小麦热激转录因子TaHsfA2-5的耐热性分析  

Thermotolerance Analysis of Heat Shock Transcription Factor TaHsfA2-5 in Wheat

作　　者：李明月 李孟军 李国良[1] 郭秀林[1] 孟祥照 LI Mingyue;LI Mengjun;LI Guoliang;GUO Xiulin;MENG Xiangzhao(Institute of Biotechnology and Food Science, Hebei Academy of Agriculture and Forestry Sciences/Plant Genetic Engineering Center of Hebei Province, Shijiazhuang 050051, China;2College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China;3Shijiazhuang Academy of Agriculture and Forestry Science, Shijiazhuang 050000, China)

机构地区：[1]河北省农林科学院生物技术与食品科学研究所,石家庄050051 [2]河北师范大学生命科学学院,石家庄050024 [3]石家庄市农林科学院,石家庄050000

出　　处：《西北植物学报》2022年第2期181-189,共9页Acta Botanica Boreali-Occidentalia Sinica

基　　金：河北省自然科学基金项目(C2021301024);河北农科院现代农业创新工程项目(494-0402-JBNS2XB,494-0402-JBN-C7GQ)。

摘　　要：热激转录因子(heat shock transcription factor,Hsf)在真核生物中广泛存在,通过调控下游转录因子、功能酶以及分子伴侣的表达从而响应多种非生物胁迫。该研究以小麦(Triticum aestivum)品种‘沧6005’幼苗为材料,采用同源克隆技术从37℃热胁迫处理的二叶一芯幼叶中克隆目的基因TaHsfA2-5,并分析该基因的亚细胞定位,经农杆菌介导、利用蘸花法转化拟南芥野生型植株,筛选阳性苗进行基础耐热性和获得耐热性分析,并对热胁迫后转基因拟南芥HSR基因的表达进行分析,以探讨小麦热激转录因子TaHsfA2-5基因的生物学功能。结果表明:(1)成功获得小麦热激转录因子基因TaHsfA2-5,该基因编码405个氨基酸,分子量为44.9 kDa;序列比对分析显示,小麦TaHsfA2-5蛋白与大麦HvHsfA2b蛋白相似性最高,达到88.07%。(2)激光共聚焦显微镜观察表明,小麦TaHsfA2-5蛋白定位于细胞核。(3)qRT-PCR分析发现,TaHsfA2-5在小麦成熟的根、雄蕊、雌蕊、萼片、成熟种子以及幼胚中呈现出较高的表达水平;在热胁迫条件下,TaHsfA2-5在小麦叶片以及根中呈现出不同程度的上调表达趋势。(4)表型观察发现,与野生型拟南芥相比,转小麦TaHsfA2-5基因拟南芥能够提高热胁迫下植株的基础耐热性和获得耐热性,同时能够恢复拟南芥缺失突变体AtHsfA2的耐热表型,热胁迫下不同株系叶绿素含量与表型相一致。(5)HSR基因表达分析发现,过表达TaHsfA2-5拟南芥均能够不同程度地上调所检测的HSR基因的表达量,表明小麦TaHsfA2-5基因可能通过调控多个拟南芥热胁迫相关基因的表达,从而增强其热胁迫耐性。Heat shock transcription factor(Hsf)exists widely in eukaryotes and responds to various abiotic stresses by regulating the expression of downstream transcription factors,functional enzymes and molecular chaperones.In this study,the seedlings of wheat(Triticum aestivum)‘Cang 6005’was used as material.The target gene TaHsfA2-5 was isolated from young leaves treated by heat shock at 37℃using homologous cloning method,the subcellular location of the gene was analyzed,and the wild type Arabidopsis thaliana plants were transformed by agrobacterium tumefaciens mediated dip-flower method.The positive seedlings were screened for basal and acquired thermotolerance analysis,and the expression of HSR gene of transgenic Arabidopsis under heat stress was analyzed for exploring the biological function of TaHsfA2-5.The results show that:(1)the wheat heat shock transcription factor TaHsfA2-5 was successfully obtained,which encoded 405 amino acids with a molecular weight of 44.9 kDa.Sequence alignment showed that TaHsfA2-5 protein of wheat had the highest similarity with HvHsfA2b protein of barley,which reached 88.07%.(2)The observation results of laser confocal microscope showed that TaHsfA2-5 was located in the nucleus.(3)qRT-PCR analysis showed that TaHsfA2-5 was highly expressed in mature roots,stamens,pistils,sepals,mature and immature embryos of wheat,and under heat stress,TaHsfA2-5 showed different upregulated expression trends in wheat leaves and roots.(4)Phenotypic observation showed that transgenic Arabidopsis with TaHsfA2-5 could improve the basal and acquired thermotolerance of seedlings under heat stress when compared with wild-type,while restored the thermotolerance phenotype of the deletion mutant AtHsfa2.The chlorophyll content of different lines after heat stress was consistent with the phenotypes.(5)HSR gene expression analysis showed that overexpression of TaHsfA2-5 in Arabidopsis up-regulated HSR gene expression levels to varying degrees,suggesting that TaHsfA2-5 may enhance thermotolerance by regulating

关 键 词：小麦 热激转录因子 TaHsfA2-5 亚细胞定位 特性 

分 类 号：Q785[生物学—分子生物学] Q786