木薯干旱响应基因MeHDS1的克隆与分析

Cloning and Functional Analysis of MeHDS1 from Cassava Responsing Drought

HD-Zip是植物中所特有的转录因子,在植物体响应环境因子过程中起着重要的作用。以木薯cDNA为模板,利用RT-PCR技术从木薯中克隆了一个HD-Zip家族成员基因全长,命名为MeHDS1。序列分析结果表明,MeHDS1具有822个氨基酸,分子量89.07 kD,等电点为5.79,其开放阅读框长2 469 bp,具有典型HD结构域及START结构域。该转录因子与棉花GL2蛋白的同源性很高,推断其同属第IV亚家族。MeHDS1蛋白内含有一个核定位信号,亚细胞定位试验结果也证明,MeHDS1蛋白定位于细胞核与细胞壁中。实时荧光PCR分析表明,该基因在木薯根部表达量最高,受干旱诱导上调表达。通过对其生物信息学分析及其在木薯中表达谱分析结果表明,MeH DS1可能作为转录调控因子参与木薯非生物胁迫应答反应。

The HD-Zip transcription factors are unique to the plant kingdom. They play important roles in plant responsing to the environmental factors. Based on the cDNA of cassava, using RT-PCR technology, one gene sequence was obtained, named it as MeHDS1. The sequence was analyzed, we got a 2 469 bp gene which have integrated ORF, MeHDS1 encoded a protein which contained 822 amino acids （ 89.07 kD ） with an isoelectric point of 5.79. MeHDS1 have typical HD-domain, START domain. It has high homology to GL2 gene of cotton and Arabidopsis, so it might belong to HD-Zip IV subfamily. There have a nuclear localization signal in MeHDS1 protein, and which was localized in the nucleus and cell wall by subcellular localization assay in tobacco epidermal cells. Real-time PCR results showed that, MeHDS! was upregulated under drought, and its variation of expression was more highly in root cells than that in leaves cells. Through its bioinformatics and expression analysis, we concluded that MeHDS] may be involved in cassava abiotic stress responsed as a transcription factor.