Pichia kudriavzevii inhibits the growth of Colletotrichum gloeosporioides through 2-PE targeting cell membrane

Abstract

Anthracnose is a major post-harvest disease affecting fruit and vegetables, causing losses due to fruit rot and decreased marketability, and the annual loss caused by anthracnose is at least within tens of billions of dollars in the world. This study evaluated the antifungal activity of Pichia kudriavzevii against Colletotrichum gloeosporioides. The substances in the fermentation solution were analyzed by gas chromatography-mass spectrometry (GC-MS), and the bacteriostatic experiments in vitro were carried out to determine 2-phenylethanol (2-PE) as the main inhibitory compound. In vitro assays demonstrated that 2-PE exerted inhibitory effects on colony growth, spore germination, germ tube elongation, and hyphal density. With the increase of 2-PE concentration, the inhibitory effect on C. gloeosporioides became stronger. When the concentration of 2-PE reached 1.50 g/L, the colony growth of C. gloeosporioides could be completely inhibited. Membrane-targeting assays revealed that 2-PE disrupted fungal cell membrane integrity. Transcriptomic analysis showed downregulation of genes involved in membrane synthesis (e.g., lanosterol synthase, CGGC5_1542) and genetic material synthesis (e.g., 60S ribonucleoprotein, CGGC5_9394). In vivo experiments confirmed that the lesion diameter of tomato and citrus anthracnose after 1.50 g/L 2-PE treatment was reduced by 69 % and 87 % compared with the control group. These findings highlight the potential of 2-PE as a natural antifungal agent targeting fungal membrane integrity and genetic material synthesis.