Synergistic roles of ericoid mycorrhizal fungi and mycorrhiza helper bacteria enhance plant stress tolerance and Cd immobilisation

作者：Jing Jiang, Huizhi Zhang, Haifeng Zhu, Yixiao Wang, Qiang Yang, Hongyi Yang, Lili Li · 年份：2025 · DOI：10.22541/au.175351878.82508543/v1 · 被引用次数：1 · 研究领域：Mycorrhizal Fungi and Plant Interactions、Plant Parasitism and Resistance

Cadmium (Cd) contamination threatens ecosystem safety. Microbial remediation offers an eco-friendly approach to reduce plant Cd accumulation, but synergistic effects between microorganisms, particularly mycorrhizal fungi and mycorrhiza helper bacteria (MHB), are often overlooked. This study revealed the synergistic Cd resistance mechanism in blueberry mediated by ericoid mycorrhizal fungus (ErMF) Oidiodendron maius 143 and MHB Enterobacter sp. R9G through integrated pot and in vitro experiments. ErMF and R9G co-inoculation significantly improved blueberry biomass, root morphology and antioxidant enzyme activities (CAT, POD and SOD) and reduced MDA. Co-inoculation concurrently restricted Cd uptake and translocation and decreased soil Cd bioavailability. Multi-spectral analyses (SEM-EDS, FT-IR, XRD and XPS) demonstrated that co-inoculation synergistically enhanced Cd immobilisation through extracellular polymer secretion, phosphate precipitation (Cd (H 2 PO 4 ) 2 ·2H 2 O) and organic–mineral composite layer formation, improving soil stability. High-throughput sequencing and enzyme activity confirmed that ErMF and R9G restructured soil microbial communities and activated Cd-passivating microorganisms. In vitro reciprocal interactions occurred: ErMF hyphal exudates (e.g., sucrose and proline) enhanced R9G growth, motility, chemotaxis and biofilm formation, while R9G promoted ErMF mycelial growth and sporulation. The ErMF-MHB synergy established a ‘plant physiological regulation–m...