Rhizosphere microbiome-mediated aluminum detoxification in acidic soils: From microbial mechanisms to...

Aluminum (Al) toxicity in acidic soils severely constrains global crop production. Classical mechanisms of plant Al tolerance, established primarily in sterile laboratory systems, have centered on organic acid secretion. However, such mechanisms do not capture the critical contributions of rhizosphere microorganisms under field conditions. This review synthesizes current advances in microbe-mediated Al detoxification, aiming to reinterpret classical tolerance mechanisms from a microbial perspective and explore strategies for translating these insights into sustainable field applications. Microorganisms alleviate Al stress through direct mechanisms including proton buffering, adsorption, precipitation, and metabolic cross-feeding, as well as indirect mechanisms such as improving phosphorus nutrition, remodeling root cell wall architecture via brassinosteroid signaling, and activating systemic plant defenses. Fungi further contribute through hyphal filtration and cross-kingdom cooperation. Revisiting classical tolerance mechanisms in a microbial context reveals that organic acid exudation, cell wall binding, and stress signaling function as integrated plant-microbe processes. Recent methodological advances in multi-omics, synthetic microbial community (SynCom) construction, and in situ visualization now enable mechanistic validation. Nevertheless, field application remains constrained by poor inoculant colonization, necessitating a shift from single strains to functionally complementary consortia. Future progress will require integrating plant genotype-microbiome interactions into breeding programs and developing closed-loop strategies that couple mechanistic discovery with field deployment. Critically, such strategies must be evaluated not only for short-term yield gains but also for their capacity to restore soil health, enhance ecosystem multifunctionality, and maintain functional resilience under climate-induced environmental stresses, thereby ensuring sustainable agriculture on acidic soils.