盐芥ThNHX1基因的克隆及序列分析

Cloning and Sequence Analysis of ThNHX1 Gene from Thellungiella halophila

为研究盐生植物的耐盐机理,根据拟南芥的序列设计引物,通过RT-PCR及RACE的方法从盐生植物盐芥中克隆出一个假定的Na+/H+逆向转运蛋白基因ThNHX1。该cDNA全长2 045 bp,开放读码框长度为1 638bp,编码一个545个氨基酸的多肽。序列分析结果表明,该序列与拟南芥的Na+/H+逆向转运蛋白基因具有很高的同源性。结构分析结果表明,ThNHX1基因与AtNHX1基因具有类似的外显子和内含子构成。系统发育分析结果表明,该蛋白与液泡型的Na+/H+逆向转运蛋白的亲缘关系较近,与质膜型的Na+/H+逆向转运蛋白亲缘关系较远。

To study salt-tolerant mechanism of halophyte, a full length cDNA fragment was amplified from Thellungiella halophila with primers designed based on the Arabidopsis thaliana AtNHX1 gene sequence using RT-PCR and 5 ＇-and 3＇-RACE methods. The eDNA sequence was 2 045 bp in length including an open reading frame of 1 638 bp, encoding a predicted polypeptide of 545 amino acids. Detailed sequence analysis showed that the gene shared the highest homology with AtNHX1. The eDNA encodes a putative Na^＋/H^＋ antiporter gene （ ThNHX1 ）. ThNHX1 had similar intron and exon structures to those of AtHNX1. The phylogenetic analysis of various Na^＋/H^＋ antiporters indicated that ThNHX1 was grouped with tonoplast Na^＋/H^＋ antiporters, and distinguished from plasma membrane Na^＋/H^＋ antiporters.