Effects of Hydrogen Sulfide on Sugar, Organic Acid, Carotenoid, and Polyphenol Level in Tomato Fruit.

Hydrogen sulfide (H 2 S) is known to have a positive effect on the postharvest storage of vegetables and fruits, but limited results are available on its influence in fruit flavor quality. Here, we presented the effect of H 2 S on the flavor quality of tomato fruit during postharvest. H 2 S decreased the content of fructose, glucose, carotene and lycopene but increased that of soluble protein, organic acid, malic acid and citric acid. These differences were directly associated with the expression of their metabolism-related genes. Moreover, H 2 S treatment raised the contents of total phenolics, total flavonoids and most phenolic compounds, and up-regulated the expression level of their metabolism-related genes (PAL5, 4CL, CHS1, CHS2, F3H and FLS) . However, the effects of the H 2 S scavenger hypotaurine on the above flavor quality parameters were opposite to that of H 2 S, thus confirming the role of H 2 S in tomato flavor quality. Thus, these results provide insight into the significant roles of H 2 S in tomato fruit quality regulation and implicate the potential application of H 2 S in reducing the flavor loss of tomato fruit during postharvest.