title: Contrasting effect of dark-chilling on chloroplast structure and arrangement of chlorophyll-protein complexes in pea and tomato: plants with a different susceptibility to non-freezing temperature.
abstract: The effect of dark-chilling and subsequent photoactivation on chloroplast structure and arrangements of chlorophyll-protein complexes in thylakoid membranes was studied in chilling-tolerant (CT) pea and in chilling-sensitive (CS) tomato. Dark-chilling did not influence chlorophyll content and Chl a/b ratio in thylakoids of both species. A decline of Chl a fluorescence intensity and an increase of the ratio of fluorescence intensities of PSI and PSII at 120 K was observed after dark-chilling in thylakoids isolated from tomato, but not from pea leaves. Chilling of pea leaves induced an increase of the relative contribution of LHCII and PSII fluorescence. A substantial decrease of the LHCII/PSII fluorescence accompanied by an increase of that from LHCI/PSI was observed in thylakoids from chilled tomato leaves; both were attenuated by photoactivation. Chlorophyll fluorescence of bright grana discs in chloroplasts from dark-chilled leaves, detected by confocal laser scanning microscopy, was more condensed in pea but significantly dispersed in tomato, compared with control samples. The chloroplast images from transmission-electron microscopy revealed that dark-chilling induced an increase of the degree of grana stacking only in pea chloroplasts. Analyses of O-J-D-I-P fluorescence induction curves in leaves of CS tomato before and after recovery from chilling indicate changes in electron transport rates at acceptor- and donor side of PS II and an increase in antenna size. In CT pea leaves these effects were absent, except for a small but irreversible effect on PSII activity and antenna size. Thus, the differences in chloroplast structure between CS and CT plants, induced by dark-chilling are a consequence of different thylakoid supercomplexes rearrangements.
authors.affiliation: Department of Metabolic Regulation, Institute of Biochemistry, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland. garstka@biol.uw.edu.pl
authors.forename: Maciej
authors.initials: M
authors.lastname: Garstka
authors.forename: Jan Henk
authors.initials: JH
authors.lastname: Venema
authors.forename: Izabela
authors.initials: I
authors.lastname: Rumak
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Gieczewska
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Rosiak
authors.forename: Joanna
authors.initials: J
authors.lastname: Koziol-Lipinska
authors.forename: Borys
authors.initials: B
authors.lastname: Kierdaszuk
authors.forename: Wim J
authors.initials: WJ
authors.lastname: Vredenberg
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Mostowska
mesh_terms: D002734:Chlorophyll / Q000378:metabolism*; D002736:Chloroplasts / Q000648:ultrastructure*; D003080:Cold Temperature; D003624:Darkness; D004591:Electrophoresis, Polyacrylamide Gel; D018551:Solanum lycopersicum / Q000378:metabolism* / Q000648:ultrastructure; D018532:Pisum sativum / Q000378:metabolism* / Q000648:ultrastructure; D010940:Plant Proteins / Q000378:metabolism*; D013050:Spectrometry, Fluorescence
chemical_list: D010940:Plant Proteins; D002734:Chlorophyll