Molecular cloning, expression analysis, and subcellular localization of FLOWERING LOCUS T (FT) in carrot (Daucus carota L.)

Flowering, an important agronomic trait for seed plants, represents the end of vegetative growth and begins to reproduce. In regulating the floral transition, FLOWERING LOCUS T (FT) encoding a mobile floral signal protein that belongs to the phosphatidylethanolamine-binding protein (PEBP) family acts as critical role. Here, an FT-like gene, DcFT, was isolated and cloned from European Daucus carota L. cultivar "Nantes-H06" (GenBank accession number KY768910), and an alignment of the DcFT protein and other FT-homolog proteins showed that it shared 88.00% similarity with CsFT from Camellia sinensis. Phylogenetic tree analysis indicated that DcFT had the closest relationship with GpFT (Gypsophila paniculata). Quantitative RT-PCR was analyzed to show that the expression pattern of DcFT in inflorescences sharply increased after 10DAA and then slowly increased reaching the maximum at 30DAA. Subcellular localization made clear that the DcFT protein was located in the nucleus and cytoplasm. Broadly speaking, DcFT is an FT-like homologous gene in carrot regulating the floral transition and could be a candidate gene for accelerating the process in carrot breeding.