为深入研究胡杨的抗盐分子机制,并获得与之相关的抗逆基因,采用SMART技术构建了胡杨盐胁迫处理cDNA文库。经随机测序,得到一个编号为SSL061的EST序列,与欧美杨的脱水素基因有较高相似性,通过PCR快速扩增文库的方法获得了胡杨脱水素基因(Pedhn)。分析表明,该cDNA的长度为813 bp,拥有681 bp的开放读码框,共编码227个氨基酸。该序列包括两个重复的富含赖氨酸的K片段和由7个连续的丝氨酸残基组成的S片段,但是缺乏Y片段。RT-PCR结果表明,胡杨在未受胁迫的情况下脱水素基因的转录水平较低,而随着盐胁迫浓度的升高,脱水素基因的转录水平总体呈上升趋势。
In order to study the molecular mechanism of resistance to salt stress of the Populus euphratica and obtain their resistance genes,cDNA library has been constructed by using SMART(Switching Mechanism at 5'end of RNA Transcript) technology.The sequence of SSL061,one of ESTs,shows similar to P.euramericana dehydrin.Then the open reading frame(ORF) encoding dehydrin screened from P.euphratica cDNA library is characterized.The cDNA,designated Pedhn,is 813 nucleotide long and has a 681bp ORF with a 227 residues deduced amino acid sequence.The Pedhn sequence contains two conserved repeats of the characterized lysine-rich K-segment preceded by a 7-serine residue stretch,but the Y-segment conserved motif is absent.In unstressed poplar,transcriptional level of Pedhn is low,and Pedhn which is induced by salt stress is clearly detected.