Rhizosphere microbiome drives Betula luminifera adaptation to antimony mining sites through functional traits and...

Rhizosphere microbiome are pivotal for plant adaptation to extreme environments. However, the regulatory mechanisms underlying their control of the ecological adaptation of native woody plants in mining areas remain unclear. Here, we integrated metagenomic and transcriptomic analyses to elucidate how the rhizosphere microbiome facilitates Betula luminifera adaptation to antimony (Sb) mining sites. Under sterile conditions, B. luminifera from mining sites prioritized shoot growth, whereas control-origin seedlings favored root development. Microbial inoculation mitigated this growth dichotomy, balancing above- and belowground biomass allocation. Notably, B. luminifera from control sites upregulated antioxidant biosynthesis genes (α- and β-tocopherol pathways), while B. luminifera from mining sites enhanced lignin synthesis under Sb stress. After inoculation with rhizosphere microbiome from the mining-site, genes related to Sb/As resistance (ACR3, arsB/C) and soil nutrient cycle (narG, phnM) were significantly enriched in the rhizosphere of B. luminifera, which were contributed by Proteobacteria and Actinobacteria. Transcriptional profiling revealed that microbial inoculation triggered systemic upregulation of phytohormone-related genes (auxin, cytokinin, abscisic acid), enhancing stress resilience and growth. These findings unveil a synergistic plant-microbe adaptation mechanism in Sb polluted soils in mining sites, highlighting microbial-mediated trait trade-offs and transcriptional plasticity as drivers of ecological success in extreme environments.