小麦NBS-LRR类抗病基因同源cDNA序列的分离与鉴定

Cloning and Character of Resistance Homologenes Contained NBS-LRR in Wheat TcLr24

利用抗病基因的保守结构设计引物,从抗叶锈病近等基因系材料TcLr24中扩增出一条703bp的条带RGA1,通过与GenBank比对,选取与RGA1高度同源的若干条带,在它们共有的保守序列位置设计引物,利用cDNA末端快速扩增(RACE)技术扩增抗病同源基因cDNA全长。扩增到3条全长cDNA,经BLASTp比较,这些序列都含有NBS保守结构域和多个LRR结构域,与很多已知植物抗病基因的功能相应区域一致。对FRGA-1、FRGA-2和FRGA-3实时定量PCR分析,表明这3个基因在小麦叶片中都是组成型表达。本研究在小麦材料TcLr24中得到3条抗病基因同源cDNA全长,为研究小麦抗病基因奠定了基础。

Resistance gene cDNA homology sequence from wheat was isolated using homology-based method.The primers were designed according to the conserved sequence of resistance gene analogs and a 703bp fragment was isolated from TcLr24.A few homologous sequences were captured when processing similarity search in GenBank database.We designed primers based on highly conserved region among the above sequences and the rapid amplification cDNA ends（RACE）was used to obtain the full length sequence of disease resistance homology gene in the TcLr24 near isogenetic lines.Three full length cDNA sequences were obtained.BLASTp analysis showed that the deduced amino acids of protein contained a NBS conserved domain and many leucine-rich repeats（LRR）domains,which were identical to the conserved domains of many plant resistance genes.These sequences appeared not to be induced by Puccinia triticina and were constitutive genes in the wheat leaf tissue by real-time PCR.In this study,we obtained three resistance homology sequences which provide the short cut for researching of wheat resistance gene.