蒋薇 靳容 刘明 赵鹏 张爱君 王丹凤 李铁鑫 范文静 唐忠厚

摘要： 植物高親和钾转运体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1 647 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。

关键词： 甘薯;IbHKT-like基因;基因克隆;表达分析;亚细胞定位

中图分类号： Q786   文献标识码： A   文章编号： 1000-4440（2021）04-0831-08

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

JIANG Wei1， JIN Rong1， LIU Ming1， ZHAO Peng1， ZHANG Ai-jun1， WANG Dan-feng1， LI Tie-xin2，FAN Wen-jing2， TANG Zhong-hou1

（1.Xuzhou Institute of Agricultural Sciences of Xuhuai District of Jiangsu Province/Sweet Potato Research Institute，Chinese Academy of Agricultural Sciences，Xuzhou 221131，China;2.College of Agronomy，Anhui Agricultural University，Hefei 230036，China）

Abstract： 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 1 647 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.

Key words： sweet potato;IbHKT-like gene;gene cloning;expression analysis;subcellular localization

钾元素约占地壳总质量的2.1%～2.3%，是地球上第七大元素，同时钾作为作物生长所必需的大量矿质营养元素之一，对于作物的生长、产量、品质以及作物对非生物环境胁迫的适应均十分重要[1]。但中国土壤中有效钾含量偏低，且低钾胁迫现象在中国甘薯种植区十分普遍，成为甘薯优质高产的主要制约因素之一。

高亲和钾离子转运体HKT（High-affinity K+ transporter）是Na+（K+）单向转运体或Na+-K+共转运体的总称，它由N端短胞质区、C端短胞质区及1个带有4个重复MPM基序（1TMS-1P-1TMS）区域的疏水核心结构组成，每个基序由2个跨膜区域和1个保守的成孔结构域（P-loop）组成。……