Fig. 4.

The 3 ms linear time plot of the variable fluorescence response in a Kalanchoë leaf upon a 0.25 ms sSP_0.25 (black-colored) and a 1 s SP (red-colored) both of 3000 µmol photons·m⁻² s⁻¹ intensity. The two pulses are given sequentially at an intermediate dark period of a few seconds. The curves with green diamonds and red squares are the graphic plots of the calculated variable fluorescence associated with the release of primary photochemical quenching without (F ^PP1) and with (F ^PP) supplemental quenching release associated with double reduction of Q_B-nonreducing RCs, respectively. F ^PP1 and F ^PP are calculated using Eqs. 4 and 6 with substitution of the parameter values estimated from the kinetic- and steady state analyses illustrated in Figs. 1 and 2, except φ and k _2AB, and are given in the table in the insert