Fig. 1. Cell division markers. (A-F) 35S::YFP29-1 expression in different clonal layers of SAMs. (G-H) 35S:H2B:mYFP expression in reconstructed L1 layer. (A,C,E,G) The first time points (0 hour) and (B,D,F,H) represent the same SAMs after the elapsed time indicated on top right-hand corner of each panel. (A,B) The reconstructed Z-series revealing all the cells in the L1 layer. Primordia at different stages of development are marked as P1, P2, P3. Arrows indicate the same cells prior to and after division. (C,D) Cells in the L2 layer (8 µm deep); the arrow points to cell division events. (E,F) Cells in the corpus (12 µm deep); the arrows point to cell division events. (G,H) The reconstructed images of the L1 layer expressing 35S::H2B:mYFP. Arrows in G indicate cells in division, and arrows in H are the same cells after an hour, showing decondensed chromatin after completion of mitosis. (I-L) Reconstructed views of different growth stages of the same SAM after 24-hour intervals. The earliest visible bulge on the meristem flank is considered as stage P1 (J,K). The extension of the bulge in the x/y axis and the appearance of a first sign of a groove between the SAM and the primordium is considered stage P2. Scale bar: 20 µm.