胡萝卜MADS-box基因的克隆及表达分析

Cloning and expression analysis of MADS-box genes in carrot (Daucus carrot)

植物MADS-box基因家族基因编码高度保守的转录因子,参与包括花发育在内的多种发育进程。为进一步研究胡萝卜花器官的发育,根据MADS-box基因保守区序列,设计简并引物,并利用3'-RACE法从胡萝卜(Daucus carrot)中克隆两个MADS-box基因家族的cDNA片段,根据克隆出的片段设计引物进行5'-RACE扩增以获得cDNA全长序列。序列分析和系统进化分析表明,这两个基因分别与金鱼草的DEFH49和拟南芥的AGL6序列有很高同源性。从而将两个基因分别命名为DcSEP1和DcAGL6。序列比对分析表明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,同时每个基因均有其比较保守的C-末端功能域。基因表达分析结果显示,DcSEP1和DcAGL6在营养器官根、茎、叶和萼片中均无表达,而在心皮和雄蕊中有微量表达。

Plant MADS-box genes are a family of genes that encode highly conserved transcription factors involved in many different developmental processes including flower development. For further study of the carrot floral organ development, degenerate primers were designed according to MADS-box gene conserved sequences. Two MADS-box gene cDNA fragments were obtained from carrot （Daucus carrot） using the 3＇-RACE method, and then the full-length cDNA were cloned using the 5＇-RACE method. Sequence analysis and phylogenetic analysis indicated that the two genes which designated DcSEP1 and DcAGL6 had high identities with DEFH49 （Antirrhinum majus） and AGL6 （Arabidopsis thaliana）. The sequence alignment analysis demonstrated that all the expression products contained a highly conserved MADS domain, I domain and K domain, and its unique conserved C-ter- minal domain. Expression analysis indicated that the two genes were all no expression in root, stem, leaf and sepal while had a trace expression in carpel and stamen.