光皮桦LFY同源基因的克隆及表达分析

Cloning and Expression Analysis of a LFY Gene from Betula luminifera

以珍贵用材树种光皮桦(Betula luminifera)为材料,采用同源克隆与RACE的方法,克隆获得LFY同源基因,命名为Bl LFY(Gen Bank号:KP970616)。Bl LFY基因c DNA全长1 305 bp,开放阅读框(ORF)长1 212 bp,编码403个氨基酸。基因结构分析显示,Bl LFY基因具有2个内含子和3个外显子,与其它植物同源基因具有一致的基因结构。多序列比对和系统进化分析表明,Bl LFY基因编码蛋白具有典型的N-domain和C-domain,与板栗(Castanea mollissima)及核桃(Juglans regia)等木本植物的LFY具有最高的同源性和进化关系。进一步的表达模式分析结果表明,Bl LFY基因在光皮桦植株进入成年期时表达水平最高,在开花植株的营养器官和生殖器官中均有表达,且贯穿雌、雄花序发育的整个过程,但在雌花序中的表达明显高于雄花序,说明Bl LFY基因可能与花期转换和花器官的发育有关,但在雌、雄花序发育过程中的调控作用可能不同。

In this study,through homology cloning and RACE strategy,a LFY homologue,named Bl LFY,was isolated from a precious timber tree Betula luminifera. The full length c DNA of Bl LFY was 1 305 bp with a 1 212 bp open reading frame,which encoded 403 amino acids. And,the analysis of gene structure revealed that there were two introns and three exons in genomic sequence of Bl LFY,indicating same gene structure between Bl LFY and LFY homologues from other plants. Multiple sequence alignment showed typical conserved N-domain and C-domain in Bl LFY protein. The phylogenetic analysis showed the highest identity and close evolution relation of Bl LFY to those LFY proteins from trees,such as Castanea mollissima and Juglans regia. Furthermore,expression analysis showed that the transcript of Bl LFY was accumulated when plants transited to reproductive phase. Meanwhile,Bl LFY gene was both detected in vegetative and reproductive organs of flowering plants,and consecutively expressed in all developmental stages of male and female inflorescence. However,interestingly,the expression of Bl LFY was much higher in female inflorescence than male inflorescence. These results suggested that Bl LFY gene may play important roles in floral transition and development of floral organs,and may be involved in the different process of female and male inflorescences.