Interaction of the CsMADS6 protein with the promoters of PSY, PDS, and CCD1. A, Probes used for EMSA. The predicted CArG elements are underlined in red. Numbers indicate the positions relative to the ATG start codon. B, EMSA showing the binding of CsMADS6 to the promoters of PSY, PDS, and CCD1. + and − indicate the presence and absence, respectively, of a probe or protein; 20× and 30× indicate 20-fold and 30-fold excess, respectively, of unlabeled probes. Red arrows indicate the positions of protein-DNA complexes or free probes. C, Schematic diagrams of vectors used for the dual-luciferase assay. In the reporter vectors, the promoters from PSY, PDS, and CCD1 are fused to the LUC reporter gene. pK, Empty vector; pK-CsMADS6, CsMADS6 overexpression vector. D, Dual-luciferase assay showing relative CsMADS6 activation of the PSY, PDS, and CCD1 promoters. The data are expressed as means ± sd from at least four biological replicates. Asterisks indicate significant differences relative to the empty vector control by one-way ANOVA tests (**, P < 0.01).