title: The glutathione status of mature Scots pines during the third season of UV-B radiation exposure.
abstract: Impacts of UV-B radiation on the glutathione level were studied in mature Scots pine needles (Pinus sylvestris L.) during the third season of a UV-B field experiment. Studies were made on 4-week-old (July) to 14-week-old (September) current-year needles and 3-year-old needles which had their third UV-B-exposure season in progress. Depending on the season and the year (1996-98), the supplemental UV-B dose varied from 0.92 to 5.09 kJ m-2 day-1 UV-BBE compared to 0.47-2.44 kJ m-2 day-1 UV-BBE under the ambient treatment. Fully grown UV-B-treated current-year needles showed lower total glutathione concentrations after the vegetation period in September, whereas in UV-B-treated 3-year-old needles the total glutathione content was significantly lower and the proportion of oxidized glutathione (GSSG%) 56% higher in July. The significant differences in total glutathione in current-year needles in September and in active 3-year-old needles in July seem to indicate that the effect of enhanced UV-B radiation on glutathione status could be cumulative.
authors.affiliation: University of Oulu, Department of Biology, PO Box 3000, FIN-90014 Oulu, Finland. kirsi.laakso@oulu.fi
authors.forename: K
authors.initials: K
authors.lastname: Laakso
authors.forename: H
authors.initials: H
authors.lastname: Kinnunen
authors.forename: S
authors.initials: S
authors.lastname: Huttunen
mesh_terms: D004781:Environmental Exposure; D005978:Glutathione / Q000032:analysis*; D018515:Plant Leaves / Q000737:chemistry; D012621:Seasons; D014197:Trees / Q000254:growth & development; D014466:Ultraviolet Rays / Q000009:adverse effects*
chemical_list: D005978:Glutathione