Spatial Dependence for Hydrogen Peroxide-Directed Signaling in Light-Stressed Plants

In this article, the role of the reactive oxygen species (ROS) hydrogen peroxide (H 2 O 2 ) as a signaling molecule involved in plant response to a sudden change in light intensity will be considered in a spatial context. The relatively low reactivity of H 2 O 2 compared with other ROS However, another view is promulgated here that allows for compartment-specific H 2 O 2 -mediated signaling associated with acclimation to high light. It is proposed that a spatial component to signaling is maintained by limiting the accumulation of H 2 O 2 to its sites of production. This would allow H 2 O 2 to initiate distinct signals depending on its subcellular origin Conversely, breakdown in the integrity of this spatial component, such that H 2 O 2 diffuses into other subcellular compartments, would promote oxidative stress and trigger signaling associated with cell death.