Multiple-activating ARFs directly bind to the BA1 promoter. (A) EMSAs showing that ARF29 and ARF34 bind to probes A, B, C, and DR5. (B) EMSA showing that all ARFs tested bind to a 9xAuxRE DR5 probe. (C) Schematic showing simplified BA1 genomic locus. Promoter fragment used for probe A in EMSAs is shown as boxed region; dashed box in probe A corresponds to 100-bp probe A*. Values below boxes indicate position relative to BA1 start codon (+1). Gray lines indicate TGTC core AuxRE elements. (D) EMSA showing that mutation of core TGTCs in probe A* eliminates binding of ARF4, ARF16, ARF27, and ARF34.