O2-dependent large electron flow functioned as an electron sink, replacing the steady-state electron flux in photosynthesis in the cyanobacterium Synechocystis sp. PCC 6803, but not in the cyanobacterium Synechococcus sp. PCC 7942
| Autor: | Amane Makino, Hiroshi Yamamoto, Chikahiro Miyake, Ryosuke Hayashi, Satoko Shimizu, Keiichiro Shaku, Katsumi Amako, Masahiro Tamoi, Seiji Akimoto, Ginga Shimakawa, Toshio Sugimoto |
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| Rok vydání: | 2014 |
| Předmět: |
Chlorophyll
Cyanobacteria Light Cell Respiration Mutant Quantum yield chemistry.chemical_element Photosynthesis Applied Microbiology and Biotechnology Biochemistry Oxygen Analytical Chemistry Microbiology Electron Transport Species Specificity Respiration Molecular Biology Synechococcus biology Organic Chemistry Synechocystis Photosystem II Protein Complex General Medicine biology.organism_classification chemistry Biophysics Photorespiration Oxidation-Reduction Bacteria Biotechnology |
| Zdroj: | Bioscience, Biotechnology, and Biochemistry. 78:384-393 |
| ISSN: | 1347-6947 0916-8451 |
| DOI: | 10.1080/09168451.2014.882745 |
| Popis: | To determine whether alternative electron flow (AEF) can replace the photosynthetic electron flow in cyanobacteria, we used an open O2-electrode system to monitor O2-exchange over a long period. In air-grown Synechocystis sp. PCC 6803 (S. 6803(WT)), the quantum yield of PSII, Y(II), held even after photosynthesis was suppressed by CO2 shortage. The S. 6803 mutant, deficient in flavodiiron (FLV) proteins 1 and 3, showed the same phenotype as S. 6803(WT). In contrast, Y(II) decreased in Synechococcus sp. PCC 7942 (S. 7942). These results suggest that AEF functioned as the Y(II) in S. 6803 and replaced the photosynthetic electron flux. In contrast, the activity of AEF in S. 7942 was lower. The affinity of AEF for O2 in S. 6803 did not correspond to those of FLVs in bacteria or terminal oxidases in respiration. AEF might be driven by photorespiration. |
| Databáze: | OpenAIRE |
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