Multi-omics analysis reveals the regulatory mechanism of ozone treatment on postharvest russeting and senescence in cowpea

Cowpea undergoes rapid postharvest senescence characterized by rust spots, wilting, and nutritional loss, which significantly diminishes its commercial value. This study investigated the mechanisms by which ozone (O 3 ) treatment mitigates these effects using integrated microbial diversity, transcriptomic, and metabolomic analyses. Results showed that O 3 treatment significantly maintained cowpea firmness and soluble solids while retarding color changes. Microbial analysis revealed that O 3 maintained microbial homeostasis by suppressing pathogenic genera, including Gibellulopsis , Fusarium , Alternaria , Pantoea , and Pseudomonas . Transcriptomic profiling indicated that O 3 upregulated flavonoid biosynthesis genes ( CYP73A and CHS ), promoting the accumulation of antioxidants such as catechin and kaempferol-3-O-galactoside. Furthermore, O 3 activated the MAPK signaling cascade and induced pathogen defense genes ( RBOH and PR1 ), enhancing reactive oxygen species (ROS) homeostasis. O 3 also preserved cell membrane integrity by downregulating lipid peroxidation genes ( LOX2S and LOX1_5 ) and strengthened the surface barrier by upregulating cutin and wax synthesis genes ( CER1 ). Metabolomic analysis confirmed the enrichment of bioactive alkaloids, flavonoids (e.g., catechin and kaempferol-3-O-galactoside), and terpenoids, which are linked to heightened stress resistance. Collectively, O 3 delays cowpea senescence and rust spot formation by modulating microbial communities, activating defense signaling, and enhancing antioxidant capacity, providing a robust theoretical basis for ozone-based postharvest preservation.