Antifungal activity and mechanism of plasma-activated water against Colletotrichum gloeosporioides in postharvest pepper anthracnose

Colletotrichum gloeosporioides ( C. gloeosporioides ) is the primary pathogen of pepper anthracnose. Plasma-activated water (PAW), a novel non-thermal method with strong oxidation, shows great potential for microbial inactivation and disease control. This study evaluated PAW’s antifungal effect, mechanisms, and potential in controlling pepper anthracnose by treating C. gloeosporioides spores. Results demonstrated that PAW-7 achieved a 99.9% sterilization rate, completely inhibited mycelial growth, and decreased spore germination to 2.67%. Mechanistic analysis revealed that PAW induced structural damage to the spores, triggered the accumulation of MDA and ROS and leakage intracellular nucleic acids and proteins. Transcriptomic analysis revealed that PAW exerted its antifungal effect by producing excessive RONS, disrupting MAPK signaling, compromising cell wall and membrane integrity, promoting chitin and ergosterol degradation, and inducing oxidative stress that impaired ribosomal function, cellular transcription, translation, and protein synthesis, ultimately leading to fungal cell death. Moreover, treatment with PAW significantly mitigated pepper decay rate and weight loss by effectively suppressing microbial load while controlling the development of anthracnose. Among the treatments, the PAW-7 group effectively preserved the nutritional quality of the peppers during storage. This work highlighted the possibility of using PAW as a successful measure of dealing with pepper anthracnose. • PAW caused 99.9% sterilization of C. gloeosporioides by ROS overaccumulation. • PAW disrupted the cell membrane, causing protein and nucleic acid leakage. • RNA-seq suppressed MAPK stress signaling, inhibiting chitin/ergosterol synthesis. • PAW lowered pepper decay rate below 10%, reducing microbes and weight loss.