茶树硝酸根转运蛋白基因NRT2.5的克隆及表达分析

摘要

通过RACE克隆从茶树[Camellia sinensis (L.)]叶片中获得NRT2.5基因cDNA全长序列。所得基因序列全长为2457 bp，其中开放阅读框为1362 bp，编码454个氨基酸，推测蛋白分子量为48.7 kD，理论等电点为9.63。生物信息学分析表明，该基因与可可树、拟南芥等的NRT2.5基因具有高度同源性，且其编码的蛋白质具有 NRT 家族共有的结构特征。实时定量 PCR 分析表明，NRT2.5基因在茶树不同组织中均有表达，但主要在成熟叶和根中表达；不同氮浓度处理后，茶树NRT2.5基因在低浓度下的表达量高于高浓度下。%The full cDNA length of NRT2.5 gene was obtained via rapid amplification of cDNA ends (RACE) from tea plant [Camellia sinessis (L.)] leaves. The cDNA sequence of this gene was 2 457 bp and opening reading frame (ORF) was 1 362 bp, encoding for 454 amino acids. The putative protein of this gene had an isoelectric point of 9.63 and a calculated molecular weight of 48.7 kD. Bioinformatics analysis showed that NRT2.5 of tea plant was highly homologous to the genes such as TcNRT2.5 and AtNRT2.5, and its encoded protein had the common structural characteristics of NRT family. Fluorescence quantitative real-time PCR analysis showed that NRT2.5 gene were detected in all the tested tissues of tea plant but was mainly detected in the mature leaves and roots. The expression level in different nitrogen concentration showed that the expression of NRT2.5 gene in low N concentration was significant higher than that in high concentration.