Graphene oxide inhibits the transfer of ARGs in rice by reducing the root endophytic bacterial complexity.

ABSTRACT

Antibiotic resistance genes (ARGs) as an emerging contaminant have attracted much attention for their transfer in agricultural ecosystems. Meanwhile, graphene oxide (GO), due to its high adsorption capacity and antibacterial properties, poses potential environmental ecological risks to the occurrence of ARGs, bacteria, and plant physiological ecology. However, the impact and mechanism of GO on the transfer of ARGs in host plants remain unclear. Therefore, this study selected rice as the research object and inoculated Bacillus subtilis carrying ARGs to investigate the influence of GO on the migration of ARGs into rice and its microbiological mechanism. The study found that GO had a certain inhibitory effect on the transfer of ARGs in rice. Although GO reduced the rhizosphere pH in rice, leading to a transition in endophytic bacteria from dominance by Burkholderia to dominance by Gordonia, this process did not directly affect the transfer of ARGs in rice. Further analysis of bacterial interactions revealed that GO could inhibit the transfer of ARGs in rice by reducing the network complexity of endophytic bacteria. Additionally, GO inhibited the formation of endophytic bacterial biofilms and mobile elements, which might affect ARGs' migration in rice. This study elucidated the key microbiological ecological processes of GO on the transfer of ARGs in rice, providing fundamental information for the ecological risk assessment of GO.