茶树CsRAV2转录因子基因的克隆与表达特性分析

Isolation of CsRAV2 Transcription Factor Gene of Tea Plant and its Expression Analysis

RAV转录因子是AP2/ERF家族的成员之一,在植物生长发育和逆境调控中起着重要作用。本研究以安吉白茶和迎霜这两个茶树(Camellia sinensis)品种为试验材料,通过PCR和RT-PCR方法分别从两种茶树的DNA和cDNA中克隆得到CsRAV2基因。分析显示,来源于两种茶树中的CsRAV2基因全长均为1 089 bp,没有内含子,分别编码362个氨基酸,含有相对保守的AP2结合域和B3结构域,具有典型的植物RAV类转录因子特征。从氨基酸组成成分、理化性质、亲水性/疏水性、三级结构上分析显示,茶树中CsRAV2转录因子是亲水性蛋白。茶树中CsRAV2转录因子与拟南芥AtRAV具有相似的三级结构。实时定量PCR分析表明,茶树中CsRAV2基因在茶树根中表达量最高,高温、低温、NaCl处理均能诱导该基因表达,不同品种间存在差异。

The RAV transcription factor, one subfamily of AP2/ERF family transcription factor, includes several genes that encode proteins involved in the development and regulation of abiotic/biotic resistance in higher plant. The CsRAV2 genes, which encoding to the RAV transcription factor, were cloned from tea plant （ Camellia sinensis） cultivars‘Anjibaicha’ and ‘Yingshuang’ by PCR and RT-PCR using DNA and cDNA as template, respectively. Then, nucleic acid and deduced amino acid sequence, phylogenetic tree, and molecular modeling were predicted and analyzed. The lengths of CsRAV2 genes from the two tea plant cultivars were 1 089 bp, encoding 362 amino acids. No intron was found in the CsRAV2 gene. The transcription factor of CsRAV2 contained two distinct DNA domains mainly found in higher plants RAV family factors, one AP2 domain together with one B3 domain. The CsRAV2 were hydrophilic protein. The protein of CsRAV2 from tea plant and AtRAV from Arabidopsis had similar three-dimension structure. Quantitative real-time PCR analysis of the expression profiles showed that the CsRAV2 gene was tissue-specific expressed in the two tea plant cultivars. The highest expression levels of the CsRAV2 gene were found in the root. The CsRAV2 gene was induced by high temperature, low temperature, PEG and high-salinity treatment, respectively. There were differences profiles between different teacultivars.