【摘要】 AKT1 (Arabidopsis potassium transport 1)是重要的钾通道蛋白基因,参与植物钾吸收和转运过程。为了探究梨(Pyrus betulifolia) PbAKT1基因对钾的响应及表达模式,本研究采用不同浓度K+处理杜梨幼苗,对PbAKT1基因进行克隆并对其所编码的蛋白进行组织特异性分析。结果表明,克隆获得的PbAKT1基因(GenBank No. MN150549) cDNA全长2 646 bp,编码881个氨基酸,有Shaker家族典型的S1～S6的跨膜结构和1个loop环;氨基酸序列的同源关系分析表明,梨PbAKT1基因与苹果(Malus domestica) MdAKT1基因的亲缘关系最近;亚细胞定位发现,该基因主要定位于细胞膜上,为亲水性稳定蛋白;PbAKT1基因在梨苗根、茎、叶片中都有表达,不存在组织特异性;缺钾条件下,该基因有明显响应。综上所述,梨PbAKT1的表达受到缺钾胁迫的诱导,可能参与梨树K+吸收和转运过程。本研究结果为进一步揭示梨树耐低钾分子机制提供基础了资料。更多还原

【Abstract】 AKT1(Arabidopsis potassium transport 1) is an important potassium channel protein gene involved in plant potassium absorption and transport. In order to study the response and expression pattern of PbAKT1 gene in Pyrus betulifolia to potassium, this study adopted K+at different concentrations(0.1 mmol/L and 3 mmol/L K+) to treat pear seedlings, cloned PbAKT1 gene and analyzed the tissue specificity of its encoded protein. Results showed that the PbAKT1 gene(GenBank No. MN150549) cDNA was 2 646 bp in length,encoding 881 amino acids. The gene had a transmembrane structure with a typical S1～S6 of the Shaker family and a loop ring. The homology analysis of amino acid sequence indicated that there was a close phylogenetic relationship between PbAKT1 gene and MdAKT1 gene(Malus domestica). Subcellular localization showed that the gene mainly presented in the cell membrane and was a hydrophilic stable protein. PbAKT1 gene was found no tissue specificity in roots, stems and leaves of pear seedlings and its expression obviously responded to low potassium stress. It was indicated that the expression of PbAKT1 was induced by potassium supply and might be involved in K+absorption and transport of pear trees. It provides basic information for further research of the molecular mechanism to low potassium stress in pear.更多还原