Abstract: The HSF gene cloned from Rigesecent Sedge(Carex rigescens(Franch.)V.Krecz.) is an important heat-resistant candidate gene.A pair of degenerate primers designed against the conserved regions was used to amplify a cDNA segment(189 bp) from the Rigescent Sedge by RT-PCR.Based on the cDNA segment sequence,primers of 3′ RACE were designed and a 902 bp cDNA segment was acquired.The primers of 5′ RACE were designed from 3′ end sequence of the segment and a 323 bp cDNA segment was acquired.The full-length cDNA(identified CrHSF,1226 bp) was gained by overlapping sequences.The sequence analysis indicates that it contains an open-reading frame from 103 bp to 1023 bp,encoding 306 amino acid residues,with 34.93 kDa of predicted molecular mass and 5.77 isoelectric points.The deduced amino acid sequence shows 59% similarity to OsHSF and it also shares significant similarities with other characterized heat shock transcription factor.In addition,the CrHSF contains no predicted signal peptide,but it contains several post-translation modification and processing sites.

Key words: Carex rigescens(Franch.)V.Krecz., Heat shock transcription factor, RT-PCR, RACE, Molecular cloning, Sequence analysis

摘要： 白颖苔草(Carex rigescens(Franch.)V.Krecz.)的热激转录因子基因是重要的耐热候选基因。通过序列多重比对设计简并引物,扩增出白颖苔草的热击转录因子基因cDNA的中间片断,并在此基础上利用RACE技术得到3′端cDNA片段和5′端cDNA片段。结果表明:通过序列拼接获得该基因的全长cDNA(1226bp),命名为CrHSF。序列分析表明其含有一个完整的开放阅读框(103～1023bp),编码蛋白质含有306个氨基酸,分子量为38.75kDa,等电点为5.85。CrHSF的氨基酸序列与OsHSF的同源性为59%,与已知的其他热激转录因子也具有较高的同源性。在CrHSF的氨基酸序列中没有预测到信号肽以及跨膜区域,但是具有多种翻译后修饰的加工位点。

关键词: 白颖苔草, 热激转录因子, RT-PCR, RACE, 基因克隆, 序列分析