Hydrogen Sulfide Maintained the Good Appearance and Nutrition in Post-harvest Tomato Fruits by Antagonizing the Effect of Ethylene

Abstract

Hydrogen sulfide (H₂S) could act as a versatile signaling molecule in delaying fruit ripening and senescence. Ethylene (C₂H₄) also plays a key role in climacteric fruit ripening, but little attention has been given to its interaction with H₂S in modulating fruit ripening and senescence. To study the role of H₂S treatment on the fruit quality and nutrient metabolism, tomato fruits at white mature stage were treated with ethylene and ethylene plus H₂S. By comparing to C₂H₄ treatment, we found that additional H₂S significantly delayed the color change of tomato fruit, and maintained higher chlorophyll and lower flavonoids during storage. Moreover, H₂S could inhibit the activity of protease, maintained higher levels of nutritional-related metabolites, such as anthocyanin, starch, soluble protein, ascorbic acid by comparing to C₂H₄ treatment. Gene expression analysis showed that additional H₂S attenuated the expression of beta-amylase encoding gene <i>BAM3</i>, UDP-glycosyltransferase encoding genes, ethylene-responsive transcription factor <i>ERF003</i> and <i>DOF22</i>. Furthermore, principal component analysis suggested that starch, titratable acids, and ascorbic acid were important factors for affecting the tomato storage quality, and the correlation analysis further showed that H₂S affected pigments metabolism and the transformation of macromolecular to small molecular metabolites. These results showed that additional H₂S could maintain the better appearance and nutritional quality than C₂H₄ treatment alone, and prolong the storage period of post-harvest tomato fruits.