长叶红砂液泡膜Na^+/H^+逆向转运蛋白基因的克隆及表达特性  

Isolation and Expression of Vacuolar Membrane Na^+/H^+ Antiporter Gene in Reaumuriatrigyna

作　　者：董禄禄 秦晓春[2] 党振华[1] 

机构地区：[1]内蒙古大学生命科学学院内蒙古自治区牧草与特色作物生物技术重点实验室,呼和浩特010021 [2]包头市园林科技研究所,内蒙古包头014010

出　　处：《西北植物学报》2015年第11期2164-2170,共7页Acta Botanica Boreali-Occidentalia Sinica

基　　金：国家自然科学基金(31360063);内蒙古自治区高等学校创新研究团队发展计划(NMGIRT1401)

摘　　要：为研究长叶红砂(Reaumuria trigyna)离子转运分子机制,利用RT-PCR和RACE技术,克隆到其液泡膜Na+/H+逆向转运蛋白基因(NHX1)的全长cDNA片段,命名为RtNHX1(NCBI序列号为KR919802)。结果表明:RtNHX1的cDNA片段全长2 622bp,开放阅读框1 662bp,5′非编码区509bp,3′非编码区451bp,编码553个氨基酸,推测分子量为60.91kD。该蛋白含有12个跨膜结构域,为疏水蛋白,与其他植物液泡膜Na+/H+逆向转运蛋白NHX1的亲缘关系较近。实时荧光定量PCR对其在NaCl胁迫下的表达检测显示,不同时间和不同浓度NaCl胁迫下,RtNHX1表达量变化均呈先升高后降低趋势,在100mmol/L NaCl胁迫6h和200mmol/L NaCl胁迫后达到最高,表达量分别超过或约是对照的3倍,一定程度反应出RtNHX1参与长叶红砂的盐胁迫应答,是该植物离子转运体系的重要元件。To investigate the molecular mechanism of the ion transport in Reaumuria trigyna ,we cloned the full length eDNA of vacuolar membrane Na＋ /H＋ antiporter gene （RtNHX1） with reverse transcription PCR and rapid amplification of eDNA ends technologies. The eDNA is 2 622 bp long,which contained a 1 662 bp open reading frame,a 509 bp 5＇-UTR,and a 451 bp 3＇-UTR. The eDNA encoded a protein with 553 amino acids and molecular weight of 60.91 kD. The protein was predicted to be composed of 12 trans- membrane domains, was characterized as a hydrophobic protein, and showed high homology with the vacuo- lar membrane Na＋/H＋ antiporter（NHX1） in other plant species. Quantitative real-time analysis showed that the expression levels of RtNHX1 under different salt concentrations and time gradients,were up-regu- lated initially and then down-regulated. The expression of RtNHX1 under the stress o{ 100 mmol/L NaC1 for 6 hours and 200 mmol/L NaC1 were reached the highest,which were over or nearly 3-fold of the con- trol,indicating that RtNHX1 participated in the salt stress response of R. trigyna and may be an important element that plays a role in the ion transporting system in this plant.

关 键 词：长叶红砂 液泡膜Na+/H+逆向转运蛋白基因 CDNA 实时荧光定量PCR NACL胁迫 表达特性 

分 类 号：Q785[生物学—分子生物学] Q789