Reactive Oxygen Species (ROS): Role in Plant Defense

Reactive oxygen species (ROS) play an important role in the defense response of plants against various pathogens and under stress conditions. Any stress condition results in the excess production of reactive oxygen species (ROS) e.g. superoxide, hydrogen peroxide and hydroxyl radicals, a phenomenon known as the oxidative burst, which is the primary defense response against pathogens in the early stages of infection. These ROS species, some of which are toxic are rapidly detoxified by various cellular enzymatic and non-enzymatic mechanisms. The present paper deals with the ROS, mechanism, chemistry and their role in the defense response of plants.