Fig. 1.

Effect of the substitutions of Ser15 and 19 within the DNA-binding domain (DBD) of Arabidopsis bZIP factors on their DNA-binding and transcriptional activity. (A) Schematic representation of bZIP factors. The DBDs and leucine zipper (zipper) domains are indicated. S¹⁵ and S¹⁹ indicate conserved Ser residues within the DBDs. (B) Binding of bZIP53, bZIP53^Ser15,19Ala (bZIP53A), bZIP53^Ser15,19Asp (bZIP53D), and unspecific protein (neg. control) to the C-box (lower bars) and mutated C-box (upper bars). Data are means (±SD), n=2. (C) Reporter gene assays in Arabidopsis protoplasts. P_(ACTCAT)2x::GUS was used as the reporter. A, substitution of Ser15 and Ser19 to Ala; D, substitution of Ser15 and Ser19 to Asp. Data are means (±SD), n=3. (D) Images of representative plants from each transgenic line expressing P_UBI10::bZIP53-GFP (bZIP53ox), P_35S::bZIP10-GFP (bZIP10ox), and P_35S::bZIP25-GFP (bZIP25ox). (This figure is available in colour at JXB online.)