Environmental pH Affects Photoautotrophic Growth of Synechocystis sp. PCC 6803 Strains Carrying Mutations in the Lumenal Proteins of PSII
| Autor: | Tim S. Crawford, Rebecca L. Macdonald, Jocelyn P. S. Chua, Louis A. Sherman, Roger D. Young, Julian J. Eaton-Rye, Tina C. Summerfield |
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| Rok vydání: | 2013 |
| Předmět: |
Chlorophyll
Transcription Genetic Physiology Mutant Plant Science Oxidative phosphorylation Buffers Environment Biology Photosynthesis Models Biological chemistry.chemical_compound Bacterial Proteins Rose bengal RNA Messenger chemistry.chemical_classification Autotrophic Processes Rose Bengal Reactive oxygen species Singlet Oxygen Alkaline pH Gene expression Oxidative stress PSII extrinsic proteins Synechocystis sp. PCC 6803 Chlorophyll A Synechocystis Wild type Photosystem II Protein Complex Heterotrophic Processes Gene Expression Regulation Bacterial Cell Biology General Medicine Hydrogen-Ion Concentration biology.organism_classification Culture Media Kinetics Oxidative Stress Spectrometry Fluorescence chemistry Biochemistry Genes Bacterial Mutation Phycobilisome |
| Zdroj: | Department of Biological Sciences Faculty Publications |
| ISSN: | 1471-9053 0032-0781 |
| DOI: | 10.1093/pcp/pct036 |
| Popis: | Synechocystis sp. strain PCC 6803 grows photoautotrophically across a broad pH range, but wild-type cultures reach a higher density at elevated pH; however, photoheterotrophic growth is similar at high and neutral pH. A number of PSII mutants each lacking at least one lumenal extrinsic protein, and carrying a second PSII lumenal mutation, are able to grow photoautotrophically in BG-11 medium at pH 10.0, but not pH 7.5. We investigated the basis of this pH effect and observed no pH-specific change in variable fluorescence yield from PSII centers of the wild type or the pH-dependent ΔPsbO:ΔPsbU and ΔPsbV:ΔCyanoQ strains; however, 77 K fluorescence emission spectra indicated increased coupling of the phycobilisome (PBS) antenna at pH 10.0 in all mutants. DNA microarray data showed a cell-wide response to transfer from pH 10.0 to pH 7.5, including decreased mRNA levels of a number of oxidative stress-responsive transcripts. We hypothesize that this transcriptional response led to increased tolerance against reactive oxygen species and in particular singlet oxygen. This response enabled photoautotrophic growth of the PSII mutants at pH 10.0. This hypothesis was supported by increased resistance of all strains to rose bengal at pH 10.0 compared with pH 7.5. |
| Databáze: | OpenAIRE |
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