Eugenol is a natural phenolic compound known for its health-promoting properties and its ability to add a floral scent to tea plants. Plant eugenol glycosides have been identified and shown to make important contributions to fruit floral quality. However, the details of their biosynthesis and metabolism in tea plants are still unknown. Here, eugenol glucoside was unambiguously identified as a native metabolite in the tea plant, and its biosynthesis was shown to be induced by low temperature treatment. Through the analysis of UGTs induced by low temperature, the glycosyltransferase CsUGT78A15 was identified in tea, and its encoded protein was shown to catalyze the glucosylation of eugenol. V_max/K_m ratios showed that eugenol was the most suitable substrate for CsUGT78A15. Sugar donor preference analysis showed that CsUGT78A15 had a higher selectivity for glucose, followed by galactose and glucuronic acid. The expression of CsUGT78A15 was correlated with the accumulation of eugenol glucoside in different tissues and genotypes of tea. Down-regulation of CsUGT78A15 led to a decreased eugenol glucoside content under cold stress, indicating that CsUGT78A15 plays an important role in the biosynthesis of eugenol glucoside under cold stress. The identification of eugenol glucoside in the tea plant and the discovery of a cold stress-induced eugenol glucosyltransferase in tea provide the foundation for the improvement of tea flavor under cold stress and the biotechnological production of eugenol glucoside.

丁香酚是一种天然酚类化合物，以其促进健康的特性和向茶树中添加花香的能力而闻名。已鉴定出植物丁香酚糖苷，并显示出对水果花品质的重要贡献。但是，它们在茶树中的生物合成和代谢的细节仍然未知。在这里，丁香酚糖苷被明确鉴定为茶树中的天然代谢产物，其生物合成被证明是通过低温处理诱导的。通过对低温诱导的UGT的分析，鉴定了茶中的糖基转移酶CsUGT78A15，并证明其编码的蛋白催化丁香酚的糖基化。V_最大/ ķ_米比率表明丁子香酚是CsUGT78A15最合适的底物。糖供体偏好分析表明，CsUGT78A15对葡萄糖的选择性更高，其次是半乳糖和葡萄糖醛酸。的表达CsUGT78A15用丁子香酚葡糖苷的在不同组织和茶的基因型的积累相关。下调CsUGT78A15导致冷胁迫下丁香酚糖苷含量降低，表明CsUGT78A15在冷胁迫下丁香酚糖苷的生物合成中起重要作用。茶树中丁香酚糖苷的鉴定和冷胁迫诱导的茶中丁香酚葡萄糖基转移酶的发现为改善冷胁迫下茶的风味和丁香酚糖苷的生物技术生产奠定了基础。