ABSTRACT
Oxidative stress occurs when excess photon energy is redirected to the production of reactive of species (ROS) primarily in the electron transport chain systems in the chloroplast and mitochondria, and the capacity of the plant to remove ROS is overwhelmed. If unchecked ROS cell concentrations rise and cause oxidative damage to cell membranes (lipid peroxidation), proteins, RNA and DNA molecules, and ultimately, the cell dies. Woody plant adaptive responses to the oxidative stresses present in the environment, such as radiation stress, extreme temperature, water and nutrient deficit, and pest and diseases have shaped vegetation types. The environment itself could alleviate the effects of stress and compensate for the deleterious effect of oxidative stress. The ozone that enters into the leaf through the stomata decays into ROS and triggers an oxidative burst. Woody plant physiological response to oxidative stress might involve non-enzymatic means.
