菊芋Na^+/H^+逆向转运蛋白基因的克隆与表达分析  

Cloning and Analysis of a Na^+/H^+ Antiporter Gene in Helianthus tuberosus L.

作　　者：严一诺[1] 孙淑斌[1] 徐国华[1] 刘兆普[1] 

机构地区：[1]南京农业大学资源与环境学院,南京210095

出　　处：《西北植物学报》2007年第7期1291-1298,共8页Acta Botanica Boreali-Occidentalia Sinica

基　　金：国家重大支撑项目计划(2006BAD09A04)

摘　　要：根据同源序列设计简并引物,通过RT-PCR及RACE的方法从菊芋中克隆了Na+/H+逆向转运蛋白基因。序列分析表明,该基因全长2148 bp,开放读码框为1647 bp,可编码长549个氨基酸的多肽,与其它植物已克隆的Na+/H+逆向转运蛋白具有很高的同源性。系统发育分析表明该蛋白(HtNHX1)与液泡型Na+/H+逆向转运蛋白的亲缘关系较近,与质膜型Na+/H+逆向转运蛋白亲缘关系较远。NaCl胁迫条件下RT-PCR检测结果表明,HtNHX1随NaCl浓度增加和处理时间延长表达持续增强,但到了第3天表达量开始下降。HtNHX1逆向转运蛋白基因的转录调控可能是决定菊芋耐盐能力的一个重要因素。A full length cDNA of NHX1 gene in Helianthus tuberosus L. （HtNHX1） was cloned using RT- PCR and RACE,and this fragment was subsequently cloned,sequenced and analyzed. The data shows that the HtNHX1 is 2 148 bp in length,including an open reading frame of 1 647 bp which encodes a predicted polypeptide of 549 amino acids. Homology analysis indicated that HtNHX1 protein shares high identity with other reported NHXs. Phylogenetic analysis showed that HtNHX1 share the same group with vacuolar-type Na^＋/H^＋ antiporter,and distinguished from plasma membrane-type Na^＋/H^＋ antiporter. RT-PCR results revealed that HtNHX1 expression was continuously enhanced in the roots of H. tuberosus under different concentration NaCl stress and treatment time, and began to reduce after 3 days of treatment. Therefore, there is one possibility that the regulation of HtNHX1 at transcriptional level was an important factor to cope with salt stress.

关 键 词：菊芋 NA+/H+逆向转运蛋白 HtNHX1 CDNA RACE 

分 类 号：Q548.1[生物学—生物化学]