金钗石斛SEP3-like基因的克隆及其在春化过程中的表达分析

A SEP3-like Gene in Dendrobium nobile(DnSEP3-like):Cloning,Characterization and Vernalization-induced Transcription Patterns

通过同源克隆从低温春化处理的金钗石斛腋芽中分离到1个SEP3-like基因的全长cDNA。该cDNA含有长度为684bp的开放阅读框,可编码由227个氨基酸组成的蛋白质。同源搜索和系统进化分析表明,该蛋白与拟南芥AtSEP3同源,并同属于MADS-BOX家族的SEP亚家族中的SEP3分支,故将该基因暂定名为DnSEP3-like。与其它的石斛属的SEP3蛋白类似,DnSEP3-like蛋白缺失C-末端的部分基序。DnSEP3-like基因的表达受春化作用的影响,其转录产物随春化时间延长逐渐积累,在春化20d时达到峰值,暗示该基因可能参与春化调控开花的生物学过程。

Vernalization is required for floral transition in Dendrobium nobile.From the axillaries of vernalized D.nobile,a full-length cDNA that predictably encode a peptide in length of 227AA was identified in this study.BlastX searching indicates it is similar to AtSEP3 and the following phylogenetic analysis indicates both of them belong to the SEP3 clade in SEP subfamily.Thus,this protein was named DnSEP3-like.DnSEP3-like protein lacks a certain motif in C-region,which is similar to some other SEP3 proteins in Dendrobium species.Expression of DnSEP3-like gene is up-regulated with the extending of vernalizaiton,suggesting that it would function in vernalization-induced floral transition.