Arbuscular mycorrhizal fungi reshape rhizosphere microbial communities to alleviate phosphorus deficiency in soda-saline soils

Microbial activity and P availability are severely limited in soda saline-alkali soils, restricting plant growth. Although arbuscular mycorrhizal (AM) fungi enhance P uptake, how they modulate rhizosphere microbes to improve P availability there remains unclear. Here, we combined a microcosm experiment with metagenomic sequencing and partial least squares path modeling to examine how inoculation with Rhizophagus intraradices affected rhizosphere properties, P fractions, phosphatase activities, microbial community composition, and growth of Elaeagnus angustifolia under soda saline‑alkali stress. AM inoculation markedly promoted plant growth and root development, improved soil physicochemical conditions, and stimulated both alkaline and acid phosphatase activities via a coordinated “stress alleviation—community reassembly—network optimization—accelerated turnover” pathway. Specifically, AM fungi restructured the rhizosphere microbiome by enriching phosphate‑solubilizing taxa, mainly Actinobacteria ( Streptomyces ) and Proteobacteria (Pseudoxanthomonas , Sphingomonas ), thereby intensifying organic P mineralization and shifting the system from static P‑pool maintenance to rapid P flux. These results demonstrate that AM fungi collaborate with functional microbial guilds to create a dynamic P‑turnover system that alleviates P limitation by promoting root proliferation, expanding absorptive surfaces, modifying the rhizosphere microenvironment, and regulating phosphate‑solubilizing bacterial communities. This study provides a theoretical basis for sustainable management of soda saline‑alkali soils.