Phenylalanine ammonia lyase was characterized in roots of Pinus sylvestris L. The Km for the pine root enzyme with phenylalanine as a substrate was l.2 ± 0.4 X 10-4 M. The enzyme had a pH activity optimum of 9 and the subunit molecular weight was 70 to 72 kD as determined by Western blotting. Enzyme activity could be inhibited by D,L-2-aminooxy 3 phenylpropionic acid at 1 μ. Treatments with zymosan, pectinase, light or kinetin and naphthylacetic acid did not induce higher phenylalanine ammonia lyase or peroxidase activity in pine roots. No significant differences were observed in phenylalanine ammonia lyase or peroxidase activity in mycorrhizal and nonmycorrhizal short roots in the P. sylvestris-L. laccata symbiosis 15 weeks after cultivation.
Keywords: Laccaria laccata; Pinus sylvestris L; mycorrhiza; peroxidase; phenylalanine ammonia lyase.