On 9 June, the HPSC lecture series welcomed Prof. Rob Roelfsema (University of Würzburg) for an insightful talk on “Coordination of Ion Fluxes During Opening and Closure of Stomatal Pores.” Focusing on biophysiological approaches, he presented recent research on how guard cells regulate stomatal opening and closure, enabling plants to balance CO2-uptake and water loss.
By combining techniques such as intracellular microelectrodes, ion-selective scanning electrodes, fluorescent ion indicators, and light-gated channels, his team investigates how ion transport at the plasma and vacuolar membranes of guard cells is coordinated. A key insight discussed was that ion transport proteins not only are important for dynamic stomatal movements that occur in approximately one hour, but also for the basal level of stomatal conductance, which is likely to be important for slow adaptive responses to changes in environmental conditions. In addition, it was highlighted that ion fluxes across the plasma membrane and tonoplast are coordinated through cytosolic calcium signals.
The talk provided important insights into processes which are highly relevant for understanding mechanisms of drought adaptation and potentially improving crop water-use efficiency in the context of climate change. We thank Rob Roelfsema for the inspiring presentation and the stimulating discussion with PhD students and researchers.
