Antioxidants in Erica andevalensis: A comparative study between wild plants and cadmium-exposed plants under controlled conditions

Abstract

Erica andevalensis is an endemic species from SW Iberian Peninsula, always growing in metal-enriched and acid soils. In the present study, a comparison was made between wild E. andevalensis plants collected from the field and cultivated ones exposed to different cadmium levels (0, 0.5, 5 and 50 mu M). Wild plants contain higher levels of ascorbic acid (around 8000 nmol g(-1) FW) than lab-cultivated control plants (around 3000 nmol g(-1) FW). Glutathione levels follow an opposite trend being smaller in wild plants than lab-cultivated ones. Moreover, the total antioxidant capacity of wild plants is 90 times higher than in cultivated plants non-exposed to cadmium. Cadmium treatment of lab-cultivated plants did not affect the growth of E. andevalensis or the glutathione levels. However, the total antioxidative capacity increased in plants exposed to 50 mu M of cadmium. Cadmium was added to the soil and it was transported into leaves reaching levels of 3.299 +/- 0.781 mu g Cd/g DW in plants exposed to 50 mu M. These results underline a possible importance of antioxidants in the metal tolerance show by the high antioxidant capacity detected in both wild and lab-cultivated plants exposed to high cadmium levels. (C) 2010 Elsevier Masson SAS. All rights reserved.