Impact of single amino acid on AtFT-mediated floral induction. A to F, Functional assessment of novel FT alleles using the PVX-based VIF. MM tobacco plants mock-inoculated (A), or infected with PVX/mAtFT (B), PVX/AtFT (C), PVX/AtFTT27A (D), PVX/AtFTY85A (E), PVX/AtFTR119A (F), and PVX/AtFTR173A (G) resulted in distinctive flowering phenotypes. Plants were photographed at 5 weeks postinoculation. Bar = 4 cm. H to L, RT-PCR detection and sequencing confirmation of virally expressed wild type and mutant AtFT mRNAs as indicated in each. The start codons and the mutated start codons are underlined. M, Flowering time of Arabidopsis Col, ft-10, and transgenic ft-10/SUC2:AtFT, ft-10/SUC2:mAtFT, ft-10/SUC2:AtFTY85A, ft-10/SUC2:FTR119A, ft-10/SUC2:AtFTR173A, and ft-10/SUC2:FTT27A plants under LD conditions. Flowering times were determined as the number of rosette (white bars) and cauline (gray bars) leaves in three to five independent single-copy transgenic lines for each gene. A representative line for each transgene is shown (also see Supplemental Table S2).