What does critical temperature tell us about the resistance of polar lichens to freezing stress? Applicability of linear cooling method to ecophysiological studies.
Lichens from polar regions are well adapted to low temperature and considered cryoresistant. However, interspecific differences in their cryoresistance exist according to the degree of their adaptation and severity of the environment. In our study, we applied linear cooling technique in order to eva...
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ftmasarykunivojs:oai:ojs.journals.muni.cz:article/33533 2023-05-15T13:46:41+02:00 What does critical temperature tell us about the resistance of polar lichens to freezing stress? Applicability of linear cooling method to ecophysiological studies. Hájek, Josef Puhovkin, Anton Giordano, Davide Sekerák Jr., Jiří 2023-02-20 application/pdf https://journals.muni.cz/CPR/article/view/33533 eng eng Masaryk Univerzity https://journals.muni.cz/CPR/article/view/33533/28612 https://journals.muni.cz/CPR/article/view/33533 Copyright (c) 2023 Czech Polar Reports Czech Polar Reports; Vol 12 No 2 (2022); 246–255 Czech Polar Reports; Vol. 12 No. 2 (2022); 246–255 1805-0697 1805-0689 cryoresistance chlorophyll fluorescence photosystem II primary photosynthesis info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2023 ftmasarykunivojs 2023-02-21T00:22:21Z Lichens from polar regions are well adapted to low temperature and considered cryoresistant. However, interspecific differences in their cryoresistance exist according to the degree of their adaptation and severity of the environment. In our study, we applied linear cooling technique in order to evaluate the interspecific differences in several lichen species. Thalli segments of Umbilicaria antarctica, Nephroma antarctica, Placopsis contortuplicata and Lasallia pustulata were exposed to the cooling from 20 to –35°C at a constant rate of 2°C min-1. Simultaneously with the cooling, chlorophyll fluorescence parameters evaluating potential (FV/FM) and effective yield of primary photochemical processes in PSII (FPSII) were measured in 30 s interval. Temperature response curves of FV/FM and FPSII formed typical S-curves that were species specific. Critical temperature (cooling point at which FPSII equals 0), was found in a narrow range of –25 to –28°C, suggesting that all experimental lichen species have a high resistance to sub-zero temperatures. The method of linear cooling used in this study has proven its applicability in ecophysiological studies since it is sensitive enough for the evaluation of species-specific differences in cryoresistance. This study describes different parameters that can be derived from the S-curves and discuss their proper use in ecophysiological and stress physiology studies. Article in Journal/Newspaper Antarc* Antarctica Masaryk University Journals |
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Open Polar |
collection |
Masaryk University Journals |
op_collection_id |
ftmasarykunivojs |
language |
English |
topic |
cryoresistance chlorophyll fluorescence photosystem II primary photosynthesis |
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cryoresistance chlorophyll fluorescence photosystem II primary photosynthesis Hájek, Josef Puhovkin, Anton Giordano, Davide Sekerák Jr., Jiří What does critical temperature tell us about the resistance of polar lichens to freezing stress? Applicability of linear cooling method to ecophysiological studies. |
topic_facet |
cryoresistance chlorophyll fluorescence photosystem II primary photosynthesis |
description |
Lichens from polar regions are well adapted to low temperature and considered cryoresistant. However, interspecific differences in their cryoresistance exist according to the degree of their adaptation and severity of the environment. In our study, we applied linear cooling technique in order to evaluate the interspecific differences in several lichen species. Thalli segments of Umbilicaria antarctica, Nephroma antarctica, Placopsis contortuplicata and Lasallia pustulata were exposed to the cooling from 20 to –35°C at a constant rate of 2°C min-1. Simultaneously with the cooling, chlorophyll fluorescence parameters evaluating potential (FV/FM) and effective yield of primary photochemical processes in PSII (FPSII) were measured in 30 s interval. Temperature response curves of FV/FM and FPSII formed typical S-curves that were species specific. Critical temperature (cooling point at which FPSII equals 0), was found in a narrow range of –25 to –28°C, suggesting that all experimental lichen species have a high resistance to sub-zero temperatures. The method of linear cooling used in this study has proven its applicability in ecophysiological studies since it is sensitive enough for the evaluation of species-specific differences in cryoresistance. This study describes different parameters that can be derived from the S-curves and discuss their proper use in ecophysiological and stress physiology studies. |
format |
Article in Journal/Newspaper |
author |
Hájek, Josef Puhovkin, Anton Giordano, Davide Sekerák Jr., Jiří |
author_facet |
Hájek, Josef Puhovkin, Anton Giordano, Davide Sekerák Jr., Jiří |
author_sort |
Hájek, Josef |
title |
What does critical temperature tell us about the resistance of polar lichens to freezing stress? Applicability of linear cooling method to ecophysiological studies. |
title_short |
What does critical temperature tell us about the resistance of polar lichens to freezing stress? Applicability of linear cooling method to ecophysiological studies. |
title_full |
What does critical temperature tell us about the resistance of polar lichens to freezing stress? Applicability of linear cooling method to ecophysiological studies. |
title_fullStr |
What does critical temperature tell us about the resistance of polar lichens to freezing stress? Applicability of linear cooling method to ecophysiological studies. |
title_full_unstemmed |
What does critical temperature tell us about the resistance of polar lichens to freezing stress? Applicability of linear cooling method to ecophysiological studies. |
title_sort |
what does critical temperature tell us about the resistance of polar lichens to freezing stress? applicability of linear cooling method to ecophysiological studies. |
publisher |
Masaryk Univerzity |
publishDate |
2023 |
url |
https://journals.muni.cz/CPR/article/view/33533 |
genre |
Antarc* Antarctica |
genre_facet |
Antarc* Antarctica |
op_source |
Czech Polar Reports; Vol 12 No 2 (2022); 246–255 Czech Polar Reports; Vol. 12 No. 2 (2022); 246–255 1805-0697 1805-0689 |
op_relation |
https://journals.muni.cz/CPR/article/view/33533/28612 https://journals.muni.cz/CPR/article/view/33533 |
op_rights |
Copyright (c) 2023 Czech Polar Reports |
_version_ |
1766245093646270464 |