title: Interactive effects of ozone and low UV-B radiation on antioxidants in spruce (Picea abies) and pine (Pinus sylvestris) needles.
abstract: To study the role of low UV-B radiation in modulating the response of antioxidants to ozone, 4-year-old pine (Pinus sylvestris L.) and spruce (Picea abies L.) seedlings potted in natural soil, were exposed in phytochambers to fluctuating ozone concentrations between 9 and 113 nl 1-1according to field data recorded at Mt Wank (1175 m above sea level, Bavaria, Germany) and two-times ambient O3levels. UV-B radiation was either added at a biologically effective level of ca 1.2 kJ m-2day-1, which is close to that found in March at Mt Wank, or was excluded by filters (<0.08 kJ m-2day-1). After one growth phase current-year needles were collected and analysed for antioxidative enzyme activities (superoxide dismutase, SOD, EC 1.15.1.1; catalase, CAT, EC 1.11.1.6; guaiacol peroxidase, POD, EC 1.11.1.7) and soluble antioxidants (ascorbate, glutathione). CAT, POD, ascorbate and glutathione, but not SOD, were increased in needles of both species in response to twice ambient O3levels. UV-B radiation in the presence of ambient O3caused an increase in total SOD activity in spruce but had no effects on antioxidants in pine. Twice ambient O3levels together with low UV-B radiation counteracted the O3-induced increases in ascorbate and CAT in pine but not in spruce. Under these conditions spruce needles showed the highest antioxidative protection and revealed no indication of lipid peroxidation. Pine needles exposed to UV-B and elevated O3levels showed elevated lipid peroxidation and a 5-fold increase in dehydroascorbate, suggesting that this species was less protected and suffered higher oxidative stress than spruce.
authors.affiliation: L. O. Baumbusch and M. Eiblmeier, Albert-Ludwigs-Univ. Freiburg, Inst für Forstbotanik und Baumphysiologie, Am Flughafen 17, D-79085 Freiburg, Germany; J.-P. Schnitzler, Fraunhofer Inst für Atmosphärische Umweltforschung, Kreuzeckbahnstr. 19, D-82467 Garmisch-Partenkirchen, Germany; W. Heller and H. Sandermann, Jr, GSF-Forschungszentrum für Umwelt und Gesundheit, Inst für Biochemische Pflanzenpathologie, Ingolstädter Landstr. 1, D-85758 Oberschleissheim, Germany; A. Polle (corresponding author, e-mail apolle@gwdg.de), Forstbotanisches Inst, Univ. Göttingen, Büsgenweg 2, D-37077 Göttingen, Germany.
authors.forename: Lars O
authors.initials: LO
authors.lastname: Baumbusch
authors.affiliation: L. O. Baumbusch and M. Eiblmeier, Albert-Ludwigs-Univ. Freiburg, Inst für Forstbotanik und Baumphysiologie, Am Flughafen 17, D-79085 Freiburg, Germany; J.-P. Schnitzler, Fraunhofer Inst für Atmosphärische Umweltforschung, Kreuzeckbahnstr. 19, D-82467 Garmisch-Partenkirchen, Germany; W. Heller and H. Sandermann, Jr, GSF-Forschungszentrum für Umwelt und Gesundheit, Inst für Biochemische Pflanzenpathologie, Ingolstädter Landstr. 1, D-85758 Oberschleissheim, Germany; A. Polle (corresponding author, e-mail apolle@gwdg.de), Forstbotanisches Inst, Univ. Göttingen, Büsgenweg 2, D-37077 Göttingen, Germany.
authors.forename: Monika
authors.initials: M
authors.lastname: Eiblmeier
authors.affiliation: L. O. Baumbusch and M. Eiblmeier, Albert-Ludwigs-Univ. Freiburg, Inst für Forstbotanik und Baumphysiologie, Am Flughafen 17, D-79085 Freiburg, Germany; J.-P. Schnitzler, Fraunhofer Inst für Atmosphärische Umweltforschung, Kreuzeckbahnstr. 19, D-82467 Garmisch-Partenkirchen, Germany; W. Heller and H. Sandermann, Jr, GSF-Forschungszentrum für Umwelt und Gesundheit, Inst für Biochemische Pflanzenpathologie, Ingolstädter Landstr. 1, D-85758 Oberschleissheim, Germany; A. Polle (corresponding author, e-mail apolle@gwdg.de), Forstbotanisches Inst, Univ. Göttingen, Büsgenweg 2, D-37077 Göttingen, Germany.
authors.forename: Jörg-Peter
authors.initials: JP
authors.lastname: Schnitzler
authors.affiliation: L. O. Baumbusch and M. Eiblmeier, Albert-Ludwigs-Univ. Freiburg, Inst für Forstbotanik und Baumphysiologie, Am Flughafen 17, D-79085 Freiburg, Germany; J.-P. Schnitzler, Fraunhofer Inst für Atmosphärische Umweltforschung, Kreuzeckbahnstr. 19, D-82467 Garmisch-Partenkirchen, Germany; W. Heller and H. Sandermann, Jr, GSF-Forschungszentrum für Umwelt und Gesundheit, Inst für Biochemische Pflanzenpathologie, Ingolstädter Landstr. 1, D-85758 Oberschleissheim, Germany; A. Polle (corresponding author, e-mail apolle@gwdg.de), Forstbotanisches Inst, Univ. Göttingen, Büsgenweg 2, D-37077 Göttingen, Germany.
authors.forename: Werner
authors.initials: W
authors.lastname: Heller
authors.affiliation: L. O. Baumbusch and M. Eiblmeier, Albert-Ludwigs-Univ. Freiburg, Inst für Forstbotanik und Baumphysiologie, Am Flughafen 17, D-79085 Freiburg, Germany; J.-P. Schnitzler, Fraunhofer Inst für Atmosphärische Umweltforschung, Kreuzeckbahnstr. 19, D-82467 Garmisch-Partenkirchen, Germany; W. Heller and H. Sandermann, Jr, GSF-Forschungszentrum für Umwelt und Gesundheit, Inst für Biochemische Pflanzenpathologie, Ingolstädter Landstr. 1, D-85758 Oberschleissheim, Germany; A. Polle (corresponding author, e-mail apolle@gwdg.de), Forstbotanisches Inst, Univ. Göttingen, Büsgenweg 2, D-37077 Göttingen, Germany.
authors.forename: Heinrich
authors.initials: H
authors.lastname: Sandermann
authors.affiliation: L. O. Baumbusch and M. Eiblmeier, Albert-Ludwigs-Univ. Freiburg, Inst für Forstbotanik und Baumphysiologie, Am Flughafen 17, D-79085 Freiburg, Germany; J.-P. Schnitzler, Fraunhofer Inst für Atmosphärische Umweltforschung, Kreuzeckbahnstr. 19, D-82467 Garmisch-Partenkirchen, Germany; W. Heller and H. Sandermann, Jr, GSF-Forschungszentrum für Umwelt und Gesundheit, Inst für Biochemische Pflanzenpathologie, Ingolstädter Landstr. 1, D-85758 Oberschleissheim, Germany; A. Polle (corresponding author, e-mail apolle@gwdg.de), Forstbotanisches Inst, Univ. Göttingen, Büsgenweg 2, D-37077 Göttingen, Germany.
authors.forename: Andrea
authors.initials: A
authors.lastname: Polle
keywords: Ascorbate; UV-B; catalase; glutathione; ozone; peroxidase; superoxide dismutase; ultraviolet radiation