东亚砂藓 bZIP 转录因子 RjbZIP 基因的克隆及表达分析

摘要

In order to study biological function of bZIP transcription factor in bryophytes,a full length cDNA se-quence of bZIP transcription factor was cloned from Racomitrium japonicum using RT-PCR,named RjbZIP.The full length of RjbZIP cDNA sequence was 1 477 bp,containing a 1 422 bp open reading frame (ORF),and encoding a protein of 473 amino acids,molecular weight was 5.1 1 4 kDa and theoretical pI was 6.97.The predicted RjbZIP protein belonged to unstable protein,and located in nuclues without transmembrane structure and signal peptide. The protein contained a typical structure of bZIP domain,including one leucine zipper motif,one basic domain and one glutamine rich.domain.The quantitative RT-PCR results showed that RjbZIP gene could express in the proceed of quick dehydration,slow dehydration and rehydration,and its transcriptional responses subject to rehydration was the most sensitive.Therefore,the RjbZIP gene was speculated to participate the stress reaction of R.japonicum,and the results laid the foundations for the further study on its function.%为研究 bZIP 转录因子在苔藓植物中的生物学功能，以东亚砂藓转录组测序获得的一个与 bZIP 转录因子同源性较高的基因片段为基础，采用 RT-PCR 技术克隆得到该基因的 cDNA 全长序列，命名为 RjbZIP。该基因 cDNA 全长为1477 bp，包含1个1422 bp 的开放阅读框，编码473个氨基酸，预测蛋白分子量为5．114 kDa，等电点为6．97。RjbZIP 蛋白属于不稳定蛋白，无跨膜区和信号肽结构，亚细胞定位于细胞核。该蛋白含有典型的 bZIP 结构域，该结构域包含一个亮氨酸拉链区，一个碱性结构域和一个谷氨酰胺丰富区。实时荧光定量 PCR 分析显示，在快速脱水、缓慢脱水和脱水后复水处理过程中，东亚砂藓 RjbZIP 基因均能被诱导表达，且对脱水后复水的反应更为迅速，推测该基因参与东亚砂藓抵抗逆境胁迫的应答，为后续进一步研究其功能特征奠定了基础。