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Impact of UV Radiation on the Early Development of the Giant Kelp ( Macrocystis pyrifera ) Gametophytes § ¶
Author(s) -
Huovinen Pirjo S.,
Oikari Aimo O. J.,
Soimasuo Markus R.,
Cherr Gary N.
Publication year - 2000
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1562/0031-8655(2000)0720308iourot2.0.co2
Subject(s) - macrocystis pyrifera , gametophyte , spore , germination , kelp , chromosomal translocation , germ tube , botany , biology , cell division , elongation , spore germination , biophysics , biochemistry , cell , pollen , materials science , ultimate tensile strength , gene , metallurgy
ABSTRACT The mechanisms and dose‐response of UV action on the early development of Macrocystis pyrifera (L.) C. Agardh gametophytes were investigated. Post‐release, zoospores undergo germination, germ tube elongation, DNA synthesis, nuclear division and translocation, which were followed for 41 h under laboratory conditions. The spores were exposed to UV radiation before germination (3 h post‐release) or before nuclear division (20 h post‐release). Biologically effective UV‐B doses (BED DNA300 nm ) higher than those used in the experiments are needed for a 50% inhibition in germination (BED 50 > 1600 J m −2 ). Nuclear division/translocation was more sensitive to UV radiation. When the spores were cultured in the dark, UV exposure at both 3 and 20 h post‐release resulted in a dose‐responsive inhibition of nuclear division/translocation (BED 50 64 and 86 J m −2 ). Culturing in the light indicated recovery in the spores that were irradiated at 3 h post‐release (BED 50 356 J m −2 ), whereas no light‐dependent recovery occurred within 41 h of culture when irradiated at 20 h post‐release (BED 50 80 J m −2 ). The results present a possible mechanism of UV inhibition in early life stages of the giant kelp, suggesting that environmentally relevant UV‐B levels can perturb or delay the development and recruitment of the gametophytes by inhibiting nuclear events.