Influence of solar UV radiation on the nitrogen metabolism in needles of Scots pine (Pinus sylvestris L.).
Needles of 20-year-old Scots pine (Pinus sylvestris L.) saplings were studied in an ultraviolet (UV) exclusion field experiment (from 2000 to 2002) in northern Finland (67 degrees N). The chambers held filters that excluded both UV-B and UV-A, excluded UV-B only, transmitted all UV (control), or lacked filters (ambient). UV-B/UV-A exclusion decreased nitrate reductase (NR) activity of 1-year-old needles of Scots pines compared to the controls. The proportion of free amino acids varied in the range 1.08-1.94% of total proteins, and was significantly higher in needles of saplings grown under UV-B/UV-A exclusion compared to the controls or UV-B exclusion. NR activity correlated with air temperature, indicating a "chamber effect". The study showed that both UV irradiance and increasing temperature are significant modulators of nitrogen (N) metabolism in Scots pine needles.
Department of Instrumental Analysis, Provincial Sanitary-Epidemiological Station, State Sanitary Inspection, Pradnicka 76, PL-31-202 Kraków, Poland.
Marek
M
Krywult
Jerzy
J
Smykla
Heli
H
Kinnunen
Françoise
F
Martz
Marja-Liisa
ML
Sutinen
Kaisa
K
Lakkala
Minna
M
Turunen
D000393:Air Pollutants / Q000378:metabolism*; D004463:Ecology / Q000379:methods; D005387:Finland; D009584:Nitrogen / Q000378:metabolism*; D041605:Pinus sylvestris / Q000378:metabolism* / Q000528:radiation effects; D018515:Plant Leaves / Q000378:metabolism* / Q000528:radiation effects; D012621:Seasons; D036226:Seedlings / Q000378:metabolism / Q000528:radiation effects; D013696:Temperature; D014466:Ultraviolet Rays
D000393:Air Pollutants; D009584:Nitrogen