中文摘要：

小分子热激蛋白（s HSP）不仅在应激条件下高效表达,还在正常状态的细胞中广泛存在,参与一些重要细胞生理活动的调节。为研究坛紫菜应答高温和失水等逆境胁迫的分子机制,本研究以坛紫菜转录组测序获得的unigene序列为基础,采用RACE或直接PCR扩增,克隆获得了坛紫菜2种s HSP的全长基因：Ph Hsp22和Ph Dna J。序列分析结果表明,Ph Hsp22序列全长857 bp,包含一个519 bp的开放阅读框,所编码的多肽包含172个氨基酸,分子量为19.1 ku,等电点为5.24（收录号：KM102540）;Ph Dna J序列全长1 616 bp,包含一个1 290 bp的开放阅读框,所编码的多肽包含429个氨基酸,分子量为46.1 ku,等电点为6.43,属于Hsp40亚家族（收录号：KM102541）。基因表达水平的定量分析结果表明,两个基因在高温胁迫不同时间水平和不同失水胁迫程度下的表达均呈现出一致的表达模式,即在胁迫初期表达水平显著上调,但随着胁迫的持续,这两个基因的表达水平开始逐渐下调。结果表明,这2个基因在逆境胁迫下的表达可能存在一个反馈调节机制。

英文摘要：

Small heat shock proteins（sHsp）,representing an important molecular chaperone in eukaryotic cells,play important roles not only in a variety of stress responses,but also in development and signal transduction of normal cell.In this study,based on unigene sequences which were obtained from whole transcriptome sequencing of Pyropia haitanensis,two full-length s HSP genes were obtained by rapid amplification of cDNA ends（RACE） or direct PCR,which named Ph Hsp22 and PhDnaJ.The full-length cDNA of the Ph Hsp22 gene comprised 857 nucleotides and contained an open reading frame of 519 bp（Gen Bank accession：KM102540）,encoding a protein of 172 amino acid residues with the predicted molecular weight of 19.1 ku and theoretical isoelectric point of 5.24;the full-length cDNA of the PhDnaJ gene comprised 1 616 nucleotides and contained an open reading frame of 1 290 bp（Gen Bank accession：KM102541）,encoding a protein of 429 amino acid residues with the predicted molecular weight of 46.1 ku and theoretical isoelectric point of 6.43.On the basis of conserved motifs and phylogenetic tree analysis,PhDnaJ belongs to the subfamily of Hsp40.The expressions of the two genes,as measured by real-time quantitative PCR,were significantly induced by high-temperature stress and desiccation stress,and had identical expression patterns：during high-temperature and desiccation stress,the expression levels of the two genes all significantly increased firstly and then decreased.These results suggested that the expressions of Ph Hsp22 and PhDnaJ genes are feedback regulated by high-temperature and desiccation stresses.