Numerical simulation of the in vivo fluorescence in plants

The variable fluorescence in the fast phase of chlorophyll a fluorescence induction phenomenon is closely related to the electron transport in photosystem II (PS II) of plants. We present here two theoretical models that simulate successfully the experimental data on the O-J-I-P fluorescence transient using PS II reactions. The “core” of both these proposed theoretical models are charge stabilization and the two-electron-gate process on the acceptor side of PS II. The data for dynamic analysis of the models were obtained through numerical integration with a specialized simulation software Gepasi. We have simulated the fluorescence transients under three different experimental conditions: (1) variation of the light intensity; (2) DCMU treatment; and (3) re-exposure of the samples to actinic light after a defined period of darkness.