Antifungal impact of ozone micro-nano bubbles against anthracnose causative pathogen Colletotrichum gloeosporioides sensu lato: Unravelling the enzymatic and proteomic responses

Anthracnose, caused by fungus Colletotrichum gloeosporioides , leads to significant economic and postharvest losses in fresh fruit. Chlorine-based wash is often preferred as cheaper alternatives to fungicides during the packhouse handling processing. Strict chlorine residual limits or restrictions due to public safety, heightens the need for greener alternatives such as micro-nano bubble (MNB) water technology. Thus, this study investigated the comparative response of C. gloeosporioides sensu lato to ozone (O 3 )-MNB water and sodium hypochlorite (NaOCl) treatment based on enzymatic bioassays, and overall regulation of proteins. For both treatments in comparison to the untreated control, viability assays and morphological changes revealed spore mortality and obvious disruption to the cell morphology with loss in intracellular organelles such as mitochondria. Biochemical assays revealed that hydrogen peroxide and malondialdehyde concentrations were higher compared to the control. These treatments inhibited the antioxidant enzyme systems of superoxide dismutase and ascorbate peroxidase, leading to membrane lipid peroxidation. Proteomic analysis revealed that differentially expressed proteins were primarily involved in cellular processes, cellular metabolic processes, and oxidative stress resistance for both NaOCl and O 3 -MNB. Moreover, O 3 -MNB suppressed peptide hydrolase and alcohol oxidase 1, key proteins involved in cellular metabolic energy production, and upregulated caffeine-induced death protein 2. Overall, O 3 -MNB water treatment demonstrated antifungal efficacy against C. gloeosporioides sensu lato as a promising disinfectant. Proteomics data are available via ProteomeXchange with project accession: PXD071932.