摘要
植物MADS-box基因家族编码高度保守的转录因子,参与了包括花发育在内的多种发育进程。为阐释双子叶植物草原龙胆(Eustoma grandiflorum)花器官发育的分子调控机制,根据MADS-box基因保守序列设计简并引物,用3'-RACE方法从草原龙胆中克隆了4个花器官特异表达的MADS-box家族基因。序列和系统进化树分析表明,这4个基因分别与金鱼草DEF基因、矮牵牛FBP3基因和FBP6基因以及拟南芥SEP3基因具有很高的同源性,分别属DEF/GLO、AG-like和SEP-like亚家族。从而将这4个基因分别命名为EgDEF1、EgGLO1、EgPLE1和EgSEP3-1。推导的氨基酸序列显示,这些基因编码的蛋白质都包含高度保守的MADS结构域、I结构域和K结构域,每个基因均有其亚家族特异的C-末端功能域。基因特异性RT-PCR检测结果显示:EgDEF1在萼片、花瓣、雄蕊及胚珠中高丰度表达,在心皮中微量表达;而EgGLO1在花瓣和雄蕊中高丰度表达,在萼片中微量表达;在根、茎、叶等营养器官中均未检测到上述2个基因的表达。EgPLE1在雌蕊、心皮和胚珠中特异表达,但表达的丰度存在差异,在雄蕊中的表达有所减弱。SEP-like亚家族基因EgSEP3-1在四轮花器官和胚珠中均特异表达,且表达丰度相对一致。
Plant MADS-box genes are a family of highly conserved transcription factors involved in many different developmental processes, including flower development. To elucidate the molecular mechanisms of floral development in the dicotyledonous species lisianthus （Eustoma grandiflorum）, we isolated cDNA of four flower-specific MADS-box genes from this plant by the method of 3＇ rapid amplification of cDNA ends using degenerate primers designed according to the MADS-box protein family conserved region from flower buds. Sequence and phylogenetic analysis indicated a high degree of predicted protein sequence identity with DEF from Antirrhinum majus, FBP3 and FBP6 from Petunia, and SEP3 from Arabidopsis thaliana. The four genes were termed EgDEF1, EgGLO1, EgPLE1 and EgSEP3-1, respectively. Alignment of the predicted amino acid sequences from these genes, as well as with that from previously published subfamily members, revealed the MADS, intervening （I） and keratin-like （K） domains. Gene-specific RT-PCR performed with RNA isolated from the vegetative organs and floral organs revealed both EgDEF1 and EgGLO1 strongly expressed in petals and stamens. EgDEF1 expression was strongly detected in sepals and ovules, but EgGLO1 expression was weak in sepals and not detected in ovules. EgPLE1 is specifically expressed in stamens, carpels, and ovules, but the expression in stamens was low. EgSEP3-1 was strongly expressed in four flower whorls. Thus, the four MADS-box genes are expressed specifically in the floral organs of lisianthus.
出处
《植物学通报》
CAS
CSCD
北大核心
2008年第4期415-429,共15页
Chinese Bulletin of Botany
基金
国家948项目(No.2005-4-35)
