应用RT-PCR、RACE技术，从病原诱导的中间偃麦草叶片cDNA中，分离出1个编码ERF基因的全长cDNA序列，该基因暂命名为TiERF1a，编码由292个氨基酸组成的蛋白质，具有ERF转录因子典型的结构，即保守的AP2/ERF DNA 结合域、核定位位点和酸性激活区。TiERF1a的氨基酸序列与一个水稻ERF蛋白OsBIERF3具有66%的同源性，与拟南芥AtERF1同源性仅39.7%，为植物ERF转录因子家族B3亚群的一个新成员。表达分析结果表明，纹枯病菌、赤霉病菌侵染可诱导TiERF1a基因的上调表达，与防卫相关的激素乙烯、茉莉酸也可诱导该基因上调表达，且TiERF1a对外源乙烯、茉莉酸的响应时期早于对纹枯病菌、赤霉病菌响应时期，说明TiERF1a可能通过乙烯、茉莉酸信号途径参与寄主调控对纹枯病菌、赤霉病菌的防御反应。
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.