Photoinhibition of photosynthesis in Antarctic lichen Usnea antarctica. I. Light intensity- and light duration-dependent changes in functioning of photosystem II
The paper deals with the differences in sensitivity of Antarctic lichen to photoinhibition. Thalli of Usnea antarctica were collected at the James Ross Island, Antarctica (57°52´57´´W, 63°48´02´´S) and transferred in dry state to the Czech Republic. After rewetting in a laboratory, they were exposed...
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ftmasarykunivojs:oai:ojs.journals.muni.cz:article/12814 2023-05-15T13:46:41+02:00 Photoinhibition of photosynthesis in Antarctic lichen Usnea antarctica. I. Light intensity- and light duration-dependent changes in functioning of photosystem II Barták, Miloš Hájek, Josef Očenášová, Petra 2012-01-01 application/pdf http://journals.muni.cz/CPR/article/view/12814 eng eng Masaryk Univerzity http://journals.muni.cz/CPR/article/view/12814/11130 http://journals.muni.cz/CPR/article/view/12814 Copyright (c) 2020 Czech Polar Reports https://creativecommons.org/licenses/by-nc-nd/4.0 CC-BY-NC-ND Czech Polar Reports; Vol 2 No 1 (2012); 42-51 Czech Polar Reports; Vol. 2 No. 1 (2012); 42-51 1805-0697 1805-0689 chlorophyll fluorescence high light potential quantum yield effective quantum yield info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2012 ftmasarykunivojs 2022-06-26T10:16:32Z The paper deals with the differences in sensitivity of Antarctic lichen to photoinhibition. Thalli of Usnea antarctica were collected at the James Ross Island, Antarctica (57°52´57´´W, 63°48´02´´S) and transferred in dry state to the Czech Republic. After rewetting in a laboratory, they were exposed to 2 high light treatments: short-term (30 min), and long-term (6 h). In short-term treatment, the sample were exposed to 1000 and 2000 µmol m-2 s-1 of photosynthetically active radiation (PAR). In long-term experiment, PAR of 300, 600, and 1000 µmol m-2 s-1 were used. Photosynthetic efficiency of U. antarctica thalli was monitored by chlorophyll fluorescence parameters, potential (FV/FM) and actual (FPSII) quantum yield of photochemical processes in photosystem II in particular. In short-term treatments, the F0, FV and FM signals, as well as the values of FV/FM, and FPSII showed light-induced decrease, however substantial recovery after consequent 30 min. in dark. Longer exposition (60 min) to high light led to more pronounced decrease in chlorophyll fluorescence than after 30 min treatment, however dark recovery was faster in the thalli treated before for longer time (60 min). Long-term treatment by high light caused gradual decrease in FV/FM and FPSII with the time of exposition. The extent of the decrease was found light dose-dependent. The time course was biphasic for FV/FM but not for FPSII. The study showed that wet thalli of Usnea antarctica had high capacity of photoprotective mechanisms to cope well either with short- or long-term high light stress. This might be of particular importance in the field at the James Ross Island, particularly at the begining of growing season when melting water is available and, simultaneously, high light stress may happen on fully sunny days. Article in Journal/Newspaper Antarc* Antarctic Antarctica James Ross Island Ross Island Usnea antarctica Masaryk University Journals Antarctic Ross Island |
institution |
Open Polar |
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Masaryk University Journals |
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English |
topic |
chlorophyll fluorescence high light potential quantum yield effective quantum yield |
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chlorophyll fluorescence high light potential quantum yield effective quantum yield Barták, Miloš Hájek, Josef Očenášová, Petra Photoinhibition of photosynthesis in Antarctic lichen Usnea antarctica. I. Light intensity- and light duration-dependent changes in functioning of photosystem II |
topic_facet |
chlorophyll fluorescence high light potential quantum yield effective quantum yield |
description |
The paper deals with the differences in sensitivity of Antarctic lichen to photoinhibition. Thalli of Usnea antarctica were collected at the James Ross Island, Antarctica (57°52´57´´W, 63°48´02´´S) and transferred in dry state to the Czech Republic. After rewetting in a laboratory, they were exposed to 2 high light treatments: short-term (30 min), and long-term (6 h). In short-term treatment, the sample were exposed to 1000 and 2000 µmol m-2 s-1 of photosynthetically active radiation (PAR). In long-term experiment, PAR of 300, 600, and 1000 µmol m-2 s-1 were used. Photosynthetic efficiency of U. antarctica thalli was monitored by chlorophyll fluorescence parameters, potential (FV/FM) and actual (FPSII) quantum yield of photochemical processes in photosystem II in particular. In short-term treatments, the F0, FV and FM signals, as well as the values of FV/FM, and FPSII showed light-induced decrease, however substantial recovery after consequent 30 min. in dark. Longer exposition (60 min) to high light led to more pronounced decrease in chlorophyll fluorescence than after 30 min treatment, however dark recovery was faster in the thalli treated before for longer time (60 min). Long-term treatment by high light caused gradual decrease in FV/FM and FPSII with the time of exposition. The extent of the decrease was found light dose-dependent. The time course was biphasic for FV/FM but not for FPSII. The study showed that wet thalli of Usnea antarctica had high capacity of photoprotective mechanisms to cope well either with short- or long-term high light stress. This might be of particular importance in the field at the James Ross Island, particularly at the begining of growing season when melting water is available and, simultaneously, high light stress may happen on fully sunny days. |
format |
Article in Journal/Newspaper |
author |
Barták, Miloš Hájek, Josef Očenášová, Petra |
author_facet |
Barták, Miloš Hájek, Josef Očenášová, Petra |
author_sort |
Barták, Miloš |
title |
Photoinhibition of photosynthesis in Antarctic lichen Usnea antarctica. I. Light intensity- and light duration-dependent changes in functioning of photosystem II |
title_short |
Photoinhibition of photosynthesis in Antarctic lichen Usnea antarctica. I. Light intensity- and light duration-dependent changes in functioning of photosystem II |
title_full |
Photoinhibition of photosynthesis in Antarctic lichen Usnea antarctica. I. Light intensity- and light duration-dependent changes in functioning of photosystem II |
title_fullStr |
Photoinhibition of photosynthesis in Antarctic lichen Usnea antarctica. I. Light intensity- and light duration-dependent changes in functioning of photosystem II |
title_full_unstemmed |
Photoinhibition of photosynthesis in Antarctic lichen Usnea antarctica. I. Light intensity- and light duration-dependent changes in functioning of photosystem II |
title_sort |
photoinhibition of photosynthesis in antarctic lichen usnea antarctica. i. light intensity- and light duration-dependent changes in functioning of photosystem ii |
publisher |
Masaryk Univerzity |
publishDate |
2012 |
url |
http://journals.muni.cz/CPR/article/view/12814 |
geographic |
Antarctic Ross Island |
geographic_facet |
Antarctic Ross Island |
genre |
Antarc* Antarctic Antarctica James Ross Island Ross Island Usnea antarctica |
genre_facet |
Antarc* Antarctic Antarctica James Ross Island Ross Island Usnea antarctica |
op_source |
Czech Polar Reports; Vol 2 No 1 (2012); 42-51 Czech Polar Reports; Vol. 2 No. 1 (2012); 42-51 1805-0697 1805-0689 |
op_relation |
http://journals.muni.cz/CPR/article/view/12814/11130 http://journals.muni.cz/CPR/article/view/12814 |
op_rights |
Copyright (c) 2020 Czech Polar Reports https://creativecommons.org/licenses/by-nc-nd/4.0 |
op_rightsnorm |
CC-BY-NC-ND |
_version_ |
1766245067594399744 |