两种国兰C类花发育MADS基因的克隆与表达研究

该研究以蕙兰(Cymbidium faberi)和墨兰(Cymbidium sinense)为材料,利用RT-PCR对AGAMOUS(AG)基因进行克隆,并利用qRT-PCR进行组织表达。结果表明:(1)获得3个AG基因均属于植物特有的C类MIKC型MADS-box基因,其中2个蕙兰AG基因命名为CfAG1(登录号MW654188)和CfAG2(登录号MW654189),1个墨兰AG基因命名为CsAG1(登录号MW654190)。(2)CfAG1在盛花期合蕊柱中高丰度表达,在花蕾期花蕾和盛花期子房中中度表达;CfAG2在盛花期子房中高丰度表达,在盛花期合蕊柱中中度表达,花蕾期花蕾、盛花期花瓣(包含唇瓣)中少量表达;CsAG1在盛花期的合蕊柱中表达量最高,花蕾期花蕾、盛花期子房表达量次之,表达量最低的部位是盛花期萼片和叶片。研究认为,CfAG1和CsAG1表达特性相似,这3个基因均具有组织特异性,均能调控合蕊柱和子房的发育。该研究为后续探讨兰属植物花型发育与进化、分子育种及新品种培育奠定了基础。

Cloning and Expression of C type Flower Development MADS Gene in Two Species of Chinese Orchid

Using Cymbidium faberi and Cymbidium sinense as experimental material, we cloned AGAMOUS (AG) genes by RT PCR, and the tissue expression was studied by real time fluorescence quantitative PCR (qRT PCR). It was found that: (1) three AG genes were obtained, they belong to MIKC MADS box gene, and the two AG genes of C. faberi were named as CfAG1 (accession number: MW654188) and CfAG2 (accession number: MW654189). The AG gene of C. sinense was named as CsAG1 (accession number: MW654190). (2) CfAG1 was highly expressed in the gynostemium at full blossom stage, and moderately expressed in buds at bud stage and ovaries at full blossom stage. CfAG2 was highly expressed in ovary at full blossom stage, moderately expressed in gynostemium at full blossom stage, and slightly expressed in buds at bud stage and petals (including lip petals) at full blossom stage. The relative expression of CsAG1 gene was the highest in the gynostemium at full blossom stage, followed by buds at bud stage and ovary at full blossom stage, and the lowest expression was in sepals and leaves at full blossom stage. The study indicated that the expression characteristics of CfAG1 and CsAG1 were similar. These three genes are tissue specific and can regulate the development of gynostemium and ovary. The results provided basic data and scientific basis for the following research on the development and evolution of floral pattern, molecular breeding and new variety breeding of Cymbidium.