小麦3个被白粉菌诱导基因表达的分析

Analysis of the Blumeria graminis-enhanced Expression of Three Wheat Genes

含有抗白粉病基因Pm2 1的小麦 簇毛麦 6VS/6AL易位系在接种白粉菌后 ,叶片无任何病症。应用mRNA差异显示技术从小麦 簇毛麦 6VS/ 6AL易位系分离到 3个叶绿体蛋白基因片段 ,它们是TaD5、TaD2 3和TaD33,3个基因片段分别与小麦叶绿体基因rbcL ,拟斯卑尔脱山羊草叶绿体RNA聚合酶α亚基基因rpoA和大麦 1,5 二磷酸核酮糖羧化酶活化酶基因(Rubiscoactivase ,RcaA2 )同源性达 97%、98%和 88%。据此推测TaD5、TaD2 3和TaD33分别是 6VS/ 6AL易位系中的rbcL、rpoA和 1,5 二磷酸核酮糖羧化酶活化酶基因的片断。Northern分析表明这 3个叶绿体基因的表达在白粉菌诱导下得到增强。

The leaves of Triticum aestivum-Haynaldia villosa 6VS/6AL translocation line 92R137 containing powdery mildew resistance gene Pm21 shows no disease symptoms after inoculation with Blumeria graminis. To understand the resistance mechanism, mRNA differential display was used to isolate genes up-regulated by Blumeria graminis infection, from the translocation line 92R137 (Fig.1). Sequence and homology analysis showed that three of the cloned gene fragments were shown to be parts of the chloroplast protein genes. The TaD5 exhibited 97% homology to T. aestivum chloroplast gene rbcL for large subunit of ribulose 1,5-bisphosphate carboxylase/oxygenase (Fig. 3), TaD23 revealed 98% homology to Aegilops speltoides chloroplast rpoA gene and TaD33 showed 88% homology to Hordeum vulgare Rubisco activase gene (Fig.4). Northern analysis showed that the three genes' expression was enhanced by Blumeria graminis infection (Fig.2). These results suggested that the capacity of chloroplast RNA transcription and CO 2 absorption were increased. These may supply material and energy for resistant reaction against powdery mildew.