Xu Lili, Yue Qianyu, Bian Feng'e, Sun Hong, Zhai Heng, Yao Yuxin
State Key Laboratory of Crop Biology, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (Huang-Huai Region), Ministry of Agriculture, College of Horticulture Science and Engineering, Shandong Agricultural UniversityTai'an, China.
Front Plant Sci. 2017 Aug 18;8:1426. doi: 10.3389/fpls.2017.01426. eCollection 2017.
This study assessed the primary impacts of exogenous melatonin (MT) treatment on grape berry metabolism. Exogenous MT treatment increased the endogenous MT content and modified berry ripening. Transcriptomic analysis revealed that the processes of polyphenol metabolism, carbohydrate metabolism and ethylene biosynthesis and signaling were the three most significantly altered biological processes upon MT treatment. Further experiments verified that MT treatment increased the contents of total anthocyanins, phenols, flavonoids and proanthocyanidins in berries. Additionally, the contents of 18 of the 22 detected individual phenolic compounds were enhanced by MT treatment; particularly, the resveratrol content was largely increased concomitantly with the up-regulation of gene expression. Meanwhile, MT treatment enhanced the antioxidant capacity of berries. On the other hand, it was indicated that ethylene participated in the regulation of polyphenol metabolism and antioxidant capacity under MT treatment in grape berries. In summary, MT enhances the polyphenol content and antioxidant capacity of grape berries partially via ethylene signaling.
本研究评估了外源褪黑素（MT）处理对葡萄果实代谢的主要影响。外源MT处理增加了内源MT含量并改变了果实成熟过程。转录组分析表明，多酚代谢、碳水化合物代谢以及乙烯生物合成和信号传导过程是MT处理后三个变化最显著的生物学过程。进一步实验证实，MT处理增加了果实中总花青素、酚类、黄酮类和原花青素的含量。此外，MT处理使检测到的22种单个酚类化合物中的18种含量增加；特别是，白藜芦醇含量大幅增加，同时基因表达上调。同时，MT处理增强了果实的抗氧化能力。另一方面，研究表明乙烯参与了MT处理下葡萄果实中多酚代谢和抗氧化能力的调控。总之，MT部分通过乙烯信号传导提高了葡萄果实的多酚含量和抗氧化能力。
