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作 者 ：周月琴，庞 磊，李叶云，江昌俊*

期 刊 ：西北植物学报 2013年 7期 页码：1292~1297

关键词：茶树；硝酸还原酶；cDNA克隆；qRT-PCR；

Keywords:Camellia sinensis, nitrate reductase, cDNA cloning, qRT-PCR,

摘 要 ：利用茶树全器官转录组文库中硝酸还原酶（NR）的EST，通过RACE技术扩增出NR基因的cDNA，并利用实时荧光定量PCR检测了NR基因在不同茶树品种中的表达。结果表明：NR基因cDNA全长2 927 bp，开放阅读框2 652 bp，编码一个有884个氨基酸蛋白质，GenBank登录号为JX987133。经BlastX比对，与GenBank中登录的烟草NR相似性达到74%。茶树NR蛋白属于亲水性蛋白，可能为胞质蛋白。25个茶树品种叶片中NR表达水平差异明显，最高值是最低值的22.75倍。 因NR是植物氮代谢过程中的关键限速酶，推测25个茶树品种间氮吸收利用能力存在差异。

Abstract:In this study,the cDNA of nitrate reductase (NR) gene in Camellia sinensis was amplified via RACE technology by the EST taken from the transcript library of whole organs in tea plants.And expression levels of NR in different tea cultivars were studied using qRT-PCR technology.The results indicated that the cDNA full-length was 2 927 bp,with 2 652 bp ORF encoding 884 amino acid,the accession number was JX987133 and the sequence was 74% similar to that of tobacco by BlastX.The deduced NR protein is hydrophobic located in the cytoplasm.The expression levels in different cultivars varied greatly and the ratio between the maximum and the minimum reached 22.75.As the fact that nitrate reductase is a key enzyme in the process of nitrogen metabolism,maybe the nitrogen uptake and utilization efficiency differ among these tea cultivars.

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