Hydrogen sulfide retards fruit softening and prevents flesh browning in cold-stored peaches by regulating cell wall-modifying enzymes, phenolic, and proline metabolism

Abstract

Utilizing transcriptome analysis, higher expression of genes encoding hydrogen sulfide (H2S) synthetase in fruit stored at 0 ℃, where the expression pattern of differentially expressed genes (DEGs) correlated with softening and phenolic synthesis demonstrated more alterations than fruit storage at 5 ℃ and 15 ℃. Further research into how exogenous H2S affected the unappealing swift softening and internal browning (IB) of fruit was investigated. H2S orchestrated the cell wall-modifying enzymes, inhibiting polygalacturonase, cellulase, β-glucosidase, and pectin methyl esterase, and incompletely suppressing α/β-galactosidase and α-mannosidase during later storage. In H2S-treated fruit, total phenolic content was higher and IB symptoms were alleviated. In addition to enhancing phenylpropanoid metabolism, correlation analysis supported the hypothesis that H2S promoted phenolics in fruit by possibly facilitating proline accumulation. Cys192 and Cys217 of PpMYB75, which are involved in the biosynthesis of anthocyanin, were potential targets for persulfidation, and application of H2S reduced anthocyanin content in peach fruit. Together, our results demonstrate that H2S could ameliorate the chilling injury of cold-stored peach fruit and provide a perspective for controlling phenolic synthesis.