Characteristics of the light‐induced generator potentials in the liverwort Conocephalum conicum

Light‐induced generator potentials were examined in the liverwort Conocephalum conicum L. by applying sub‐threshold light stimuli (400–750 nm). The fluenceresponse dependence was determined for various wavelengths. At low values of quantum flux density (less than 1 μmol m−2 s−1) the plant reacts to the light pulses with hyperpolarization which, with a rise in the pulse intensity, is masked by the depolarization of the transmembrane potential. The action spectrum of depolarization shares many features with the absorption specturm of photosynthetic pigments. Application of inhibitors and electron donors showed a predominant role of photosystem II in the formation of the generator potential. No significant Emerson enhancement was observed after simultaneous illumination with light beams of 650 and 700 nm.