Extended Data Fig. 10: 14-3-3 proteins enhance FD DNA binding by altering its C-terminal conformation.

a, Domain architecture of FD and alignment of C13 and SAP regions from group A bZIP proteins of Arabidopsis. Mutations (Mu7 and Mu8) of FD are also shown. b, Modeled and predicted structure of the DNA-bound FDc homodimer, DNA-bound FDc and GRF7 heterotetramer, and DNA-bound FDc Mu7 and Mu8. c, Gel-shift analysis of the interactions between single MBP-FDc^T282E wild−type (WT) or mutant proteins or combination of GRF7 and MBP-FDc proteins with WT and MT DNA probes. d, Flowering time (total leaf number, TLN) of transgenic fd-3 plants carrying gFD::3HA3Flag-FD Mu7 and Mu8. Different letters represent significant differences among genotypes (P < 0.05, using one-way ANOVA followed by Tukey’s pairwise multiple comparison, P = 1.11 * 10⁻¹⁶; n = 26 and 27 for gFD::3HA3Flag-FD Mu7 and Mu8, respectively; and n = 24 and 23 for fd-3 and Col-0 seedlings respectively, all grown under long-days (LDs). The same data for Col-0 and fd-3 are also shown in j. e, Confocal images of shoot apical meristem cells of fd-3 plants expressing gFD::mVenus-FD Mu7 and Mu8. Scale bars = 2 μm. The confocal images are representative of three independent meristems. Gel-shift assays in c were performed twice with similar results.