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Titolo:
Patterns of DNA damage and photoinhibition in temperate South-Atlantic picophytoplankton exposed to solar ultraviolet radiation
Autore:
Buma, AGJ; Helbling, EW; de Boer, MK; Villafane, VE;
Indirizzi:
Univ Groningen, Dept Marine Biol, NL-9750 AA Haren, Netherlands Univ Groningen Haren Netherlands NL-9750 AA L-9750 AA Haren, Netherlands Estac Fotobiol Playa Union, RA-9100 Trelew, Chubut, Argentina Estac Fotobiol Playa Union Trelew Chubut Argentina RA-9100 but, Argentina Consejo Nacl Invest Cient & Tecn, RA-9100 Trelew, Chubut, Argentina Consejo Nacl Invest Cient & Tecn Trelew Chubut Argentina RA-9100 rgentina
Titolo Testata:
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY
fascicolo: 1-2, volume: 62, anno: 2001,
pagine: 9 - 18
SICI:
1011-1344(20010901)62:1-2<9:PODDAP>2.0.ZU;2-#
Fonte:
ISI
Lingua:
ENG
Soggetto:
EFFECTIVE UV-RADIATION; B RADIATION; MARINE-PHYTOPLANKTON; OZONE DEPLETION; ICE ALGAE; ANTARCTIC PHYTOPLANKTON; CARBON FIXATION; PHOTOSYNTHESIS; COMMUNITIES; IMPACT;
Keywords:
UVR; phytoplankton; DNA; CPD; photosynthetic inhibition; mid-latitudes;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
51
Recensione:
Indirizzi per estratti:
Indirizzo: Buma, AGJ Univ Groningen, Dept Marine Biol, POB 14, NL-9750 AA Haren, Netherlands Univ Groningen POB 14 Haren Netherlands NL-9750 AA Netherlands
Citazione:
A.G.J. Buma et al., "Patterns of DNA damage and photoinhibition in temperate South-Atlantic picophytoplankton exposed to solar ultraviolet radiation", J PHOTOCH B, 62(1-2), 2001, pp. 9-18

Abstract

Natural marine phytoplankton assemblages from Bahia Bustamante (Chubut, Argentina, 45 degreesS, 66.5 degreesW), mainly consisting of cells in the picoplankton size range (0.2-2 mum), were exposed to various UVBR (280-315 nm)and UVAR (315-400 mn) regimes in order to follow wavelength-dependent patterns of cyclobutane pyrimidine dimer (CPD) induction and repair. Simultaneously, UVR induced photosynthetic inhibition was studied in radiocarbon incorporation experiments. Biological weighting functions (BWFs) for photoinhibition and for CPD induction, the latter measured in bare calf thymus DNA, differed in the UVAR region: carbon incorporation was reduced markedly due to UVAR, whereas no measurable UVAR effect was found on CPD formation. In contrast, BWFs for inhibition of photosynthesis and CPD accumulation were fairly similar in the UVBR region, especially above 300 um. Incubation of phytoplankton under full solar radiation caused rapid CPD accumulation over theday, giving maximum damage levels exceeding 500 CPD.MB-1 at the end of theafternoon. A clear daily pattern of CPD accumulation was found, in keepingwith the DNA effective dose measured by a DNA dosimeter. In contrast, UVBRinduced photosynthetic inhibition was not dose related and remained nearlyconstant during the day. Screening of U-VBR or UVR did not cause significant CPD removal, indicating that photoreactivation either by PAR or UVAR wasof minor importance in these organisms. Fligh CPD levels were found in situ early in the morning, which remained unaffected notwithstanding treatments favoring photorepair. These results imply that a proportion of cells had been killed by UVBR exposure prior to the treatments. Our data suggest thatthe limited potential for photoreactivation in picophytoplankton assemblages from the southern Atlantic Ocean causes high CPD accumulation as a result of UVBR exposure. (C) 2001 Elsevier Science BY All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 01/04/20 alle ore 11:33:50