Antioxidant enzyme activity in Pinus mugo Turra, P. sylvestris L. and in their putative hybrids

Specific activity dynamics and isozyme composition of antioxidant enzymes ascorbate peroxidase (APX), catalase (CAT) and superoxide dismutase (SOD) were followed during the vegetation period in the young needles of Pinus mugo Turra, P. sylvestris L. and their putative hybrids. Tested enzymes differed in their dynamics showing the highest APX and CAT activities in the spring and autumn and the highest SOD activity in summer. The outlined course of enzyme activity was characteristic for all the three taxa compared. The level of specific enzyme activities was relatively constant in investigated taxa reaching statistical significance in some months of the scored period only. The same was true of the antioxidant enzyme activities of P. mugo individuals growing at different altitudes. Of the enzymes assayed, catalase was the most active. Hybrid individuals exhibited prevailingly intermediate level of their enzyme activity compared to the parental species. The dynamics of SOD correlated with intensity of UV irradiation during vegetation period. Partial correlation was observed between specific enzyme activities and isozyme composition.