Class III peroxidase and polyphenol oxidase activities in aquatic macrophytes during vegetative period in Bardača a wetland
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.