耐盐小偃麦乙烯受体基因TtETR1克隆及表达特性分析  

Cloning and expression characteristics of ethylene receptor gene TtETR1 in response to salt stress in Tritipyrum

作　　者：石鹿溪 田怀志 熊兴伟 穆远航 张菊 何方 张庆勤[1] 张素勤[1,2] SHI Lu-xi;TIAN Huai-zhi;XIONG Xing-wei;MU Yuan-hang;ZHANG Ju;HE Fang;ZHANG Qing-qin;ZHANG Su-qin(College of Agriculture,Guizhou University,Guiyang,Guizhou 550025,China;Guizhou Subcenter of National Wheat Improvement Center,Guiyang,Guizhou 550025,China)

机构地区：[1]贵州大学农学院,贵州贵阳550025 [2]国家小麦改良中心贵州分中心,贵州贵阳550025

出　　处：《南方农业学报》2023年第1期13-21,共9页Journal of Southern Agriculture

基　　金：国家自然科学基金项目(31860380,32160442);贵州省科技计划项目(黔科合平台人才[2018]5781号)。

摘　　要：【目的】克隆耐盐小偃麦的乙烯受体基因TtETR1,并进行表达特性分析,为TtETR1基因的功能分析和小麦耐盐遗传育种提供理论参考。【方法】以耐盐八倍体小偃麦为材料,根据小偃麦转录组数据筛选盐胁迫响应关键基因TtETR1,利用同源克隆技术获得其cDNA序列,利用生物信息学软件进行分析,并通过实时荧光定量PCR(qRT-PCR)检测其在盐胁迫下的表达特性。【结果】TtETR1基因的开放阅读框(ORF)长度为2310 bp,编码769个氨基酸残基,其上游2000 bp启动子包含茉莉酸甲酯与脱落酸信号响应、干旱和厌氧诱导、分生组织表达等作用元件。TtETR1蛋白分子质量为85.76 kD,理论等电点(pI)为6.22,为含跨膜结构的分泌型蛋白,定位于细胞质膜上,二级结构主要由α-螺旋和无规卷曲构成,含有REC_ETR-like、HATPase_ETR2_ERS2-EIN4-like、cGMP磷酸二酯酶-腺苷酸环化酶-FhlA(GAF)、组氨酸激酶(HisKA)等结构域,具有丝氨酸为主、苏氨酸为辅的乙烯信号转导进行磷酸化修饰与调控的位点。盐胁迫下TtETR1基因在根中的相对表达量最高,分别是茎和叶的1.6和2.8倍,且显著高于未盐胁迫处理(对照)(P<0.05),但恢复处理后,TtETR1基因的相对表达量迅速下降至对照水平,与转录组数据分析结果一致。【结论】TtETR1基因在根系中受盐胁迫诱导高效表达,从而提高植物的耐盐性。【Objective】Ethylene receptor gene TtETR1 was cloned from salt-tolerant Tritipyrum,and its expression characteristics were investigated in order to lay foundation for TtETR1 gene function analysis and wheat salt-tolerant breeding.【Method】Tritipyrum(2n=8x=56)was selected as material.According to the previous transcriptome data,special TtETR1 gene was screened from salt-tolerant Tritipyrum under salt stress.The cDNA sequence was obtained by homologous cloningand analyzed by bioinformatics softwares.Real-time quantitative fluorescence PCR(qRT-PCR)was used to detect its expression characteristics under salt stress.【Result】The full-length open reading frame(ORF)of TtETR1 gene was 2310 bp,encoding 769 amino acid residues.The upstream 2000 bp promoter contained functional elements such as methyl jasmonate and abscisic acid signal response,drought and anaerobic induction and meristem expression.The molecular weight of TtETR1 protein was 85.76 kD and the isoelectric point(pI)was 6.22.TtETR1 was a secretory protein with transmembrane structure.It was located in the cell plasma membrane,and contained ethylene receptor ETR,GAF(cGMP phosphodiesterase-adenylylcyclase-FhlA),HisKA(histidine kinase A),and HATPase domains.The secondary structure mainly consisted ofα-helix and random coil.It contained domains like REC_ETR-like,HATPase_ETR2_ERS2-EIN4-like,cGMP phosphodiesterase-adenylate cyclase-FHLA(GAF)and histidine kinase(HisKA),and site for phosphorylation modification and regulation of ethylene signal transduction dominated by serine and supplemented by threonine.The relative expression level of TtETR1 gene in roots under salt stress was the highest,which were 1.6 times and 2.8 times of that in stems and leaves respectively,and significantly higher than that in non-salt stress treatment(control)(P<0.05).However,after restoration treatment,the relative expression level of TtETR1 gene decreased rapidly to the control level,which was consistent with the results of transcriptome data analysis.【Conclusion】TtETR1 gene

关 键 词：小偃麦 盐胁迫 乙烯受体(ETR) 基因克隆 表达水平 

分 类 号：S512.903.53[农业科学—作物学]