ITS Fertilization effects on A. adsurgens microbiome and metabolome: Implications for plant growth and nutritional quality enhancement

Astragalus adsurgens (A. adsurgens) enhances sustainable livestock and ecological development, yet fertilization's impact on its growth quality remains understudied. This study investigated how Trichoderma guizhouense NJAU 4742 (B), sheep manure (M), and NPK fertilizer (NPK) affected A. adsurgens' rhizosphere microbiome and root metabolome. Three treatments significantly increased plant height, with the B group notably enhancing ether extract (EE). Differential rhizosphere bacteria and fungi (Brucella, Enterobacter, Stenotrophomonas and Mucoromycota) and growth-promoting metabolic pathways were identified via KEGG enrichment pathway analysis. Specifically, the B group exhibited the pathways linked to the increased EE content. Key metabolites in KEGG enriched pathways were significantly positively correlated with differential microbes. In the B group, Brucella and D-glucose-6-phosphate involved in starch and sucrose metabolism, significantly promoted plant growth and EE content. In the M group, Mucoromycota and garbanzol associated with flavonoid biosynthesis, enhanced A. adsurgens growth. In the NPK group, methyl jasmonate and Brucella showed a positive relationship, collectively supporting plant growth. Mantel test analysis linked rhizosphere microorganisms to plant height and root metabolites to EE content of A. adsurgens/ soil organic carbon (OC) content. These findings demonstrated how fertilization strategies enhance plant growth and quality by modulating rhizosphere microbiome and root metabolome.