Physiologia Plantarum, April, 2010, Vol.138, p.463(11)
To authenticate to the full-text of this article, please visit this link: http://dx.doi.org/10.1111/j.1399-3054.2009.01312.x Byline: Natallia Bondarava (a), Christine M. Gross (b), Maria Mubarakshina (b,c), Jochen R. Golecki (a), Giles N. Johnson (d), Anja Krieger-Liszkay (b,*) Abstract: The function of cytochrome b559 (cyt b559) in photosystem II (PSII) was studied in a tobacco mutant in which the conserved phenylalanine at position 26 in the [beta]-subunit was changed to serine. Young leaves of the mutant showed no significant difference in chloroplast ultra structure or in the amount and activity of PSII, while in mature leaves the size of the grana stacks and the amount of PSII were significantly reduced. Mature leaves of the mutant showed a higher susceptibility to photoinhibition and a higher production of singlet oxygen, as shown by spin trapping electron paramagnetic resonance (EPR) spectroscopy. Oxygen consumption and superoxide production were studied in thylakoid membranes in which the Mn cluster was removed to ensure that all the cyt b559 was present in its low potential form. In thylakoid membranes, from wild-type plants, the larger fraction of superoxide production was 3-(3,4-dichlorophenyl)-1,1-dimethylurea-sensitive. This type of superoxide formation was absent in thylakoid membranes from the mutant. The physiological importance of the plastoquinol oxidation by cyt b559 for photosynthesis is discussed. Author Affiliation: (a)Institut fur Biologie II , Universitat Freiburg, Schanzlestr. 1, 79104 Freiburg, Germany (b)CEA, iBiTecS, CNRS URA 2096, Service de Bioenergetique Biologie Structurale et Mecanisme, 91191 Gif-sur-Yvette Cedex, France (c)Institute of Basic Biological Problems RAS, 142290 Pushchino, Moscow region, Russia (d)Faculty of Life Sciences, University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK Article History: Received 29 June 2009; revised 10 October 2009 Article note: (*) e-mail: firstname.lastname@example.org
Active Oxygen ; Plant Biochemistry ; Phenylalanine ; Photosynthesis ; Oxidases ; Superoxides
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