Two P1BS motifs are necessary for the function of the EZ2 enhancer. (A) Diagram showing the structure of the EZ2 enhancer element and its derivatives with mutations in P1BS4 (EZ2mP1BS4), P1BS3 (EZ2mP1BS3), or both (EZ2mP1BS4–3). (B) Seedlings grown for 10 days in media supplemented with 1 mM (P+) or 0 mM Pi (P–), subjected to histochemical GUS assays, and photographed using Nomarsky optics. The name of each construct is indicated at the top of each set of three images, which show the expression pattern for cotyledons, lateral roots, and root apical meristems from top to bottom, respectively. Bars, 100 μm. (This figure is available in colour at JXB online.)