title: Resistance of Arabidopsis thaliana L. photosynthetic apparatus to UV-B is reduced by deficit of phytochromes B and A.
abstract: The photosynthetic responses of 25-day-old Arabidopsis phyA phyB double mutant (DM) compared with the wild type (WT) to UV-B radiation (1Wm-2, 30min) were investigated. UV-B irradiation led to reduction of photosystem 2 (PS-2) activity and the photosynthetic rate. In plants grown under both white and red light (λm- 660nm) the reduction was greater in DM plants compared to the WT. Without UV-B irradiation a decrease in PS-2 activity was observed in DM grown under RL only. It is assumed that the lower content of UV-absorbing pigments and carotenoids observed in DM may be one of the reasons of reduced PS-2 resistance to UV-B. Higher decrease in activities under UV in DM plants grown under RL compared to DM plants grown under white light is likely due to the lack of activity of cryptochromes in plants grown under red light. Rates of post-stress recovery of photosynthetic activity of DM compared with WT plants under white and red light of low intensity were studied. Almost complete recovery of the activity was found which was not observed under dark conditions and in the presence of a protein synthesis inhibitor, chloramphenicol. It is assumed that phytochrome system participates in stress-protective mechanisms of the photosynthetic apparatus to UV-radiation.
authors.affiliation: Institute of Basic Biological Problems, Russian Academy of Sciences, Institutskaya Street 2, Pushchino, Moscow Region 142290, Russia; Institute for Biological Instrumentation, Russian Academy of Sciences, Institutskaya Street 7, Pushchino, Moscow Region 142290, Russia; Controlled Photobiosynthesis Laboratory, Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya Street 35, Moscow 127276, Russia.
authors.forename: Aleksandra Yu
authors.initials: AY
authors.lastname: Khudyakova
authors.affiliation: 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. Electronic address: vkreslav@rambler.ru.
authors.forename: Vladimir D
authors.initials: VD
authors.lastname: Kreslavski
authors.affiliation: Institute of Basic Biological Problems, Russian Academy of Sciences, Institutskaya Street 2, Pushchino, Moscow Region 142290, Russia.
authors.forename: Galina N
authors.initials: GN
authors.lastname: Shirshikova
authors.affiliation: Institute of Basic Biological Problems, Russian Academy of Sciences, Institutskaya Street 2, Pushchino, Moscow Region 142290, Russia.
authors.forename: Sergey K
authors.initials: SK
authors.lastname: Zharmukhamedov
authors.affiliation: Institute of Basic Biological Problems, Russian Academy of Sciences, Institutskaya Street 2, Pushchino, Moscow Region 142290, Russia.
authors.forename: Anatoly A
authors.initials: AA
authors.lastname: Kosobryukhov
authors.affiliation: 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; Department of Plant Physiology, Faculty of Biology, M.V. Lomonosov Moscow State University, Leninskie Gory 1-12, Moscow 119991, Russia; Bionanotechnology Laboratory, Institute of Molecular Biology and Biotechnology, Azerbaijan National Academy of Sciences, Matbuat Avenue 2a, Baku 1073, Azerbaijan. Electronic address: suleyman.allakhverdiev@gmail.com.
authors.forename: Suleyman I
authors.initials: SI
authors.lastname: Allakhverdiev
mesh_terms: D017360:Arabidopsis / Q000502:physiology*; D056931:Cryptochromes; D008027:Light; D009154:Mutation; D010788:Photosynthesis / Q000528:radiation effects; D045322:Photosynthetic Reaction Center Complex Proteins / Q000528:radiation effects*; D045332:Photosystem II Protein Complex / Q000528:radiation effects; D051942:Phytochrome A / Q000172:deficiency* / Q000235:genetics; D051939:Phytochrome B / Q000172:deficiency* / Q000235:genetics; D014466:Ultraviolet Rays
chemical_list: D056931:Cryptochromes; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D051942:Phytochrome A; D051939:Phytochrome B
keywords: Arabidopsis thaliana; Photosynthesis; Photosystem 2; Phytochrome A; Phytochrome B; Resistance to UV-B