玉米NAM-2基因的克隆及生物信息学分析

Cloning and Bioinformatics Analysis of NAM-2 Gene in Maize

NAC转录因子家族是一类在植物非生物胁迫的应答中起重要作用的转录因子家族,为了明确玉米NAC转录因子NAM-2在应答逆境胁迫中的作用,对其基因序列进行了克隆和生物信息学分析,利用qRT-PCR法对其进行组织表达分析和干旱、盐非生物胁迫条件下的表达模式分析。结果显示,NAM-2基因全长编码框为1122 bp,编码373个氨基酸,相对分子质量为40.59 kDa,理论等电点8.70,为碱性蛋白,亚细胞定位结果显示定位于细胞核中。结构域分析结果表明,在蛋白质N端拥有一个NAM结构域,进化分析显示,它与高粱亲缘关系最近。组织表达分析显示,NAM-2基因在根、茎、叶中均有表达,在叶片中的表达水平最高。胁迫处理表达分析结果表明,在干旱和盐胁迫下基因表达均下调,初步推测NAM-2基因可能与玉米响应逆境胁迫有密切的关系,为进一步探索其在玉米中的抗逆分子机制奠定了基础。

NAC transcription factors comprise one of the large gene families,which act as master regulators in abiotic stress responses.To investigate the role of maize NAC transcription factor in response to environmental stresses,a NAM-2 gene was cloned and its sequence was analyzed by bioinformatics analyses.Then quantitative real-time PCR(qRT-PCR)was used to study the expression pattern of NAM-2 in different tissues,and under a variety of abiotic stresses treatment.The results showed that the full-length reading frame of the NAM-2 gene was 1122 bp in length,encoding 373 amino acids with predicted molecular weight of 40.59 kDa.The theoretical isoelectric point of NAM-2 was 8.70,indicating that it was a basic protein.The results of subcellular localization showed that it was localized to the nucleus.Domain analysis indicated that there was a NAM domain at the N-terminus of NAM-2 protein.Evolutionary analysis showed that it was closely related to sorghum.Tissue expression analysis showed that NAM-2 gene was expressed in root,stem and leaf,and the expression level was the highest in leaf.The expression analysis of stress treatment showed that the expression of this gene was down-regulated by drought and salt stresses.It is preliminarily speculated that NAM-2 gene may be closely related to the response of maize to adversity stress,and it may be a useful gene for engineering crops with improved tolerance to abiotic stresses.