Hydrogen Sulfide Prolongs Postharvest Storage of Fresh-Cut Pears (Pyrus pyrifolia) by Alleviation of Oxidative Damage and Inhibition of Fungal Growth

Hydrogen sulfide (H(2)S) has proved to be a multifunctional signaling molecule in plants and animals. Here, we investigated the role of H(2)S in the decay of fresh-cut pears (Pyrus pyrifolia). H(2)S gas released by sodium hydrosulfide (NaHS) prolonged the shelf life of fresh-cut pear slices in a dose-dependent manner. Moreover, H(2)S maintained higher levels of reducing sugar and soluble protein in pear slices. H(2)S significantly reduced the accumulation of hydrogen peroxide (H(2)O(2)), superoxide radicals (•O(2) (−)) and malondialdehyde (MDA). Further investigation showed that H(2)S fumigation up-regulated the activities of antioxidant enzymes ascorbate peroxidase (APX), catalase (CAT), and guaiacol peroxidase (POD), while it down-regulated those of lipoxygenase (LOX), phenylalanine ammonia lyase (PAL) and polyphenol oxidase (PPO). Furthermore, H(2)S fumigation effectively inhibited the growth of two fungal pathogens of pear, Aspergillus niger and Penicillium expansum, suggesting that H(2)S can be developed as an effective fungicide for postharvest storage. The present study implies that H(2)S is involved in prolonging postharvest storage of pears by acting as an antioxidant and fungicide.