摘要： HKT蛋白家族主要参与控制K⁺的吸收和K⁺/Na⁺的选择性运输，对提高植物抗胁迫能力具有重要的作用。为了研究AtHKT1组织表达水平与植物耐盐性的关系，利用生物信息学技术对HKT类蛋白的同源性、AtHKT1基因表达情况及其启动子顺式作用元件进行分析和预测，在此基础上将AtHKT1启动子导入到本生烟草细胞中，根据GUS染色结果，分析AtHKT1基因在本生烟草中的组织表达水平。生物信息学分析结果显示，拟南芥和小麦处于不同的进化分支，亲缘关系较远，提示AtHKT1的功能可能与小麦中相应蛋白存在一定的差异。AtHKT1基因在拟南芥许多器官和组织中都有丰富的表达，其中在叶、根和花中的表达量较高，证实AtHKT1基因可能具有重要的生理功能。AtHKT1启动子可能是一个逆境响应启动子，包含多种能够响应环境胁迫的重要元件。因此，AtHKT1基因表达很可能受到环境胁迫的调控。GUS染色结果显示，转pHKT1-gus本生烟草幼苗叶、维管系统、根以及花的染色较深，进一步证实AtHKT1在这些区域表达量较高。以上结果表明，AtHKT1基因表达调控有利于实现Na⁺的转运，进而调节植物耐盐性。除此之外，还可能有其他一些未知的功能，这进一步增加了AtHKT1功能的复杂性。目前，有关HKT类蛋白K⁺和Na⁺转运方式的机制并不明确，通过分析AtHKT1基因在本生烟草中的表达水平，为进一步了解AtHKT1基因的作用机制提供参考。

关键词: AtHKT1基因, 本生烟草, 启动子, 表达水平, GUS染色

Abstract: The HKT protein family is mainly involved in controlling the absorption of K⁺ and the selective transport of K⁺/Na⁺, which plays an important role in improving the stress resistance of plants.In order to study the relationship between the tissue expression level of AtHKT1 and salt tolerance of plants,the homology of HKT proteins,the expression of AtHKT1 gene and the cis-acting elements of AtHKT1 promoter were analyzed and predicted using bioinformatics techniques. On the basis,the AtHKT1 promoter was introduced into Nicotiana benthamiana. GUS staining results were used to analyze the tissue expression level of AtHKT1 gene in Nicotiana benthamiana. The results of bioinformatics analysis showed that Arabidopsis thaliana and wheat were located in different evolutionary branches and their genetic relationship was far, suggesting that the function of AtHKT1 might be different from the corresponding protein in wheat. AtHKT1 gene was abundantly expressed in many organs and tissues of Arabidopsis thaliana, especially in leaves, roots and flowers, which confirmed that AtHKT1 gene was likely to have important physiological functions. The AtHKT1 promoter might be a stress-responsive promoter containing a number of important elements that responded to environmental stress. Therefore, the expression of AtHKT1 gene was likely to be regulated by environmental stress. Results of GUS staining showed that the coloration of leaves,vascular system,roots and flowers of the seedlings with pHKT1-gus was deeper,further confirming that the expression level of AtHKT1 in these regions was high. The above results indicated that the regulation of AtHKT1 gene expression was conducive to the translocation of Na⁺,thereby regulating the salt tolerance of plants.In addition, there might be other unknown features that further increase the complexity of AtHKT1 functionality. At present, the mechanism of K⁺ and Na⁺ transport of HKT proteins is not clear. The expression level of AtHKT1 gene in Nicotiana benthamiana was analyzed to provide reference for further understanding the action mechanism of AtHKT1 gene.

Key words: AtHKT1 gene, Nicotiana benthamiana, Promoter, Expression level, GUS staining

中图分类号: 

• Q78

• S572.03