title: Effects of exogenous 24-epibrassinolide on the photosynthetic membranes under non-stress conditions.
abstract: In the present work the effects of exogenous 24-epibrassinolide (EBR) on functional and structural characteristics of the thylakoid membranes under non-stress conditions were evaluated 48 h after spraying of pea plants with different concentrations of EBR (0.01, 0.1 and 1.0 mg.L(-1)). The results show that the application of 0.1 mg.L(-1) EBR has the most pronounced effect on the studied characteristics of the photosynthetic membranes. The observed changes in 540 nm light scattering and in the calorimetric transitions suggest alterations in the structural organization of the thylakoid membranes after EBR treatment, which in turn influence the kinetics of oxygen evolution, accelerate the electron transport rate, increase the effective quantum yield of photosystem II and the photochemical quenching. The EBR-induced changes in the photosynthetic membranes are most probably involved in the stress tolerance of plants.
authors.affiliation: Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev, St. 21, Sofia 1113, Bulgaria. Electronic address: aneli@bio21.bas.bg.
authors.forename: Anelia G
authors.initials: AG
authors.lastname: Dobrikova
authors.affiliation: Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev, St. 21, Sofia 1113, Bulgaria.
authors.forename: Radka S
authors.initials: RS
authors.lastname: Vladkova
authors.affiliation: Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev, St. 21, Sofia 1113, Bulgaria.
authors.forename: Georgi D
authors.initials: GD
authors.lastname: Rashkov
authors.affiliation: Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev, St. 21, Sofia 1113, Bulgaria.
authors.forename: Svetla J
authors.initials: SJ
authors.lastname: Todinova
authors.affiliation: Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev, St. 21, Sofia 1113, Bulgaria.
authors.forename: Sashka B
authors.initials: SB
authors.lastname: Krumova
authors.affiliation: Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev, St. 21, Sofia 1113, Bulgaria.
authors.forename: Emilia L
authors.initials: EL
authors.lastname: Apostolova
mesh_terms: D060406:Brassinosteroids / Q000494:pharmacology*; D002734:Chlorophyll / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D018532:Pisum sativum / Q000187:drug effects / Q000378:metabolism*; D010788:Photosynthesis / Q000187:drug effects; D013260:Steroids, Heterocyclic / Q000494:pharmacology*; D020524:Thylakoids / Q000187:drug effects / Q000378:metabolism
chemical_list: D060406:Brassinosteroids; D013260:Steroids, Heterocyclic; D002734:Chlorophyll; D010100:Oxygen; C023623:brassinolide
keywords: Brassinosteroids; Calorimetric transitions; Chlorophyll fluorescence; Oxygen evolution; Pea plants; Thylakoid membranes