Ökophysiologie der Pflanzen

Desiccation-induced chlorophyll fluorescence quenching

Aeroterrestrial algae and cyanobacteria, most lichens, many mosses and a few vascular plants are desiccation tolerant. In most habitats, desiccation comes along with high solar irradiation. In the desiccated state, photosynthesis is not working and, hence, all light absorbed by the photosynthetic apparatus must be dissipated by a highly efficient and safe way to prevent photodamage. In many cryptogams it has been observed that PS II is transformed to a dissipative trap for light in the desiccated state. Indicative for this state is the presence of strong quenching of the basal chlorophyll fluorescence (Fo). We are investigating the photoprotective efficiency of the quenching mechanism. To this end we are exploring means to manipulate desiccation-induced quenching (qdes) in aeroterrestrial green microalgae which are either free living or serve as photobionts in lichens. We are alo exploring the acclimative potential in these algae, for example when growing in high light.

Publications:

Wieners PC, Mudimu O, Bilger W (2012) Desiccation-induced non-radiative dissipation in isolated green lichen algae. Photosynth Res 113: 239-247

Bilger W (2014) Desiccation-induced quenching of chlorophyll fluorescence in cryptogams. In: B Demmig-Adams, G Garab, WW Adams III, Govindjee, eds, Non-Photochemical Quenching and Energy Dissipation in Plants, Algae and Cyanobacteria. Springer, Dordrecht, pp 409-420