p-coumaric acid prevents Colletotrichum gloeosporioides by inhibiting membrane targeting and organic acid metabolism

The objective of this study was to investigate the antifungal activity of p-coumaric acid (p-CA) against Colleto-trichum gloeosporioides (C. gloeosporioides), and elucidate the underlying antifungal mechanism from aspects of organic acid secretion and membrane targeting level. p-CA treatment inhibited increase of lesion diameter on fruit and mycelial growth, spore germination and germ tube elongation caused by C. gloeosporioides, the effect was positively correlated with the concentration. Importantly, C. gloeosporioides secretes organic acids during its growth, including malic acid, citric acid and lactic acid. However, the addition of p-CA inhibited the increase of total acid content and the decrease of pH value, as well as the secretion of organic acids. In summary, p-CA can inhibit the growth of C. gloeosporioides in fruit, and plays an inhibitory role by inducing cell membrane damage and inhibiting organic acid secretion.