title: Recovery of photosynthetic systems during rewetting is quite rapid in a terrestrial cyanobacterium, Nostoc commune.
abstract: Recovery processes of photosynthetic systems during rewetting were studied in detail in a terrestrial, highly drought-tolerant cyanobacterium, Nostoc commune. With absorption of water, the weight of N. commune colony increased in three phases with half-increase times of about 1 min, 2 h and 9 h. Fluorescence intensities of phycobiliproteins and photosystem (PS) I complexes were recovered almost completely within 1 min, suggesting that their functional forms were restored very quickly. Energy transfer from allophycocyanin to the core-membrane linker peptide (L(CM)) was recovered within 1 min, but not that from L(CM) to PSII. PSI activity and cyclic electron flow around PSI recovered within 2 min, while the PSII activity recovered in two phases after a time lag of about 5 min, with half times of about 20 min and 2 h. Photosynthetic CO(2) fixation was restored almost in parallel with the first recovery phase of the PSII reaction center activity. Although the amount of absorbed water became more than 20 times the initial dry weight of the N. commune colony in the presence of sufficient water, about twice the initial dry weight was enough for recovery and maintenance of the PSII activity.
authors.affiliation: Department of Life Science, Faculty of Science, Himeji Institute of Technology, Harima Science Garden City, Hyogo, 678-1297 Japan. satohkaz@sci.himeji-tech.ac.jp
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Satoh
authors.forename: Manabu
authors.initials: M
authors.lastname: Hirai
authors.forename: Junko
authors.initials: J
authors.lastname: Nishio
authors.forename: Takaharu
authors.initials: T
authors.lastname: Yamaji
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kashino
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Koike
mesh_terms: D000064:Acclimatization / Q000502:physiology; D002245:Carbon Dioxide / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D000458:Cyanobacteria / Q000187:drug effects* / Q000502:physiology / Q000528:radiation effects; D008027:Light; D045342:Light-Harvesting Protein Complexes; D010101:Oxygen Consumption / Q000502:physiology; D010788:Photosynthesis / Q000187:drug effects* / Q000502:physiology / Q000528:radiation effects; D045322:Photosynthetic Reaction Center Complex Proteins / Q000378:metabolism*; D010798:Phycocyanin / Q000378:metabolism; D011506:Proteins / Q000378:metabolism; D012988:Soil Microbiology; D013050:Spectrometry, Fluorescence; D013997:Time Factors; D014867:Water / Q000494:pharmacology*
chemical_list: D045342:Light-Harvesting Protein Complexes; D045322:Photosynthetic Reaction Center Complex Proteins; D011506:Proteins; C002497:allophycocyanin; D014867:Water; D010798:Phycocyanin; D002734:Chlorophyll; D002245:Carbon Dioxide