盐角草高亲和钾离子转运蛋白SeHKT1基因的克隆及表达分析

摘要

利用RACR技术从盐生植物盐角草中克隆SeHKT1基因，GenBank登录号为KP739261，用生物信息学方法对获得的基因序列进行分析，利用qRT-PCR方法研究SeHKT1基因在不同组织和不同盐胁迫下的表达特性。结果表明，该基因cDNA序列含有1个1761 bp的完整 ORF，编码550个氨基酸，Blast分析表明该蛋白与毕氏海篷子SbHKT1蛋白亲缘关系较近。qRT-PCR分析表明SeHKT1基因在NaCl处理下地上部和地下部均诱导上调表达，主要在盐角草根部表达，在地上部表达相对较低，200 mmol/L NaCl处理6 h后在根部表达量达到最高，随后逐渐降低；在钾饥饿条件下，该基因在根部和地上部的相对表达量均高于对照。说明SeHKT1不仅能响应NaCl胁迫，还能在缺钾条件下提高表达，发挥高亲和钾离子载体功能。%A putative high-affinity potassium transporter gene namedSeHKT1was cloned from halophyteSalicornia europaea using RACE techniques with GenBank number of KP739261. The characteristics of sequence was analyzed by bioinformatics and the expression patterns were verified by Real-time PCR in different tissues and under different salt stresses. The results showed that theSeHKT1was highly closely related toSbHKT1 ofSorghum bicolor and with a 1 761 bp open reading frame(ORF)and encoding a polypeptide of 550 amino acids. Real-time PCR results showed that theSeHKT1 was expressed both in shoot and root by NaCl stimulus, but the transcription level were higher in root than shoot. The expression level reached highest level at 6 h and decreased after this time point in root under 200 mmol/L NaCl solution treatment. Under potassium starvation condition, theSeHKT1 was also induced in both of roots and shoots with high level. All of these results demonstrateSeHKT1 not only response NaCl stresses, but also regulate potassium absorption under potassium starvation environment.