Antioxidative responses to different altitudes in Plantago major

Abstract

The contents of antioxidants were investigated in leaves and in roots of Plantago major, which were collected from different altitudes of Mahan Mountain. A strong correlation between antioxidant content and elevation was observed. As altitude increased, the content of glutathione (GSH) increased both in leaves and in roots, while the activities of guaiacol peroxidase (POX) and superoxide dismutase (SOD) increased only in roots, and declined in leaves. Analyses of isozyme of POX and SOD showed that at high altitude (3300 m) the POX isozyme 5 and the SOD isozyme 8 were induced in roots, but not in leaves. It seemed that the POX isozyme 5 and the SOD isozyme 8 were required for adaptation as the oxidant level increased with lower temperature and higher light intensity as altitude increased. There were no significantly meaningful differences in SOD isozyme profiles and POX isozyme profiles in leaves among three altitudes. These results indicated that Plantago major could not grow at much higher altitude than 3300 m. The present study also suggested that high altitude had different effects on antioxidant system in leaves and in roots.