The effect of ultraviolet-C on the senescence of bitter gourd fruit and the key factors analyzed by transcriptomic and metabolomic analyses.

Bitter gourd (Momordica charantia L.) is a tropical and subtropical vegetable that is popular for its rich nutritional content. However, its immature fruit has a short shelf life and spoils easily. This study assessed the effects of ultraviolet-C (UV-C) irradiation on the storage and quality of postharvest bitter gourd fruit. Exposure for 40 s maintained fruit firmness, delayed senescence, increased the antioxidant capacity and minimized damage by reactive oxygen species. Transcriptomic and metabolomic analyses identified 12,733 differentially expressed genes and 282 metabolites during storage. The downregulation of genes for ethylene synthesis and cell wall degradation delayed ripening and senescence, while the upregulation of phenylpropanoid biosynthetic genes enhanced its antioxidant properties. Key transcription factors, such as MYB, bHLH, and bZIP, were implicated in the delayed senescence treatment. This research elucidates the mechanisms of prevention of bitter gourd with UV-C and offers insights into the genetic and metabolite candidates for enhanced strategies of postharvest preservation.