萎凋是多数茶类加工的第一个环节，其主要目的是通过水分散失、酶活性增强调整茶叶的特征成分来提高茶叶品质，是一个能够影响茶叶最终的颜色、滋味和口感等的生理、生化和分子调控过程。在本研究中，作者对龙井43采收后的新鲜叶片分别进行室温（25°C，CK）、高温（38°C，S1）和低温（4°C，S2）放置4h，然后提取总蛋白，利用iTRAQ差异蛋白组学技术进行DEPs鉴定，同时对不同处理下茶叶中儿茶素类的含量以及儿茶素相关基因进行检测和表达分析。

Abstract

In this study, isobaric tags for relative and absolute quantitation (iTRAQ) technology was used to investigate three samples from postharvest tea leaves that were treated at room temperature (25°C, control group), high temperature (38°C), and low temperature (4°C) for 4 h, respectively. In heat and cold treatments, a total of 635 and 566 differentially expressed proteins (DEPs) were determined, respectively. DEPs were annotated to GO and KEGG databases, which revealed that DEPs involved in various aspects of biological process. Three catechins-related DEPs, CsCHI, CsF3H, and CsANR were identified. Both catechins contents and the expression profiles of catechins biosynthesis related genes changed significantly under different temperature treatments. The correlations between catechins contents, gene expression profiles and DEPs were analyzed. This study provides potential new insights into the molecular basis for tea production of postharvest leaves and catechins content changes at diverse temperature conditions, and will guide the improvement of tea processing technology.