Table 3.

Parameter values used in up-the-gradient simulations.

DOI: http://dx.doi.org/10.7554/eLife.18165.028

Symbol	description	unit	value
Δt	numerical time step	s (seconds)	0.01
R	area of cytoplasmic compartment	µm2	260
l	length of cell edge compartment	µm	15 for short cells edges; 8.6 for the each of the two compartments of a long edge *
CA	default initial concentration of auxin in cytoplasmic compartments	Au/ µm2	0.01 (Figure 7A,D, Figure 7—figure supplment 1A.) 0.005 (other Figs.)
CPIN	default initial concentration of PIN1 at cell edge compartments	Au /µm	0.1†
ɛPIN	limit for noise addition during initialisation of PIN1 concentrations at cell edges	dimensionless	0.025†
ɛAux	limit for noise addition during initialisation of Auxin concentrations	dimensionless	0.025†
T	PIN-dependent active auxin efflux rate	µm2/Au.s	80
ρ	production rate of Auxin	Au /µm2.s	0.0003‡
µ	degradation rate of Auxin	/s	0.005
PINi	Total amount of PIN1 in a cell available for binding to edge compartments	Au /µm	0.1
D	Passive permeation rate of auxin	µm/s	10
b	Exponentiation base for PIN1 allocation to the membrane	dimensionless	6
I	Auxin import rate	µm / s	0

* For cells with hexagonal geometries, each cell edge has a length of 10 µm.

^† Values given for the initial concentration of PIN1 at cell edge compartments, and the limit for noise addition to this concentration, are those used in simulations used to generate Figure 7A and Figure 7—figure supplement 1A. In all other simulations, C_PINand ɛ_PIN = 0. The value given for ɛ_Aux applies only to Figure 7D, in all other simulations, ɛ_Aux = 0.

^‡ Value given for the production rate of auxin applies to the simulations used to generate Figures 7D, 8A, B, 11H, 14D and 16E,F. In the simulation used to generate Figure 7A and Figure 7—figure supplement 1A, ρ = 0.0025 A_u /µm².s.