巴西橡胶树NAC转录因子HbNAC1基因的克隆及生物信息学分析

Cloning and Bioinformatics Analysis of a NAC Transcription Factor HbNAC1 from Hevea brasiliensis

为了研究植物特有的NAC(NAM,ATAF1/2和CUC2)转录因子在巴西橡胶树生长发育、胁迫应答和激素调节中的功能,对巴西橡胶树NAC转录因子进行了克隆和分析。根据橡胶树胶乳cDNA文库中筛选到的NACEST序列,利用RACE-PCR技术克隆了橡胶树HbNAC1的cDNA序列。生物信息学分析显示HbNAC1基因开放阅读框(ORF)为891bp,编码了一个296个氨基酸组成的中性不稳定水溶性蛋白,该蛋白的N-端具有保守的NAC结构域,C-端高度变异,具备了NAC转录因子的基本特征。HbNAC1定位在细胞核中,具有3个糖基化位点和21个磷酸化位点,三级结构由3个α-螺旋和9个β-折叠组成。序列比对和系统进化分析显示HbNAC1蛋白属于NAC转录因子家族中的ANAC011亚族,推测其可能作为一种氨基酸合成相关的调节酶参与调控植物的免疫反应。

In order to identify the role of plant-specific NAC（NAM,ATAF1/2 and CUC2）transcription factors in the growth and development,stress responses and hormone regulation of Hevea brasiliensis,the HbNAC1 gene was cloned and analyzed.The sequence of HbNAC1 was cloned from cDNA using RACE-PCR based on the EST sequence isolated from the cDNA library of Hevea brasiliensis latex.Bioinformatics analysis showed that HbNAC1 has an open reading frame（ORF）of 891 bp,encoding a neutral,unstable,water-soluble protein with 296 amino acids.The HbNAC1 protein with a conserved NAC domain in the N-terminus and highly divergent C-terminus had the basic characteristics of the NAC transcription factors.It was predicted to locate in the nucleus and contain three glycosylation sites and twenty-one phosphorylation sites.The tertiary structure of HbNAC1 was predicted to be consisted of three α-helices and nine β-sheets.Sequence alignment and phylogenetic analysis revealed that HbNAC1 was a member of NAC transcription factor family belonging to ANAC011 subgroup,and proposed to participate in regulation of plant immunity response as a specific enzyme related to amino-acid biosynthesis.