Abstract:Antioxidative systems were investigated in leaves and roots of Plantago major L. which were collected from Mahan Mountain at different altitudes. The content of glutathione (GSH) in reduced form was increased in leaves and roots with the increasing altitude. The activities of peroxidase (POX) and superoxide dismatase superoxide dismutase (SOD) in roots also increased as the altitude was increased, while that in leaves they declined at higher altitude. Analyses of isozymes of SOD and POX in leaves and roots showed that high altitude (3 300 m) induced the SOD isozymes 8 and POX isozyme 5 in roots, which appeared to be required for protection against lower temperature and higher light intensity as altitude was increased. The present study suggested that high altitude had affected differently the antioxidative system in leaves and roots.