Hydrogen peroxide (H2O2) is commonly known as a bleaching and disinfecting agent. However, it is also constantly produced in living cells. Often as a byproduct of biological processes, sometimes intentionally, for example to kill pathogens. It is also thought that H2O2 plays an important role as a signaling molecule. To investigate this biological function, research teams from TU Kaiserslautern (TUK) and Saarland University have developed an H2O2-sensitive sensor for plant cells. The sensor reveals where in the cell hydrogen peroxide is produced and how the signaling pathways run. The work has been published in the renowned journal „The Plant Cell“.