Enhancing ecological restoration efficiency in antimony mining areas using arbuscular mycorrhizal fungi: Perspectives from plant physiology and transcriptomic analysis

Abstract

The high concentration of antimony (Sb) pollution poses severe challenges to ecological restoration in Sb mining areas in southwestern China. Arbuscular mycorrhizal fungi (AMF) have demonstrated considerable application potential this context; however, related research remains insufficient. This study systematically evaluated the enhancement effects and mechanisms of different AMF inoculations on ecological restoration efficiency using two pioneer plant species, Trifolium repens (Tr) and Artemisia argyi (Aa) in southwestern Sb mining areas, through plant physiology and transcriptomics analysis. The results showed that Rhizophagus intraradices (Ri) and mixed inoculation consistently exhibited superior growth-promoting effects, increasing the dry weight biomass by 1.89–6.13-fold and 1.90–7.44-fold, respectively. This was associated with increased phosphorus absorption and reduced Sb concentration in plant tissues, which mitigated environmental stress and enhanced both heavy metal tolerance and plant growth. Funneliformis mosseae (Fm) showed significant growth promotion only in soils with high pH and calcium content. Additionally, AMF inoculation increased the total Sb uptake by the plants in each pot while also activating soil nutrients, thereby improving the plant growth environment, which is a critical ecological restoration objective. Transcriptome analysis revealed that the effects of AMF on host plants varied depending on plant functionality and soil properties. In Tr, AMF regulated genes associated with signal transduction, oxidative stress response, and metal ion transport, while AMF in Aa primarily induced significant co-enrichment in photosynthetic pathways. This study substantiates the growth-promoting effects of AMF on pioneer plants and their improvement of rhizosphere soil physicochemical properties, providing a feasible strategy for ecological restoration of Sb mining areas.