Fig. 7. Redistribution of AtPIN1::GFP in BY-2 protoplasts and oryzalin-treated BY-2 cells. (A) Stably transformed BY-2 cells exhibit a polar pattern of AtPIN1::GFP because the radial surface (but not their longitudinal membranes) was clearly fluorescent. (B) High-magnification of the transverse membranes shows that the two sides of the cell-cell contact are indeed labelled. (C-H) Progressive relocation of AtPIN1::GFP-labelling during the process of making protoplasts. (C) Bottom cell becomes rounder and labelling begins to extend to the whole plasma membrane. Notice the more intense labelling when cells are still in contact (top cells). (D) The arrow marks the cell followed over time and shown in the two following sequences (E) and (G). (E) When the protoplast finally detaches from its neighbour, differential staining is still displayed for a few minutes on the plasma membrane (arrowhead). (F) Corresponding DIC image of (E). (G) Same protoplast at a later stage, AtPIN1::GFP labelling of plasma membrane is still conserved but it has extended to the whole surface. (H) Corresponding DIC image. (I-L) Progressive relocation of AtPIN1::GFP under oryzalin treatment. (I) After 10 minutes, cells begin to round up, labelling is still observed on cell plate and transverse cell surface. (J-L) Labelling at the cell surface is still observed as long as there is some cell-cell contact, regardless of the loss of the ribbon form of BY-2 cells (arrowheads). Bars, 16 µm.