小麦热激转录因子基因TaHsfA2-12的特性及耐热性调控功能  

Characteristics and Thermotolerance Regulating Role of Heat Shock Transcription Factor Gene TaHsfA2-12 in Wheat(Triticum aestivum)

作　　者：苑赛男 胡栋[1] 刘畅[3] 彭义峰[4] 张华宁[1] 张玉杰 张园园[1] 于学超 李国良[1] 郭秀林[1] YUAN Sai-Nan;HU Dong;LIU Chang;PENG Yi-Feng;ZHANG Hua-Ning;ZHANG Yu-Jie;ZHANG Yuan-Yuan;YU Xue-Chao;LI Guo-Liang;GUO Xiu-Lin(Institute of Genetics and Physiology,Hebei Academy of Agriculture and Forestry Sciences/Plant Genetic Engineering Center of Hebei Province,Shijiazhuang 050051,China;College of Life Sciences,Hebei Normal University,Shijiazhuang 050024,China;College of Plant Protection,Nanjing Agricultural University,Nanjing 210095,China;Shijiazhuang Academy of Agriculture and Forestry Science,Shijiazhuang 050000,China)

机构地区：[1]河北省农林科学院遗传生理研究所/河北省植物转基因中心,石家庄050051 [2]河北师范大学生命科学学院,石家庄050024 [3]南京农业大学植物保护学院,南京210095 [4]石家庄市农林科学研究院,石家庄050000

出　　处：《农业生物技术学报》2020年第7期1141-1155,共15页Journal of Agricultural Biotechnology

基　　金：国家重点研发项目(2018YFD0300504);河北省自然科学基金重点项目(C2016301085);河北省自然科学基金(C2019301133);河北省现代农业科技创新工程项目(494-0402-YBN-S2XB;494-0402-YBN-C7GQ)。

摘　　要：植物中的热激转录因子(heat shock transcription factors,Hsfs)在耐热性获得、耐热性传代记忆及其他胁迫过程中发挥重要的调控作用。本研究通过同源克隆技术从37℃热胁迫1.5 h的小麦(Triticum aestivum)幼叶中克隆获得一个新的基因TaHsfA2-12(GenBank No.MK931301),其编码序列全长1134 bp,编码377个氨基酸残基。蛋白质序列含DNA结合结构域(DNA binding domain,DBD)、核定位信号序列RRKELAEALLSKKRGR、核输出信号序列LLSLGLE和激活域序列ESFWKELLSL。TaHsfA2-12蛋白质与粗山羊草(Aegilops tauschii)中AtHsfA2蛋白一致性高达98%。通过瞬时转化烟草(Nicotiana tabacum)表皮细胞并经4',6-二脒基-2-苯基吲哚(4',6-diamidino-2-phenylindole,DAPI)染色发现,正常条件下该蛋白定位于细胞核。qRT-PCR分析表明,正常生长条件下TaHsfA2-12在小麦幼嫩和成熟的根、茎、叶以及雌蕊、雄蕊、萼片、幼胚和成熟胚等多个组织中组成型表达,多数组织中表达量较低,成熟种子中表达量较高(P<0.05)。37℃热胁迫和20%PEG6000显著上调TaHsfA2-12的表达(P<0.05),水杨酸(salicylic acid,SA)和过氧化氢则下调该基因表达。表型观察显示,TaHsfA2-12不仅能提高热胁迫下转基因拟南芥(Arabidopsis thaliana)植株的基础耐热性和获得耐热性,还能恢复拟南芥缺失突变体AtHsfA2的耐热表型,不同株系叶绿素含量与表型相一致。不同热胁迫处理后,转基因拟南芥植株多个热激蛋白(heat shock protein,Hsp)基因的表达均高于野生型对照。本研究结果为深入研究小麦Hsfs家族基因特性与功能提供理论依据。Plant heat shock transcription factors(Hsfs)plays a central role in thermotolerance,transgenerational thermomemory and many stress responsive processes.In this paper,a new gene TaHsfA2-12(GenBank No.MK931301)was isolated from young leaves of wheat(Triticum aestivum)treated under heat shock(HS)at 37℃for 1.5 h through homologous clone technique.The CDS length of gene TaHsfA2-12 was 1134 bp encoding 377 amino acids residues.The amino acid sequence of TaHsfA2-12 contained a DNA-binding domain(DBD),a nuclear localization signal of RRKELAEALLSKKRGR peptide,a nuclear export signal of LLSLGLE peptide and an aromatic,large hydrophobic and acidic amino residues of ESFWKELLSL peptide.The TaHsfA2-12 protein shared 98%identities with the AtHsfA2 from Aegilops tauschii.TaHsfA2-12 protein was dyed with 4',6-diamidino-2-phenylindole(DAPI)and observed in tobacco(Nicotiana tabacum)epidermal cells under Confocal,the result revealed that the TaHsfA2-12 was localized in the nuclei under the normal conditions.qRT-PCR revealed that the gene TaHsfA2-12 constitutively expressed in different tissues of wheat under the normal conditions,such as young and mature root,shoot,leaf and pistil,stamen,sepal and embryos.The TaHsfA2-12 expression levels were lower in majority of tissues and higher in mature seed(P<0.05).TaHsfA2-12 was obviously up-regulated by heat shock(HS)and 20%PEG6000,but down-regulated by H2O2 and salicylic acid(SA),respectively.Phenotypes observation indicated that TaHsfA2-12 not only improved the basal thermotolerance and acquired thermotolerance of transgenic Arabidopsis seedlings,but also could rescue the thermotolerance phenotype defect of AtHsfA2 deletion mutant under HS.Chlorophyll content of different lines were consistent with phenotypes.TaHsfA2-12 could activate a suite of heat shock protein(Hsp)genes expression in transgenic Arabidopsis plants after different HS,suggesting molecular mechanism of regulating thermotolerances of TaHsfA2-12.These results will be benefited to deeply investigate the biological character

关 键 词：小麦热激转录因子(TaHsfs) 生物学特性 亚细胞定位 耐热性调控 

分 类 号：S512.1[农业科学—作物学]