Fig. 2: Schematic growth and patterning of an indeterminate meristem, illustrated by a one-dimensional filament.

a–c Uniform tissue growth rate and threshold size for division. a Morphogen generated at the right end (apex) forms a gradient. Above threshold T1, cells adopt red identity, between T1 and T2, white identity, and below T2 blue identity. b Tissue growth rate (green line) and size at which cells divide (magenta), are both constant. c Fate of cells generated by a cell or cells at the right end of the filament shown continuously over time, with final cell pattern shown at the bottom. Red and white domains maintain the same size (domain size homeostasis) while the blue domain increases in size over time. Wall thickness increases with time and cells have uniform sizes. d–f Same as (a–c) but with threshold size for division modulated by morphogen concentration to give a rising curve. Cell size increases from right to left, with blue cells no longer dividing as they never reach the increased size threshold. g–i Same as (d–f), but with tissue growth rate modulated by morphogen concentration, with the highest rate at an intermediate concentration. The result of this combination of growth rate and cell division threshold curves is slow-growing small cells in the red domain, faster growing larger cells in the white domain, and slow-growing large cells in the blue domain.