Functional Verification And Expression Pattern Of Citrus PEBP Gene Family Members

Citrus is the world’s most widely cultivated fruit trees,occupies an important position in the production of fruit trees,but the juvenile phase of citrus severely impact the early economic benefits and breeding process,how to shorten the juvenile phase become a hot issue of fruit tree breeding.PEBP family of genes has been shown to play an important role in flowering regulation in many species.In this study,four PEBP family genes: Ci FTα,Ci FTβ,Ci TFL1 and Ci BFT were cloned from lemons,and we constructed their overexpression vectors and their promoter vectors which were fused with GUS gene.The ectopic expression was observed in tobacco and Arabidopsis,and the phenotypic changes and expression patterns of transgenic lines were observed.The main findings are as follows:1.Two of the Ci FT splicer were amplified from the c DNA of lemon,one of the splicer was DNA transcription sequence its intron sequences completely sheared,named Ci FTα;the other was the DNA transcription sequence its intron cuted incompletely,named Ci FTβ.Comparing with the complete DNA sequence,Ci FTβ lacks only the first intron.When the Ci FTβ amino acid sequence was translated by software,it was found that the translation was prematurely terminated.But overexpression of Ci FTα and Ci FTβin Arabidopsis,It was found that all transgenic lines flowered earlier than wild-type lines.In Arabidopsis,Ci FTβ transgenic lines flowered slightly than Cl FTα transgenic lines.Indicating that Ci FTα and Cl FTβ both have the function of promoting flowering,and that the intron of Ci FTβ may also play a role in regulating its transcription in Arabidopsis.2.Ci TFL1 and Ci BFT were overexpressed in Arabidopsis and tobacco,and it was found that all the transgenic lines flowered significantly late than wild type lines,and the transgenic lines of Ci TFL1 flowered significantly later than the Ci BFT transgenic lines,indicating that both Ci BFT and Ci TFL1 have the function of delayed flowering,Ci BFT and Ci TFL1 were functional redundancy.Meanwhile,the Arabidopsis transgenic lines of Ci TFL1 showed phenotypic abnormalities of inflorescence,loss of floral organs and increased number of branches.Indicating that Ci TFL1 not only regulators of plant flowering time,but also playing a regulatory role in plant floral organs and branches.3.The promoter vector of Ci FT,Ci TFL1 and Ci BFT was expressed in Arabidopsis and GUS staining was carried out for different tissues in different growth stages.It was found that Ci FT mainly expressed in the veins of the plants and in the inflorescence and its stem also found a large number of GUS protein;Ci TFL1 are expressed in the whole growth stages of its various tissues and organs in plants,showing the characteristics of constitutive promoter;and Ci BFT mainly expressed in the roots of plants,and small amounts of GUS protein can be found in the leaves.