BiFC visualization of bZIP63 dimerization in transfected Arabidopsis protoplasts. Epifluorescence (A, B) and DIC (C) images of protoplasts that were transfected with plasmids encoding fusion proteins. Green color indicates the fluorescence as a result of bZIP63 dimerization in BiFC. The dimer of bZIP63 was located in the nucleus . Bar in A = 50 μm, bar in B and C = 5 μm.