大豆GmNAC131基因的生物信息学及表达分析

Bioinformatics and Expression Analysis of GmNAC131 Gene in Soybean

NAC基因在多种作物中具有抵御生物与非生物胁迫的作用,为了分析大豆NAC131基因的功能,本研究从Williams 82大豆中克隆GmNAC131基因,对该基因及其编码蛋白质的特征、结构、功能及不同组织的表达量进行生物信息学分析;采用qRT-PCR方法分析非生物胁迫后不同时间段基因的诱导表达。结果表明:GmNAC131基因cDNA全长1 945 bp,开放阅读框长1 053 bp,编码350个氨基酸,蛋白质分子量为39.49 ku,等电点为7.62。GmNAC131基因组包含3个外显子和2个内含子。GmNAC131蛋白在16~166位氨基酸处含有1个高度保守的NAC结构域。编码蛋白中没有信号肽,没有跨膜结构,蛋白质组成具有疏水性。GmNAC131定位在细胞核中,具有8个糖基化位点和34个磷酸化位点。GmNAC131蛋白与野大豆、豇豆、绿豆及黧豆的NAC蛋白具有较高的相似性,与GsNAC在相同分支。转录组数据表明GmNAC131基因在大豆不同组织中都表达,在根中表达量最高,在叶中表达量最低。4℃低温胁迫24 h过程中GmNAC131基因表达量波动变化;250 mmol·L-1 NaCl胁迫12 h表达量出现最大值;30%PEG6000胁迫0.5 h表达量最高;100μmol·L-1ABA胁迫6 h表达量达到最大值。表明大豆该基因可能参与响应高盐和干旱等非生物胁迫。

NAC genes have the resistant function to the biological and abiotic stress in many crops. In order to explore the function in soybean, this study cloned a NAC gene GmNAC131 from Williams 82 and analyzed the characteristics of the gene and its coding protein sequence, the protein structure and function, and the expression level of the gene in different tissues by bioinformatics. We analyzed the induced expression of abiotic stress at different time periods by fluorescence quantitative. The cDNA length of GmNAC131 was 1 945 bp, and the open reading frame(ORF) was 1 053 bp. GmNAC131 encoded 350 amino acids, with a molecular weight of 39.49 ku and an isoelectric point of 7.62, contained 3 exons and 2 introns. GmNAC131 contained a highly conserved NAC domain at amino acids from 16 to 166. There was no signal peptide, no transmembrane structure, and the protein composition was hydrophobic. GmNAC131 was located in the nucleus with 8 glycosylation sites and 34 phosphorylation sites. GmNAC131 had a high similarity with NAC proteins of Glycine soja, Vigna unguiculata, Mucuna pruriens, and Cajanus cajan, and shared the same branch with GsNAC. Transcriptome data showed that GmNAC131 gene was expressed in different tissues of soybean, with the highest expression in root and the lowest expression in leaf. The expression of GmNAC131 gene fluctuated during 24 h of low temperature stress at 4 ℃, the expression peaked at 12 h under 250 mmol·L-1 NACL stress, reached its maximum at 0.5 h under 30% PEG6000 stress and reached its maximum at 6 h under 100 mol·L-1 ABA stress.It suggested that the gene might be involved in abiotic stresses such as salt tolerance and drought tolerance in soybean.