title: Photochemical activity and the structure of chloroplasts in Arabidopsis thaliana L. mutants deficient in phytochrome A and B.
abstract: The reduced content of photoreceptors, such as phytochromes, can decrease the efficiency of photosynthesis and activity of the photosystem II (PSII). For the confirmation of this hypothesis, the effect of deficiency in both phytochromes (Phy) A and B (double mutant, DM) in 7-27-day-old Arabidopsis thaliana plants on the photosynthetic activity was studied in absence and presence of UV-A radiation as a stress factor. The DM with reduced content of apoproteins of PhyA and PhyB and wild type (WT) plants with were grown in white and red light (WL and RL, respectively) of high (130 μmol quanta m-2s-1) and low (40 μmol quanta m-2s-1) intensity. For DM and WT grown in WL, no notable difference in the photochemical activity of PSII was observed. However, the resistance of the photosynthetic apparatus (PA) to UV-A and the rate of photosynthesis under light saturation were lower in the DM compared to those in the WT. Growth in RL, when the photoreceptors of blue light-cryptochromes-are inactive, resulted in the significant decrease of the photochemical activity of PSII in DM compared to that in WT including amounts of QB-non-reducing complexes of PSII and noticeable enhancement of thermal dissipation of absorbed light energy. In addition, marked distortion of the thylakoid membrane structure was observed for DM grown in RL. It is suggested that not only PhyA and PhyB but also cryptochromes are necessary for normal functioning of the PA and formation of the mechanisms of its resistance to UV-radiation.
authors: Institute of Basic Biological Problems, Russian Academy of Sciences, Institutskaya Street 2, Pushchino, Moscow Region, 142290, Russia. vkreslav@rambler.ru.|Controlled Photobiosynthesis Laboratory, Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya Street 35, Moscow, 127276, Russia. vkreslav@rambler.ru.
authors: Vladimir D
authors: VD
authors: Kreslavski
authors: Institute of Basic Biological Problems, Russian Academy of Sciences, Institutskaya Street 2, Pushchino, Moscow Region, 142290, Russia.
authors: Anatoly A
authors: AA
authors: Kosobryukhov
authors: Technical University of Berlin, Institute of Chemistry, Max-Volmer-Laboratory of Biophysical Chemistry, Straße des 17. Juni 135, 10623, Berlin, Germany.
authors: Franz-Josef
authors: FJ
authors: Schmitt
authors: Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Institutskaya Street 3, Pushchino, Moscow Region, 142290, Russia.
authors: Galina A
authors: GA
authors: Semenova
authors: Institute of Basic Biological Problems, Russian Academy of Sciences, Institutskaya Street 2, Pushchino, Moscow Region, 142290, Russia.
authors: Galina N
authors: GN
authors: Shirshikova
authors: Institute of Basic Biological Problems, Russian Academy of Sciences, Institutskaya Street 2, Pushchino, Moscow Region, 142290, Russia.|Controlled Photobiosynthesis Laboratory, Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya Street 35, Moscow, 127276, Russia.
authors: Aleksandra Yu
authors: AY
authors: Khudyakova
authors: Institute of Basic Biological Problems, Russian Academy of Sciences, Institutskaya Street 2, Pushchino, Moscow Region, 142290, Russia. suleyman.allakhverdiev@gmail.com.|Controlled Photobiosynthesis Laboratory, Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya Street 35, Moscow, 127276, Russia. suleyman.allakhverdiev@gmail.com.|Department of Plant Physiology, Faculty of Biology, M.V. Lomonosov Moscow State University, Leninskie Gory 1-12, Moscow, 119991, Russia. suleyman.allakhverdiev@gmail.com.|Bionanotechnology Laboratory, Institute of Molecular Biology and Biotechnology, Azerbaijan National Academy of Sciences, Matbuat Avenue 2a, Baku, 1073, Azerbaijan. suleyman.allakhverdiev@gmail.com.
authors: Suleyman I
authors: SI
authors: Allakhverdiev
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D002736:Chloroplasts / Q000378:metabolism* / Q000648:ultrastructure; D056931:Cryptochromes / Q000378:metabolism; D008027:Light; D055668:Photochemical Processes; D055519:Photoreceptors, Plant / Q000378:metabolism; D010788:Photosynthesis / Q000502:physiology*; D045332:Photosystem II Protein Complex / Q000378:metabolism*; D051942:Phytochrome A / Q000172:deficiency* / Q000235:genetics; D051939:Phytochrome B / Q000172:deficiency* / Q000235:genetics; D018515:Plant Leaves / Q000378:metabolism; D014466:Ultraviolet Rays
chemical_list: D056931:Cryptochromes; D055519:Photoreceptors, Plant; D045332:Photosystem II Protein Complex; D051942:Phytochrome A; D051939:Phytochrome B
keywords: Arabidopsis thaliana L; Photosynthetic apparatus; Photosystem II; Phytochromes A and B; Stress resistance; UV-radiation