Calcium is an important second messenger in all eukaryotic organisms. In plants, cellular cytosolic calcium concentration changes occur in response to biotic and abiotic stress factors but also during developmental processes. To investigate Calcium signaling within living plants, we use genetically encoded calcium sensors - calcium-binding, fluorescent proteins - expressed in plant cells. Changes in cellular calcium concentrations thereby lead to changes in the spectral properties of the sensors. Using a confocal laser scanning microscope, stimulus-specific, spatially and temporally changes in cellular calcium concentrations are monitored in living cells.
Within the DFG funded research group 964 “Calcium signaling via protein phosphorylation in plant model cell types during environmental stress adaptation" we are currently investigating the molecular mechanisms of plant adaptation strategies to nutrient deficiency. A special emphasis is given on potassium sensing and transport by ion channels and transporters and their regulation by calcium-based networks.