Figure 4

Stage 3. Co-expression of DMP1-eGFP and ER markers during stage 3 shows cells with partial colocalization (a-c and d-f) and cells lacking colocalization (g-j). Accordingly, in cells expressing DMP1-eGFP alone, ER with cisternal morphology can be distinguished in the background in some of them (k) but not in others (l). Co-expression of DMP1-eGFP (a) and RFP-p24 (b) shows colocalization with the ER network (c) except for tubular structures where RFP-p24 is excluded (insets a-c). Tubular network dissociating from the ER (d-f). Weak residual DMP1-eGFP signals in the cisternal ER network (d-f, arrows). Vacuolar sheet formation inside the vacuole occurs preferentially at the periphery of cells (g, arrows) that still exhibit a DMP1-labeled tubular network and cytosolic vesicles which are either connected to this network (K, inset) or suspended in the cytosol (k, inset, and g, arrow). Tubules are often closely spaced but unconnected (k, inset). DMP1-eGFP (g) and YFP-HDEL (h, false-colored) do not colocalize (j) and Golgi vesicles labeled by Man49-mCherry are intact (I false-colored, arrow). Man49-mCherry accumulates to some extent in the apoplast (i, arrowhead). Scale bar, 20 μm.