Pteris vittata, well-known for its arsenic-accumulating capability, represents a promising candidate for efficient arsenic phytoextraction. Recent studies have highlighted rhizospheric arsenite-oxidizing bacteria (As(III)OB) as key to enhancing phytoextraction. These bacteria oxidize arsenite (As(III)) into arsenate (As(V)), a form more readily absorbed by P. vittata. However, the molecular mechanisms by which P. vittata assembles its rhizosphere bacterial communities remain unclear. In this study, we performed pot experiments using arsenic-contaminated soil collected near an abandoned mine in northeastern Japan. Amplicon sequencing revealed the orders Burkholderiales and Hyphomicrobiales as core As(III)OB. Additionally, untargeted LC-HRMS analysis revealed distinct metabolite profiles between rhizospheric and bulk soils. Further correlation analyses between metabolite features and bacterial community composition identified specific metabolites strongly correlated (r > 0.8) with the abundance of Burkholderiales. The predicted chemical structures of these metabolites closely resembled pterosins, secondary metabolites unique to ferns. Multi-omics correlation analyses suggest that P. vittata secretes pterosin-like metabolites specifically to recruit As(III)OB into its rhizosphere, thereby enhancing arsenic bioavailability. Collectively, our findings provide important multi-omics insights into the pivotal plant-microbe interactions driving effective metal phytoextraction.
