中文摘要：

目的克隆地黄中介体亚基基因Rg Med6,分析其编码的蛋白序列特征和基因表达特性。方法利用地黄转录组数据库进行同源比对,获得拟南芥Med6的同源基因片段,通过序列拼接获得RgM ed6的全长开放阅读框（ORF）,在NCBI上进行BLASTp获得RgM ed6的同源蛋白,用MAFFT进行多序列联配,应用MEGA 6.0构建系统进化树,以实时荧光定量PCR技术检测Rg Med6在地黄不同组织以及逆境胁迫下的相对表达量。结果获得1条924 bp的c DNA序列,包含1个771bp的完整ORF,编码256个氨基酸,具有Med6蛋白的典型结构域和1个潜在的核定位信号序列。Rg Med6在检测的5个地黄组织（器官）中均有表达,其中在地黄叶片里表达强度最大,其次为花蕾,在茎中表达量最低。在连作地黄块根中RgM ed6的表达量降低,Na Cl胁迫处理下Rg Med6的表达量升高。结论首次克隆了地黄中介体亚基基因Rg Med6,为阐明其在地黄生长发育和逆境胁迫中的分子功能奠定基础。

英文摘要：

Objective To clone RgM ed6 gene, which coded a subunit of mediator complex, from Rehmannia glutinosa, and to analyze the characteristics of protein sequence and gene expression. Methods The transcriptional EST database of R. glutinosa was used to search analogs of AtM ed6 gene by BLAST, the full-length open reading frame（ORF） of RgM ed6 was obtained by assembling the ESTs. BLASTp, the online analysis tool of NCBI was used to get the homologous sequences of RgM ed6, and MAFFT has been performed to analyze the multiple sequence alignment. Phylogenetic tree has been constructed using MEGA 6.0 software. Quantitative RT-PCR has been applied to detecting the transcription level of RgM ed6 in five tissues as well as in tuberous roots or leaves under three stresses. Results The cD NA sequence of RgM ed6 containing 924 bp was obtained. The ORF of RgM ed6 was 771 bp encoding 256 amino acids, which had typical structural domains and a potential nuclear localization signal（NLS）. RgM ed6 showed the highest expression level in leaves, followed by buds, but very weak in stems. The transcription level of RgM ed6 mR NA was reduced under continuous cropping conditions in tuberous roots while it increased under salinity stress in leaves. Conclusion RgM ed6, a mediator subunit gene from R. glutinosa has been obtained for the first time, which can lay the foundation for further studies about its molecular function in development and responses to stress.