Abstract: Thinopyrum intermedium is a wild wheat-relative that possesses multi-resistances to wheat diseases. In order to understand its defense mechanism, a pathogen-inducible ERF gene, tentatively named TiERF1a, was isolated from leaf cDNA of Thinopyrum intermedium through RT-PCR and RACE approach. The TiERF1a protein contains a conserved AP2/ERF DNA binding domain, a nuclear localization site and a transcription activation domain. The amino acid sequence of TiERF1a shares 66.3% homology with OsBIERF3 and 39.7% homology with AtERF1a. The TiERF1a gene encodes a protein belonging to one new member of B3 subgroup of ERF transcription factor family. The expression of TiERF1a was induced respectively by Rhizoctonia cerealis and Fusarium graminearum, as well as ethylene and methyl jasmonate (MeJA). However, the induced expression of TiERF1a by MeJA and ethylene was earlier than that by the pathogen infection, suggesting the MeJA and ethylene pathways may be involved in regulating the host defence responses.

Key words: Thinopyrum intermedium, Ethylene-responsive factor (ERF), Transcription factor, Cloning, Expression