Figure 2

Nuclear and cellular collapse during the wound response. The GFP-Nit1 line N1P2E was wounded and a confocal Z-series was immediately collected at 60 sec intervals from a region abutting the wound. (A) Nuclear contraction of a nucleus (adjacent to the white arrow) in a wound-proximal cotyledon epidermal cell that after wounding displayed the aggregation response (aggregates indicated by red arrows) then collapsed. (B) Cellular collapse by one of several cells in the wound site that displayed GFP-Nit1 aggregates and contractions. The red arrow points to the edge of the contracting cell and the white arrow to the wall of an adjacent cell. Note the detachment of the cell from the wall (most evident at 48 min after wounding). (C) Reversibility of transmitted response. An agarose-mounted 35S GFP-Nit1 plant was wounded above the root meristem and imaged by the acquisition of Z-series at 2 min intervals for 60 min (see supplemental data for complete image series). In the first time point after wounding, the aggregation response had spread throughout much of the root meristem. Over time, the aggregates reverted back to a cytoplasmic distribution pattern and cytoplasmic streaming was evident. Images in A are single confocal optical sections, B and C are reconstructions from Z-series stacks. The numbers in the lower right of each panel indicate time in min from the start of imaging. Scale bars A, B = 25 μm; C = 20 μm.