中文摘要：

【目的】克隆谷胱甘肽还原酶基因CsGRs,研究CsGRs在茶树抵御不同逆境胁迫中的作用。【方法】在茶树转录组数据库中搜索茶树CsGRs,根据获得的基因片段,设计反转录PCR（RT-PCR）引物和RACE-PCR特异引物,从茶树中克隆CsGRs的cDNA全长序列,并利用在线生物信息学软件对其进行分析。采用实时荧光定量PCR（qRT-PCR）分析CsGRs在茶树不同组织间的表达差异及其在低温、干旱、高盐胁迫和ABA处理下的表达模式,利用分光光度计测定低温胁迫和干旱胁迫下叶片中还原型谷胱甘肽（GSH）的含量变化。【结果】RT-PCR克隆获得CsGR1的cDNA全长,其长度为1 827 bp,包含1 482 bp开放阅读框（ORF）,编码493个氨基酸;RACE扩增获得712 bp和1 624 bp的5′和3′末端序列,拼接并进行RT-PCR验证后得到CsGR2序列,全长2 282 bp,包含1 698 bp ORF,编码565个氨基酸;CsGR1和CsGR2的GenBank登录号分别为KF906411和KF418080。CsGR1和CsGR2编码的蛋白质分子量分别为53.9 kD和61.0 kD,无信号肽位点,均为非分泌性蛋白。亚细胞定位预测CsGR1主要定位在细胞质等亚细胞中,无叶绿体锚定信号肽位点;CsGR2中N-端的71个氨基酸残基具有叶绿体转运信号功能,主要定位在叶绿体上。序列相似性比较显示,CsGR1与其他植物中胞质GR的相似性均在80%以上,而与叶绿体GR的相似性低于60%;CsGR2与其他叶绿体GR的相似性70%以上,与胞质GR的相似性在50%左右。二者在核酸序列和氨基酸序列水平上分别有63.4%和49.9%的相似性,且蛋白质二级结构也具有较高的相似性。系统发育树显示,CsGR1与胞质GR聚为一类,而CsGR2与叶绿体GR聚在一起,且都与葡萄的亲缘关系最近。二者均含有氧化还原二硫键活性位点、谷胱甘肽结合位点以及NADPH结合的Arg保守位点等结构域。CsGR1为胞质GR,CsGR2为双向定位在叶绿体和线粒体上的叶绿体GR。CsGR1在花和根中表达量较高,在叶片和茎中表达量低

英文摘要：

【Objective】 The objectives of the present study were to clone the genes of glutathione reductase family（CsGRs） from tea plant（Camellia sinensis） and investigate their functions under different abiotic stresses. 【Method】 According to the sequences of CsGR genes obtained from the transcriptome database of tea plant, specific primers were designed for reverse transcription-polymerase chain reaction（RT-PCR） and rapid amplification of cDNA ends PCR（RACE-PCR） to clone the full-length sequences of CsGRs. The bioinformatic characteristics of the cloned CsGRs were analyzed using online service. The expression profiles of CsGRs in various tissues and in response to cold, drought, salt and abscisic acid（ABA） treatment were investigated using quantitative real-time PCR（qRT-PCR）. Spectrophotometer technique was employed to determine the content of glutathione（GSH） upon cold and drought stress. 【Result】 CsGR1 was isolated from tea plant using RT-PCR and had 1 827 bp in length containing a 1 482 bp open reading frame（ORF） encoded 493 amino acid residues. For CsGR2 isolating, 712 bp and 1 624 bp in length of 5′ and 3′ terminal sequences were amplified by RACE-PCR, respectively, after sequences assembling and verified by RT-PCR, CsGR2 with 2 282 bp in length containing a 1 698 bp ORF encoded polypeptide of 565 amino acids was obtained. CsGR1 and CsGR2 were submitted to GenBank with accession number KF906411 and KF418080, respectively. The molecular weights of CsGR1 and CsGR2 encoded protein were 53.9 and 61.0 kD, respectively, and both of them did not contain the signal peptide sites, indicating that they were not the secretory proteins. Subcellular localization prediction showed that CsGR1 might localize in cytoplasm without chloroplast transit peptides（cTP）, whereas CsGR2, containing a putative cTP of 71 amino acid residues at the N-terminal, was most likely to target to chloroplast. Comparison of sequences similarity with reported GRs showed that CsGR1 had more than 80% simil