甘薯组氨酸激酶蛋白IbHK5响应干旱和盐胁迫的功能分析  

Functional analysis of the sweetpotato histidine kinase protein IbHK5 in response to drought and salt stresses

作　　者：霍如雪 葛祥菡 石嘉 李雪蕊 戴圣杰 刘振宁 李宗芸 HUO Ru-Xue;GE Xiang-Han;SHI Jia;LI Xue-Rui;DAI Sheng-Jie;LIU Zhen-Ning;LI Zong-Yun(College of Agriculture and Forestry Sciences,Linyi University,Linyi 276000,Shandong,China;School of Life Sciences,Jiangsu Normal University,Xuzhou 221116,Jiangsu,China)

机构地区：[1]临沂大学农林科学学院,山东临沂276000 [2]江苏师范大学生命科学学院,江苏徐州221116

出　　处：《作物学报》2025年第3期650-666,共17页Acta Agronomica Sinica

基　　金：财政部和农业农村部国家现代农业产业技术体系建设专项(CARS-10);江苏省高校生物学优势学科建设项目(PAPD);国家自然科学基金项目(32070344);山东省高等学校青创科技计划项目(2021KJ055)资助。

摘　　要：组氨酸激酶是植物双组分信号系统中的一类重要元件,参与了植物生长发育、逆境响应等多种生物学功能。本研究在甘薯中鉴定到一个与拟南芥AHK5同源的基因Ib HK5。亚细胞定位研究表明,Ib HK5蛋白主要定位于细胞质和细胞核中。利用拟南芥异源超表达和甘薯发状根遗传转化技术研究了Ib HK5参与干旱胁迫和盐胁迫的生物学功能。结果表明,Ib HK5在拟南芥中的异源超表达能够增强拟南芥的耐旱性和耐盐性,超表达株系中表现出较高的POD、SOD和CAT酶活,较少的H_(2)O_(2)和O^(2-)的积累,以及相对表达量较高的POD、SOD、CAT和GPX等ROS清除系统相关基因。同样,Ib HK5在甘薯中的超表达也能增强甘薯的耐旱性和耐盐性,甘薯发状根也表现出较高的POD、SOD和CAT酶活,较少的H_(2)O_(2)和O^(2-)的积累。酵母双杂交试验表明,Ib HK5能与拟南芥AHP1、AHP2、AHP3和AHP5蛋白互作。上述结果证实Ib HK5是参与干旱胁迫和盐胁迫的一个正调控因子。研究结果有助于解析甘薯抵御干旱胁迫和盐胁迫的生理机制与分子机制,也能够为耐干旱、耐盐的甘薯定向改良和品种选育提供一定的理论依据。Histidine kinase is a key component of the two-component system in plants,playing a crucial role in regulating plant growth,development,and responses to various stresses.In this study,IbHK5,a histidine kinase homologous to Arabidopsis AHK5,was identified in sweetpotato.Subcellular localization analysis revealed that the IbHK5 protein is localized in both the cytoplasm and nucleus.To investigate its biological function in response to drought and salt stress,IbHK5 was ectopically expressed in Arabidopsis and overexpressed in sweetpotato using an Agrobacterium rhizogenes-mediated in vivo root transformation system.The results showed that overexpression of IbHK5 in Arabidopsis enhanced both drought and salt tolerance.The transgenic plants exhibited higher activities of POD,SOD,and CAT enzymes,lower levels of H_(2)O_(2) and MDA,and increased expression of stress-related genes,including AtPOD,AtSOD,AtCAT,and AtGPX.Similarly,overexpression of IbHK5 in sweetpotato enhanced drought and salt tolerance,with transgenic hairy roots showing elevated POD,SOD,and CAT enzyme activities as well as reduced H_(2)O_(2) and MDA content.Furthermore,yeast two-hybrid assays demonstrated that IbHK5 interacts with Arabidopsis proteins AHP1,AHP2,AHP3,and AHP5,indicating its involvement in signal transduction pathways.These results suggest that IbHK5 is a positive regulator of drought and salt stress tolerance.This study provides insights into the physiological and molecular mechanisms underlying drought and salt stress responses in sweetpotato and offers a theoretical foundation for the genetic improvement and breeding of drought-and salt-tolerant sweetpotato varieties.

关 键 词：甘薯 双组分信号系统 组氨酸激酶 IbHK5 干旱胁迫 盐胁迫 

分 类 号：S531[农业科学—作物学]