转录因子CsICE1调控茶树早期低温应答分子机制的研究

Our previous work showed that CsICE1 isolated from tea plants was a transcription factor involving early low temperature response. It was proved that CsICE1 was a key control gene in ICE1-CBFs-COR low temperature response pathway. Based on these data, in the present project we will first identify the fundamental characteristics of CsICE1 as a transcription factor and detect expression differences of CsICE1 on different tea tissues or organs and different tea varieties in room temperature and low temperature. An overexpression vector will be constructed to transform Arabidopsis thaliana and tobacco respectively. Cold tolerance of the transgenic plants will be evaluated in order to identify the function of CsICE1. Meanwhile, the full length of CsCBFs controlled by CsICE1 and their promoters will be isolated. The cis-acting elements in promoters of CsCBFs will be analyzed. Specific binding of CsICE1 and MYC elements will be investigated by EMSA based on fluorescent in order to identify CsICE1 regulatory ability to CsCBFs. The current project is an extension of our earlier work. It will, on the one hand, provide genes of valuable significance for tea plants genetic engineering related to stress and cold resistance breeding, and on the other hand, will help to reveal the molecular regulation mechanism of CsICE1 on the downstream target genes CBFs, and provide the theory basis on early low temperature response network using CsICE1 as a node. Therefore, this project holds both important theory significance and practical potentials.

在前期研究中，我们在茶树中克隆到一个与早期低温应答相关的转录因子CsICE1，并证明其是茶树ICE1-CBFs-COR低温应答途径中上游关键的调控基因。在此基础上，本项目拟首先分析CsICE1作为转录因子的基本特征，检测常温和低温胁迫下CsICE1在茶树不同组织器官及不同品种间的表达差异。构建超表达载体转化拟南芥和烟草，鉴定CsICE1抗寒功能。同时，克隆CsICE1的下游调控基因CsCBFs全长和启动子，并分析其中顺式作用元件；采用基于荧光的凝胶迁移技术检测CsICE1与MYC元件的特异结合，以鉴定CsICE1对CsCBFs基因的调控能力。本项目是已有研究的深入和延续，将为茶树抗寒育种和抗逆工程提供重要的基因资源，并有助于揭示CsICE1对下游靶基因CBFs的分子调控机制，为解析以CsICE1为调控节点的茶树早期低温应答网络提供理论依据，因而具有重要理论意义和潜在应用价值。