[Reactive oxygen species in plants--production, deactivation and role in signal transduction].

Reactive oxygen species (RFT) are continuously produced in plants as byproducts of many metabolic reactions, connectedwith photosynthesis, photorespiration and cellular respiration. RFT species are highly toxic and rapidly detoxified by various cellular enzymatic and nonenzymatic mechanisms. Oxidative stress occurs when there is a serious imbalance between the production of RFT and antioxidative defense. RFT cause cellular damage by oxidizing biocompounds such as: membrane lipids, proteins and DNA. RFT participate in signal transduction by initialization a chain reaction in response to stress conditions or influence gene expression. An overview of the latest literature is presented in terms of RFT production, antioxidant free radical scavenging and redox signaling in plant cells.