Bacterial-fungal interactions shape the distribution of antibiotic resistance genes in soil-vegetable systems under...

The persistent accumulation of antibiotic resistance genes (ARGs) in agricultural soils, largely attributed to the widespread application of organic fertilizers, poses a substantial risk to human health. Investigating the occurrence patterns and key driving factors of ARGs in soil-vegetable systems under different fertilization regimes is essential for addressing this pervasive public health issue. Here, a pot experiment was conducted to characterize the ARG profiles in soil, root, and leaf compartments and to examine the ecological associations between bacterial-fungal interactions and ARG distributions. The results showed that ARGs were notably enriched in vegetable roots, and the extensive overlap of ARG subtypes between soil and vegetable tissues indicates a close linkage between soil and plant-associated resistomes. The application of animal manure-derived fertilizers markedly increased the total ARG abundance and the proportion of high-risk ARGs in roots, concurrently with enhanced bacterial-fungal co-occurrence patterns. Bio-organic fertilizers containing Bacillus and Trichoderma significantly increased ARG abundance in leaves, which was associated with strong correlations between potential ARG-hosting and highly abundant ARGs. Proteobacteria, Gemmatimonadota, and Planctomycetota were identified as putative ARG-hosting bacterial taxa. Bacterial community assembly in soil was more consistent with the neutral community model and exhibited higher network complexity in association with fungal communities than in vegetable tissues. Bacterial-fungal interactions, mobile genetic elements, and soil properties were jointly associated with variations in soil resistomes and plant-associated ARG patterns. This study advances our understanding of the ecological distribution and regulatory drivers of ARGs in soil-vegetable systems and provides valuable insights for evaluating resistome-related risks under organic fertilization practices.