Rubber plantation impacts on antibiotic resistance genes in tropical groundwater

Hainan island, China. Uncovering the distribution and mechanisms of antibiotic resistance genes (ARGs) in groundwater is crucial for safeguarding public health and environmental sustainability. Despite this, the influence of land use on tropical groundwater ARG profiles remains a critical knowledge gap. Our study employs metagenomic sequencing to delve into the composition, diversity, and driving forces behind ARGs in Hainan's tropical rainforests and rubber plantations. Our findings reveal a startling contrast: the total abundance of ARGs in rubber plantations soars above that in tropical rainforests, yet no significant differences emerge in α or β diversity. We pinpoint β-Proteobacteria as the primary carriers of ARGs, with Burkholderiaceae bacterium standing out as the key species-level player. Our analysis further unveils that the bacterial community wields the greatest influence (68.5 %) on ARG abundance, while land use exerts a substantial direct impact (27.3 %) and an indirect influence (24.9 %) by shaping the groundwater environment and microbial ecology. Moreover, mobile genetic elements (MGEs) serve a pivotal indirect role (31.5 %) in ARG abundance, albeit without affecting diversity. These insights lays the groundwork for mitigating the dissemination of resistance genes and their potential harm to human health. Land use impacts on ARG abundance and richness in tropical groundwater A: Study objective; B: ARG and diversity; C: Main drivers of ARG abundance and diversity. ARGs: antibiotic resistance genes; MGEs: Mobile genetic elements. Land use: Rainforest and rubber plantations. Significant level: * p < 0.05; * * p < 0.01; * ** p < 0.001. • The abundance of antibiotic resistance genes (ARGs) in rubber plantations is higher than that in rainforests. • There are no significant differences in ARG α and β diversity between rubber plantations and rainforests. • The main carriers of ARGs in groundwater are members of the β-Proteobacteria. • Mobile genetic elements (MGEs) has great direct effects on ARG abundance. • Land use influences water quality and bacteria, which subsequently affects ARG abundance.