Phosphorus Mining Activities Alter Endophytic Bacterial Communities and Metabolic Functions of Surrounding Vegetables and Crops

[Aims] The goal was to evaluate the effect of phosphorus mining on the endophytic bacterial community of surrounding crops and vegetables and screen beneficial bacteria. [Methods] 16S rRNA sequencing was used to assess endophytic bacterial diversity, community, and metabolic function variations in surrounding plants, including Glycine max, Triticum aestivum, and Lactuca sativa. [Results] The results showed that phosphorus mining caused a decline in the endophytic bacterial diversity of plants, including the Shannon and Simpson indices (P < 0.05). Rhizobium was significantly enriched in lettuce, soybean, and wheat roots in the phosphate mining area compared with corresponding samples from a nonphosphate mining area (P < 0.05). The metabolic function prediction based on Phylogenetic Investigation of Communities by Reconstruction of Unobserved States showed that endophytic bacteria in lettuce, soybean, and wheat roots developed various strategies to cope with phosphorus mining stress. We further isolated 11 endophytic bacteria from the three plant types, of which Enterobacter sp. P35, Pseudomonas aeruginosa P33, and Rhizobium pusense P25 showed strong resistance to multiple heavy metals. Several endophytic bacteria, including Pseudomonas aeruginosa P33, Sphingomonas panni P15, and Bacillus cereus P3, showed multiple growth-promoting properties for plants. [Conclusions] To our knowledge, this is the first study to examine the effects of phosphate mining on endophytic bacteria in human food sources (vegetables and crops), providing a comprehensive understanding of the ecological effects of phosphate mining. The results also highlight the need to pay attention to the easily neglected effect of phosphorus mining on the microecology and provide a basis for screening bacteria for remediation.