【摘要】 谷胱甘肽-S-转移酶(glutathione-S-transferase, GST)是参与谷胱甘肽催化反应的关键酶,在生物解毒、应激耐受和次级代谢等多个方面发挥生物学功能。本研究以藏药喜马拉雅紫茉莉为材料,基于前期转录组数据,从c DNA中克隆出谷胱甘肽-S-转移酶(GST)基因Mh GSTL3,该基因开放阅读框(ORF)全长717bp,编码238个氨基酸。利用多种生物信息学分析方法对该基因预测和分析,结果显示,该基因编码蛋白的相对分子质量为27.08kDa,理论等电点pI值为5.21,推测该蛋白为稳定的弱酸性亲水型蛋白,不含信号肽,不存在跨膜结构;通过多序列比对,发现该蛋白具有两个GST家族典型的保守活性位点;系统进化分析表明,与该蛋白同源性最高的是欧洲栓皮栎。利用实时荧光定量PCR检测得出Mh GSTL3在花中表达量最高,果中最低;低温胁迫时该基因在根和叶中的表达量均升高,根中升高显著。该研究首次从喜马拉雅紫茉莉中克隆出了Mh GSTL3的cDNA全长,并揭示了Mh GSTL3在不同组织及温度下的差异表达,为今后对Mh GSTL3基因分子机制的探究提供理论参考。更多还原

【Abstract】 Glutathione-S-transferase(GST) played an important role in detoxification, stress tolerance and secondary metabolism. In this study, Mh GSTL3 was cloned from the cDNA of Mirabilis himalayana based on the previous transcriptome data. The protein encoded by the gene was analyzed by bioinformatics, including physical and chemical properties, hydrophobicity, signal peptide, sub-cellular localization secondary structure and tertiary structure and phylogenetic tree. The results showed that ORF was 717 bp in length and encoding 238 amino acids. The predicted molecular weight was 27 kDa and the theoretical pI was 5.21. Phylogenetic analysis showed that MhGSTL3 protein had the highest homology with the GSTL3 protein of Quercus suber. The expression of MhGSTL3 was the highest in flowers and the lowest in fruits. Under low temperature stress, the expression of the gene increased in both roots and leaves. The results provided a theoretical reference for the future research on the molecular mechanism of Mh GSTL3 gene.更多还原