Hydrogen peroxide-a central hub for information flow in plant cells

Background Hydrogen peroxide (H2O2) was initially recognized as a toxic reactive oxygen species, able to cause damage to a variety of cellular structures. However, it became clear in the last decade that H2O2 can also act as a potent signalling molecule, involved in a plethora of physiological functions. Scope In the present review, we offer a brief summary of H2O2 signalling events and focus on the mechanisms of its perception and signal transduction, the factors that act downstream, as well as H2O2 interference with other information transfer mechanisms. Conclusion The significant scientific effort in the last 10 years to determine the position of H2O2 in signal transduction networks in plants demonstrated that it is essential for both the communication with external biotic and abiotic stimuli and the control of developmentally regulated processes. In addition, H2O2 complements, synergizes or antagonizes many cellular regulatory circuits by active interaction with other signals and plant hormones during growth, development and stress responses. Therefore, further understanding of H2O2 signal transduction is not only of fundamental, but also of practical importance, since this knowledge may contribute to improve agricultural practices and reduce stress-induced damage to crops.