Figure 8.

EdU labeling during S. moellendorffii root bifurcation. Confocal images of root meristems treated for 7 h with 7.5 µM EdU at different stages during branching are shown. Nuclei of cells that underwent S-phase during these 7 h, incorporated EdU (magenta). Cell walls were stained with Calcofluor-white (green). Scale bars: 50 µm. White asterisks indicate the location of the ICs. A–C, A single IC in each root tip. D–F, Two adjacent ICs formed by a symmetrical division. G–I, Two ICs are only separated by one or two layers of cells. J–L, Further development of the two meristems, including enlargement of the root tip. Panels K and L are composed of two different z-stack planes (see Supplemental Movies S12 and S13 for the full stacks), each containing an apical cell.