C and D, Dual luciferase assay of the repression activity of GFP-TOC1 and GFP-5X on promoter of AT5G02580 (C) and CDF5 (D) in protoplasts of toc1 and hda15toc1 (h15t1) mutants. AT5G02580:LUC, CDF5:LUC reporters and the effectors (empty GFP, GFP-TOC1, and GFP-5X) were co-transfected to toc1 and hda15 toc1 protoplasts with 35S:Renilla-LUC as internal control. Data are means ± SEM (n = 5 biological trials) relative to empty GFP which is set as 1. Different letters indicate statistically significant differences (student's t test, p<0.05). 