Trans-2-hexenal maintains the quality of postharvest fresh common beans (Phaseolus vulgaris L.) by regulating reactive oxygen species metabolism, cell wall metabolism, and lignin biosynthesis

Although the impact of postharvest trans-2-hexenal (E2H) application in maintaining the quality of horticultural products has been widely studied, its effect on fresh common beans and the preservation mechanism remain unexplored. In this study, the impacts of E2H on reactive oxygen species (ROS) and cell wall metabolisms, and lignin biosynthesis in common beans were investigated. Fresh common beans fumigated with E2H (0, 0.5, 1.0, 1.5, and 2.0 μL L −1 ) were stored at 20 ± 1 °C for 12 days. Results showed that 1.0 μL L −1 E2H remarkedly repressed the decline of chlorophyll content to delay the yellowing, maintained ROS homeostasis, modulated cell wall metabolism-related enzyme activities to regulate cell wall components, and inhibited lignin biosynthesis-related enzyme activities to reduce lignin accumulation, thereby alleviating softening and lignification in common beans. These findings indicated that E2H could improve antioxidant activity, delay softening, and attenuate lignification to mitigate the quality deterioration in common beans.