skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Impact of ultraviolet-B radiation on photosystem II activity and its relationship to the inhibition of carbon fixation rates for antarctic ice algae communities

Abstract

One goal of the Icecolors 1993 study was to determine whether or not photosystem II (PSII) was a major target site for photoinhibition by ultraviolet-B radiation (Q{sub UVB}, 280-320 nm) in natural communities. Second, the degree to which Q{sub UVB} inhibition of PSII could account for Q{sub UVB} effects on whole cell rates of carbon fixation in phytoplankton was assessed. On 1 October, 1993, at Palmer Station (Antarctica), dense samples of a frazil ice algal community were collected and maintained outdoors in the presence or absence of Q{sub UVB} and/or ultraviolet-A (Q{sub UVA}, 320-400 nm) radiation. The time of day course of UV inhibition of primary production was tracted. Over the day, {phi}{sub IIe}{degrees} declined due to increasing time-integrated dose exposure of Q{sub UVB}. The Q{sub UVB}-driven inhibition of {phi}{sub IIe}{degrees} increased from 4% in the early morning hours to a maximum of 23% at the end of the day. The Q{sub UVB} photoinhibition of PSII quantum yield did not recover by 6 h after sunset. In contrast, photoinhibition by Q{sub UVA} and photosynthetically available radiation (Q{sub PAR}, 400-700 nm) recovered during the late afternoon. Fluorescence-based estimates of carbon fixation rates were linearly correlated with measured carbon fixation. Fluorescence overestimatedmore » the observed Q{sub UVB} inhibition in measured carbon fixation rates. Researchers should be cautious in using fluorescence measurements to infer ultraviolet inhibition for rates of carbon fixation until there is a greater understanding of the coupling of carbon metabolism to PSII activity for natural populations. Despite these current limitations, fluorescence-based technologies represent powerful tools for studying the impact of the ozone hole on natural populations on spatial/temporal scales not possible using conventional productivity techniques. 55 refs., 11 figs., 2 tabs.« less

Authors:
;  [1];  [2]
  1. Univ. of California, Santa Barbara, CA (United States)
  2. Univ. of Amsterdam (Netherlands)
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
181884
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Phycology; Journal Volume: 31; Journal Issue: 5; Other Information: PBD: Oct 1995
Country of Publication:
United States
Language:
English
Subject:
56 BIOLOGY AND MEDICINE, APPLIED STUDIES; PHOTOSYNTHESIS; BIOLOGICAL RADIATION EFFECTS; ALGAE; PRODUCTIVITY; OZONE LAYER; ENVIRONMENTAL EFFECTS; ANTARCTICA; ULTRAVIOLET RADIATION

Citation Formats

Schofield, O., Prezelin, B.B., and Kroon, B.M.A.. Impact of ultraviolet-B radiation on photosystem II activity and its relationship to the inhibition of carbon fixation rates for antarctic ice algae communities. United States: N. p., 1995. Web. doi:10.1111/j.0022-3646.1995.00703.x.
Schofield, O., Prezelin, B.B., & Kroon, B.M.A.. Impact of ultraviolet-B radiation on photosystem II activity and its relationship to the inhibition of carbon fixation rates for antarctic ice algae communities. United States. doi:10.1111/j.0022-3646.1995.00703.x.
Schofield, O., Prezelin, B.B., and Kroon, B.M.A.. Sun . "Impact of ultraviolet-B radiation on photosystem II activity and its relationship to the inhibition of carbon fixation rates for antarctic ice algae communities". United States. doi:10.1111/j.0022-3646.1995.00703.x.
@article{osti_181884,
title = {Impact of ultraviolet-B radiation on photosystem II activity and its relationship to the inhibition of carbon fixation rates for antarctic ice algae communities},
author = {Schofield, O. and Prezelin, B.B. and Kroon, B.M.A.},
abstractNote = {One goal of the Icecolors 1993 study was to determine whether or not photosystem II (PSII) was a major target site for photoinhibition by ultraviolet-B radiation (Q{sub UVB}, 280-320 nm) in natural communities. Second, the degree to which Q{sub UVB} inhibition of PSII could account for Q{sub UVB} effects on whole cell rates of carbon fixation in phytoplankton was assessed. On 1 October, 1993, at Palmer Station (Antarctica), dense samples of a frazil ice algal community were collected and maintained outdoors in the presence or absence of Q{sub UVB} and/or ultraviolet-A (Q{sub UVA}, 320-400 nm) radiation. The time of day course of UV inhibition of primary production was tracted. Over the day, {phi}{sub IIe}{degrees} declined due to increasing time-integrated dose exposure of Q{sub UVB}. The Q{sub UVB}-driven inhibition of {phi}{sub IIe}{degrees} increased from 4% in the early morning hours to a maximum of 23% at the end of the day. The Q{sub UVB} photoinhibition of PSII quantum yield did not recover by 6 h after sunset. In contrast, photoinhibition by Q{sub UVA} and photosynthetically available radiation (Q{sub PAR}, 400-700 nm) recovered during the late afternoon. Fluorescence-based estimates of carbon fixation rates were linearly correlated with measured carbon fixation. Fluorescence overestimated the observed Q{sub UVB} inhibition in measured carbon fixation rates. Researchers should be cautious in using fluorescence measurements to infer ultraviolet inhibition for rates of carbon fixation until there is a greater understanding of the coupling of carbon metabolism to PSII activity for natural populations. Despite these current limitations, fluorescence-based technologies represent powerful tools for studying the impact of the ozone hole on natural populations on spatial/temporal scales not possible using conventional productivity techniques. 55 refs., 11 figs., 2 tabs.},
doi = {10.1111/j.0022-3646.1995.00703.x},
journal = {Journal of Phycology},
number = 5,
volume = 31,
place = {United States},
year = {Sun Oct 01 00:00:00 EDT 1995},
month = {Sun Oct 01 00:00:00 EDT 1995}
}