Seasonal Changes in the Activities of Apoplastic, Cytoplasmic, Ionically and Covalently Bound Isoperoxidases from Norway Spruce (Picea abies (L.) Karst.) Needles: A Comparison between Three Collection Sites with Different Ambient Ozone Concentrations

Apoplastic, cytoplasmic, ionically and covalently bound isoperoxidases were investigated from needles o f Norway spruce (Picea abies (L.) Karst.) and a pronounced genetic variability o f the isoenzyme pattern was found. The enzymatic activity o f each group o f isoperoxidases was determined between November 1989 to November 1990 from needles o f three locations (Velmerstot, Glindfeld, Haltern) with different ozone concentrations. Apoplastic peroxidases o f needles from trees grown in Velmerstot and Glindfeld showed up to two-fold higher activi­ ties than the same group o f peroxidases from Haltern. Based on the recorded increased ozone concentrations in Velmerstot and Glindfeld a positive correlation between the activity o f the apoplastic peroxidases and ambient ozone concentrations at the different locations could be demonstrated. A putative role o f the apoplastic peroxidases as a bioindicator for air pollutants is discussed.