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.

Autor: Garstka, Maciej, Venema, Jan Henk, Rumak, Izabela, Gieczewska, Katarzyna, Rosiak, Malgorzata, Koziol-Lipinska, Joanna, Kierdaszuk, Borys, Vredenberg, Wim J., Mostowska, Agnieszka
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Zdroj: Planta: An International Journal of Plant Biology; Aug2007, Vol. 226 Issue 5, p1165-1181, 17p, 2 Color Photographs, 2 Charts, 5 Graphs
Abstrakt: 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. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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