Analysis of RR19/HPts (HPt2, 7 and 9) interactions in C. roseus cells using BiFC assays. Cells were co-transformed using a combination of plasmids expressing HPt2/RR19 (A-H), HPt7/RR19 (I-P) and HPt9/RR19 (Q-X) as indicated. For each combination, an additional co-transformation was performed with the CFP nuclear marker (B, F, J, N, R, V). Co-localization of the two fluorescence signals is shown in the merged image (C, G, K, O, S, W). The morphology was observed by differential interference contrast (DIC) microscopy (D, H, J, P, T, X). Scale bar = 10 μm. As negative controls, two combinations of plasmids were used: YFPN-RR19/bZIP- YFPC and bZIP-YFPN/YFPC-RR19 (Ya-b, Za-b), supplemented by a co-transformation with the CFP nuclear marker. The morphology was observed by differential interference contrast (DIC) microscopy (Yb, Zb). Scale bar = 10 μm.