叶锈菌与‘TcLr19’小麦互作体系中PR1基因的克隆及分析

利用RT-PCR和cDNA末端快速扩增技术(RACE),从被小麦叶锈菌诱导的抗叶锈病近等基因系材料TcLr19中获得1个病程相关蛋白1(Pathogenesis-related proteins 1,PR1)基因,暂命名为TcLr19PR1。该基因长度为810bp,包含495bp ORF区,编码164个氨基酸,基因产物具有植物防御体系中病程相关蛋白SCP保守结构域,与多个植物病程相关蛋白1基因具有较高同源性。利用半定量分析表明,TcLr19PR1基因受叶锈菌诱导后表达量变化明显,非亲和组合表达高于亲和组合。Southern杂交验证说明TcLr19PR1在小麦基因组中为低拷贝。利用‘中国春’缺体-四体系成功将该基因定位在小麦7D染色体上,为进一步明确叶锈菌与‘TcLr19’小麦互作体系中病程相关蛋白1基因的抗叶锈相关性奠定了基础。

Cloning and analysis of a PR1 gene from TcLr19 wheat in the defense responses to Puccinia triticina

Plant pathogenesis-related proteins have an important role in plant disease resistance responses and systemic acquired resistance.In this paper,RT-PCR and RACE were combined to isolate a plant pathogenesis-related protein 1 gene which was named as TcLr19PR1 tentatively from the near-isogenic lines ’TcLr19’ induced by leaf rust pathogen.The TcLr19PR1 gene was 810 bp in length and consisted of an open reading frame(ORF) of 495 bp encoding 164 amino acids and containing a conserved domain of pathogenesis related protein SCP.The TcLr19PR1 gene had a high homology with most of plant pathogenesis-related protein 1 genes.Semi-quantitative PCR showed that the expressive quantity of TcLr19PR1 gene induced by leaf rust pathogen had a visible change.However,expression in incompatible interactions was higher than that of compatible interactions,which indicated that the gene may be involved in wheat resistance response.TcLr19PR1 gene had low copies in the wheat genome demonstrated by Southern blot.The TcLr19PR1 gene had been located on chromosome 7D by nulli-tetrasomic lines of ’Chinese Spring’,which provide a shortcut for further researches in the leaf rust resistance of pathogenesis-related protein 1 gene.