Detailed Information on Publication Record
2016
Sensitivity of photosynthetic processes to freezing temperature in extremophilic lichens evaluated by linear cooling and chlorophyll fluorescence
HÁJEK, Josef, Miloš BARTÁK, Jana HAZDROVÁ and Marie FORBELSKÁBasic information
Original name
Sensitivity of photosynthetic processes to freezing temperature in extremophilic lichens evaluated by linear cooling and chlorophyll fluorescence
Authors
HÁJEK, Josef (203 Czech Republic, guarantor, belonging to the institution), Miloš BARTÁK (203 Czech Republic, belonging to the institution), Jana HAZDROVÁ (203 Czech Republic, belonging to the institution) and Marie FORBELSKÁ (203 Czech Republic, belonging to the institution)
Edition
Cryobiology, Academic Press, 2016, 0011-2240
Other information
Language
English
Type of outcome
Článek v odborném periodiku
Field of Study
10600 1.6 Biological sciences
Country of publisher
United States of America
Confidentiality degree
není předmětem státního či obchodního tajemství
Impact factor
Impact factor: 1.996
RIV identification code
RIV/00216224:14310/16:00091424
Organization unit
Faculty of Science
UT WoS
000389010600005
Keywords in English
Usnea antarctica; Usnea aurantiaco-atra; Umbilicaria cylindrica; cryoresistance; Antarctica; James Ross Island; temperature stress
Tags
International impact, Reviewed
Změněno: 13/4/2017 21:54, Ing. Andrea Mikešková
Abstract
V originále
Extremophilic lichens and their photosynthesizing photobionts from the cold regions of Earth are adapted to perform photosynthesis at subzero temperatures. To evaluate interspecific differences in the critical temperature for primary photochemical processes of photosynthesis, we exposed lichen thalli of Usnea antarctica, Usnea aurantiaco-atra, and Umbilicaria cylindrica to linear cooling from +20 to minus 50 °C at a constant rate of 2 °C/min. Simultaneously, two chlorophyll fluorescence parameters (FV/FM: potential yield of photosynthetic processes in photosystem II, YieldPSII: effective quantum yield of PS II) evaluating a gradual subzero temperature-induced decline in photosynthetic processes were measured by a modulated fluorometer. For the studied species, the response of FV/FM and YieldPSII to declining temperature showed an S-curve shape. The decline in FV/FM and YieldPSII at low temperatures started at minus 5 and +5 °C, respectively in the majority of cases. The decline was, however, species-specific. U. aurantiaco-atra showed a constant-rate decline of YieldPSII from the physiological temperature 20 °C. U. antarctica exhibited the first sign of FV/FM decline at minus 12 °C. The critical temperature related to full inhibition of the photosynthetic processes in PSII (FV/FM), was found at minus 20 °C. However, this occurred at minus 30 °C for U. cylindrica. In an individual sample, the critical temperature for FV/FM was typically lower than for YieldPSII. The method of linear cooling combined with simultaneous measurements of chlorophyll fluorescence parameters proved to be an efficient tool in the estimation of extremophilic species sensitivity/resistance to freezing.
Links
LM2010009, research and development project |
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LM2015078, research and development project |
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