BiFC-based interactions between YDA and EIN3. Interactions with (A–C) bright, (D–F) YFP, and (G–I) merged. Pairs of proteins of YDA and EIN3 fused with halves of the YFP molecule were transiently expressed in wild tobacco leaves and reconstituted YFP fluorescence was imaged in epidermis on the abaxial leaf blades. Only EIN3 fused with halves of the YFP molecule was used as a negative control. Plasmid containing YFP was used as a positive control. Bar, 40 μm for A, D, and G; bar, 20.0 μm for B, C, E, F, H, and I.