Melatonin Accumulation in Sweet Cherry and Its Influence on Fruit Quality and Antioxidant Properties

Abstract

Although the effects of melatonin on plant abiotic and biotic stress resistance have been explored in recent decades, the accumulation of endogenous melatonin in plants and its influence on fruit quality remains unclear. In the present study, melatonin accumulation levels and the expression profiles of five synthesis genes were investigated during fruit and leaf development in sweet cherry (Prunus avium L.). Melatonin was strongly accumulated in young fruits and leaves, then decreased steadily with maturation. Transcript levels of PacTDC and PacSNAT were highly correlated with melatonin content in both fruit and leaves, indicating their importance in melatonin accumulation. Furthermore, application of 50 and 100 μmol·L−1 of melatonin to leaves had a greater influence on fruit quality than treatments applied to fruits, by significantly improving fruit weight, soluble solids content, and phenolic content including total phenols, flavanols, total anthocyanins, and ascorbic acid. Meanwhile, melatonin application promoted the antioxidant capacity of fruit assayed by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azinobis (3-ethylben zothiazoline-6-sulfonic acid) (ABTS), and ferric reducing antioxidant power (FRAP). These results provide insights into the physiological and molecular mechanisms underlying melatonin metabolism of sweet cherry.

Melatonin Treatment to Pomegranate Trees Enhances Fruit Bioactive Compounds and Quality Traits at Harvest and during Postharvest Storage

“…For instance, 0.1 mM melatonin treatment of tomato plants increased antioxidant compounds, such as lycopene, β-carotene, total phenolics and flavonoids, and antioxidant activity in tomato fruit when plants were grown under acid rain stress conditions [ 40 ]. Accordingly, leaves’ treatment of sweet cherry trees with 0.05 or 0.1 mM of melatonin improved total phenol, flavanol, anthocyanin and ascorbic concentrations in fruit at harvest [ 41 ]. However, the effects of melatonin postharvest treatments on increasing fruit bioactive compounds and antioxidant activity have been addressed in more fruit species.…”

Novel insights in health-promoting properties of sweet cherries

“…The fiber content of sweet cherries contributes to the health-promoting characteristics ( McCune, Kubota, Stendell-Hollis, & Thomson, 2010 ). Sweet cherries are also enriched with melatonin, which might function as an antioxidant agent, capable to protect from oxidative stress ( Xia et al, 2020 ; Zhao et al, 2013 ). A review about the health benefits of sweet cherries ( Prunus avium L.) has been recently reported ( Gonçalves, Bento, Silva, Simões, & Silva, 2019 ).…”

Effects of Light Quality and Phytochrome Form on Melatonin Biosynthesis in Rice

“…For example, melatonin treatment enhances plant tolerance against many stresses, including salt [6,7], drought [8,9], viruses [10], pathogens [11,12], waterlogging [13], and senescence [14], among others [15][16][17]. Melatonin is also involved in plant development processes such as growth [18,19], seed viability [20], flowering [21,22], endoplasmic reticulum (ER) quality control [23,24], secondary metabolite synthesis [25], and others [26]. The pleiotropic effects of melatonin are due to the combined effects of its antioxidant activity and signaling or hormonal activity [5], although its metabolites, such as 2-hydroxymelatonin and cyclic 3-hydroxymelatonin, are also involved in physiological activity such as tiller growth [27,28].…”