MYB3 repressor activity is enhanced by LNK1 and LNK2. A, Transactivation assays in Arabidopsis protoplasts that were cotransfected with plasmids carrying C4Hpro-GUS and overexpression vectors containing 35S:MYB3, 35S:LNK1, 35S:LNK1D556N, 35S:LNK1D614N, or 35S:LNK1D556N-D614N, as indicated. Values are means ± sd of three biological repeats. Asterisks indicate statistically significant differences compared with C4Hpro-GUS, 35S:MYB3 or 35S:LNK1 (P < 0.05, Student’s t test). B, EMSA of a probe including the MYB3 binding site AATAGTT with His-MYB3, His-LNK1, His-ENT-LNK3, and His-LNK3 purified from E. coli BL21 (DE3). The arrow indicates the protein probe complex.