甘薯IbHKT-like基因的克隆与表达分析

Cloning and expression analysis of IbHKT-like gene in sweet potato

植物高亲和钾转运体HKT基因具有Na^(+)(或K^(+))单向运输或Na^(+)-K^(+)共转运作用。为了探究甘薯高亲和钾转运体HKT的离子转运情况及其对非生物胁迫的响应,本研究克隆得到1个甘薯钾离子转运体IbHKT-like基因。生物信息学分析结果表明,IbHKT-like基因序列全长为1647 bp,编码548个氨基酸。IbHKT-like蛋白有2个TrkH(细菌钾转运系统Trk亚基)保守结构域,10个跨膜片段。进化树分析结果表明,IbHKT-like蛋白与旋花科的矮牵牛InHKT6氨基酸序列十分相似,相似度为90.63%。亚细胞定位结果显示,IbHKT-like蛋白主要定位在细胞质膜,在叶绿体中存在少量分布。组织特异性分析结果表明,IbHKT-like基因在叶中表达量最高。实时荧光定量PCR结果显示,IbHKT-like基因的表达受到低温、干旱、高盐及过氧化氢胁迫的诱导,说明IbHKT-like基因可能在甘薯抵御非生物胁迫中发挥着重要的作用。

The plant high affinity potassium transporter HKT gene had Na^(+)(or K^(+))unidirectional transport effect or Na^(+)-K^(+)co-transport effect.To explore the ion transport of high affinity potassium transporter HKT in sweet potato and its response to abiotic stress,a potassium transporter IbHKT-like gene of sweet potato was cloned in this study.Results of bioinformatics analysis showed that,the full length of IbHKT-like gene sequence was 1647 bp,encoding 548 amino acids.The IbHKT-like protein had two TrkH(Trk subunit of potassium transport system in bacteria)conservative domains and ten transmembrane fragments.Results of evolutionary tree analysis showed that,the amino acid sequence of IbHKT-like protein was very similar to that of InHKT6 in petunia of Convolvulaceae,with the similarity of 90.63%.Subcellular localization showed that,the IbHKT-like protein mainly located in the cytoplasmic membrane and rarely located in the chloroplast.Results of tissue-specific analysis showed that,the expression quantity of IbHKT-like gene was the highest in the leaves.The results of real-time fluorescent quantitative PCR showed that,the expression of IbHKT-like gene was induced by low temperature,drought,high salinity and hydrogen peroxide,indicating that IbHKT-like gene may play an important role in the resistance of sweet potato to abiotic stress.