Fig 3. Simulation of constitutive activation of different nodes in the absence of ABA for two assumptions regarding the effect of Ca²⁺c on ABI2.

Panel (A) indicates the original assumption (i.e., no additional edge) and panel (B) represents the assumption that Ca²⁺_c inhibits ABI2. The y-axis denotes the percentage of closure across 4500 simulations when ABA is off. The x-axis denotes the time steps (rounds of node update) of the simulation. (A) In the absence of inhibition of PP2Cs by Ca²⁺_c, only the constitutive activation (CA) of ROS (squares) yields a nonzero percentage of closure in the absence of ABA. All the other situations lead to 0% closure. (B) When assuming Ca²⁺_c inhibition of ABI2, there is a baseline percentage of closure of 21.5% (see Methods). The constitutive activation of Ca²⁺_c (filled circles), ROS (squares), InsP3/6 (downward triangles) or of cADPR (stars) yields 100% closure, but with different timing. The constitutive activation of PA or S1P gives a slightly increased response compared to baseline.