Changes in quality attributes, ascorbate-glutathione (AsA-GSH) cycle, and melatonin (MLT) synthesis were evaluated in cherry tomato fruit treated with MLT solution at 0.1 mM during storage at room temperature for 16 days. According to the results, the MLT treatment was beneficial to maintaining fruit quality as indicated by the declines in weight loss, fruit decay, and titratable acid (TA), accompanied by the maintenance of fruit firmness, total soluble solids (TSS) as well as TSS/TA ratio. Also, the MLT treatment not only effectively inhibited oxidative damage via reducing relative electrolyte leakage and malondialdehyde content, but also improved antioxidant capacity via stimulating AsA-GSH cycle. Moreover, the MLT treatment promoted endogenous MLT synthesis by upregulating the expressions of biosynthetic genes consisting of SlTDC, SlT5H, SlSNAT, and SlASMLT. Thus, our results suggested that the MLT treatment might be involved in maintaining quality in cherry tomato fruit during room temperature by promoting antioxidant capacity and enhancing endogenous MLT. PRACTICAL APPLICATIONS: As a typical climacteric fruit, cherry tomato fruit ripen rapidly and are easily infected by various pathogenic fungi during storage under ambient conditions, which leads to short storage life and a decrease in economic value. The results showed that the application of MLT maintained cherry tomato quality via improving antioxidant capacities and enhancing endogenous MLT. Therefore, MLT treatment could become a promising postharvest strategy for quality maintenance in cherry tomatoes during room storage.
Keywords: antioxidant activity; cherry tomato fruit; melatonin; quality; storage.
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