BARTÁK, Miloš, Josef HÁJEK, Hana VRÁBLÍKOVÁ and Jaroslava DUBOVÁ. High-Light Stress and Photoprotection in Umbilicaria antarctica Monitored by Chlorophyll Fluorescence Imaging and Changes in Zeaxanthin and Glutathione. Plant Biology. Stuttgart: Thieme, Georg Thieme Verlag, 2004, vol. 6, No 3, p. 333-341. ISSN 1435-8603.
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Basic information
Original name High-Light Stress and Photoprotection in Umbilicaria antarctica Monitored by Chlorophyll Fluorescence Imaging and Changes in Zeaxanthin and Glutathione
Name in Czech Radiační stres a fotoochrana u lišejníku Umbilicaria antarctica monitorované pomocí zobrazovací metody fluorescence chlorofylu a změn v obsahu zeaxantinu a glutationu.
Authors BARTÁK, Miloš (203 Czech Republic, guarantor), Josef HÁJEK (203 Czech Republic), Hana VRÁBLÍKOVÁ (203 Czech Republic) and Jaroslava DUBOVÁ (203 Czech Republic).
Edition Plant Biology, Stuttgart, Thieme, Georg Thieme Verlag, 2004, 1435-8603.
Other information
Original language English
Type of outcome Article in a journal
Field of Study 10600 1.6 Biological sciences
Country of publisher Germany
Confidentiality degree is not subject to a state or trade secret
WWW Thieme(Plant Biology, abstract)
Impact factor Impact factor: 1.582
RIV identification code RIV/00216224:14310/04:00019753
Organization unit Faculty of Science
UT WoS 000221700600011
Keywords in English Antioxidants - lichen - low temperature - oxidative stress - photoinhibition - photosynthesis
Changed by Changed by: prof. Ing. Miloš Barták, CSc., učo 57. Changed: 26/5/2006 11:16.
Abstract
The effect of high light on spatial distribution of chlorophyll (Chl) fluorescence parameters over a lichen thallus (Umbilicaria antarctica) was investigated by imaging of Chl fluorescence parameters before and after exposure to high light (1500 micromol m-2 s-1, 30 min at 5 degC). False colour images of FV/FM and FII distribution, taken over thallus with 0.1 mm2 resolution, showed that maximum FV/FM and FII values were located close to the thallus centre. Minimum values were typical for thallus margins. After exposure to high light, a differential response of FV/FM and FII was found. The marginal thallus part exhibited a loss of photosynthetic activity, manifested as a lack of Chl fluorescence signal, and close-to-centre parts showed a different extent of FV/FM and FII decrease. Subsequent recovery in the dark led to a gradual return of FV/FM and FII to their initial values. Fast (30 min) and slow (1 - 22 h) phase of recovery were distinguished, suggesting a sufficient capacity of photoprotective mechanisms in U. antarctica to cope with low-temperature photoinhibition. Glutathione and xanthophyll cycle pigments were analyzed by HPLC. High light led to an increase in oxidized glutathione (GSSG), and a conversion of violaxanthin to zeaxanthin, expressed as their de-epoxidation state (DEPS). The responses of GSSG and DEPS were reversible during subsequent recovery in the dark. GSSG and DEPS were highly correlated to non-photochemical quenching (NPQ), indicating involvement of these antioxidants in the resistance of U. antarctica to high-light stress. Heterogeneity of Chl fluorescence parameters over the thallus and differential response to high light are discussed in relation to thallus anatomy and intrathalline distribution of the symbiotic alga Trebouxia sp.
Abstract (in Czech)
V práci byl studován vliv radiačního stresu na lišejník Umbilicaria antarctica. Bylo zjištěno, že radiační stres zvýšil obsah oxidovaného glutationu (GSSG), a způsobil konverzi violaxanthinu na zeaxanthin, což se projevilo nárůstem hodnot DEPS. Tyto změny byly reverzibilní během zotavení lišejníků ve tmě. Hodnoty GSSG and DEPS byly těsně korelovány s NPQ, což indikuje zapojení antioxidantů do fotoochrany U. antarctica vůči silnému záření.
Links
GA522/03/0754, research and development projectName: Fotoinhibice a fotoochrana u lišejníků v extrémních podmínkách
Investor: Czech Science Foundation, Photoinhibition and photoprotection in lichens under extreme conditions
MSM 143100007, plan (intention)Name: Ekologie pobřežní antarktické vegetační oázy
Investor: Ministry of Education, Youth and Sports of the CR, Ecology of the coastal vegetation
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