Analysis of the Blumeria graminis-enhanced Expression of Three Wheat Genes
NIU Ji-Shan YU Ling CHEN Pei-Du LIU Da-Jun (Key Open Laboratory of Agriculture Ministry for Crop Cytogenetics, Nanjing Agricultural University, Nanjing 210095)
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.