Hydrogen sulfide delays postharvest ripening of white fleshed strawberry by regulating phytohormone accumulation and ROS generation

The white fleshed strawberry cultivar 'Snow Princess' of Fragaria ananassa, known for its unique flavor and visual appeal, is highly regarded worldwide. However, the inherent presence of endogenous phytohormones and reactive oxygen species accelerate the postharvest ripening process, leading to a shorter shelf life. Despite extensive research on the ability of hydrogen sulfide (H2S) to delay fruit ripening and senescence, its potential application to white fleshed strawberries remains unexplored. In this study, the effects of sodium hydrosulfide (NaHS) and hypotaurine on regulating postharvest ripening in white-fleshed strawberries (cv. 'Snow Princess') were evaluated. The findings revealed that NaHS treatment delayed weight loss, preserved sensory characteristics, and decreased the decay index, with an optimal NaHS concentration of 1.5 mM. Further research indicated that H2S synthesis gene expression was enhanced, and H2S synthesis enzyme activity was increased in the NaHS treatment group, leading to endogenous H2S accumulation. Furthermore, NaHS treatment repressed ethylene production and reduced respiratory rate. Concurrently, NaHS treatment increased alternative oxidase activity and decreased abscisic acid level, resulting in inhibited hydrogen peroxide and malondialdehyde generation. Ultimately, NaHS treatment delayed postharvest ripening of 'Snow Princess' strawberries, resulting in increased levels of total soluble solids, titratable acid, and total flavonoid. These findings underscore the potential of NaHS for prolonging the shelf life of white fleshed strawberries and offer insight into the role of H2S in postharvest strawberries.