Isolation of genes expressed during compatible interactions between powdery mildew (Blumeria graminis) and wheat

Powdery mildew of wheat is an important disease caused by the obligately biotrophic fungus Blumeria graminis. In compatible interactions, the powdery mildew fungus undergoes a series of developmental stages to form haustoria within host cells through which nutrients are obtained. In this study, we utilized the cDNA-AFLP technique to isolate wheat genes expressed at 5 days' post-inoculation. The expression patterns of several sequences identified in the cDNA-AFLP profiling were further investigated by Northern hybridization and RT-PCR analyses. Genes with sequence similarity to GenBank accessions AAR91119, P20076, BT009372, ABA99697, BAD81963 or AAO72574 showed greater expression in susceptible rather than resistant or mock-inoculated leaves. In addition, several sequences with similarity to CAD27894, XM_466672, AAT79487 or AAM64566 were expressed only in the compatible interactions. Possible involvement of these genes in susceptibility of host wheat upon powdery mildew infection is further discussed.