Antioxidative system in wild populations of Erica andevalensis

Abstract

Erica andevalensis is an edapho-endemic heather that grows in metal-enriched and acidic soils from pyrite mine areas (SW Iberian Peninsula). Taking into account that metals may cause oxidative damages through the production of reactive oxygen species, we have analysed the level of oxidative stress markers and antioxidative responses of some wild populations of E. andevalensis, with the aim to detect symptoms of oxidative stress in wild populations. Despite the high levels of Fe and Mn found in leaves, the plants did not present any visual signs of damage. Moreover, there was no correlation between the metal levels found in soils and those found in plants. E. andevalensis growing in the most polluted soils did not present the highest content of metals in its leaves, with the exception of Zn. With regard to the antioxidant molecules, no differences were found in the levels of ascorbic acid, neither in the reduced nor total forms, although these molecules were highly oxidised. Furthermore, no differences were found in catalase and superoxide dismutase activities, but plants growing in the most polluted soils presented the highest peroxidase activity, together with the highest lipid peroxidation, but not the lowest levels of pigments. When all the data were analysed together, we found that E. andevalensis is able to prevent oxidative stress damage, as indicated by the low levels of lipid peroxidation and hydrogen peroxide found, as compared with other plant species.