发状念珠藻干旱胁迫响应基因NfGR的克隆与鉴定  

Cloning and Identification of Drought-stress Responsive Gene NfGR in Nostoc flagelliforme

作　　者：岳思君[1] 范红丽[1] 郑蕊[1] 周娟[1] 苏建宇[1] 

机构地区：[1]宁夏大学生命科学学院西部特色生物资源保护与利用教育部重点实验室,银川750021

出　　处：《西北植物学报》2016年第10期1955-1961,共7页Acta Botanica Boreali-Occidentalia Sinica

基　　金：国家自然科学基金(31360025;31260023;31560418);宁夏大学研究生创新项目(GIP201611)

摘　　要：该研究采用PCR技术,从发状念珠藻细胞中克隆了谷胱甘肽还原酶(glutathione reductase,GR)基因,命名为NfGR,其开放阅读框长1 374bp,编码458个氨基酸,蛋白相对分子量为49.42kD,理论等电点为5.49。氨基酸序列分析表明,NfGR蛋白具有NADPH结合位点超家族(NADB-Rossmann superfamily)和吡啶氧化还原酶二聚体超家族(Pyr_redox_dim superfamily)2个结构域,与点形念珠藻(Nostoc punctiforme)的相似性达93%。系统进化树分析表明,NfGR与点形念珠藻处在同一进化枝上,亲缘关系较近。qRT-PCR表达分析表明,在不同浓度PEG-6000处理下,NfGR基因均保持上调表达,其中,PEG-6000浓度为8%时,NfGR基因的相对表达量达到峰值(32.69)。研究推测,谷胱甘肽还原酶可能参与了发状念珠藻对干旱胁迫过程的响应。Glutathione reductase is one of enzymes participating in the oxidation reduction reaction in organ- isms, which plays an important role in the process of stress tolerance. As a kind of cyanobacteria, Nostoc flagelliforme possesses strongly resistance to environment stresses, so it is meaningful to study the role ofglutathione reductase in the resistant mechanism. In order to explore the biological functions of glutathione reductase in process of stress tolerance in N. flagelliforme, we cloned the complete open reading frame of the gene NfGR, and took a bioinformatics analysis of gene sequence. The ORF of NfGR contains 1 374 bp, encoding 458 amino acids, and its relative molecular weight and theoretical isoelectric point is 49.42 kD and 5.49, respectively. Amino acid sequence analysis showed that the protein NfGR has two domains of NADB-Rossmann superfamily and Pyr redox dim superfamily, and amino acid sequence of NfGR protein is similar to that of Nostoc punctiforme with similarity up to 93%. Phylogenetic tree reconstructed by neighbor joining method clearly showed that NIGR protein was classified into a subgroup with N. puncti- forme, which suggested their close relationship, qRT-PCR result showed that the expressions of NfGRgene were up-regulated under different concentrations of PEG-6000, and reached peak at 8% PEG-6000 concentration, with the relative expression level of 32. 69. It is hypothesized that glutathione reductase may be involved in the response to stress resistance of N. flagelliforme according to its expression char- acteristics.

关 键 词：发状念珠藻 谷胱甘肽还原酶 基因克隆 荧光定量PCR 

分 类 号：Q785[生物学—分子生物学] Q786