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Effects of UV-B radiation and simulated herbivory on phlorotannins in the brown alga Ascophyllum nodosum

1997; Inter-Research; Volume: 157; Linguagem: Inglês

10.3354/meps157139

1616-1599

Henrik Pavia, Gunnar Cervin, Arne Lindgren, Per Åberg,

Seaweed-derived Bioactive Compounds

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 157:139-146 (1997) - doi:10.3354/meps157139 Effects of UV-B radiation and simulated herbivory on phlorotannins in the brown alga Ascophyllum nodosum Henrik Pavia*, Gunnar Cervin, Annelie Lindgren, Per Åberg Department of Marine Botany, University of Göteborg, Carl Skottsbergs Gata 22, S-413 19 Göteborg, Sweden *E-mail: henrik.pavia@marbot.gu.se Models and experiments seeking to explain intraspecific variation in brown algal phlorotannins (polyphenolics) have mainly focused on the effect of 2 factors, herbivory and resource availability (carbon/nutrients). The possible importance of other biotic and abiotic factors, e.g. pathogenic micro-organisms, heavy metals and UV radiation, has often been suggested but only rarely experimentally tested. In the present study the effects of increased UV-B irradiance and simulated grazing (clipping) on phlorotannin production in the brown alga Ascophyllum nodosum were investigated. The 2 treatments were applied simultaneously in a crossed factorial experiment in order to test for interactive, as well as separate, effects. Carbon and nitrogen content of the algae was also determined for each treatment. The effect of the experimental treatments on the feeding selectivity of a natural herbivore was tested in a subsequent feeding preference experiment with the crustacea Idotea granulosa. An increase (~50%) in UV-B radiation during a 2 wk period resulted in a significant increase (~30%) in mean phlorotannin concentration, while no significant changes in phlorotannin levels following simulated grazing were observed. The additional UV light caused a slight increase in the nitrogen content of the algae, indicating that the response in phlorotannin production was not caused by nutrient deficit. Absorption spectra of A. nodosum extracts, before and after removal of phlorotannins with polyvinylpolypyrrolidone, revealed that phlorotannins can contribute to absorption in the UV-B range (280 to 320 nm). The results imply that phlorotannins can function as inducible screens against harmful UV radiation. The grazer I. granulosa showed a clear preference for algae that had been exposed to an addition of UV-B radiation, in spite of their increased phlorotannin levels, supporting the notion that small marine herbivores in general are tolerant to chemical defenses of algae. Brown algae · Ascophyllum · Chemical defenses · Herbivory · Idotea · Induced responses · Isopods · Phlorotannins · Polyphenolics · Seaweeds · UV-B radiation Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 157. Publication date: October 16, 1997 Print ISSN:0171-8630; Online ISSN:1616-1599 Copyright © 1997 Inter-Research.