[ESTs analysis of resistance to powdery mildew in wheat at primary infected stage]

A wheat line, Bai Nong 3217 x Mardler BC5F4 with resistance to powdery mildew was used in the study. A suppression subtractive hybridization cDNA library was constructed from wheat leaves challenged by Erysiphe graminis DC at primary stage. Seven hundred and sixty ESTs were acquired, and the ESTs similarity analysis based on BLASTx software was finished by comparing sequences in nr database of GenBank. Two hundred and seventy one ESTs' functions were identified in the total ESTs. The results showed that GTP-binding proteins associated signal pathway, salicylic acid pathway, MAP pathway etc were supposed to involved in the disease resistance reaction. SAR genes were rich not only in varieties but also in quantity, including five kinds of phyogenesis-related proteins, induced defence-resistance genes, heat shock proteins and genes induced by abiotic-stresses etc. There are lots of evidence to testify PAL pathway, cell wall modification, cell survive system serving in the disease resistance. In the function unknown ESTs, many homologous ESTs were found from other biotic and abiotic-stresses selected cDNA libraries after BLASTn analysis, the stresses included pathogen, salt, drought, cold, high temperature etc. The novel ESTs was 16.6% in total ESTs.