Identification and characterization of flowering time regulatory gene FLC of Paeonia ostii 'Fengdan'

Tree peony is a traditional ornamental flower, but the extremely short flowering period greatly limits their ornamental value. Flowering time related gene PoFLC encoded 178 amino acids was cloned from petals of Paeonia ostii 'Fengdan' based on the third-generation full-length transcriptome sequence. Then, expression profiles of PoFLC in different flower developmental stages and different tissues were analyzed using quantitative real-time PCR (qRT-PCR). The half opening stage showed the highest relative expression level of PoFLC during different flower developmental stages, while the petal showed the highest relative expression level of PoFLC in different tissues. Subcellular localization analysis presented PoFLC was localized in the nucleus. The over -expression vector of PoFLC was constructed and T2 generation transgenic Arabidopsis were obtained. The bolting time and flowering time of transgenic plants were significantly later than wild type. It is speculated that the formation of late-flowering phenotype in transgenic Arabidopsis might relate to the overexpression of PoFLC. It is anticipated that PoFLC might play an important role in delay flowering, and the results might provide a theo-retical basis for further study on the role of PoFLC in regulation flowering period, and benefit the future mo-lecular breeding researches of tree peony.