Table 2.
Parameter values used in simulations of the flux-based model.
| 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 |
| CPIN | default initial concentration of PIN1 at cell edge compartments | Au /µm | 0.01† |
| 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 | 1 |
| γ | Unbinding rate of PIN1 from the cell edge | /s | 0.1 |
| ρ | production rate of Auxin | Au/µm2.s | 0.0001§ |
| µ | degradation rate of Auxin | /s | 0.02 |
| α | Flux-dependent promotion of PIN1 allocation to a cell edge | dimensionless | 1# |
| D | Passive permeation rate of auxin | µm/s | 5 |
| Pmax | Maximum concentration of PIN1 at a cell edge | Au /µm | 0.01¶ |
| I | Auxin import rate | µm / s | 0 |
* For cells with hexagonal geometries, each cell edge has a length of 10 µm.
† Value given is that used in simulations used to generate Figure 7.B and Figure 7—figure supplement 1B. In all other simulations, CPIN = 0.
‡ Values apply to simulations used to generate Figure 7B (ɛPIN) and Figure 7—figure supplement 1B, and Figure 7E (ɛAux). All other simulations are initialised without noise addition.
§ The value given for the auxin production rate applies to simulations used to generate Figures 9A,B, 10A, B and 16A,B. In the simulation used to generate Figure 7B and Figure 7—figure supplement 1B, ρ = 0.0025 Au/µm2.s and in the simulation used to generate Figure 7E, ρ = 0.002 Au/µm2.s.
# The value given for, α, the flux-dependent promotion of PIN allocation to cell edges, applies to simulations used to generate Figures 9A,B, 10A,B and 16A,B. In the simulation used to generate Figure 7B, α = 4 × 10−3 and in the simulation used to generate Figure 7E, α = 3.2 × 10−3.
¶ In the simulation used to generate Figures 7B, Figure 7—figure supplement 1B and 7E, Pmax = 0.04Au /µm.