Transcriptional activity of the combination of AtIDD proteins and REPRESSOR of ga1-3 (RGA) or SHR + SCARECROW (SCR) on several promoters. (A) The location of the IDD binding sequence candidates. IDDBS: TTTGTC(G/C)(T/C)(T/a)(T/a)T; MBPBS: TTGTCT; IDDBS-like1: 11bp sequence containing GTC(G/C), with more than seven nucleotides identical to IDDBS; IDDBS-like2: 11bp sequence containing GTC(G/C), with less than six nucleotides identical to IDDBS. (B) Schematic diagram of reporter and effector plasmids used in transient assays. CaMV35p: CaMV35S promoter, NOS: NOS terminator. The promoter regions of (C) SCR, (D) SCL3, (E) GA3ox1, (F) PIN1, and (G) YUC5 were used for reporter construction. As a control, an empty vector was used, and all luciferase reporter gene (LUC) activities were expressed relative to this control (value set at 1). Values shown are the average of results from three or four independent experiments. Error bars represent standard deviation (SD). Asterisks represent significantly different activity from those of AtIDD alone (* p < 0.05, ** p < 0.01).