中国农业科学 ›› 2006, Vol. 39 ›› Issue (8): 1558-1564 .

• 植物保护 • 上一篇    下一篇

小麦NBS-LRR类抗病基因同源序列的分离与鉴定

王海燕,杨文香,刘大群   

  1. 河北农业大学植物保护学院
  • 收稿日期:2005-11-23 修回日期:1900-01-01 出版日期:2006-08-10 发布日期:2006-08-10
  • 通讯作者: 王海燕 wanghaiyan wanghaiyan

Isolation and Characterization of NBS-LRR Resistance Gene Homology Sequences from Wheat

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  1. 河北农业大学植物保护学院
  • Received:2005-11-23 Revised:1900-01-01 Online:2006-08-10 Published:2006-08-10

摘要: 【目的】拟利用同源序列法分离小麦抗病基因同源片段。【方法】根据已克隆植物抗病(R)基因NBS-LRR保守区段设计两对引物,采用RT-PCR方法对小麦抗叶锈病近等基因系材料TcLr35 的RNA进行扩增。【结果】 获得了3个通读的小麦抗病基因NBS-LRR类抗病基因同源片段PS13-1、PS13-2和S2A2,长度分别为239bp、289bp和539bp,编码78、84和177个氨基酸。核苷酸比较分析表明,PS13-1和PS13-2与已克隆小麦抗白粉病基因PM3b同源性为91%;S2A2与大麦一个来源于mRNA的同源片段同源性为91%;经BLASTp比较,3个片段均含有NB-ARC保守结构域,与已知抗病基因I2C-1,L6,RPS2等相应区域相一致,具有抗病基因NBS特征结构域(P环、激酶2a等)。Northern杂交分析表明,3个同源片段在小麦叶片中为低丰度组成型表达。【结论】本研究在TcLr35小麦中成功获得了抗病基因同源序列,为最终克隆小麦抗叶锈病基因奠定了基础。

关键词: 小麦抗叶锈病基因, NBS-LRR, 同源序列

Abstract: 【Objective】In this study, resistance gene homology fragments from wheat were isolated using homology-based method. 【Method】Two pairs of primers were designed according to the amino acid conserved regions NBS-LRR of the cloned plant disease resistance genes, and the reverse transcription-polymerase chain reaction (RT-PCR) was used.【Result】Three open-reading NBS resistance gene analogues (RGAs) have been obtained. They were named as PS13-1, PS13-2, and S2A2 respectively from the RNA of TcLr35 carrying the Lr35 gene conferring resistance against wheat leaf rust by a reverse transcription-polymerase chain reaction (RT-PCR). The nucleotide sequences of the three RGAs were 239bp, 289bp and 539bp encoding 78, 84 and 177 amino acids respectively. Homology research showed that the nucleotides of PS13-1 and PS13-2 were 91% identical to wheat powdery mildew resistance gene PM3b, and the nucleotide of S2A2 was 91% identical to the sequence from the mRNA of barley. BLASTp analysis indicated that three RGAs contained the conserved motifs of NB-ARC (such as P-loop, kinase2, kinase3a and transmembrance domain). Northern hybridization showed that the RGAs expression was not induced by Puccinia recondite inoculation suggesting that the gene be a constitutive gene with low abundance in wheat. 【Conclusion】In this study, three resistance homology sequence were obtained in TcLr35, which provide the shortcut for the cloning of wheat leaf rust resistance genes.

Key words: Wheat leaf rust resistance gene, NBS-LRR, Homology sequence