Influence of solar UV radiation on the nitrogen metabolism in needles of Scots pine ( Pinus sylvestris L.)

• Published in: Environmental pollution (1987) Vol. 156; no. 3; pp. 1105 - 1111
• Main Authors: Krywult, Marek, Smykla, Jerzy, Kinnunen, Heli, Martz, Françoise, Sutinen, Marja-Liisa, Lakkala, Kaisa, Turunen, Minna
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.12.2008; Elsevier
• Subjects: Air Pollutants - metabolism; air temperature; Amino acid; Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; boreal forests; conifer needles; Ecology - methods; Ecotoxicology, biological effects of pollution; enzyme activity; Finland; forest trees; free amino acids; Fundamental and applied biological sciences. Psychology; General aspects; Nitrate reductase; Nitrogen - metabolism; Pinus sylvestris; Pinus sylvestris - metabolism; Pinus sylvestris - radiation effects; plant damage; Plant Leaves - metabolism; Plant Leaves - radiation effects; Seasons; Seedlings - metabolism; Seedlings - radiation effects; Subarctic; Temperature; tree nutrition; ultraviolet radiation; Ultraviolet Rays; UV radiation; Finland; PAR; Temperature; C; N/C; NR; PSII; UV-B BE; EtOH; Pinus sylvestris; N; HCl; BSA; F m; Nitrogen metabolism; Amino acid; F 0; KNO 3; LSD; F v; F v/ F m; UV; FMI; Subarctic; PEA; UV radiation; K 2HPO 4; NO 3; UV-B; ARC; UV-A; Nitrate reductase; DNA; NO 2; Conifer needle; Enzyme; Environmental factor; Plant leaf; Nitrogen; Metabolism; Pollution; Ultraviolet radiation; Aminoacid; Gymnospermae; Environment; Coniferales; Spermatophyta; Oxidoreductases; Solar radiation
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2008.04.009

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 °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. This research presents new information on the responses of N metabolism, particularly nitrate reductase (NR) activity, of Scots pine needles to UV radiation and temperature.