Characterization of Light-Enhanced Respiration in Cyanobacteria
In eukaryotic algae, respiratory O<sub>2</sub> uptake is enhanced after illumination, which is called light-enhanced respiration (LER). It is likely stimulated by an increase in respiratory substrates produced during photosynthetic CO<sub>2</sub> assimilation and function in...
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-12-01
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| Series: | International Journal of Molecular Sciences |
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| Online Access: | https://www.mdpi.com/1422-0067/22/1/342 |
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| author | Ginga Shimakawa Ayaka Kohara Chikahiro Miyake |
| author_facet | Ginga Shimakawa Ayaka Kohara Chikahiro Miyake |
| author_sort | Ginga Shimakawa |
| collection | DOAJ |
| description | In eukaryotic algae, respiratory O<sub>2</sub> uptake is enhanced after illumination, which is called light-enhanced respiration (LER). It is likely stimulated by an increase in respiratory substrates produced during photosynthetic CO<sub>2</sub> assimilation and function in keeping the metabolic and redox homeostasis in the light in eukaryotic cells, based on the interactions among the cytosol, chloroplasts, and mitochondria. Here, we first characterize LER in photosynthetic prokaryote cyanobacteria, in which respiration and photosynthesis share their metabolisms and electron transport chains in one cell. From the physiological analysis, the cyanobacterium <i>Synechocystis</i> sp. PCC 6803 performs LER, similar to eukaryotic algae, which shows a capacity comparable to the net photosynthetic O<sub>2</sub> evolution rate. Although the respiratory and photosynthetic electron transports share the interchain, LER was uncoupled from photosynthetic electron transport. Mutant analyses demonstrated that LER is motivated by the substrates directly provided by photosynthetic CO<sub>2</sub> assimilation, but not by glycogen. Further, the light-dependent activation of LER was observed even with exogenously added glucose, implying a regulatory mechanism for LER in addition to the substrate amounts. Finally, we discuss the physiological significance of the large capacity of LER in cyanobacteria and eukaryotic algae compared to those in plants that normally show less LER. |
| first_indexed | 2024-03-10T13:38:00Z |
| format | Article |
| id | doaj.art-aeb825b01b5542ef8e06adbba05afa10 |
| institution | Directory Open Access Journal |
| issn | 1661-6596 1422-0067 |
| language | English |
| last_indexed | 2024-03-10T13:38:00Z |
| publishDate | 2020-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | International Journal of Molecular Sciences |
| spelling | doaj.art-aeb825b01b5542ef8e06adbba05afa102023-11-21T07:25:36ZengMDPI AGInternational Journal of Molecular Sciences1661-65961422-00672020-12-0122134210.3390/ijms22010342Characterization of Light-Enhanced Respiration in CyanobacteriaGinga Shimakawa0Ayaka Kohara1Chikahiro Miyake2Department of Biological and Environmental Science, Faculty of Agriculture, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, JapanDepartment of Biological and Environmental Science, Faculty of Agriculture, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, JapanDepartment of Biological and Environmental Science, Faculty of Agriculture, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, JapanIn eukaryotic algae, respiratory O<sub>2</sub> uptake is enhanced after illumination, which is called light-enhanced respiration (LER). It is likely stimulated by an increase in respiratory substrates produced during photosynthetic CO<sub>2</sub> assimilation and function in keeping the metabolic and redox homeostasis in the light in eukaryotic cells, based on the interactions among the cytosol, chloroplasts, and mitochondria. Here, we first characterize LER in photosynthetic prokaryote cyanobacteria, in which respiration and photosynthesis share their metabolisms and electron transport chains in one cell. From the physiological analysis, the cyanobacterium <i>Synechocystis</i> sp. PCC 6803 performs LER, similar to eukaryotic algae, which shows a capacity comparable to the net photosynthetic O<sub>2</sub> evolution rate. Although the respiratory and photosynthetic electron transports share the interchain, LER was uncoupled from photosynthetic electron transport. Mutant analyses demonstrated that LER is motivated by the substrates directly provided by photosynthetic CO<sub>2</sub> assimilation, but not by glycogen. Further, the light-dependent activation of LER was observed even with exogenously added glucose, implying a regulatory mechanism for LER in addition to the substrate amounts. Finally, we discuss the physiological significance of the large capacity of LER in cyanobacteria and eukaryotic algae compared to those in plants that normally show less LER.https://www.mdpi.com/1422-0067/22/1/342oxygenlight-enhanced respirationphotosynthesisrespiratory terminal oxidases |
| spellingShingle | Ginga Shimakawa Ayaka Kohara Chikahiro Miyake Characterization of Light-Enhanced Respiration in Cyanobacteria International Journal of Molecular Sciences oxygen light-enhanced respiration photosynthesis respiratory terminal oxidases |
| title | Characterization of Light-Enhanced Respiration in Cyanobacteria |
| title_full | Characterization of Light-Enhanced Respiration in Cyanobacteria |
| title_fullStr | Characterization of Light-Enhanced Respiration in Cyanobacteria |
| title_full_unstemmed | Characterization of Light-Enhanced Respiration in Cyanobacteria |
| title_short | Characterization of Light-Enhanced Respiration in Cyanobacteria |
| title_sort | characterization of light enhanced respiration in cyanobacteria |
| topic | oxygen light-enhanced respiration photosynthesis respiratory terminal oxidases |
| url | https://www.mdpi.com/1422-0067/22/1/342 |
| work_keys_str_mv | AT gingashimakawa characterizationoflightenhancedrespirationincyanobacteria AT ayakakohara characterizationoflightenhancedrespirationincyanobacteria AT chikahiromiyake characterizationoflightenhancedrespirationincyanobacteria |