Integrated application of transcriptomics and metabolomics provides insights into the antifungal activity of α-phenylcinnamic acid against Colletotrichum gloeosporioides

Anthracnose caused by Colletotrichum gloeosporioides leads to significant economic loss of varieties of tropical and subtropical fruit. In the present study, a cinnamic acid derivative alpha-phenylcinnamic acid (alpha-PA) was found effective in control of postharvest anthracnose on mango fruit. alpha-PA strongly inhibited conidia germination, germ tube elongation, and appressorium formation. To elucidate the underlying molecular mechanisms by which alpha-PA shows antifungal activity, a transcriptomics and a widely targeted metabolomics analysis were conducted to study the changes in gene expression and metabolic profile. The result showed that the expression of 1477 genes and content of 198 metabolites were changed by alpha-PA. The following KEGG enrichment and correlation analysis suggested that biosynthesis of amino acids and some secondary metabolites were interfered by alpha-PA, including indoles which are one group of melanin precursors. In addition, qRT-PCR analysis and measurement of melanin revealed that alpha-PA down-regulated the expression of melanin biosynthesis genes and reduced melanin biosynthesis. Taken together, these data suggest that alpha-PA could decrease anthracnose in postharvest fruit by interfere with amino acid and secondary metabolite metabolism of C. gloeosporioides.