Agricultural activities affect the pattern of the resistome within the phyllosphere microbiome in peri-urban environments

The plant microbiome represents a crucial pathway for human exposure to environmental antibiotic resistance. However, little information is available regarding the plant associated resistome in human-related environments at a larger scale. Here, by high-throughput quantitative-PCR chip-based array and amplicon sequencing, we characterized antibiotic resistance genes (ARGs) and bacterial communities in plant and soil microbiomes from human highly disturbed peri-urban farmland and less disturbed forest at a watershed scale. A total of 71 ARGs were detected in the phyllosphere, which covered almost all the major recognized classes of antibiotics that are administered commonly to humans and animals. The overall pattern of the plant associated resistome in intensive anthropogenic influenced farmland was significantly different from that of forest environments (PERMANOVA, P < 0.01), indicating that agricultural activities might be important drivers in shaping the plant resistome. A bipartite network analysis suggested that all ARGs detected in the plant microbiome were also present in the soil microbiome. Together, our findings provide a better understanding of the plant resistome and suggest that land use is a key contributor to the composition of ARG profiles in the plant phyllosphere, and that the soil resistome may represent a critical reservoir of plant associated ARGs.