烟草钾转运体 NtKT12的克隆及表达分析

摘要

克隆烟草钾转运体基因，预测其结构，并分析其进化关系和功能，为研究烟草钾吸收机制奠定基础。采用RT-PCR 方法从烟草品种 K326中克隆到了一个钾转运体的同源基因，该序列全长为2532 bp，蛋白编码844个氨基酸，预测分子量为93．1 kDa，等电点为7．2。同源性分析结果显示，该基因与绒毛烟草钾转运体12、林烟草钾转运体12等具有较高的同源性，故命名为 NtKT12。生物信息学分析表明，NtKT12具有12个跨膜区。组织表达分析发现该基因在根中的表达量最高。低钾胁迫试验表明，该基因在处理6，24 h 后表达量明显高于对照。研究结果为解析NtKT12在烟草钾营养中的功能奠定一定的理论基础。%Cloned the tobacco potassium transporter gene and predicted its structure,and analyzed their evolu-tionary relationships and functions,to lay the foundation for the study of tobacco potassium absorption mechanism.In this study,a homologous gene of a potassium transporter was cloned by RT-PCR from K326.Sequences analysis showed this gene contained 2 532 bp and coded 844 amino acid residues,and the calculated molecular mass was 93.1 kDa with the theoretical isoelectric point(pI)was 7.2.Homology analysis suggested that the gene had a high homology with the potassium transporter 12 of the Nicotiana tomentosiformis and Nicotiana sylvestris,so it was named as NtKT12.Protein structure and function analysis showed that NtKT12 has 12 transmembrane domains.Expression patterns showed that the expression level was the highest in the roots.Expression patterns under low potassium treat-ment suggested NtKT12 expression level was significantly higher after 6,24 h than the control.These results provid-ed some basis for potassium function analysis of NtKT12.