A salt-tolerant synthetic microbial inoculation M9 enhanced tomato growth and altered the bacterial communities in the rhizosphere and root

Abstract Background Rhizosphere microorganisms of plants in extreme environments possess special stress tolerance, making them an ideal source for discovering novel plant growth-promoting rhizobacteria (PGPR). However, currently only a few studies have focused on the growth-promoting effects of salt-tolerant microorganisms under non-stress conditions and their impact on native microorganisms. Results Here, we determined the effects of the salt-tolerant synthetic microbial inoculation M9, isolated from the rhizosphere of Salicornia europaea L., on tomato growth and the microbial community in the rhizosphere and root. The salt-tolerant synthetic inoculation M9 demonstrated the ability of nitrogen fixation, inorganic phosphate solubilization, and potassium mobilization in vitro. Pot experiment further demonstrated that inoculation with M9 promoted tomato seedling growth, significantly altered the bacterial community structure and composition in both the rhizosphere and root compartments, and enriched specific microbial taxa. Conclusions Overall, the halophyte-derived synthetic consortium M9 not only improved tomato growth under non-stress conditions but also reshaped the rhizosphere and root microbiota, highlighting its great potential for promoting green agriculture.