Biochemical responses to abiotic stress in Beech (Fagus sylvatica L.) leaves

In two alpine forest sites, characterized by a different degree of visible stress symptoms and by corresponding different ambient ozone concentrations, a series of biochemical assays has been carried on, in order to evaluate the response of cellular detoxifying systems toward oxidative stress produced by ozone. Besides ascorbic acid (AA) levels, the activity of three scavengers enzymes (ascorbic peroxidase -AAPOX, superoxided dismutase-SOD and gluthatione reductase-GR) has been investigated. While SOD and GR did not exhibite an evident correlation with oxidative stress symptoms, both AA and AAPOX showed a behaviour parallel to the injury symptoms and to the corresponding ozone exposure doses.