Fig. 5: Negative growth is observed in deep boundaries from intact (non-dissected) pin-like shoot apices.

A Early organ outgrowth heatmap showing the surface curvature before and after 4 h. B Heatmap showing the cell sphericity changes during the same 4 h. of growth. C Heatmaps represent the volumetric growth rates including cell divisions (C) or marking dividing cells in white (D). The same samples were rotated 90° to visualize shrinking cells detected at the boundary flanking sides. E Three time points show the developmental progression of an advanced boundary with heatmaps representing the surface mean curvature (E), and the corresponding cell sphericity changes (F) and volumetric growth rates (G) for non-dividing cells. Note the presence of pale blue cells, i.e., shrinking cells, in the deep boundary (left image) and below the meristem (right image). Cell types 1 (shrinking cell), 2 (adjacent to shrinking cell), and 3 (non-adjacent organ cells) are identified in T0–T2 and T2–T4. H Growth rates for cell types 1 (n = 9), 2 (n = 8), and 3 (n = 10) at T0–T2 and T2–T4 originating from the same meristem shown in (G). Large dots indicate the mean, and black lines represent the standard deviation.