烟草NtCBL1基因的克隆、表达载体构建及表达分析

CBL是一类Ca²⁺感受蛋白，在植物适应或抵制逆境胁迫的过程中发挥重要的作用。从烟草品种K326中克隆到了一个CBL1的同源基因，该序列包含了一个642 bp的开放阅读框，编码一个由213个氨基酸残基组成的蛋白，预测分子量为24.5 kDa，等电点为5.03。同源性分析结果显示，该基因与林烟草CBL1、甜辣椒CBL1等具有较高的同源性，故命名为NtCBL1。生物信息学分析表明，NtCBL1具有CBL家族保守的EF-hand钙结合结构域。组织表达分析发现该基因在成熟期的根、茎、叶、花中均有表达，在根中的表达量最高。逆境胁迫实验表明，该基因表达受低钾、高盐、干旱、ABA和低温诱导调控，参与烟草生物与非生物逆境胁迫的响应。并成功构建了NtCBL1-pBI121过表达载体。研究结果为解析NtCBL1在响应逆境胁迫的功能奠定一定理论基础。

Cloning,Construction of Expression Vector and Expression Analysis of NtCBL1 in Nicotiana tabacum

CBL is a kind of Ca²⁺ sensor, which plays a pivotal role in adaptation or resistance to stress in plants. A CBL1 homologous gene was cloned from the tobacco cultivar K326, which contained a 642 bp ORF encoding 213 amino acid. The predictedmolecular weight was 24.5 kDa and the isoelectric point(pI) was 5.03. By the homology analysis, the gene had high homology with calcineurin B-like protein 1 of the Nicotiana sylvestris(NsCBL1) and Arabidopsis thaliana(AtCBL1), so named as NtCBL1. By bioinformatics analysis, NtCBL1 had the conserved EF-hand calcium binding domain of the CBL family. Expression patterns showed that the gene was expressed in roots, stems, leaves and flowers in mature stage, and the highest expression level in roots.Expression patterns under adversity stress indicated that the gene expression was induced by low-potassium, high-salt,anddrought, ABA and low-temperature, and participated in the response to biological and abiotic stress in Nicotiana tabacum. The research constructed NtCBL1-pBI121 overexpression vector.The results will provide some basis for the function analysis of NtCBL1 in response to stress.