小麦抗叶锈近等基因系TcLr38抗病相关基因片段的分离

Isolation of Resistance-related Gene Fragments from Wheat Near-isogenic Line TcLr38 against Leaf Rust

利用差异显示技术,分析小麦TcLr38受小麦叶锈菌诱导的mRNA表达丰度差异,获得了136条差异条带。对136条差异条带进行了回收、重扩增和反向Northern杂交检测,获得一条杂交信号阳性的片段,对该片段进行克隆、测序,该片段长度为425bp。在GenBank中进行Blast比对分析,与普通小麦(Triticum aestivum)同源性较高,并且与小麦抗盐cDNA序列也有较高的同源性;在GrainGenes中进行Blast比对,与小麦的远源亲本粗山羊草(Aegilops tauschii)、栽培一粒小麦(T.monococ-cum)和普通小麦具有较高同源性。利用SegMan软件进行电子克隆延长该片段,未找到与其相符的重叠群。因此确定该片段为TcLr38的cDNA片段,并初步推测该片段可能为一小麦抗病相关基因片段。

mRNA differential display technique was employed to isolate differentially expressed cDNA fragments from TcLr38 induced by inoculated Puccinia recondita f. sp. tritici. One hundred and thirty six differential cDNA fragments were obtained,then reamplified and detected by reverse Northern bloting. One differential fragment expressed positive signal was cloned into T-easy vector and sequenced. The length of the differential fragment was 425bp, and the sequence was compared with database in GenBank and GrainGenes by Blast program. The cDNA fragment had high homology with Triticum aestivum and a wheat salt-stressed sheath cDNA clone in GenBank, and had a high homology with Aegilops tauschii, T. monococcum,and the T. aestivum in the GrainGenes. The cDNA sequence can＇t be elongated by using the election clone method by SegMan soft. The results revealed the cDNA fragment derived from the TcLr38 may be a gene fragment related with resistance.