采用电子克隆和RT-PCR方法,从条锈菌诱导的小麦品种水源11的cDNA中分离到一个编码bZIP转录因子基因的cDNA序列,暂被命名为TabZIP。TabZIP包含一个完整的1071bp的开放阅读框,编码356个氨基酸,具有典型的bZIP保守结构域;与水稻、玉米、拟南芥等植物bZIP蛋白的氨基酸序列相似性较高;TabZIP基因在小麦根中的表达量丰富,而在茎和叶中表达量很小;在小麦与条锈菌非亲和组合中,TabZIP基因高水平表达,而在亲和组合中没有明显的变化;防卫相关激素乙烯、茉莉酸也可诱导该基因的快速上调表达,表明TabZIP可能通过乙烯、茉莉酸信号途径介导小麦对条锈病的防御反应。
In plant, basic leucine zipper (bZIP) transcription factors play various roles in developmental processes and in response to biotic and abiotic stimuli. In the present study, a novel bZIP gene, designated as TabZIP, was isolated from wheat leaves in- fected by Puccinia striiformis f. sp. tritici using in silico cloning and reverse transcription PCR approaches. TabZIP was predicted to encode a 356 amino-acid protein, which contained a bZIP transcription factor basic domain signature and a leucine zipper motif. Multiple alignment analysis based on the amino acids encoded by different bZIP genes from rice (Oryza sativa), maize (Zea mays), Arabidopsis thaliana, indicated that TabZIP was conserved among the three species of plants with highly sequence similarity. The transcript level of TabZIP was relatively high in root, but low in stem and leaf. Real-time PCR analysis revealed that TabZIP gene was rapidly and dramatically induced during incompatible interaction, whereas there was no significant effect in compatible interaction. Meanwhile, the expression of TabZIP was also induced by exogenous methyl jasmonate and ethephon. On the basis of these results, we postulate that the transcription factor encoded by gene TabZIP may be involved in wheat defense response to stripe rust fungus infection through ethyleneor jasmonic acid-dependent signal transduction pathways.