苹果属垂丝海棠钾转运基因MhHAK5的克隆及耐低钾功能鉴定

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中图分类号：S661.1：Q781 文献标识号：A 文章编号：1001-4942（2025）06-0028-09

AbstractPotassium （K）is one of the essential mineral elements for plant growth and development， which is very important for yield and quality formation. HAK5 is an important high-affinity K transporter gene， which mainly mediates K uptake under low K conditions.However，litle is known about the functional role of HAK5 in Malus. In this study，Malus haliana was used as experimental material，and its HAK5 （MhHAK5） gene was cloned and analyzed.The physicochemical properties and tissue expression specificity were analyzed by bioinformatics analysis，and the response to low K was studied through overexpressing MhHAK5 in Arabidopsis thaliana by genetic transformation.The results showed that the full length of MhHAK5 gene was 1 830 bp with the open reading frame （ORF）as 1695bp ，and it encoded 518 amino acids. The MhHAK5 protein had the molecular weight of 60.05kDa and the isoelectric point of 7.45， had four transmembrane structures， was an unstable hydrophilic transmembrane protein，and was located in nucleus.Phylogenetic analysis showed that MhHAK5 had the highest similarity with AtHAK5，AtHAK1O in Arabidopsis thaliana and OsHAK5 in rice.Furthermore，it had Ser-Gly-Gly-Gly amino acid sequence.The results of tissue expresson specificity analysis showed that MhHAK5 had the highest expression level in roots of M. halliana，and was induced by low potassium. Compared with wild type （WT），overexpression of MhHAK5 could effctively improve K+ absorption and growth-promoting plant hormone synthesis of Arabidopsis plants under low K conditions，thus ensuring root development.In summary，MhHAK5 played an important role in response to K deficiency stress.The results ofthis study could provide theoretical bases for gene improvement and breeding of K deficiency tolerant apple rootstocks.

KeywordsMalus haliana ; MhHAK5 gene； Bioinformatics analysis; Potassium deficiency stress ； Geneexpression

钾（K）是植物必需的矿质养分之一，与氮、磷的利用方式不同，K在植物体中不会被同化为有机物，主要以钾离子（ K+ ）形态存在并发挥作用[1]。（剩余13010字）