ABSTRACT

Catechins are the major compounds in tea (Camellia sinenesis L.) and are responsible for its sensory qualities and health benefits. The study investigated the response of catechins biosynthesis to temperature changes in the controlled conditions and the possible mechanisms. The low-temperature treatment inhibited the growth of young shoots, suppressed the expression of catechins biosynthesis-related genes (except CsCHS3, CsDFR2, CsLAR2), and decreased the content of total esterified catechins but increased the content of total non-esterified catechins in tea plants. When the temperature increased from 15°C to 30°C, the young shoots grew faster, and the contents of total catechins, total esterified catechins and epigallocatechin gallate in tea plants increased by 87.7%, 92.5% and 53.6%, respectively. Meanwhile, the expression of growth-related genes was upregulated in the higher temperature treatment and was consistent with the response of catechins biosynthesis-related genes to temperature. The positive correlation and the cubic function (R² > 90%) were noted between the growth of young shoots and catechins content. In brief, the response of catechins biosynthesis to temperature changes coordinately regulated by shoot growth and catechins genes expression of tea plants. Our findings provide the reference for improving tea quality by increasing its catechin contents.

摘要

儿茶素是茶中的主要化合物（茶树），并为其感官品质和健康益处负责。该研究调查了儿茶素生物合成对温度在受控条件下的响应及其可能的机制。低温处理抑制了嫩芽的生长，抑制了儿茶素生物合成相关基因（CsCHS3，CsDFR2，CsLAR2除外）的表达），降低了茶树中总酯化儿茶素的含量，但增加了总未酯化儿茶素的含量。当温度从15°C升高到30°C时，幼芽生长更快，茶树中儿茶素，酯化儿茶素和表没食子儿茶素没食子酸酯的含量分别增加了87.7％，92.5％和53.6％。同时，生长相关基因的表达在高温处理中被上调，并且与儿茶素生物合成相关基因对温度的响应一致。正相关与三次函数（R ² > 90％）被注意到在幼枝的生长和儿茶素含量之间。简而言之，儿茶素生物合成对温度变化的响应由茶树的芽生长和儿茶素基因表达协调地调节。我们的发现为通过增加儿茶素含量改善茶品质提供了参考。