Light-sheet live imaging of GFP-RabA1d accumulation during cell plate formation in the root meristem. Meristematic cells undergoing cytokinesis showed several locations of GFP-RabA1d accumulation observed in single sections of one time point at indicated depths inside the primary root (A), GFP-RabA1d accumulation in cell plates (arrowheads) of cytokinetic cells. The boxed area in A is enlarged shown in B. Detailed time-lapse imaging of GFP-RabA1d accumulation during single cell plate formation starting from spot like structures in the middle of the cell, followed by increased intensity during vesicle fusion and later formation of a ring-like structure at the margins in the growing cell plates (B). Three-dimensional reconstruction of the cell plate shown in (B) at time point 20 min (C). Comparison of cell plate growth rates in Arabidopsis plants stably transformed with in 35S::GFP:RabA1d and 35S::GFP:MAP4 constructs (ns: no significant difference) (D). Growth rates of cell plates in cells from different tissues (E). *significant difference from Wilcoxon rank sum test with Holm’s correction (p<0.05), ns: no significant difference. Bars represent 50 μm in A and 10 μm in B.