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

Activities acid Properties of Glutamine Syntheaase and of Glutamate Dehydrogenase in Scots Pine Needles (Pinus sylvestris L.) in Relation to the Habitat Studies were carried out on the properties of glutamine synthetase acid glutamate dehydrogenase determined in the needles of scots pine (Pinus sylvestris L.) from three various air-polluted locations (relatively unpolluted, moderately and heavily polluted area). The enzymes were partially purified and characterized (K-m values, pH optima, temperature dependence, Ca2+ requirement). The glutamine synthetase activity from P. sylvestris grown in a polluted area is very diminished, on the other hand the glutamate dehydrogenase activity is slightly enhanced under such conditions. The enzyme activities were correlated with the natural N-15/N-14 isotope variations. The results are discussed with respect to the possible role of these enzymes in the nitrogen metabolism of conifers under different environmental stress conditions, particularly in terms of air pollution.