Phytohormone-fungal coordination mediates functional trait adaptation in Pleioblastus amarus under elevational stress

Background and aims Arbuscular mycorrhizal fungi (AMF) play crucial roles in shaping plant functional traits and adaptation strategies. However, the AMF diversity and plant functional trait relationships in bamboo forest remain unexplored. Given their unique clonal growth pattern, bamboo forest offers an intriguing ecosystem to study mycorrhizal-plant interactions across changing elevations. Methods We conducted a field study in bamboo forest dominated by the species Pleioblastus amarus . We measured the soil fungal community, endogenous hormones, non-structural carbon (NSC) content, shoot density, and shoot biomass, as well as soil physicochemical properties in four bamboo forests with different elevation. Results Although the alpha diversity of did not differ among the four bamboo forests, soil fungal diversity significantly correlated with phytohormones in the rhizome, taxonomically displaying varying correlations with plant traits. While shoot density and shoot biomass showed opposing trends or functional trade-off, endogenous hormones and NSC content showed significant changes among the four bamboo forests. Also, soil pH, SM, and total phosphorus significantly differed among the four bamboo forests. Conclusions The taxon-specific fungal correlation with plant traits suggests that specialized fungal symbionts promote plant hormonal adjustments and evolutionary adaptation strategies in a changing environment.