Fig. 6. Structure of the FZP gene and similarity to other ERF transcription factors. (A) Schematic representation of the FZP gene structure with mutant lesions. The ERF domain (black box) is localized at the N-terminal half whereas the acidic domain (hatched box) conserved in grass BD1-like proteins is closer to the C terminus. The position of the mutations in the fzp alleles are indicated above. The amino acid numbers are indicated below. The black line indicates the putative PEST sequence and the grey line indicates the bipartite nuclear localization signal. (B) Alignment of the amino acid sequences of the ERF domains of FZP and other members of the ERF family. Asterisks indicate amino acids that confer specific GCC-box binding. Mutations of the fzp-2, fzp-3, fzp-7 and fzp-8 alleles are shown. BD1, maize BRANCHED SILKLESS; BD1B, duplicate of BD1; LEP, Arabidopsis LEAFY PETIOLE; Arabidopsis ESR1, ENHANCER OF SHOOT REGENERATION1; TINY, Arabidopsis TINY. (C) Transactivation of the GAL4-LUC reporter gene by FZP. Schematics of the constructs used are indicated on the left and described in the Material and Methods section. Relative luciferase activities in Arabidopsis leaves that had been co-bombarded with reporter and effector plasmids are indicated on the right. All luciferase activities were expressed in arbitrary units relative to values obtained with the reporter construct alone (None; set arbitrarily at 1). The values shown are averages of results from three independent experiments. Error bars indicate standard deviation.