Abstract – In this study, changes in Class III peroxidase (POX) and polyphenol oxidase (PPO) activity in
Phragmites australis (Cav.) Trin. Ex Steud. Utricularia vulgaris L. and Salvinia natans (L.) from the
Bardača wetland during one vegetation season (June-October) were monitored. The highest activities of
soluble and ionic cell wall bound peroxidases (solPOX and ionPOX, respectively) were measured for
Phragmites communis (leaf > root > rhizome), followed by Utricularia vulgaris (whole plant), then
Salvinia natans (whole plant). The results showed that during the vegetation period (August-September) the
activity of solPOX, ionPOX and PPO in Phragmites communis increased, but the activity decreased
drastically in October. For Salvinia natans and Utricularia vulgaris, a different seasonal distribution was
obtained in the PPO activity, i.e. with a maximum activity during July and a minimum one during
September. Different seasonal trends in enzyme activities are probably the result of abiotic stress caused by
changing physic-chemical environmental conditions and different adaptive capacities of the studied species
to habitat conditions. Correlations between physicochemical environmental parameters and enzyme
activities indicate the possibility of using POX and PPO activities as an important bioindicatos of
environmental status.
