Fig. 9.

PIN polarisation aligns with oriented cell growth. Numerical solution of model (1)–(4a) on a regular lattice of cells, starting from the same initial conditions as in Fig. 5, but with cells undergoing auxin-dependent, vertical growth. a In the passage parameter regime oriented cell growth has no effect on the placement of cells within the passage and only shifts the PIN alignment from horizontal to vertical for four cells. b In the spot parameter regime oriented growth disturbs the formation of spots, leading to the emergence of two new spots and modifying another into a small passage, and shifts the PIN alignment from horizontal to vertical for 35 cells. All parameters are described in Appendix Tables 2 and 3. Cells are represented in the reference configuration (Color figure online)