Antioxidant Capacity in Leaf and Root Tissues of Prunus spp under Flooding

The present study aims to evaluate the antioxidant responses and cellular damage in 'América' Japanese Plum and 'GxN-9' peach rootstock plants under soil flooding stress. Two-year-old plants propagated by cuttings were transplanted to pots (4 L) and two months after planting; they were submitted to different flood periods (2; 4 and 6 days); each period being composed of two treatments; control (irrigated daily to field capacity) and water stress (soil flooding). After each stress period; cells damage was evaluated by measuring lipid peroxidation (MDA) and hydrogen peroxide (H2O2); and the specific activity of the antioxidant enzymes Superoxide Dismutase (SOD); Catalase (CAT) and Ascorbate Peroxidase (APX) from 200 mg of leaf and root tissues. Under stressed conditions; an increase in the activity of the antioxidant enzymes and the levels of H2O2 and MDA in both cultivars and tissues were observed. Leaves showed the highest cellular damage when compared with roots; which suggests the higher activity of photosynthetic and photorespiratory metabolism. The values of MDA and H2O2 were lower in America when compared to GxN-9; indicating that the antioxidant system of the Japanese Plum cultivar is more efficient as compared to the peach rootstock under soil flood conditions.