures determine their environmental behaviour. However, the effects of different pesticide structures on rhizosphere microbial function remain unclear. Herein, the effects of nine pesticides with sulfonylurea, carbamate and pyrethroid motifs on the wheat rhizosphere microbiome were investigated, revealing the potential mechanisms of ecological risk accumulation. The inhibitory effects of the sulfonylurea motif on microbial diversity were 6 and 19 times those of the other two pesticides, and the carbamate motif disrupted rhizosphere community stability. In addition, the sulfonylurea and carbamate motifs induced 0.3-fold increases in antibiotic resistance genes compared to the control. The adverse effects of the pyrethroid motif were milder than those of the other two motifs in all assessments. With distinct structural effects, we identified key taxa that responded to these motifs, not only having the degrading potential function to specific pesticides but also contributing to the ecological risk accumulation in the rhizosphere. Our findings provide new evidence that structural motif-specific induction of antibiotic resistance genes contributes to increased ecological risks from pesticide exposure.