Detailed Information on Publication Record
2004
Photosynthetic characteristics of foliose lichens in response to light, temperature and water status of thallus
BARTÁK, Miloš, Jan GLOSER, Josef HÁJEK, Jaroslava DUBOVÁ, Hana VRÁBLÍKOVÁ et. al.Basic information
Original name
Photosynthetic characteristics of foliose lichens in response to light, temperature and water status of thallus
Name in Czech
Fotosyntetické charakteristiky foliózních lišejníků v závislosti na světle, teplotě a stupni ovlhčení stélky.
Authors
BARTÁK, Miloš (203 Czech Republic, guarantor), Jan GLOSER (203 Czech Republic), Josef HÁJEK (203 Czech Republic), Jaroslava DUBOVÁ (203 Czech Republic), Hana VRÁBLÍKOVÁ (203 Czech Republic), Peter VÁCZI (703 Slovakia), Ondřej KOMÁREK (203 Czech Republic) and Martina HÁJKOVÁ (203 Czech Republic)
Edition
Tartu, Estonia, Book of Abstracts. 5th IAL Symposium, p. 43-43, 2004
Publisher
University of Tartu
Other information
Language
English
Type of outcome
Stať ve sborníku
Field of Study
10600 1.6 Biological sciences
Country of publisher
Estonia
Confidentiality degree
není předmětem státního či obchodního tajemství
RIV identification code
RIV/00216224:14310/04:00019779
Organization unit
Faculty of Science
ISBN
9985-56-922-9
Keywords in English
lichen; chlorophyll fluorescence imaging; stress physiology
Změněno: 26/5/2006 11:25, prof. Ing. Miloš Barták, CSc.
V originále
Introduction Majority of lichens are capable to cope with extremes and rapid fluctuations in environmental factors, availability of water, light, and air temperature in particular. Photosynthesis in lichens is controlled by these factors and actual rate of photosynthetic processes reflects their interactive effect. Material and Methods To study lichen photosynthesis both in situ (mainly maritime Antarctica) and in a laboratory, fluorometric and gas exchange methods were used. In addition, spectral reflectance, photosynthetic pigments and antioxidants analyses, oxymetric evaluation of photosynthesis in photobionts, anatomic studies were applied in Lasallia pustulata, Umbilicaria hirsuta, U. antarctica, and U.decussata. Results and discussion Temperature response curves revealed that primary processes of photosynthesis (Fv/Fm - capacity of photochemical reactions in photosystem II, FII - quantum yield of PS II) had optimum at 18-22 oC, and hold high level (about 80 % of maximum) within the range of -5 to 18 oC. Temperature minimum was found at -20 to -15 oC. Hydration response curves showed that maximum values of Fv/Fm, FII retained to water saturation deficit (WSD) of 50-60 % and then decreased rapidly with desiccation. In most species, critical WSD was 70-80 % which corresponds to water potential (WP) of - 35 to -25 MPa. In situ measurements of net photosynthesis (Pn) showed Pn of 1-2 mmol (CO2) m-2 s-1 for well-hydrated U.antarctica. When exposed to high light in wet state in a laboratory, thalli showed decrease in Fv/Fm, FII and consequent recovery in dark. Chlorophyll fluorescence imaging showed intrathalline differences in the sensitivity of U. antarctica to photoinhibition. During photoinhibion, non-photochemical quenching (NPQ) and zeaxanthin formation increased simultaneously. Photosynthetic processes (FII)were linearly related to oxygen evolution rate in non-stressed symbiotic algae. Under osmotic stress, however, FII to OEC relation was curvilinear.
In Czech
byly studovány fotosyntetické procesy různých druhů lišejníků. In situ fotosyntéza foliózních lišejníků (Pn) dosahovala hodnot1-2 mmol (CO2) m-2 s-1 pro plně hydrované stélky Umbilicaria antarctica. Sensitivita vůči fotoinhici byla sledována pomocí dynamiky Fv/Fm. Byla potvrzena vnitrostélková variabilita tohoto parametru pomocí Chl fluorescence imaging. V průběhu fotoinhibice, byl zaznamenán nárůst NPQ a zeaxantinu. za stresových podmínek simulované dehydrace byly souběžně sledovány a korelovány primární (fluorometricky) a sekundární (oxymetricky) procesy fotosyntézy.
Links
| GA522/03/0754, research and development project |
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| MSM 143100007, plan (intention) |
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