木薯转录因子MeERF117的克隆及表达分析

Cloning and Expression Analysis of Cassava Transcription Factor MeERF117

AP2/ERF(APETALA2/ethylene responsive factor)类转录因子是植物应答多种逆境胁迫机制中的关键组分,研究木薯AP2/ERF家族成员将有助于解析该家族在木薯抗逆胁迫中的功能。基于已有木薯基因组序列信息,以木薯块根cDNA为模板,克隆得到一段长度为927 bp的cDNA,命名为MeERF117,该基因编码308个氨基酸。MeERF117蛋白分子量为35.08 kD,且该蛋白仅含一个AP2/ERF结构域,属于ERF转录因子家族。在进化关系上,Me ERF117蛋白与巴西橡胶树的ERF蛋白最相近。亚细胞定位观察到MeERF117蛋白分布于细胞质和核中。实时荧光定量PCR(Real-time quantitative PCR)方法检测MeERF117基因在木薯块根采后生理性变质(Post-harvest physiological deterioration,PPD)过程中的相对表达量,发现PPD的发生可提高MeERF117因子的表达水平,在PPD后期(48 h)时MeERF117的相对表达量是未发生PPD(0 h)时的2倍,表明木薯块根PPD的发生可诱导MeERF117基因的表达。本研究为后续深入解析MeERF117在木薯PPD过程的具体功能奠定基础,为培育抗采后生理变质的木薯品种提供潜在的基因资源。

As a kind of plant specific transcription factors,AP2/ERF transcription factors play an important role in various stress response.Based on the existing genome sequence information of cassava,a 927 bp cDNA named MeERF117 was cloned with cassava root c DNA as template and the gene encodes 308 amino acids.The molecular weight of Me ERF117 protein was 35.08 kD,and the analysis of conserved domain revealed that MeERF117 protein contained an AP2/ERF domain,belonging to the ERF transcription factor family.Phylogenetic tree analysis showed that the genetic relationship between MeERF117 and ERF of Hevea brasiliensis was the closest.The subcellular localization of MeERF117 protein was observed in the cytoplasm and nucleus.Besides,the expression pattern of MeERF117 gene in post-harvest physiological deterioration(PPD)process was detected by qPCR.It was found that the occurrence of PPD could increase the expression level of MeERF117 gene,and the relative expression level in the later stage of PPD(48 h)was twice than that in PPD(0 h),indicating that the occurrence of PPD in cassava can induce the expression of MeERF117 gene.This study laid a foundation for further analysis of the specific function of MeERF117 in cassava PPD process,and provided potential gene resource for cultivating cassava varieties resistant to PPD.