EN
This paper reviews plant ascorbate peroxidases (APX), an important part of the antioxidative system, maintaining the balance and uninterrupted functioning of the plant cell. The main role of APXs is to control the hydrogen peroxide concentration in cells. In reaction the enzymes use ascorbate as an electron donor. The active site is highly conserved by every member of the APX family. APXs belong to class I of the superfamily of bacterial, fungal and plant peroxidases. All the isoforms differ from each other in molecular weight, optimal pH, stability, substrate specificity, localization and level of response to specific stress conditions. It is suggested, however, that the responsible genes originated from one common gene by multiple duplication events followed by natural selection.