Extended Data Fig. 3: Spatiotemporal expression of FT, FD and TFL1 mRNAs.

a, RNA in situ hybridization images of shoot apical meristem cells expressing gFT::FT-mVenus in ft-10 mutant at 10 to 23 LD. Arrows indicate FT signal. Scale bars = 50 μm. b–d, Confocal images of shoot apical meristem cells co-expressing gFT::FT-mVenus transgene (yellow), endogenous FD (magenta) and TFL1 (turquoise) captured using multiplex fluorescent RNA in situ hybridization (RNAscope) at 13, 15 and 16 LD. Scale bars = 20 μm. b,d, Additional confocal sections at 13 and 16 LD, respectively, see also Fig. 2; c, a complete multiplex fluorescent RNA in situ hybridization section at 15 LD (close up image is shown in Fig. 2i). Probe for FT mRNA, FD mRNA and TFL1 mRNA were used. e, Control probe was used as a negative control (Method). Scale bars = 20 μm. f, RNA in situ hybridization images of cotyledon and shoot apical meristem cells expressing endogenous FT in Col-0 plants shifted to long days (LDs) after growth for 14 short days (SDs). Arrows indicate FT signal in cotyledonsand shoot apices. Scale bars = 50 μm. g, Confocal images of Col-0 shoot apical meristem cells co-expressing endogenous FT (yellow), FD (magenta) and TFL1 (turquoise) captured using multiplex fluorescent RNA in situ hybridization (RNAscope). Cells in the floral primordium that co-express endogenous FT, FD, and TFL1 are highlighted with a rectangle. The cell walls (light gray) were stained with Renaissance 2200. Scale bars = 20 μm.