Melatonin treatment maintains the quality of cherry tomato by regulating endogenous melatonin and ascorbate‐glutathione cycle during room temperature

Abstract

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.

Role of Melatonin in Directing Plant Physiology

“…The increased non-enzymatic antioxidants like AsA and GSH production are thought to be crucial for maintaining the ROS balance in plants under stress. The positive role of MT on antioxidant enzyme activity was also reported by Ye et al [97] and Yan et al [98] in barley and tomato.…”

Metabolic Profiling and Molecular Mechanisms Underlying Melatonin-Induced Secondary Metabolism of Postharvest Goji Berry (Lycium barbarum L.)

“…The current study showed that exogenous MLT treatment reduced disease incidence and lesion expansion in goji fruit during postharvest storage. As a potential antifungal agent, exogenous MLT has been shown to play positive roles in combating pathogens and restricting the postharvest decay in grapes [33], blueberry fruit [25], papaya [34], cherry tomato [35], and apple fruit [36]. Exogenous MLT application to postharvest fruit enhances the content of endogenous MLT, which, in turn, regulates many physiological changes in the fruit, including quality changes, senescence deterioration, and stress tolerance [20].…”

“…To analyze the metabolites, the MS was operated in a multi-reaction detection mode (MRM) under both positive and negative ion modes, and its parameters, including the declustering potential (DP) and collision energy (CE), were optimized. During the MS analysis, the following optimized conditions were applied: collision gas (35), ion spray voltage (+) 5500 V/(−) 4500 V, ion spray temperature (600 • C), and ion source gas (gas1: 45, gas2: 50). To ensure the repeatability of the results, quality control samples were injected every 10 samples throughout the analytical run.…”

Melatonin-mediated development and abiotic stress tolerance in plants

“…Several studies have proposed that, under various abiotic stresses, the melatonin-mediated ascorbate–glutathione (AsA–GSH) cycle serves a crucial role in scavenging reactive oxygen species in cells ( Xie et al., 2022 ; Zhang et al., 2022 ). Specifically, melatonin enhances the AsA/DHA and GSH/GSSG ratios and antioxidant capacity by stimulating the AsA–GSH cycle, thereby improving the scavenging capacity of ­O 2 · − and ­H 2 O 2 , reducing oxidative stress and providing an approach to reduce organic residues through plant detoxification mechanisms ( Dong et al., 2018 ; Hodžić et al., 2021 ; Yan et al., 2022 ). In addition, melatonin could make a direct connection with various oxidizing agents, particularly with hydroxyl radicals, to reduce the damage to cell structures (one molecule of melatonin neutralizes a maximum of 10 molecules of ROS/RNS) ( Simlat et al., 2018 ; Kyoungwhan, 2021 ).…”