BACKGROUND:Melatonin (MT) is an endogenous indoleamine that regulates senescence progression and stress response in plants. OBJECTIVE:Here, we investigated the effect of MT on the shelf-life and postharvest quality of table grapes (Vitis labrusca L. cv. ‘Fengzao’). METHODS:After harvesting, ‘Fengzao’ grapes were immersed in MT solution at various concentrations (0 [as control], 0.05, 0.1, 0.5 and 1.0 mM for 2 h and stored at 24±1 for 15 days. Physiological indicators including weight loss rate, firmness, contents of total soluble solids (TSSs), ascorbic acid (AsA), malondialdehyde (MDA), hydrogen peroxide (H2O2), and activities of catalase (CAT), ascorbate peroxidase (APX), and superoxide dismutase (SOD) were investigated. Additionally, the DNA methylation rate of ‘Fengzao’ grapes were measured using the methylation-sensitive amplification polymorphism (MSAP) technique. RESULTS:Application of MT effectively delayed grape senescence in all treatment groups compared with the control, with the longest delay observed in the 0.5 mM treatment. Additionally, the rate of DNA methylation decreased in all the 0.5 mM MT treatment groups, indicating a potential role of MT in demethylation. CONCLUSIONS:Our results suggest that the exogenous application of MT can delay the senescence of grapes during postharvest.

中文翻译：

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褪黑素处理可改善鲜食葡萄的货架期和收获后质量（Vitis labrusca L. cv。'Fengzao'）

背景：褪黑激素（MT）是内源的吲哚胺，调节植物的衰老进程和胁迫反应。目的：在这里，我们研究了MT对食用葡萄（Vitis labrusca L. cv。'Fengzao'）的货架期和收获后品质的影响。方法：收获后，将“丰枣”葡萄浸入不同浓度的MT溶液中（0（作对照），0.05、0.1、0.5和1.0 mM 2 h，并在24±1下保存15天。）包括减重在内的生理指标。率，硬度，总可溶性固形物（TSSs），抗坏血酸（AsA），丙二醛（MDA），过氧化氢（H2O2）以及过氧化氢酶（CAT），抗坏血酸过氧化物酶（APX）和超氧化物歧化酶（SOD）的活性还进行了调查 采用甲基化敏感性扩增多态性（MSAP）技术测定了“丰枣”葡萄的DNA甲基化率。结果：与对照组相比，在所有处理组中施用MT有效延迟了葡萄的衰老，在0.5 mM处理中观察到最长的延迟。此外，在所有0.5 mM MT处理组中，DNA甲基化率均降低，表明MT在去甲基化中具有潜在作用。结论：我们的结果表明，外源施用MT可以延迟采后葡萄的衰老。表明MT在脱甲基中的潜在作用。结论：我们的结果表明，外源施用MT可以延迟采后葡萄的衰老。表明MT在脱甲基中的潜在作用。结论：我们的结果表明，外源施用MT可以延迟采后葡萄的衰老。