Isolation and Identification of Differentially Expressed Genes from Wheat in Response to Blumeria graminis f. sp. tritici (Bgt)

Wheat powdery mildew, caused by the fungal pathogen Blumeria graminis f. sp. tritici ( Bgt ), is a serious wheat disease both in China and worldwide. Finding and cloning the key resistance genes to Bgt are important for wheat breeding. In this study, 23 differentially expressed genes were isolated by GeneFishing from the hybrid wheat alien disomic addition line germplasm SN6306, which is highly resistant to powdery mildew. SN6306 originated from the intergeneric hybridization between wheat Yannong 15 and Elytrigia intermedium (Host) Nevski. Among the 23 genes, a gene encoding for auxin-repressed protein ( TaARP1 ) was selected for further study, and its full-length complementary DNA (cDNA) and DNA sequences were obtained. The function of TaARP1 was investigated by real-time quantitative reverse transcription PCR and Barley Stripe Mosaic Virus-mediated gene silencing. Results showed that, after inoculation with Bgt , the expression of TaARP1 was upregulated more than ten times compared with non-inoculated controls. Ten days after inoculation with powdery mildew, BSMV: TaARP1 leaves clearly showed higher susceptibility to mildew infections than BSMV:00 leaves. Powdery mildew colonies and mycelia development were analyzed by microscopic observation. These data suggested that TaARP1 may be involved in the response to Bgt and may be a potential resistance gene to wheat powdery mildew.