L I C H E N   page of the Department of Plant Physiology and anatomy

PLEASE NOTE: the page is devoted to those people who are involved into ecophysiology
of lichens
 
• Project description
• Objectives of the project
• Methods
• Supporting items (team, facilities, instruments, some photos, publications)
• Publications

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Brief characterization of planned project (2003-2005)
The aim is to enlarge recent knowledge on ecophysiology of lichens under extreme conditions, mainly at high and low temperature, different thallus hydration and high light. The project is focused on the analysis of photoprotective mechanisms activated  in lichen thalli under high light. Those mechanism related to (1) hyphal cortex layer and exclusively to (2) photobiont will be studied separately. Measurements of changes in spectral reflectance with ongoing thalli dessication and determination of amount and role of pigments and fungi secondary metabolits will be done. Photoprotective mechanism related to photobiont will be studied using fluorometric and biochemical methods. We consider application of several fluorometric methods combined with evaluation of the amount of xanthophyll cycle pigments and antioxidants (glutathione reductase, superoxid dismutase) during high light stress induced under laboratory conditions. We expect that photoinhibition of photosynthesis will occur under high light, low temperature and high hydration of studied lichen species. Using fluorometric method, the phenomenon of photoinhibition and recovery from photoinhibition will be studied and limiting factors of photoinhibition will be evaluated. Within the project, photosynthetic activity will be studied at single thallus level by simultaneous measurements of  chlorophyll fluorescence parameters and gas exchange methods using a special chamber and instrumental set up.

Main objectives of planned research (2003-2005)
The main objective of the proposed project related to ecophysiology of lichens is to evaluate the extent of

(1) photoinhibition
(2) mycobiont-related  photoprotective mechanism
(3) photobiont-related photoprotective mechanisms
in foliose green-algal lichens exposed to extreme environmental conditions, such as: low and high thalii hydration, low and high thalli temperature.

Particular objectives and hypotheses to be proved
 

· (1) The main aim of the project is to find out whether photoinhibition occurs in well hydrated lichen thalli at low temperatures. This problem will be studied under laboratory conditions closely simulating outdoor environment. Hypothesis: Photoinhibition of photosynthesis is natural phenomenon occuring in lichens (at  the above conditions) detectable both by fluorometric and gazometric methods.

· (2) Quantification of photoprotective function of hyphal cortex layer and significance of its photoprotective pigments and compounds under extreme conditions (bright light, low/high temperature and thallus hydration/dehydration). Hypothesis: Presence of photoprotective compounds in the upper cortex may substaintially reduce the probability of photoinhibition under full thalli hydration. Under partial thalli dehydration, the photoprotection may be enhanced  by the change of thalli opticall properties resulting in an increased thallus reflectance and decreased light absorption.

· (3) Quantification of the photoprotective mechanisms related exclusively to the photobiont under the above-mentioned extreme conditions, and evaluation of proportion of cortex- and photobiont-related protective mechanisms. Hypothesis: Capacity of photobiont-related photoprotective mechanisms (xantophyll-cycle pool, antioxidative compounds) is sufficient in green algal-lichens to cope with and survive extremes in microclimate (full hydration, high light, low temperature).

· (4) Simultaneous measurements of Chl fluorescence parameters and gas exchange will be made under a wide range of irradiance and temperature in order to explain recent contradictory opinion on the relation of lichen photochemichal reactions (quantum yield of photosystem II - FII) to biochemical reactions of photosynthesis (quantum yield of CO2 fixation - FCO2) (Green et al. 1998). At present, it is not clear whether nonlinearity reported for FII to FCO2 relation is caused by internal reasons related to lichen photobiont or to not-enough-precise and noisy measurements of CO2 exchange in lichens. Source of noise in gas exchange data is believed to be  caused by varying rate of mycobiont and photobiont respiration, both of them strongly temperature and hydration related. We expect, if the measurements are done carefully under strictly controlled conditions, clear relation between FII to FCO2 will be found.   Hypothesis: Quantum yield of PS II and quantum yield of CO2 fixation are linearly correlated in lichens.

Supporting items

Team members (+ fields of responsibility)
 

M. BARTAK	fluorometric methods, gas exchange methods, ecophysiology in the lab/field
J. GLOSER	Gas exchange methods, spectral reflectance methods, ecophysiology in the lab/field, photoprotective pigments and antioxidants evaluation
J. DUBOVA	Thallus anatomy of lichens, image analysis
O. KOMAREK	algologist, cultivation and determination of extracted photobionts
P. ILIK	Palacky Univ. Olomouc (low/high temperature fluorescence)

J. HAJEK	Ph.D. student (fluorometric methods, temperature dependence of lichen  photosynthesis)
H. VRABLIKOVA	Ph.D. student (fluorometric methods with respect to lichen photoinhibition)
I. MUSILOVA	student (foliose lichen anatomy)
I. FABIANKOVA	student (foliose lichen anatomy)
P. VACZI	Ph.D. student (photobiont characteristics, HPLC pigment analysis)

 
Background of the team in particular methods (few examples of recent lichen physiology studies)

        (1) Chlorophyll fluorescence
 

      Light response curves of gross photosynthesis (GP) mesured on thallus of Cetraria islandica. Full thallus hydration
     (0 % of water saturation deficit, WSD) is indicated in green(o), slightly dehydrated thallus is indicated in orange (o), and
     violet (o), severe dehydration of thallus (71 % WSD) is indicated in  red (o). GP data points were calculated from
     quantum yield of photosystem II photochemistry (FII) measured by a  fluorometer PAM-2000.
     Ref: Hajek-Bartak-Gloser: MS submitted to Photosynthetica.

(2) Pigments analyses
 

Timecourse of deepoxidation state of xanthophyll cycle pigments ( Zea + 0.5 Anthera / (Viola + Anthera +Zea)) after photoinhibitory treatment ( 30 min exposition to 1000 mmol m-2 s-1 at 18 degree C) of algal photobiont Trebouxia sp. isolated from foliose lichen species Umbilicaria hirsuta and cultivated on TR medium. Photoinhibitory treatment lasted from time 0 to 0.5 h. Abbreviations: Zea = zeaxanthin, Anthera = antheraxanthin, Viola = violaxanthin. Source: Vrablikova, Bartak (unpublished)
(3) Gazometric methods
(4) Chlorophyll fluorescence imaging
 
CCD fluorometric camera image of Lasallia pustulata thallus showing contrasting
differences of variable fluorescence (Fv) distribution (maximum Fv is found in in central, close-to-umbilicus part of thallus /red, yellow/, minimum Fv is found in marginal parts /deep blue/ - Bartak et Hajek, unpublished).


(5) Anatomy of lichen thallus

Cross-cut section of thallus
of foliose lichen (Hypogymnia physodes) showing /from top to bottom/ 1)upper cortex layer (blue and yellow), 2)Trebouxia cells layer (orange), 3)medulla (yellowish blue), (4)lower cortex (yellow and blue). Source: Dubova et al. (unpublished).
(6) Cultivation of extracted photobiont (Trebouxia sp.)
 

Cells of Trebouxia sp. isolated from Umbilicaria hirsuta at different stages og their reproduction cycle:
left: free swimming zoospores, center: non-motile vegetative cells right: mature cells (the biggest ones)
 
Former research projects of M. Bartak
 
Project related to global changes
95045 Growth and development of clonal plants in normal and polluted sites. U.S.-Czech
                    Science and Technology Program. (J. Gloser - principal co-investigator, M. Bartak, M. Balaz -
                    co-investigators) 1995
0757/1998 Effect of global changes (elevated concentration of CO2) on physiology of plant
          growth and production. (M. Bartak - principal investigator) 1998

Projects related to plant ecology

0757/1998 Ecology of antarctic coastal oasis (P. Prosek - principal investigator, M. Bartak - co-investigator) 1998
Projects related to teaching of plant physiology
0606/1996 The Introduction of New Methods into the Teaching of Photosyntesis. Principal
                    investigator Gloser, J., co-investigator: Bartak, M.
0411/97 Inovation of the Teaching of Productional Plant Ecology: Modelling of Physiological
and Productional Processes. Principal investigator: Bartak, M., 1997
0462/1999 Modernisation of teachning plant physiology with special respect to photosynthesis.
                   (M. Bartak - principal investigator) 1999
 
Other projects
501/94/0493 Ecophysiological Aspects of Reforestation in Heavily Acidified Environments.
                    Principal investigator: Gloser, J., co-investigators: Vicherkova , M., Plhak, F., Kousalova , I.,
                    Bartak, M.
 204/94/0385 Clear-Cut Grass Vegetation and Soil Interaction Under Different Immision
                     Impacts. Principal co-investigator: Gloser, J., co-investigator: Bartak, M. A joint project with the
                     Institute of Landscape Ecology of the Academy of Sciences and the University of Agriculture and
                     Forestry, Brno. 1994-1996
521/97/0284 Did quantitative parameters of photosynthetic CO2 fixation and nitrogen
                    metabolism change during the evolution of the Triticum genus? (J. Gloser - principal
                    co-investigator, M. Bartak - co-investigator), 1997-1999.

Publications

• see either  full list of publication of the staff (including abstract titles from conferences) or
• personal list of publication (only journal publication)
• Lichen physiology-related publications
1999
Bartak, M., Hajek, J., Gloser, J. (1999): Application of fluorometric methods to measurements of lichen photosynthetic responses to changing temperature and thallus hydration. In: Ecology of Antarctic Coastal Oasis. Book of Abstracts, p. 5.
 
2000
Bartak, M., Hajek, J., Gloser, J.(2000): Application of fluorometric methods to measurements of lichen photosynthetic responses to changing  temperature and thallus hydration. In: Ecology of Antarctic Coastal Oasis. Proceedings, 2000, p. 17-26.

Bartak, M., Hajek, J., Vrablikova, H., Gloser, J. (2000): Photosynthetic response of lichenized Trebouxia sp. (Umbilicaria decussata (Vill.) Zahlbr.) from maritime Antarctica to high light stress. Abstracts. Conference:  Algae and Extreme Environments - Ecology and Physiology. Třeboň, Sept 11-16, 2000, Czech Republic, p. 40.

Hajek, J., Bartak, M. (2000): Distributional pattern of unicellular algal photobiont within the thalli of fruticose and foliose lichens. Abstracts. Conference: Prof. Němecs  Cytological Day, Brno, May 25, 2000, Czech Republic. p.16.

Hajek, J., Bartak, M., Gloser, J. (2000): Species-specific photosynthetic response of lichens to desiccation and temperature change detected by changes in chlorophyll fluorescence parameters. Abstracts. 12th FESPP Congress, Budapest, August, 2000, Hungary. Plant Physiology and Biochemistry, 38(suppl.): p.193.

Barták, M., Hájek, J., Gloser, J. (2000): Heterogeneity of chlorophyll fluorescence over thalli of several foliose macrolichens exposed to adverse environmental factors: Interspecific differences as related to thallus hydration and high irradiance. Photosynthetica, 38: 531-537. For more click  here
 

2001
Hajek, J., Bartak, M., Gloser, J. (2001): Effects of thallus temperature and hydration on photosynthetic parameters of Cetraria islandica from contrasting habitats. Photosynthetica, 39: 427-435. For abstract see Kluwer web page:  here

Bartak, M., Dubova, J., Hajková, M., Hajek, J., Musilova, I.(2001): Intrathalline distribution of an alga Trebouxia sp. and  its photosynthetic parameters in Lasallia pustulata and Umbilicaria decussata. Abstract. 52nd Conference of the Polish Botanical Society, Botany in the Time of Molecular Biology, Poznan, Poland, 2001, p. 174.

Bartak, M., Hajek, J., Vrablikova, H.(2001): Low temperature photoinhibition and recovery in fruticose (Usnea antarctica) and foliose (Umbilicaria decussata) Antarctic lichen species. Book of Abstracts. IXth Days of Plant Physiology, České Budějovice, Czech Republic, Sept. 17-21, 2001, p. 19.

Hajek, J., Bartak, M., Gloser, J.(2001): Photosynthetic response of Iceland moss  (Cetraria islandica) to thallus temperature and hydration detected by chlorophyll fluorescence. Book of Abstracts. IXth Days of Plant Physiology, České Budějovice, Czech Republic, Sept. 17-21, 2001, p.  21.
 

2002
Hajek, J. (2002): Photosynthetic response of lichen thalli to dehydration and low temperature detected by chlorophyll fluorescence. Ph.D. Thesis, Masaryk University, Brno, Faculty of Science, 134 p. (in Czech), for English abstract clickhere

Gloser, J., Bartak, M. (2002):  Gas-exchange measurement of carbon fluxes in stands of Antarctic lichens and mosses. Abstracts. Changes of the Polar Ecosystem.3rd Annual Meeting of Polar Section of the Czech Geographical Society, Nové Hrady, Oct. 2-5, 2002, Czech Republic.
Abstract is available at http://home.tiscali.cz/polarsection/contributions/Bartak.html

Bartak, M., Gloser, J. (2002):  The effect of vegetation cover of fruticose lichens on thermal regime of Antarctic coastal oasis (King George Island, South Shetlands). Abstracts. Changes of the Polar Ecosystem.3rd Annual Meeting of Polar Section of the Czech Geographical Society, Nové Hrady, Oct. 2-5, 2002, Czech Republic.
Abstract is available at http://home.tiscali.cz/polarsection/contributions/Bartak.html

Diploma theses
Vrablikova, H.(2002): The effect of photoinhibition on photochemical and non-photochemical mechanisms of
utilization of excitation energy in lichens. Diploma Thesis, Masaryk University, Brno, Faculty of Science, 56 p. (in Czech).

Kocmanova, A. (2002): Response of primary photosynthetic processes in foliose lichens to temperature.  Diploma Thesis, Masaryk University, Brno, Faculty of Science, 68 p. (in Czech).
 

2003
Barták, M., Vráblíková, H., Hájek, J. (2003) Sensitivity of photosystem 2 of Antarctic lichens to high irradiance stress: A fluorometric study of fruticose (Usnea antarctica) and foliose (Umbilicaria decussata) species. Photosynthetica, 41, 497-504.

Bartak, M., Hájek, J., Vráblíková, H. (2003): Spatial pattern of low-temperature photoinhibition on thalli of Antarctic lichen species Umbilicaria anatarctica visualized by a novel approach. Book of Abstracts. 10th Congress of the European Society for Photobiology, Vienna,  Austria, Sept. 6-11, 2003, p. 108

Hájek, J., Barták, M. (2003): Combined effect of  NaCl and temperature on chlorophyll fluorescence parameters in Lasallia pustulata and Umbilicaria hirsuta. Plant Physiology Conference of Ph.D. Students and Young Scientists , Brno, 2003, p. 113-144.

Hájek, J., Váczi, P., Barták, M. (2003): Photosynthesis in two foliose lichen species in response to a changing temperature and dehydration. Book of Abstracts. Photosynthesis in a Changing World (PHOTOCHANGE), An European Union - A High Level Scientific Conference, May 27 - June 3, 2003, Kolymbari, Greece, p. 76.

Váczi, P., Hájek, J., , Vráblíková, H., Barták, M. (2003): Alterations in fast chlorophyll fluorescence  rise detect high light stress in photosystem II of Antarctic lichen species. Plant Physiology Conference of Ph.D. Students and Young Scientists , Brno, 2003, p. 11-12.

Vráblíková, H., Barták, M. (2003): Increased level of oxidised glutathion relates to zeaxanthin content in high light-treated Umbilicaria antarctica. Plant Physiology Conference of Ph.D. Students and Young Scientists , Brno, 2003, p. 123-124.
 

2004
Barták, M., Hájek, J., Vráblíková, H., Dubová, J. (2004): High-Light Stress and Photoprotection in Umbilicaria antarctica Monitored by Chlorophyll Fluorescence Imaging and Changes in Zeaxanthin and Glutathione. Plant Biology, 6: 333-341.

Bartak, M., Gloser, J. (2004): Detection of photochemical processes in Antarctic lichen Xanthoria elegans using chlorophyll fluorescence imaging. Book of Abstracts, 10th Days of Plant Physiology, Bratislava, Slovakia, Sept. 5-9, 2004, p. 61.

Bartak, M., Gloser, J., Hájek, J., Dubová, J., Vráblíková, H., Váczi, P., Komárek, O., Hájková, M. (2004): Photosynthetic characteristics of foliose lichens in response to light, temperature and water status of thallus. 5th IAL Symposium, Lichens in Focus, Tartu, Estonia, Aug. 16-21, 2004. Book of Abstracts, p. 43.

Hájek, J., Barták, M. (2004): Osmotic stress at low temperature in Umbilicaria hirsuta, Lasalia pustulata.. Book of Abstracts, 14th FESPB Congress, Krakow, Poland, Aug. 23-27, 2004. Acta Physiologiae Plantarum, 26 (suppl.): 228.

Hájek, J., Barták, M. (2004): The role of ribitol in resistance of lichens to low temperature effects. Book of Abstracts, 10th Days of Plant Physiology, Bratislava, Slovakia, Sept. 5-9, 2004, p. 96.

Hájek, J., Barták, M. (2004): Visualization of high light effects on intrathalline variability of photosynthetic processes in hydrated Lasallia pustulata. 5th IAL Symposium, Lichens in Focus, Tartu, Estonia, Aug. 16-21, 2004. Book of Abstracts, p. 45.

Ilík, P., Kotabová, E., Kaňa, R., Hájek, J., Váczi, P., Barták, M. (2004): Unusual step(s) in the fast chlorophyll fluorescence induction in lichens. Book of Abstracts, 14th FESPB Congress, Krakow, Poland, Aug. 23-27, 2004. Acta Physiologiae Plantarum, 26 (suppl.): 174.

Váczi, P., Barták, M. (2004): Relation of quantum yield of photosystem II to oxygen evolution rate in a lichen photobiont Trebouxia erici. Book of Abstracts, 14th FESPB Congress, Krakow, Poland, Aug. 23-27, 2004. Acta Physiologiae Plantarum, 26 (suppl.): 176.

Váczi, P., Barták, M. (2004): Photochemical processes of photosynthesis and oxygen evolution rate in lichen photobiont Trebouxia erici. Book of Abstracts. Czecho-Slovak Student Scientific Conference, Brno, Czech Republic, May 1, 2004, p. 88. (in Slovak)

Váczi, P., Komárek, O. (2004): Isolation and cultivation of aerophytic green algae at limiting conditions of light and temperatures. Book of Abstracts, 10th Days of Plant Physiology, Bratislava, Slovakia, Sept. 5-9, 2004, p. 85..

Vráblíková, H., Barták, M. (2004):  Involvement of xanthophyll cycle pigments and glutathione in photoprotection of lichen Umbilicaria antarctica. In: Book of Abstracts. 14th International Congress on Photobiology, June 10-15, 2004, Cheju, Korea, p.222.

Vráblíková, H., Barták, M. (2004): Differences in the susceptibility of Lasallia pustulata and Umbilicaria antarctica to high light stress. Book of Abstracts, 14th FESPB Congress, Krakow, Poland, Aug. 23-27, 2004. Acta Physiologiae Plantarum, 26 (suppl.): 233.

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