中文摘要：

TaPIM1是从小麦中克隆获得的1个病原诱导的小麦MYB基因,编码由323个氨基酸残基组成的蛋白TaPIM1。TaPIM1具有R2R3类MYB转录因子的典型结构,即2个保守的MYBDNA结合域（R2和R3）、核定位位点和酸性激活区。TaPIM1的全长氨基酸序列与已克隆MYB蛋白的一致性仅为43.69%以下,为植物MYB转录因子家族R2R3亚群的一个新成员。小麦纹枯病菌（Rhizoctonia cerealis）、根腐病菌（Bipolaris sorokiniana）侵染可快速诱导抗病小麦中TaPIM1基因的上调表达,说明TaPIM1可能参与小麦对纹枯病菌、根腐病菌的防御反应。将TaPIM1基因构建到由组成型强启动子CaMV35S控制的双子叶转化载体pBI121上,通过农杆菌介导法将其转入烟草W38品系。通过卡那霉素抗性筛选和PCR检测,鉴定出转TaPIM1基因烟草T0代株系M66、M102、M110等12个株系。对转基因烟草T1代株系进行PCR、RT-PCR分析和青枯病菌抗性分析,结果表明,TaPIM1超量表达的转基因烟草株系M66、M102和M110对青枯病菌（Ralstonia solanacearum）的抗性显著高于未转基因烟草对照,TaPIM1正向调控烟草对某些病原菌的防御反应。

英文摘要：

In plants,MYB transcription factors play various roles in developmental processes and in responses to biotic and abiotic stresses.In this paper,a pathogen-induced MYB gene of wheat,TaPIM1,was isolated from cDNAs of wheat leaves inoculated with Rhizoctonia cerealis.TaPIM1 gene encodes a protein TaPIM1 consisting of 323 amino acids.TaPIM1 protein contains two MYB DNA binding domains（R2,R3）,two nuclear localization sites and two transcription activation domains.The en-tire sequence of TaPIM1 protein shares a low identity of below 43.69% with other plant MYB proteins.TaPIM1 is a new member of R2R3 type of MYB transcription factors of transcription families.The transcript of TaPIM1 was obviously upregulated after challenge with fungal pathogens Rhizoctonia cerealis or Bipolaris sorokiniana,respectively.The gene transformation vector pBI-35S：TaPIM1 was constructed,in which the TaPIM1 was driven by the CaMV 35S promoter.The vector pBI-35S：TaPIM1 was transferred into tobacco cultivar W38 by Agrobacterium-mediated transformation method.Twelve TaPIM1 transgenic tobacco lines,such as M66,M102 and M110,were obtained through screening.The T1 plants of these transgenic lines were subjected to PCR,RT-PCR analyses and evaluated for Ralstonia solanacearum resistance.The results showed that three transgenic lines,including M66,M102,and M110,overexpressed TaPIM1 and showed significantly enhanced resistance to R.solanacearum compared with the host tobacco W38 plants.The resistance degree was correlated with the transcript level of the TaPIM1 in these transgenic lines.These results suggested that TaPIM1 may positively modulate defense response to certain pathogens.