Stomatal opening kinetics during dark-to-light transition
Stomatal opening kinetics were measured in fully expanded, dark-adapted leaves. In order to avoid circadian effects in the measurements, only three plants were measured at a time. All gas exchange parameters were recorded every 10 sec for 300 sec in the dark plus 3200 sec under 1000 µmol photons m-2 s-1, 400 ppm CO2 and block temperature 28 °C using an IRGA. The curves were plotted by averaging 10 readings every 100 sec. The half-time needed to g s reach steady state (t50%) were estimated using theg s curves (Lima et al., 2019). The maximum slope of g s response (Sl max) was estimated by calculating dg s/dt when the rates of change reached an acceleration plateau. Non-linear regression equations were obtained (y ~ y o +a (1 - e (-bx ))) and further derived to obtain the rate of change. Subsequently, the data undergone curve fitting using linear plateau model (y ~a + b (x - c ) (xc )) to estimate the time when g s reach maximum rate of change in light-induced stomatal opening (Figure S2).