Metabolomic Analysis of Antifungal Secondary Metabolites from Achaetomium sophora HY17 in Co-Culture with Botrytis cinerea HM1

Secondary metabolites produced by endophytic fungi living in medicinal plants are important resources in the field of biological control. In this study, <i>Achaetomium sophora</i> HY17, an endophytic fungus of <i>Sophora alopecuroides</i>, was taken as the research object and <i>Botrytis cinerea</i> HM1 as the target pathogen, and the response characteristics and antifungal mechanism of secondary metabolites produced during their interaction were explored through a co-culture system combined with metabonomic analysis. The key findings are as follows: (1) <i>A. sophora</i> HY17 produces many kinds of secondary metabolites, such as alkaloids, flavonoids, and phenolic acids, among which 10 different metabolites, such as Sophoridine, Matrine, and Luteolin, are significantly up-regulated during the interaction process and are the core antifungal active substances; (2) KEGG pathway enrichment analysis revealed that the phenylalanine metabolic pathway was significantly enriched during the interaction between the two fungi, and the activation of this pathway was the key regulatory mechanism underlying <i>A. sophora</i> HY17's ability to cope with pathogen stress and synthesize antifungal metabolites. This study reports <i>A. sophora</i> HY17 as a new species, confirms its broad application prospects as a multifunctional and efficient biocontrol strain, and provides a core theoretical basis and target direction for mining antifungal substances from endophytic fungi to develop new biocontrol agents.