一种分离自疣粒野生稻的弹球菌属内生真菌新种及其促生长潜力OA

An endophytic fungal strain,designated O164,was isolated from the roots of Oryza meyeriana within the Xishuangbanna Nature Reserve.Based on molecular phylogenetic and morphological analyses,the strain was identified as a novel species of the phylum Basidiomycota,Sphaerobolus oryzae sp.nov.Axenic co-cultivation experiments with cultivated rice(Oryza sativa)demonstrated that,compared with non-inoculated controls,strain O164 significantly enhanced rice seedling growth.Specifically,it increased chlorophyll content,root length,plant height,and root fresh mass by 27.8%,31.7%,55.3%,and 31.2%,respectively.Furthermore,strain O164 exhibited sensitivity to salt stress but strong tolerance to osmotic stress.Scanning electron microscopy observations revealed the colonization pattern of strain O164 on rice roots,with extensive hyphal penetration into epidermal cells and subsequent progression toward the vascular cylinder.Metabolomic analysis was employed to investigate the impact of O164 colonization on differentially accumulated metabolites in rice and elucidate its growth-promoting mechanisms.The results indicated that strain O164 reprogramed rice metabolic pathways,primarily through the modulation of lipid metabolism and nitrogen reallocation.This was accompanied by significant upregulation of key growth-promoting metabolites and stress-resistance factors,including kaurenoic acid,L-histidine trimethylbetaine,and pinoresinol-4-O-β-D-glucopyranoside.In conclusion,these findings contribute to a deeper understanding of plant-endophyte interactions and provide a new reference for advancing the application of plant endophytic fungi in agricultural production.