药用植物箭叶淫羊藿EsMIXTA基因的克隆及其表达分析

Characterization of a MIXTA-like Gene and Gene Expression Pattern from Epimedium Saggitatum

植物的表皮毛是植物与外界环境接触的主要部位,同时它是分泌植物次生代谢物质的主要场所,因此了解表皮毛的分子发育机制,对于进一步应用分子生物学手段提高药用植物的有效成分在表皮毛中的合成有着重要的意义。该研究以箭叶淫羊藿为例,通过基因同源克隆的方法结合快速扩增cDNA末端片段技术(RACE)从箭叶淫羊藿cDNA中克隆到了一个MYB基因家族R2R3-MYB基因并命名为EsMIXTA。通过系统发育重建、蛋白质结构域分析发现EsMIXTA蛋白并具有典型的R2、R3结构域及MIXTA结构域,结果显示该基因属于MYB基因家族的第九亚组(subgroup 9)。基因表达分析结果表明EsMIXTA基因在箭叶淫羊藿根、叶和花器官中都普遍表达,但在根中表达量要明显高于其他组织,结合根毛发育的形态学特点,我们认为EsMIXTA基因的高表达很可能和表皮发育及根毛发育有着密切的关系,这很可能和根部具有更多表皮毛有极大的相关性,进一步的功能验证有待继续开展。

Trichomes are specialized epidermal cells that secret a variety of secondary metabolites to be served as chemical factories. Understanding of molecular mechanism regulating trichome initiation and development is essential for promoting amount of secondary metabolite. In this study, we characterized a EsMIXTA gene belong to R2R3 MYB subgroup 9 using RACE method from traditional Chinese medicine herb Epimedium sagittatum. EsMIXTA protein harbors typical R2, R3 and subgroup 9 motif and belongs to subgroup 9 genes through alignment analysis and phylogenetic reconstruction. Real time PCR results revealed EsMIXTA expression is universal in root, leaf and floral organs, furthermore highest expression in roots were detected. The expression results in combination with morphological observation suggested the function of EsMIXTA is related to trichome hair root development.