ACTIVITIES AND PROPERTIES OF GLUTAMINE-SY NTHETASE AND OF GLUTAMATE-DEHYDROGENASE IN SCOTS PINE NEEDLES (PINUS-SYLVESTRIS) IN RELATION TO THE HABITAT

Activities acid Properties of Glutamine Syntheaase and of Glutamate De hydrogenase in Scots Pine Needles (Pinus sylvestris L.) in Relation to the Habitat Studies were carried out on the properties of glutamine s ynthetase acid glutamate dehydrogenase determined in the needles of sc ots pine (Pinus sylvestris L.) from three various air-polluted locatio ns (relatively unpolluted, moderately and heavily polluted area). The enzymes were partially purified and characterized (K-m values, pH opti ma, temperature dependence, Ca2+ requirement). The glutamine synthetas e activity from P. sylvestris grown in a polluted area is very diminis hed, on the other hand the glutamate dehydrogenase activity is slightl y enhanced under such conditions. The enzyme activities were correlate d with the natural N-15/N-14 isotope variations. The results are discu ssed with respect to the possible role of these enzymes in the nitroge n metabolism of conifers under different environmental stress conditio ns, particularly in terms of air pollution.