Table 1.
Model parameters.
| Parameter | Description | Units | Default | Min | Max | Touch | Anoxia | Osmotic | Cold |
|---|---|---|---|---|---|---|---|---|---|
| x | Amount of Ca2+ in cytosol | μM | |||||||
| y | Amount of Ca2+ in intracellular store | μM | |||||||
| B | Plasma membrane-based Ca2+ pump | μM/s | 20 | 10 | 30 | 20 | 2.5 | 8 | 13 |
| D | Endomembrane-based Ca2+/H+ exchanger | μM/s | 36 | 18 | 54 | 36 | 34 | 58 | 50 |
| σB | SD in B for cell population | μM/s | 0 | 0 | 5 | 0.1 | 1.7 | 1 | 3 |
| σD | SD in D for cell population | μM/s | 0 | 0 | 5 | 0.1 | 5 | 4 | 3 |
| A | Ca2+ permeable channel (external → cytosol) | μM/s | 2 | Fixed | |||||
| C | Ca2+ permeable channel (intracellular store → cytosol) | μM/s | 60 | Fixed | |||||
| x(0) | Initial amount of Ca2+ in cytosol | μM | 160 | Fixed | |||||
| y(0) | Initial amount of Ca2+ in intracellular store | μM | 0.1 | Fixed | |||||
| R | ROS concentration | μM | 0.05 | Fixed | |||||
| Kd | Buffering parameter | μM | 0.6 | Fixed | |||||
| Bmax | Buffering parameter | μM | 250 | Fixed | |||||
| K | Half maximal saturating Ca2+ concentration | μM1/n | 1 | Fixed | |||||
| n | Hill coefficient | – | 4 | Fixed |
The “default” model is the reference model. Parameters B, D, σB, and σD are changed in the range minimum – maximum and plotted in Figures 5 and 6. Best fit parameters for touch, cold, anoxia, and osmotic stress correspond to curves in Figure 7. All other model parameters are held constant in this work.