Table_4_An Integrated Metabolome and Transcriptome Analysis Reveal the Regulation Mechanisms of Flavonoid Biosynthesis in a Purple Tea Plant Cultivar.XLSX

Purple tea plant cultivars, enrich with flavonoids and anthocyanins, are valuable materials for manufacturing tea with unique color and flavor. Researchers found that ‘Zijuan’ leaves changed from purple to green mainly caused by the decreased flavonoids and anthocyanins concentrations. The mechanism of flavonoids and anthocyanin biosynthesis has been studied in many purple tea plant cultivars and the key genes which regulated the biosynthesis of flavonoid and anthocyanins in different purple tea plant cultivars were quite different. Also, the molecular regulation mechanism underlying the flavonoids and anthocyanins biosynthesis during leaves development and color changes is less-thoroughly understood. In this study, an integrative analysis of transcriptome and metabolome was performed on the purple leaves and green leaves of ‘Zijuan’ tea plant to reveal the regulatory networks correlated to flavonoid biosynthesis and to identify key regulatory genes. Our results indicated that the ‘Zijuan’ new shoots leaves were purple might be due to the copigmentation of quercetin and kaempferol derivatives. In ‘Zijuan’ tea plant cultivar, flavonoids metabolites concentrations in purple leaves and green leaves were significantly influenced by the genes involved in flavonoid biosynthesis, transcriptional regulation, transport, and hormone response. Transcription factors including NAC008, MYB23, and bHLH96 and transporters such as ABC transporter I might be responsible for the flavonoid and anthocyanins accumulation in purple leaves. This study provides a new insight into the metabolism and molecular mechanisms underlying flavonoid and anthocyanin biosynthesis in tea plant.

富含类黄酮（flavonoids）与花青素（anthocyanins）的紫叶茶树品种，是制备色泽与风味独具特色的茶叶的珍贵原料。研究人员发现，‘紫鹃’茶树叶片由紫转绿的核心诱因是其体内类黄酮与花青素的含量降低。目前已有诸多研究针对多种紫叶茶树品种的类黄酮与花青素合成机制展开探索，且不同紫叶茶树品种中调控类黄酮与花青素合成的关键基因存在显著差异。而关于茶树叶片发育及色泽转变过程中类黄酮与花青素合成的分子调控机制，目前仍未得到充分阐明。本研究以‘紫鹃’茶树的紫叶与绿叶为材料，开展转录组（transcriptome）与代谢组（metabolome）联合分析，旨在揭示与类黄酮合成相关的调控网络并筛选关键调控基因。研究结果表明，‘紫鹃’茶树新梢呈紫色可能与槲皮素与山奈酚衍生物的辅着色作用密切相关。在‘紫鹃’茶树品种中，紫叶与绿叶内的类黄酮代谢物含量显著受类黄酮合成、转录调控、物质转运及激素响应相关基因的调控。包括NAC008、MYB23及bHLH96在内的转录因子（transcription factors），以及ABC转运蛋白I（ABC transporter I）等转运体，可能参与调控紫叶中类黄酮与花青素的积累。本研究为解析茶树类黄酮与花青素合成的代谢及分子机制提供了全新视角。