论文部分内容阅读
NAC转录因子是高等植物所特有的具有多种生物功能的转录因子,在植物生长发育、抵抗逆境和激素调节等过程中发挥着重要作用。本研究利用RACE-PCR技术,克隆获得了紫花苜蓿NAC转录因子Ms NAC1(Gen Bank登录号为JN099384.1)基因的c DNA序列。生物信息学分析显示,Ms NAC1基因的开放阅读框(ORF)为993 bp,编码一个由330个氨基酸残基组成的亲水性蛋白,N-端具有保守的NAM结构域,C-端高度变异,具备NAC转录因子的基本特征;Ms NAC1蛋白被定位在细胞核中,含有2条核定位信号序列,具有9个糖基化位点和23个磷酸化位点,三级结构为对称的同型二聚体。多重比对发现,Ms NAC1蛋白与拟南芥ATAF1和水稻Os NAC6蛋白的同源性较高;系统进化分析表明,Ms NAC1蛋白属于NAC转录因子家族中的ATAF亚族,与ATAF1的亲缘关系最近。非生物逆境胁迫下的表达分析显示,Ms NAC1基因在高盐、干旱和低温胁迫下表达量均呈现先上调后下调的趋势,不同处理时间的差异达到极显著水平,并且根中的表达量上调幅度高于叶片,说明该基因可能参与调控非生物逆境胁迫的生理响应。
NAC transcription factor is a kind of transcription factor that is unique to higher plants and has many biological functions. It plays an important role in the process of plant growth, resistance to stress and hormone regulation. In this study, we cloned the cDNA sequence of NAC transcription factor Ms NAC1 (GenBank accession number JN099384.1) by RACE-PCR. Bioinformatics analysis showed that the ORF of Ms NAC1 gene was 993 bp, encoding a hydrophilic protein consisting of 330 amino acid residues with a conserved NAM domain at the N-terminus and a C-terminal highly variable , With the basic features of NAC transcription factor; Ms NAC1 protein is located in the nucleus, contains two nuclear localization signal sequence, with 9 glycosylation sites and 23 phosphorylation sites, the tertiary structure of the symmetrical homotype two Polymer. Multiple alignment showed that Ms NAC1 had high homology with Arabidopsis ATAF1 and rice Os NAC6. Phylogenetic analysis showed that Ms NAC1 belongs to the ATAF subfamily of NAC transcription factors and has the closest genetic relationship with ATAF1 . Under abiotic stress, the expression of Ms NAC1 showed a downward trend after up-regulation and under high salt stress, drought stress and low temperature stress, and the difference was significant at different treatment times and the expression of Ms NAC1 was up-regulated Amplitude higher than leaves, indicating that the gene may be involved in the regulation of physiological responses to abiotic stress.