Cloning And Expression Analysis Of Several Flowering Related Genes In Poncirus Trifoliata And Early Flower Mutant

Flowering transition is a key process for all kinds of plants. Flower locus T(FT), one of flower meristem identity gene in plants, promotes flowering and is positively regulated by CONSTANS(CO), which responds to day length. Loss of FT causes delay in flowering. FT acts in part downstream of CO and mediates signals for flowering in an antagonistic manner with its homologous gene, TERMINAL FLOWER (TFL). What is more, FT has already been identified as one gene which is negatively regulated by FLOWER LOCUS C(FLC). FLC represses FT in flowering process; its function could be counteracted by vernalization.Early Poncirus, a mutant of Poncirus trifoliate found in Hubei Province, was taken as the material for research in this article. Genes mentioned above involved in flowering regulation pathway were cloned from the Early Poncirus and Poncirus trifoliate:1.621bp ESTs of CO were cloned from Poncirus trifoliate and its mutant, homolog level reached 70%;2.Full homolog genes of FT were cloned from Poncirus trifoliate and its mutant, 74% sequences are identical with arabdopsis;3.606bp fragments of TFL were cloned from both Poncirus trifoliate and its mutant, 73% sequences are identical with arabdopsis;4.By homolog sequences analysis and southern blot, we concluded that there is little difference of FT and TFL in both Poncirus trifoliate and Early Poncirus on nucleic level.5.Half quantitative RT-PCR was applied to analyze gene expression, TFL was detected in vegetative stage of Poncirus trifoliate and its mutant, and FT reached its peak during flowering time.However, the possibilities that there is mutants existed in upstream or downstream genes of FT in the flowering regulation process still remain. FLC should be our focus of our research in the next stage.