Nano-selenium mitigates antibiotic resistance in paddy ecosystems via microbiome remodeling and environmental filtering shifts.

The dissemination of antibiotic resistance genes (ARGs) in paddy ecosystems poses a serious threat to environmental health. A pot experiment was conducted to assess the efficacy of alkyl glycoside-stabilized selenium nanoparticles (AG-SeNPs) in mitigating ARG abundance within the soil, phyllosphere, and rice grains. Functional prediction, null model analysis, variance partitioning, and structural equation modeling were employed to identify ARG hosts, key metabolic pathways, and environmental drivers of ARG dynamics. Results showed that foliar application of AG-SeNPs (30 g ha IMPORTANCE: The dissemination of antibiotic resistance genes within agricultural soil-plant systems poses a severe threat to food safety and public health. This study demonstrates that foliar application of nano-selenium fertilizer effectively reduces ARG abundance in the soil, phyllosphere, and rice grains. We found that nano-selenium functions not by direct bactericidal action but by beneficially reshaping the microbial communities in both the leaves and soil, thereby suppressing the pathways for ARG transmission. Our findings provide a novel and sustainable strategy to mitigate antibiotic resistance in agricultural ecosystems, potentially reducing the risk of these genes entering the human food chain via rice.