Role of tocopherols in the antioxidative defences against copper excess in wheat roots

The present paper deals with the effects of copper on roots of wheat and its tolerance to oxidative stress. In particular, the aim was to study the effects of tocopherols in the response to an oxidative stress induced in wheat (Triticum durum cv. Adamello) treated with copper for 960 min. For this purpose, determinations of tocopherols, free radicals, hydrogen peroxide and superoxide dismutase were carried out to evaluate if tocopherol, besides antioxidant function can be involved in the response to oxidative stress. The determination of the NADPH/NADP ratio was also carried out to establish the ability of the cell in regenerating tocopherols. After 120 min of treatment NADPH and a-tocopherol progressively decreased, whereas the NADPH/NADP ratio and ?-tocopherol started to recover. At the same time, superoxide dismutase reached a peak as well as hydrogen peroxide. This study highlights the possible role of tocopherols in contrasting the deleterious effects of Cu excess being them involved in signalling.