Roles of Reactive Oxygen Species and Nitric Oxide in Interactions Between Plants and Pathogens

Production of reactive oxygen species (ROS) during host-pathogen interactions is termed oxidative burst. The most important ROS include singlet oxygen (1O2), superoxide anion O2-., the hydroxyperoxyl radical (HO2·), hydrogen peroxide (H2O2) and the hydroxyl radical (·OH). Nitric oxide (NO), which has a close relation with the ROS, belongs to reactive nitrogen species (RNS). The ROS and NO are involved in regulation of plant growth and development and in responses to environmental stress, and play an important role especially in their defense against pathogenic invasion. Different roles of the ROS and NO in host-pathogen interactions are discussed.