Binding of WRKY28 to mutated ICS1 promoter fragments. (A) EMSAs were performed with annealed 30-bp oligonucleotides containing the ICS1 promoter region indicated as -445/-460 in the legend of Figure 3 with mutations as indicated in panel B. Plus signs above the lanes indicate binding mixtures containing 0.5 μg recombinant GST/WRKY28. Minus signs above the lanes indicate binding mixtures without recombinant protein. The position of the protein-DNA complexes is indicated by an arrow. Plus and minus signs in panel B indicate the relative abundance of the shifted probe.