Disruption of MAPK Signalling and Amino Acid Biosynthesis Underlies the Antifungal Biocontrol Mechanism of Coniochaeta velutina Against Colletotrichum gloeosporioides: A Transcriptome and Metabolome Analysis.

Abstract

This study isolated an endophytic fungus, Coniochaeta velutina, from healthy Camellia oleifera leaves and investigated its inhibitory mechanism on Colletotrichum gloeosporioides using transcriptomics and metabolomics analyses. These helped evaluate the gene expression and metabolite content differences between the treatment and control groups. The transcriptomic analysis detected a total of 15,310 expressed genes, with 3,938 showing significant differential expression (p < 0.05). These genes were primarily enriched in the following pathways: mitogen activated protein kinases (MAPK) signaling, antibiotic biosynthesis, amino acid metabolism, carbon metabolism, and peroxidase pathways. Metabolomics analysis identified 452 metabolites in both groups, with 138 showing significant differences. They were mainly enriched in secondary metabolite biosynthesis, amino acid biosynthesis, and α-linolenic acid metabolism. Transcriptome and metabolome association analysis along with qPCR results significantly increased intracellular pectolinarigenin metabolites in the treatment group, leading to disrupted MAPK signaling and reduced amino acid biosynthesis essential for maintaining normal cell growth. Notably, the decrease in terpenoid compounds was the primary reason for Colletotrichum gloeosporioides being inhibited by the biocontrol fungus Coniochaeta velutina. Therefore, these findings provide valuable insights into the biocontrol mechanisms of Coniochaeta velutina against Colletotrichum gloeosporioides and offer a promising foundation for developing new anthracnose prevention and control strategies.