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 ) (x ≤ c )) to
estimate the time when g s reach maximum rate of
change in light-induced stomatal opening (Figure S2).