Postharvest white light combined with different UV-B doses differently promotes anthocyanin accumulation and antioxidant capacity in mango peel

Fruit peel color is an important index of mango fruit quality. Therefore, increasing the anthocyanin accumulation and improving coloration in red mango are crucial for mango industry. The anthocyanin accumulation in mango is light-regulated. However, the effect of white light combined with different doses of UV-B on anthocyanin biosynthesis has not been clarified. Also lacking is a comprehensive analysis of responses of mango fruit peel to UV-B/white light treatments. In this study, green mature 'Guifei' mango fruits were subjected to white light combined with low (WL+UV-BL) or high dose UV-B (WL+UV-BH). Anthocyanin concentration, anthocyanin-related gene expression, reactive oxygen species (ROS), antioxidant, and plant hormone concentrations, and antioxidant enzyme activity were measured. The results showed that especially a WL+UV-BH regimen promoted anthocyanin formation in mango peel. Anthocyanin- and light signal-related gene expression, ROS content, antioxidant enzyme activity, antioxidant concentrations, and total antioxidant capacity were also increased by UV-B/white light. Such treatments led to higher concentrations of jasmonic acid and cytokines, but decreased content of 1-aminocyclopropane-1-carboxylic acid and salicylic acids. Commercially, our findings may contribute to improving the commercial quality of mango. Scientifically, the present data sheds light on the mango fruit peel-specific molecular and physiological response network under UV-B/white light treatments.