D 2004

Involvement of xanthophyll cycle pigments and glutathione in photoprotection of lichen Umbilicaria antarctica

VRÁBLÍKOVÁ, Hana and Miloš BARTÁK

Basic information

Original name

Involvement of xanthophyll cycle pigments and glutathione in photoprotection of lichen Umbilicaria antarctica

Name in Czech

Zapojeni pigmentu xantofyloveho cyklu a glutathionu do fotoprotekce lisejniku Umbilicaria antarctica

Authors

VRÁBLÍKOVÁ, Hana (203 Czech Republic) and Miloš BARTÁK (203 Czech Republic, guarantor)

Edition

Jeju, Korea, 14th International congress on photobiology, June 10-15, 2004, Program & Abstracts, p. 222-222, 299 pp. 2004

Publisher

Korean Society of Photoscience

Other information

Language

English

Type of outcome

Stať ve sborníku

Field of Study

10600 1.6 Biological sciences

Country of publisher

Republic of Korea

Confidentiality degree

není předmětem státního či obchodního tajemství

RIV identification code

RIV/00216224:14310/04:00010172

Organization unit

Faculty of Science

Keywords in English

high light stress; lichens; zeaxanthin; glutathione; chlorophyll fluorescence

Tags

Změněno: 10/2/2005 11:41, Mgr. Hana Cempírková, Ph.D.

Abstract

ORIG CZ

V originále

High light (HL) stress could be expected even in HL-adapted lichens when their thalli, cells of symbiotic photobiont in particular, are exposed to HL in wet state. Among several physiological photoprotective mechanisms activated during such situations, conversion of violaxanthin to zeaxanthin (Z) and capacity of glutathione (GSH) pool are of major importance. Until now, however, changes in GSH pool and its redox state have been studied in lichens only in relation to water stress. Our experiments focused on changes in Z (expressed as de-epoxidation state of xanthophyll cycle pigments - DEPS) and GSH during HL stress imposed on Umbilicaria antarctica. HL stress was induced by applying a strong light of 1800 umol m-2 s-1 for 30 min on hydrated thalli of U. antarctica at 20degC. Timecourse of HL stress and recovery was monitored by chlorophyll fluorescence (maximal quantum yield, Fv/Fm, non-photochemical quenching, NPQ). HL stress led to a photoinhibition demonstrated as a decrease of Fv/Fm and an increase in NPQ. During subsequent 10 h recovery under low light, Fv/Fm and NPQ recovered almost to pre-photoinhibitory levels. HL-induced increase in DEPS, maximum of which was recorded immediately after HL exposure. Then, DEPS decreased during 10 h to initial level. Total GSH strongly decreased after HL and proportion of its oxidised to reduced form slightly increased. During 10 h recovery, total GSH did not increase to initial value indicating that re-synthesis of GSH was not completed.

In Czech

Mezi fyziologicke fotoprotektivni mechanismy, chranici lisejniky pred svetelnym stresem, patri konverze violaxantinu na zeaxantin a kapacita antioxidacni molekuly glutathionu.

Links

GA522/03/0754, research and development project
Name: 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