Optogenetics is the control of cells by means of light. Light-regulated proteins are used as genetically encoded tools in order to control the 'behavior' of cells, tissues or even complex organisms. One of these proteins is the Channelrhodopsin from the single cell, green algae Chlamydomonas reinhardtii. Channelrhodopsin is now a well established tool in optogenetics. The Channelrhodopsin apoprotein gains its light sensitivity through the cofactor retinal. In neurobiology, Channelrhodopsins are often used in fundamental research in order to specifically control the 'firing' of action potentials in neurons via the application of bluelight pulses. Even plants can are capable of generating actionpotential-like electrical signals, albeit at a much slower time scale. Nevertheless, these signals may be so fast that they allow insects to be captured in case of the Venus flytrap (Dionaea muscipula). But also other plants respond with electrical responses to environmental signals. In order to understand the characteristics and importance of electrical signaling in plants, we employ optogenetic tools.