Strontium Chloride Maintains Storage Quality of Fresh-Cut Peach by Modulating Antioxidant System, NO, and H2S Metabolism

Strontium (Sr) is an essential trace element that plays a critical role in bone health, calcium absorption, cardiovascular function, and nerve function. In this experiment, fresh-cut peaches were treated with different concentrations of strontium chloride (SrCl2) to study the effects of SrCl2 on the antioxidant system, endogenous nitric oxide (NO) metabolism, and endogenous hydrogen sulfide (H2S) metabolism, aiming to investigate the regulatory mechanism of Sr on postharvest quality of horticultural products. The results showed that, compared with the control, 320 μM SrCl2 significantly suppressed the respiration rate by 15.10% and delayed the respiratory peak by 2 days. Meanwhile, SrCl2 treatment effectively inhibited the rise in electrolyte leakage (EL), color difference, and weight loss, and delayed the decline in fruit firmness. In addition, SrCl2 treatment significantly up-regulated the gene expression levels and enzyme activities of the antioxidant system, the AsA-GSH cycle, NO, and H2S metabolism, which reduced the loss of antioxidants, enhanced the ability of fruits to scavenge hydrogen peroxide (H2O2), hydroxyl radical (˙OH), and superoxide anion (O2−˙), and lowered the malondialdehyde (MDA) content. It suggests that SrCl2 treatment has a positive effect on maintaining the postharvest quality of fresh-cut peaches, which appears to be associated with increased endogenous production of NO and H2S, thereby enhancing antioxidant system activity.