Time course analysis of cell wall degradation. The blue ellipse highlights a single cell for focus. (A) Time 0, has an intact PM. Also note the characteristic aggregate of mitochondria and chlorophyll containing material within the cell, indicated by the black arrow. Inset: Late-PCD (LPCD) stage cell with a collapsed PM and visibly intact cell wall. The collapse of the PM occurs between the stages shown in panels A and B. (B) Time 6 hours, recognize that within this 6 hour time span, the PM of the cell of interest has collapsed, and some cell wall degradation has began to occur. (C) Time 12 hours, note the cell of interest now has little visible cell wall content. (D) Time 24 hours, note the cell of interest now appears to have very little visible cell wall content and cellular wall degradation is nearly complete. Scale bars: A-D = 100 μm, Inset = 20 μm.