蚕豆耐盐相关基因VfHKT1;1的克隆、生物信息学分析及表达特性

Cloning,bioinformatics analysis and gene expression pattern of VfHKT1;1 in Vicia faba L.

高亲和性钾离子转运蛋白(high affinity K+transporter,HKT)能够调节细胞及整株的Na+/K+转运,在植物盐胁迫调控中发挥着重要作用。采用RT-PCR和PCR方法克隆获得蚕豆VfHKT1;1基因全长编码序列,该基因包含1659 bp的开放阅读框,编码552个氨基酸。系统进化树分析发现,该蛋白属于HKT第Ⅰ亚家族,命名为VfHKT1;1,且VfHKT1;1蛋白氨基酸序列与苜蓿MtHKT1;1的序列相似度最高。生物信息学分析发现,VfHKT1;1蛋白结构稳定,不具有信号肽结构,含有8个跨膜区域,且蛋白含有HKT家族典型的保守结构域TrKH,属于典型的跨膜离子转运体。实时荧光定量PCR分析表明,VfHKT1;1基因的表达具有明显的组织特异性。在盐胁迫诱导下,VfHKT1;1基因在根中的表达水平受到抑制,而在叶片中的表达水平上升,且在盐处理1h后达到最高值,随后随着盐处理时间的延长又逐渐下降。

High affinity K+transporter(HKT)involve in salt tolerance response through maintaining Na+/K+homeostasis in cellar and whole plant.VfHKT1;1 gene was cloned using RT-PCR and PCR in this work and the gene encoded an open reading frame(1659 bp)consisting of 552 amino acids.Phylogenetic tree analysis indicated that VfHKT1;1 belong to HKT subfamilyⅠand shared the highest sequence similarity with MtHKT1;1,so it was named as VfHKT1;1.The bioinformatics analysis showed that VfHKT1;1 was stable,which also contained 8 transmembrane regions and no signal peptide.It was supposed to be an ion transporter which usually located at membrane because it contains a typical TrKH conserved functional domain of HKT family.Real-time fluorescent quantitative PCR showed different expression levels of VfHKT1;1 gene in root and leaf.The expression of VfHKT1;1 gene in root was suppressed under salt stress.Whereas it had higher transcript levels in leaf under salt stress,the expression peak appeared at 1 h after NaCl treatment.Then,the expression level of VfHKT1;1 gene gradually declined with the NaCl treatment time.