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EFFECTS OF UV RADIATION ON GROWTH AND PHLOROTANNINS IN FUCUS GARDNERI (PHAEOPHYCEAE) JUVENILES AND EMBRYOS 1
Author(s) -
Henry Brianne E.,
Van Alstyne Kathryn L.
Publication year - 2004
Publication title -
journal of phycology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.85
H-Index - 127
eISSN - 1529-8817
pISSN - 0022-3646
DOI - 10.1111/j.1529-8817.2004.03103.x
Subject(s) - biology , fucus , algae , botany , intertidal zone , juvenile , brown algae , embryo , ecology , fishery
Diminishing levels of atmospheric ozone are increasing UV stress on intertidal algae. Early developmental stages tend to be more susceptible to environmental stresses; however, little research has examined how these stages are protected from UV radiation (UVR). Many brown algae contain high levels of phlorotannins, which are thought to function in screening UVR. In this study, we tested the effects of ambient levels of UV‐B and UV‐A on growth and phlorotannin production in 1‐ to 2‐cm juvenile and microscopic postsettlement embryos of the intertidal alga Fucus gardneri Silva . Algae were grown in four light treatments: 1) ambient light; 2) under cellulose acetate, which lowered light quantity but did not affect light quality; 3) under Mylar TM , which filtered UV‐B; and 4) under Plexiglas TM , which blocked UV‐A and UV‐B. Over a 3‐week period, UV‐B inhibited and UV‐A enhanced the growth of F. gardneri embryos, whereas the growth of juveniles was not affected. Phlorotannin concentrations of both embryos and juveniles did not differ in any of the light treatments. Our results suggest that embryos of F. gardneri are susceptible to UV light but develop a tolerance to it as they mature. This tolerance may result from increases in phlorotannin concentrations that occur during maturation; however, phlorotannin production in embryonic or juvenile stages is either not induced by UV light or takes more than 3 weeks to occur.