Antioxidant enzymes activities in Vicia seedlings during drought stress.

Drought greatly affects normal plant growth, endangering physiological and biochemical processes in plants. Under the influence of unfavorable environmental conditions, antioxidant protection systems in plant cell can be activated regardless of the stage of growth and development of plants. The experiment was conducted on three vetches species (V. sativa, V. villosa and V. pannonica) under PEG-induced drought stress. Activity of antioxidant enzymes: superoxide dismutase (SOD, EC 1.15.1.1), ascorbate peroxidase (APx, EC 1.11.1.1) and catalase (CAT, EC 1. 11. 1. 6), was determined in shoots and roots of 10-day-old seedlings. Lack of water during germination period activated all the examined antioxidant enzymes in both organs of all tested Vicia species. The activity of SOD and APx generally increased at higher stress levels, while the enzyme CAT showed different patterns of action in all tested species. The results of this study suggest that drought stress causes the production of oxygen radicals that lead to oxidative stress in plants.