Abstract

Reactive Sulfur Species (RSS) has emerged as a signaling molecules that plays a crucial role in the postharvest preservation of fruits and vegetables. This chapter summarizes the various functions of exogenous application of RSS – i.e. H2S as its main molecule –, such as delaying ripening and senescence, enhancing the resistance to cold and diseases, and emphasizes the underlying mechanisms. The application of appropriate concentrations of exogenous H2S primarily operate through stimulating the antioxidant system, while showing beneficial effects on physiological metabolism relevant to storage quality and shelf life including energy, sugar, phenolic, membrane lipid and cell wall metabolism, among others. In addition, exogenous H2S reduce storage loss by modulating the expression patterns of senescence-related genes, like those linked to ethylene. The H2S and NO regulation counteracts ethylene-derived detrimental effects during ripening and senescence. Higher levels of H2S acts either as a regulator to induce disease resistance, and also as a fungicide to inhibit the growth and pathogenicity of fungi. Furthermore, the use of RSS emerges as a potent tool for the exogenous application of horticultural produces for storage and shelf-life preservation, albeit the approval for use of H2S gas on fresh foods is still pending at the global level.