The full-length cDNA of LeMBFl was cloned from tomato by Homology-based cloning method, which contained an ORF of 420 bp and encoded a protein of 139 amino acid residues containing a conserved MBFl transcription activation domain. Compared with Solatium tuberosum StMBF1, Nkotiana tabacum NtMBF1 and Vitis vinifera VvMBFl , the deduced amino acid sequence of LeMBFl shares 99.3%, 91.4% and 84.2% similarity, respectively. To analyze the pathogen resistance of multiprotein bridging factor gene LeMBFl in tomato, the LeMBF1-overexpressing tomatoes and wild type lines were inoculated with Pst. DC3000 and Yusarium. oxysporum respectively. The phenotypic analysis of pathogen resistance displayed that the plaque number on the LeNBFl-overexpressing tomato leaves was significantly less than the control plants. qRT-PCR analysis showed that the expression levels of pathogenesis-related PRl and PR6 genes were significantly increased in LeMBFl -overexpessing tomato plants. These results indicated that LeMBFl elevated the pathogen resistance of tomato plants by activating the expression of some PR genes.%采用同源序列克隆法,从番茄中克隆了多蛋白桥梁因子基因LeMBF1,该基因包含一个完整的420 bp的开放阅读框,编码139个氨基酸,具有MBF1保守结构域.LeMBF1氨基酸序列与马铃薯StMBF1、烟草NtMBF1和葡萄VvMBF1的氨基酸序列相似度分别是99.3％、91.4％和84.2％.为了研究番茄多蛋白桥梁因子LeMBF1在植物抗病性中的作用,以LeMBF1超表达转基因番茄和野生型番茄为材料,对其进行接种病原细菌Pst.DC3000和尖孢镰刀菌Fusarium.oxysporum的生物胁迫实验.抗菌表型分析发现,LeMBF1超表达转基因番茄叶片上的菌斑数明显少于对照植株;实时定量PCR分析表明,LeMBF1超表达番茄植株中防卫基因PR1、PR6的表达水平明显增强.由此可见,LeMBF1可能通过教活部分PR5基因的表达提高了植物的抗病性.
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