中文摘要：

以地黄（Rehmannia glutinosa）叶片c DNA为模板,克隆地黄扩展蛋白基因,获得一条972 bp的c DNA序列,包含了762 bp的开放阅读框（ORF）,命名为Rg EXPA10,Gen Bank登录号为KF011918,编码253个氨基酸。以基因组DNA为模板,扩增出一条1 207 bp的序列,测序结果显示包含3个外显子和2个内含子,Gen Bank登录号为KF011919。应用生物信息学方法分析其氨基酸序列结构特征,结果显示,Rg EXPA10包含DPBB_1和Pollen_allerg_1结构域,有26氨基酸的核定位序列和19氨基酸的跨膜结构域。进化分析发现在拟南芥26个α扩展蛋白中,Rg EXPA10与At EXPA8的同源性最高。在22个植物的同源蛋白中,地黄Rg EXPA10与番茄扩展蛋白的亲缘关系最近。以实时荧光定量PCR（q RT-PCR）检测Rg EXPA10基因的表达量,发现Rg EXPA10在地黄未展开的幼嫩叶片里表达最强,其次为膨大中的块根,在衰老的叶片中表达最弱。出苗后60和90天时,在地黄块根中的表达较强。在连作、盐和渍水3种逆境胁迫下,地黄叶片内Rg EXPA10的表达量均显著降低。为研究Rg EXPA10在地黄发育和逆境胁迫中的分子功能奠定基础。

英文摘要：

Using c DNA from Rehmannia glutinosa leaf as template, a 972 bp fragment of expansin gene which containing a 762 bp ORF that encoded 253 amino acids, was cloned, named Rg EXPA10, which Gen Bank accession number for this gene is KF011918. A 1 207 bp genomic sequence of Rg EXPA10 was amplified by PCR with leaf DNA as template, sequencing analysis revealed that three exons and two introns in Rg EXPA10 genomic sequence, and which Gen Bank accession number is KF011919. Molecular and bioinformatic analyses indicated that Rg EXPA10 protein have DPBB_1 and Pollen_allerg_1 domain, also including a 26 aa nuclear localization signal and a 19 aa transmembrane region. Phylogenetic analysis revealed that Rg EXPA10 showed the highest homology with At EXPA8 among the 26 α-expansins in Arabidopsis thaliana. However, the Rg EXPA10 indicated the highest homology with the expansin from Solanum lycopersicum among 22 plant species. Expression patterns using q RT-PCR analysis showed that Rg EXPA10 mainly expressed in unfolded leaf, followed by the tuberous root at stage of expanding period, and rarely expressed in senescing leaf. And Rg EXPA10 showed higher expression level in tuberous root at 60 and 90 days after emergence. The transcription level of Rg EXPA10 significantly reduced under all the three stresses including continuous cropping conditions, salinity and waterlogging. This study will lay foundations for molecular function in development and regulation of different stresses for R. glutinosa.