牡丹PlSEP1基因的鉴定与调控开花时间功能研究

Identification and Function Study in Flowering Time Regulation of PlSEP1 Gene in Tree Peony

SEPALLATA1(SEP1)基因是重要的MADS-box家族基因,在植物开花时间调控中发挥重要作用。为明确牡丹中PlSEP1基因在牡丹开花过程中的生物学功能及表达特性,进一步了解其参与开花时间调控的机制,基于前期得到的牡丹二次开花品种海黄花芽发育过程转录组数据中筛选到的一个MADS-box家族基因PlSEP1,应用实时荧光定量PCR检测PlSEP1基因在牡丹花芽发育过程中的相对表达量,通过在拟南芥中过量表达PlSEP1基因探究其发挥的功能。结果显示,获得的PlSEP1基因具有735 bp的CDS序列,共编码244个氨基酸。经生物信息学分析得知,PlSEP1编码的蛋白具有稳定的亲水性,并且不含信号肽。进化分析显示,PlSEP1与拟南芥、大豆亲缘关系较近;亚细胞定位发现,PlSEP1蛋白在细胞核中表达;实时荧光定量PCR结果表明,PlSEP1在花芽中表达量最高,且在分化期达到最高。拟南芥中过量表达PlSEP1会导致开花时间提前,表明PlSEP1参与调控开花过程。

SEPALLATA1(SEP1)gene is a member of MADS-box gene family which plays an important role in flowering time regulation.In order to clarify the biological function and expression characteristics of PlSEP1 gene in tree peony during flowering,and further understand the mechanism of PlSEP1 gene involved in the regulation of flowering time.A MADS-box family gene,PlSEP1,was screened from the transcriptome data of floral bud development in the reblooming cultivar of tree peony,High noon,the relative expression of PlSEP1 gene in the floral bud development of tree peony was detected by quantitative Real-time PCR,and the function of PlSEP1 gene was explored through over expression in Arabidopsis thaliana.The results showed that,PlSEP1 encoded 244 amino acid with a ORF of 735 bp.The bioinformative analysis showed that PlSEP1 encoded a stable hydrophilic protein,which contained none signal peptide.Phylogenetic tree showed that the PlSEP1 was close with its homologs in Arabidopsis thaliana,Glycine max.Subcellular location assay showed that PlSEP1 protein was located in the nucleus.PlSEP1 expressed highest in flower buds,and reached the highest in the differentiation stage.The phenotype of early flowering in over-expression transgene plant suggested that PlSEP1 regulate flowering time.