Abstract:The EST-3 related to the powdery mildew in the wheat was amplified by in silico cloning.And the cDNA sequence had been confirmed by RT-PCR.The result indicated that a new sequence with 875 bp length was cloned,which contained an integrated ORF,encoding 229 amino acids,GenBank accession number is JK841279.Based on domain structure,it has GST domain structure in N-terminal and C-terminal.The trend of EST-3 expression by RT-PCR was very identity to the expression by SSH-cDNA,and their sequences have 98% consistency.As showed that the result of in silico cloning was right.The amino acid sequence showed highly comparability with the glutathione-S-transferase(GST) from GenBank,and their sequences have 97% consistency.Expression analysis revealed that the expression of GST in wheat was inhibited after infection by powdery mildew for 24 h,then it began to express after infection for 48 h and increased gradually.It reached the highest level after infection for 72 h,and decreased after infection for 96 h.The result suggested that GST belong to the gene induced by powdery mildew,and it might be involved in powdery mildew response of wheat.