Effects of <i>Funneliformis mosseae</i> on the growth and rhizosphere bacterial communities of <i>Astragalus adsurgens</i> and <i>Stipa grandis</i> under combined cadmium and salt stress

The phytoremediation efficiency of heavy metal‐contaminated saline soils is limited by low plant biomass and low accumulation of salt or heavy metals. Arbuscular mycorrhizal fungi (AMF) can directly promote plant growth or indirectly affect plant growth by regulating rhizosphere microbial communities; however, few studies have investigated the regulation of AMF on rhizosphere bacteria in heavy metal‐contaminated saline soils. This study investigated the effects of AMF ( Funneliformis mosseae ) on the growth and rhizosphere bacteria in Astragalus adsurgens Pall. and Stipa grandis P. Smirn. in cadmium (Cd)‐contaminated saline soils. The results revealed that F. mosseae improved the growth of the two grasses through distinct strategic mechanisms. In A. adsurgens , F. mosseae decreased shoot sodium ion (Na + ) and Cd concentrations, increased Na + , Cd, and nutrient accumulations, enhanced the stability of the interaction network of the top 15 bacterial species with significant differences, and resulted in higher resistance of bacteria to external disturbances. F. mosseae increased the relative abundances of Paludibaculum , Pedomicrobium , and Aquicella , which positively correlated with biomass, Na + , and Cd accumulations. In S. grandis , F. mosseae promoted Na + , Cd, and nutrient accumulations and regulated interactions among the top 15 bacterial species with significant differences. Total nodes, total links, and average degree of the network increased, indicating a closer and more complex relationship between bacteria. F. mosseae increased the relative abundance of Devosia , Exiguobacterium , Pseudoxanthomonas , and Aliihoeflea , which positively correlated with biomass, Na + , and Cd accumulations. This study presented data to support plant‐mediated remediation of heavy metal‐contaminated saline soils using AMF symbiosis.