Gao Feibiao, Han Kangning, Ma Weilan, Zhang Jing, Xie Jianming
College of Horticulture, Gansu Agricultural University, Lanzhou 730070, China.
Foods. 2025 Apr 3;14(7):1247. doi: 10.3390/foods14071247.
Melatonin (MT) is an elicitor that stimulates phenolic compounds biosynthesis and accumulation in fruits and vegetables. However, its role in regulating phenolic compounds and the phenylpropane metabolism during pepper ripening is unclear. To investigate how exogenous MT regulates phenolic compounds biosynthesis during pepper ripening, pepper plant surfaces were sprayed with different MT concentrations (0 and 100 µmol·L) 10 days after anthesis. MT treatment improved pepper fruits quality. In particular, total phenolics and flavonoids compounds levels were elevated, indicating that MT affected phenolic compounds metabolism. Furthermore, metabolomics identified 15 substances exhibiting high fold-change values after MT treatment, including chlorogenic acid, gallic acid, ferulic acid, caffeic acid, cynarin, -coumaric acid, cinnamic acid, gentianic acid, benzoic acid, sinapic acid, -hydroxybenzoic acid, protocatechuic acid, rutin, quercetin, and kaempferol. Shikimate dehydrogenase, phenylalanine ammonia-lyase, cinnamate-4-hydroxylase, 4-coumarate-Coa ligase, chalcone synthase, and chalcone isomerase activities were also evaluated. MT upregulated the expression of genes involved in phenolic compounds synthesis during pepper ripening and that of corresponding genes involved in the endogenous MT anabolic pathway, promoting endogenous. The polyphenolics and carbohydrates are indicators of the botanical and geographical origin of Serbian autochthonous clones of red spice MT synthesis throughout pepper ripening. In summary, exogenous MT accelerates phenolic compounds synthesis in pepper fruits by activating phenylpropane metabolism and modulating endogenous hormone signaling networks. This is expected to offer a revolutionary strategy to reinforce pepper plants resistance and quality.
褪黑素（MT）是一种能刺激水果和蔬菜中酚类化合物生物合成和积累的诱导剂。然而，其在辣椒成熟过程中调节酚类化合物和苯丙烷代谢的作用尚不清楚。为了研究外源MT如何调节辣椒成熟过程中酚类化合物的生物合成，在开花后10天，用不同浓度的MT（0和100 µmol·L）喷洒辣椒植株表面。MT处理改善了辣椒果实的品质。特别是，总酚和黄酮类化合物水平升高，表明MT影响了酚类化合物的代谢。此外，代谢组学鉴定出15种在MT处理后呈现高倍数变化值的物质，包括绿原酸、没食子酸、阿魏酸、咖啡酸、洋蓟素、对香豆酸、肉桂酸、龙胆酸、苯甲酸、芥子酸、对羟基苯甲酸、原儿茶酸、芦丁、槲皮素和山奈酚。还评估了莽草酸脱氢酶、苯丙氨酸解氨酶、肉桂酸-4-羟化酶、4-香豆酸-CoA连接酶、查尔酮合酶和查尔酮异构酶的活性。MT上调了辣椒成熟过程中参与酚类化合物合成的基因以及参与内源性MT合成途径的相应基因的表达，促进了内源性MT的合成。多酚和碳水化合物是塞尔维亚红辣椒本土克隆植物来源和地理起源的指标。总之，外源MT通过激活苯丙烷代谢和调节内源激素信号网络来加速辣椒果实中酚类化合物的合成。这有望为增强辣椒植株的抗性和品质提供一种革命性的策略。
