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Ishihara JI, Takahashi H. Raman spectral analysis of microbial pigment compositions in vegetative cells and heterocysts of multicellular cyanobacterium. Biochem Biophys Rep 2023; 34:101469. [PMID: 37125074 PMCID: PMC10133670 DOI: 10.1016/j.bbrep.2023.101469] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 04/06/2023] [Accepted: 04/11/2023] [Indexed: 05/02/2023] Open
Abstract
The one-dimensional multicellular cyanobacterium, Anabaena sp. PCC 7120, exhibits a simple topology consisting of two types of cells under the nitrogen-depleted conditions. Although the differentiated (heterocyst) and undifferentiated cells (vegetative cells) were distinguished by their cellular shapes, we found that their internal states, that is, microbial pigment compositions, were distinguished by using a Raman microscope. Almost of Raman bands of the cellular components were assigned to vibrations of the pigments; chlorophyll a, β-carotene, phycocyanin, and allophycocyanin. We found that the Raman spectral measurement can detect the decomposition of both phycocyanin and allophycocyanin, which are components of the light-harvesting phycobilisome complex in the photosystem II. We observed that the Raman bands of phycocyanin and allophycocyanin exhibited more remarkable decrease in the heterocysts when compared to those of chlorophyll a and β-carotene. This result indicated the prior decomposition of phycobilisome in the heterocysts. We show that the Raman measurement is useful to detect the change of pigment composition in the cell differentiation.
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Affiliation(s)
- Jun-ichi Ishihara
- Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chuo-ku, 260-8673, Chiba, Japan
- Corresponding author.
| | - Hiroki Takahashi
- Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chuo-ku, 260-8673, Chiba, Japan
- Molecular Chirality Research Center, Chiba University, 1-33 Yayoicho, Inage-ku, 263-852, Chiba, Japan
- Plant Molecular Science Center, Chiba University, 1-8-1 Inohana, Chuo-ku, 260-8675, Chiba, Japan
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2
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Ishihara JI, Imai Y. Position-dependent changes in phycobilisome abundance in multicellular cyanobacterial filaments revealed by Raman spectral analysis. MICROPUBLICATION BIOLOGY 2023; 2023:10.17912/micropub.biology.000799. [PMID: 38584724 PMCID: PMC10997965 DOI: 10.17912/micropub.biology.000799] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 04/17/2023] [Accepted: 04/27/2023] [Indexed: 04/09/2024]
Abstract
The one-dimensional filamentous cyanobacterium, Anabaena sp. PCC 7120, shows a simple morphological pattern consisting of two distinct cell types under nitrogen-deprived conditions. We found that microbial pigment composition in differentiated (heterocyst) and undifferentiated cells (vegetative cells) can be distinguished using Raman microscopy. The Raman bands associated with phycocyanin and allophycocyanin were of higher intensity in vegetative cells than those in heterocysts. However, these bands had statistically lower intensity in vegetative cells located further away from heterocysts. That is, the pigment composition in individual cells is affected by locational information in a filament.
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Affiliation(s)
| | - Yuto Imai
- Faculty of International Politics and Economics, Nishogakusha University
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3
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Liu WJ, Liu H, Chen YE, Yin Y, Zhang ZW, Song J, Chang LJ, Zhang FL, Wang D, Dai XH, Wei C, Xiong M, Yuan S, Zhao J. Chloroplastic photoprotective strategies differ between bundle sheath and mesophyll cells in maize ( Zea mays L.) Under drought. FRONTIERS IN PLANT SCIENCE 2022; 13:885781. [PMID: 35909748 PMCID: PMC9330506 DOI: 10.3389/fpls.2022.885781] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 06/27/2022] [Indexed: 05/24/2023]
Abstract
Bundle sheath cells play a crucial role in photosynthesis in C4 plants, but the structure and function of photosystem II (PSII) in these cells is still controversial. Photoprotective roles of bundle sheath chloroplasts at the occurrence of environmental stresses have not been investigated so far. Non-photochemical quenching (NPQ) of chlorophyll a fluorescence is the photoprotective mechanism that responds to a changing energy balance in chloroplasts. In the present study, we found a much higher NPQ in bundle sheath chloroplasts than in mesophyll chloroplasts under a drought stress. This change was accompanied by a more rapid dephosphorylation of light-harvesting complex II (LHCII) subunits and a greater increase in PSII subunit S (PsbS) protein abundance than in mesophyll cell chloroplasts. Histochemical staining of reactive oxygen species (ROS) suggested that the high NPQ may be one of the main reasons for the lower accumulation of ROS in bundle sheath chloroplasts. This may maintain the stable functioning of bundle sheath cells under drought condition. These results indicate that the superior capacity for dissipation of excitation energy in bundle sheath chloroplasts may be an environmental adaptation unique to C4 plants.
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Affiliation(s)
- Wen-Juan Liu
- Institute of Quality Standard and Testing Technology Research, Sichuan Academy of Agricultural Sciences, Chengdu, China
| | - Hao Liu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yang-Er Chen
- College of Life Sciences, Sichuan Agricultural University, Ya’an, China
| | - Yan Yin
- Plant Science Facility of the Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Zhong-Wei Zhang
- College of Resources Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Jun Song
- Institute of Quality Standard and Testing Technology Research, Sichuan Academy of Agricultural Sciences, Chengdu, China
| | - Li-Juan Chang
- Institute of Quality Standard and Testing Technology Research, Sichuan Academy of Agricultural Sciences, Chengdu, China
| | - Fu-Li Zhang
- Institute of Quality Standard and Testing Technology Research, Sichuan Academy of Agricultural Sciences, Chengdu, China
| | - Dong Wang
- Institute of Quality Standard and Testing Technology Research, Sichuan Academy of Agricultural Sciences, Chengdu, China
| | - Xiao-Hang Dai
- Institute of Quality Standard and Testing Technology Research, Sichuan Academy of Agricultural Sciences, Chengdu, China
| | - Chao Wei
- Institute of Quality Standard and Testing Technology Research, Sichuan Academy of Agricultural Sciences, Chengdu, China
| | - Mei Xiong
- Institute of Quality Standard and Testing Technology Research, Sichuan Academy of Agricultural Sciences, Chengdu, China
| | - Shu Yuan
- College of Resources Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Jun Zhao
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
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4
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Zhang Q, Yu S, Wang Q, Yang M, Ge F. Quantitative Proteomics Reveals the Protein Regulatory Network of Anabaena sp. PCC 7120 under Nitrogen Deficiency. J Proteome Res 2021; 20:3963-3976. [PMID: 34270261 DOI: 10.1021/acs.jproteome.1c00302] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Anabaena sp. PCC 7120 (Anabaena 7120) is a photoautotrophic filamentous cyanobacterium capable of fixing atmospheric nitrogen. It is a model organism used for studying cell differentiation and nitrogen fixation. Under nitrogen deficiency, Anabaena 7120 forms specialized heterocysts capable of nitrogen fixation. However, the molecular mechanisms involved in the cyanobacterial adaptation to nitrogen deficiency are not well understood. Here, we employed a label-free quantitative proteomic strategy to systematically investigate the nitrogen deficiency response of Anabaena 7120 at different time points. In total, 363, 603, and 669 proteins showed significant changes in protein abundance under nitrogen deficiency for 3, 12, and 24 h, respectively. With mapping onto metabolic pathways, we revealed proteomic perturbation and regulation of carbon and nitrogen metabolism in response to nitrogen deficiency. Functional analysis confirmed the involvement of nitrogen stress-responsive proteins in biological processes, including nitrogen fixation, photosynthesis, energy and carbon metabolism, and heterocyst development. The expression of 10 proteins at different time points was further validated by using multiple reaction monitoring assays. In particular, many dysregulated proteins were found to be time-specific and involved in heterocyst development, providing new candidates for future functional studies in this model cyanobacterium. These results provide novel insights into the molecular mechanisms of nitrogen stress responses and heterocyst development in Anabaena 7120.
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Affiliation(s)
- Qi Zhang
- College of Fisheries and Life Science, Dalian Ocean University, Dalian 116000, China.,State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.,University of Chinese Academy of Sciences, Beijing 100039, China
| | - Shengchao Yu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.,University of Chinese Academy of Sciences, Beijing 100039, China
| | - Qiang Wang
- State Key Laboratory of Crop Stress Adaptation and Improvement, Key Laboratory of Plant Stress Biology, School of Life Sciences, Henan University, Kaifeng 475004, China
| | - Mingkun Yang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.,University of Chinese Academy of Sciences, Beijing 100039, China
| | - Feng Ge
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.,University of Chinese Academy of Sciences, Beijing 100039, China
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5
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He H, Miao R, Huang L, Jiang H, Cheng Y. Vegetative cells may perform nitrogen fixation function under nitrogen deprivation in Anabaena sp. strain PCC 7120 based on genome-wide differential expression analysis. PLoS One 2021; 16:e0248155. [PMID: 33662009 PMCID: PMC7932525 DOI: 10.1371/journal.pone.0248155] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 02/20/2021] [Indexed: 11/25/2022] Open
Abstract
Nitrogen assimilation is strictly regulated in cyanobacteria. In an inorganic nitrogen-deficient environment, some vegetative cells of the cyanobacterium Anabaena differentiate into heterocysts. We assessed the photosynthesis and nitrogen-fixing capacities of heterocysts and vegetative cells, respectively, at the transcriptome level. RNA extracted from nitrogen-replete vegetative cells (NVs), nitrogen-deprived vegetative cells (NDVs), and nitrogen-deprived heterocysts (NDHs) in Anabaena sp. strain PCC 7120 was evaluated by transcriptome sequencing. Paired comparisons of NVs vs. NDHs, NVs vs. NDVs, and NDVs vs. NDHs revealed 2,044 differentially expressed genes (DEGs). Kyoto Encyclopedia of Genes and Genomes enrichment analysis of the DEGs showed that carbon fixation in photosynthetic organisms and several nitrogen metabolism-related pathways were significantly enriched. Synthesis of Gvp (Gas vesicle synthesis protein gene) in NVs was blocked by nitrogen deprivation, which may cause Anabaena cells to sink and promote nitrogen fixation under anaerobic conditions; in contrast, heterocysts may perform photosynthesis under nitrogen deprivation conditions, whereas the nitrogen fixation capability of vegetative cells was promoted by nitrogen deprivation. Immunofluorescence analysis of nitrogenase iron protein suggested that the nitrogen fixation capability of vegetative cells was promoted by nitrogen deprivation. Our findings provide insight into the molecular mechanisms underlying nitrogen fixation and photosynthesis in vegetative cells and heterocysts at the transcriptome level. This study provides a foundation for further functional verification of heterocyst growth, differentiation, and water bloom control.
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Affiliation(s)
- Hongli He
- Jilin Provincial Key Laboratory of Plant Resource Science and Green Production, Jilin Normal University, Siping, Jilin Province, China
| | - Runyu Miao
- Jilin Provincial Key Laboratory of Plant Resource Science and Green Production, Jilin Normal University, Siping, Jilin Province, China
| | - Lilong Huang
- Jilin Provincial Key Laboratory of Plant Resource Science and Green Production, Jilin Normal University, Siping, Jilin Province, China
| | - Hongshan Jiang
- Jilin Provincial Key Laboratory of Plant Resource Science and Green Production, Jilin Normal University, Siping, Jilin Province, China
| | - Yunqing Cheng
- Jilin Provincial Key Laboratory of Plant Resource Science and Green Production, Jilin Normal University, Siping, Jilin Province, China
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6
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Popova AA, Semashko TA, Kostina NV, Rasmussen U, Govorun VM, Koksharova OA. The Cyanotoxin BMAA Induces Heterocyst Specific Gene Expression in Anabaena sp. PCC 7120 under Repressive Conditions. Toxins (Basel) 2018; 10:toxins10110478. [PMID: 30453523 PMCID: PMC6266585 DOI: 10.3390/toxins10110478] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 11/10/2018] [Accepted: 11/12/2018] [Indexed: 12/12/2022] Open
Abstract
Cyanobacteria synthesize neurotoxic β-N-methylamino-l-alanine (BMAA). The roles of this non-protein amino acid in cyanobacterial cells are insufficiently studied. During diazotrophic growth, filamentous cyanobacteria form single differentiated cells, called heterocysts, which are separated by approximately 12–15 vegetative cells. When combined nitrogen is available, heterocyst formation is blocked and cyanobacterial filaments contain only vegetative cells. In the present study, we discovered that exogenous BMAA induces the process of heterocyst formation in filamentous cyanobacteria under nitrogen-replete conditions that normally repress cell differentiation. BMAA treated cyanobacteria form heterocyst-like dark non-fluorescent non-functional cells. It was found that glutamate eliminates the BMAA mediated derepression. Quantitative polymerase chain reaction (qPCR) permitted to detect the BMAA impact on the transcriptional activity of several genes that are implicated in nitrogen assimilation and heterocyst formation in Anabaena sp. PCC 7120. We demonstrated that the expression of several essential genes increases in the BMAA presence under repressive conditions.
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Affiliation(s)
- Alexandra A Popova
- Institute of Molecular Genetics, Russian Academy of Sciences, Kurchatov Square, 2, 123182 Moscow, Russia.
- Winogradsky Institute of Microbiology, Research Center of Biotechnology, Russian Academy of Sciences, Prospekt 60 let Oktyabrya, 7/2, 117312 Moscow, Russia.
| | - Tatiana A Semashko
- Scientific-Research Institute of Physical-Chemical Medicine, 119435 Moscow, Russia.
| | - Natalia V Kostina
- Soil Science Faculty, Lomonosov Moscow State University, Leninskie Gory, 1-12, 119991 Moscow, Russia.
| | - Ulla Rasmussen
- Department of Ecology, Environment and Plant Sciences, Stockholm University, 106 91 Stockholm, Sweden.
| | - Vadim M Govorun
- Scientific-Research Institute of Physical-Chemical Medicine, 119435 Moscow, Russia.
| | - Olga A Koksharova
- Institute of Molecular Genetics, Russian Academy of Sciences, Kurchatov Square, 2, 123182 Moscow, Russia.
- Belozersky Institute of Physical-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory, 1, 40, 119992 Moscow, Russia.
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7
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Tamamizu K, Kumazaki S. Spectral microscopic imaging of heterocysts and vegetative cells in two filamentous cyanobacteria based on spontaneous Raman scattering and photoluminescence by 976 nm excitation. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1860:78-88. [PMID: 30414930 DOI: 10.1016/j.bbabio.2018.11.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 10/30/2018] [Accepted: 11/07/2018] [Indexed: 11/29/2022]
Abstract
Photosynthetic pigment-protein complexes are highly concentrated in thylakoid membranes of chloroplasts and cyanobacteria that emit strong autofluorescence (mainly 600-800 nm). In Raman scattering microscopy that enables imaging of pigment concentrations of thylakoid membranes, near infrared laser excitation at 1064 nm or visible laser excitation at 488-532 nm has been often employed in order to avoid the autofluorescence. Here we explored a new approach to Raman imaging of thylakoid membranes by using excitation wavelength of 976 nm. Two types of differentiated cells, heterocysts and vegetative cells, in two diazotrophic filamentous cyanobacteria, Anabaena variabilis, and Rivularia M-261, were characterized. Relative Raman scattering intensities of phycobilisomes of the heterocyst in comparison with the nearest vegetative cells of Rivularia remained at a significantly higher level than those of A. variabilis. It was also found that the 976 nm excitation induces photoluminescence around 1017-1175 nm from the two cyanobacteria, green alga (Parachlorella kessleri) and plant (Arabidopsis thaliana). We propose that this photoluminescence can be used as an index of concentration of chlorophyll a that has relatively small Raman scattering cross-sections. The Rivularia heterocysts that we analyzed were clearly classified into at least two subgroups based on the Chla-associated photoluminescence and carotenoid Raman bands, indicating two physiologically distinct states in the development or aging of the terminal heterocyst.
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Affiliation(s)
- Kouto Tamamizu
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Shigeichi Kumazaki
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.
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8
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Santamarï A-Gï Mez J, Mariscal V, Luque I. Mechanisms for Protein Redistribution in Thylakoids of Anabaena During Cell Differentiation. PLANT & CELL PHYSIOLOGY 2018; 59:1860-1873. [PMID: 29878163 DOI: 10.1093/pcp/pcy103] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 05/25/2018] [Indexed: 06/08/2023]
Abstract
Thylakoid membranes are far from being homogeneous in composition. On the contrary, compositional heterogeneity of lipid and protein content is well known to exist in these membranes. The mechanisms for the confinement of proteins at a particular membrane domain have started to be unveiled, but we are far from a thorough understanding, and many issues remain to be elucidated. During the differentiation of heterocysts in filamentous cyanobacteria of the Anabaena and Nostoc genera, thylakoids undergo a complete reorganization, separating into two membrane domains of different appearance and subcellular localization. Evidence also indicates different functionality and protein composition for these two membrane domains. In this work, we have addressed the mechanisms that govern the specific localization of proteins at a particular membrane domain. Two classes of proteins were distinguished according to their distribution in the thylakoids. Our results indicate that the specific accumulation of proteins of the CURVATURE THYLAKOID 1 (CURT1) family and proteins containing the homologous CAAD domain at subpolar honeycomb thylakoids is mediated by multiple mechanisms including a previously unnoticed phenomenon of thylakoid membrane migration.
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Affiliation(s)
- Javier Santamarï A-Gï Mez
- Instituto de Bioqu�mica Vegetal y Fotos�ntesis, CSIC and Universidad de Sevilla, Avda Am�rico Vespucio 49, Seville E-41092, Spain
| | - Vicente Mariscal
- Instituto de Bioqu�mica Vegetal y Fotos�ntesis, CSIC and Universidad de Sevilla, Avda Am�rico Vespucio 49, Seville E-41092, Spain
| | - Ignacio Luque
- Instituto de Bioqu�mica Vegetal y Fotos�ntesis, CSIC and Universidad de Sevilla, Avda Am�rico Vespucio 49, Seville E-41092, Spain
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9
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Popova AA, Rasmussen U, Semashko TA, Govorun VM, Koksharova OA. Stress effects of cyanotoxin β-methylamino-L-alanine (BMAA) on cyanobacterial heterocyst formation and functionality. ENVIRONMENTAL MICROBIOLOGY REPORTS 2018; 10:369-377. [PMID: 29624906 DOI: 10.1111/1758-2229.12647] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 03/28/2018] [Accepted: 04/01/2018] [Indexed: 06/08/2023]
Abstract
Various species of cyanobacteria, diatoms and dinoflagellates are capable of synthesizing the non-proteinogenic neurotoxic amino acid β-N-methylamino-L-alanine (BMAA), which is known to be a causative agent of human neurodegeneration. Similar to most cyanotoxins, the biological and ecological functions of BMAA in cyanobacteria are unknown. In this study, we show for the first time that BMAA, in micromolar amounts, inhibits the formation of heterocysts (specialized nitrogen-fixing cells) in heterocystous, diazotrophic cyanobacteria [Anabaena sp. PCC 7120, Nostoc punctiforme PCC 73102 (ATCC 29133), Nostoc sp. strain 8963] under conditions of nitrogen starvation. The inhibitory effect of BMAA is abolished by the addition of glutamate. To understand the genetic reason for the observed phenomenon, we used qPCR to study the expression of key genes involved in cell differentiation and nitrogen metabolism in the model cyanobacterium Anabaena sp. PCC 7120. We observed that in the presence of BMAA, Anabaena sp. PCC 7120 does not express two essential genes associated with heterocyst differentiation, namely, hetR and hepA. We also found that addition of BMAA to cyanobacterial cultures with mature heterocysts inhibits nifH gene expression and nitrogenase activity.
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Affiliation(s)
- Alexandra A Popova
- Institute of Molecular Genetics, Russian Academy of Sciences, Kurchatov Square, 2, 123182 Moscow, Russia
| | - Ulla Rasmussen
- Department of Ecology, Environment and Plant Sciences, Stockholm University, 106 91 Stockholm, Sweden
| | - Tatiana A Semashko
- Scientific-Research Institute of Physical-Chemical Medicine, Moscow 119435, Russia
| | - Vadim M Govorun
- Scientific-Research Institute of Physical-Chemical Medicine, Moscow 119435, Russia
| | - Olga A Koksharova
- Institute of Molecular Genetics, Russian Academy of Sciences, Kurchatov Square, 2, 123182 Moscow, Russia
- Lomonosov Moscow State University, Belozersky Institute of Physical-Chemical Biology, Leninskie Gory, 1, 40, Moscow, 119992, Russia
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10
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Nozue S, Katayama M, Terazima M, Kumazaki S. Comparative study of thylakoid membranes in terminal heterocysts and vegetative cells from two cyanobacteria, Rivularia M-261 and Anabaena variabilis, by fluorescence and absorption spectral microscopy. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2017; 1858:742-749. [DOI: 10.1016/j.bbabio.2017.05.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 04/15/2017] [Accepted: 05/17/2017] [Indexed: 10/19/2022]
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Onishi A, Aikawa S, Kondo A, Akimoto S. Energy transfer in Anabaena variabilis filaments adapted to nitrogen-depleted and nitrogen-enriched conditions studied by time-resolved fluorescence. PHOTOSYNTHESIS RESEARCH 2017; 133:317-326. [PMID: 28210833 DOI: 10.1007/s11120-017-0352-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 02/07/2017] [Indexed: 06/06/2023]
Abstract
Nitrogen is among the most important nutritious elements for photosynthetic organisms such as plants, algae, and cyanobacteria. Therefore, nitrogen depletion severely compromises the growth, development, and photosynthesis of these organisms. To preserve their integrity under nitrogen-depleted conditions, filamentous nitrogen-fixing cyanobacteria reduce atmospheric nitrogen to ammonia, and self-adapt by regulating their light-harvesting and excitation energy-transfer processes. To investigate the changes in the primary processes of photosynthesis, we measured the steady-state absorption and fluorescence spectra and time-resolved fluorescence spectra (TRFS) of whole filaments of the nitrogen-fixing cyanobacterium Anabaena variabilis at 77 K. The filaments were grown in standard and nitrogen-free media for 6 months. The TRFS were measured with a picosecond time-correlated single photon counting system. Despite the phycobilisome degradation, the energy-transfer paths within phycobilisome and from phycobilisome to both photosystems were maintained. However, the energy transfer from photosystem II to photosystem I was suppressed and a specific red chlorophyll band appeared under the nitrogen-depleted condition.
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Affiliation(s)
- Aya Onishi
- Graduate School of Science, Kobe University, Kobe, 657-8501, Japan
| | - Shimpei Aikawa
- Graduate School of Engineering, Kobe University, Kobe, 657-8501, Japan
| | - Akihiko Kondo
- Graduate School of Engineering, Kobe University, Kobe, 657-8501, Japan
| | - Seiji Akimoto
- Graduate School of Science, Kobe University, Kobe, 657-8501, Japan.
- Molecular Photoscience Research Center, Kobe University, Kobe, 657-8501, Japan.
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12
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Magnuson A, Cardona T. Thylakoid membrane function in heterocysts. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1857:309-19. [PMID: 26545609 DOI: 10.1016/j.bbabio.2015.10.016] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Revised: 09/30/2015] [Accepted: 10/29/2015] [Indexed: 01/19/2023]
Abstract
Multicellular cyanobacteria form different cell types in response to environmental stimuli. Under nitrogen limiting conditions a fraction of the vegetative cells in the filament differentiate into heterocysts. Heterocysts are specialized in atmospheric nitrogen fixation and differentiation involves drastic morphological changes on the cellular level, such as reorganization of the thylakoid membranes and differential expression of thylakoid membrane proteins. Heterocysts uphold a microoxic environment to avoid inactivation of nitrogenase by developing an extra polysaccharide layer that limits air diffusion into the heterocyst and by upregulating heterocyst-specific respiratory enzymes. In this review article, we summarize what is known about the thylakoid membrane in heterocysts and compare its function with that of the vegetative cells. We emphasize the role of photosynthetic electron transport in providing the required amounts of ATP and reductants to the nitrogenase enzyme. In the light of recent high-throughput proteomic and transcriptomic data, as well as recently discovered electron transfer pathways in cyanobacteria, our aim is to broaden current views of the bioenergetics of heterocysts. This article is part of a Special Issue entitled Organization and dynamics of bioenergetic systems in bacteria, edited by Conrad Mullineaux.
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Affiliation(s)
- Ann Magnuson
- Department of Chemistry - Ångström Laboratory, Uppsala University, Box 523, SE-75120, Uppsala, Sweden.
| | - Tanai Cardona
- Department of Life Sciences, Imperial College London, London SW7 2AZ, England, UK
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13
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Nozue S, Mukuno A, Tsuda Y, Shiina T, Terazima M, Kumazaki S. Characterization of thylakoid membrane in a heterocystous cyanobacterium and green alga with dual-detector fluorescence lifetime imaging microscopy with a systematic change of incident laser power. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1857:46-59. [PMID: 26474523 DOI: 10.1016/j.bbabio.2015.10.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Revised: 09/29/2015] [Accepted: 10/11/2015] [Indexed: 12/01/2022]
Abstract
Fluorescence Lifetime Imaging Microscopy (FLIM) has been applied to plants, algae and cyanobacteria, in which excitation laser conditions affect the chlorophyll fluorescence lifetime due to several mechanisms. However, the dependence of FLIM data on input laser power has not been quantitatively explained by absolute excitation probabilities under actual imaging conditions. In an effort to distinguish between photosystem I and photosystem II (PSI and PSII) in microscopic images, we have obtained dependence of FLIM data on input laser power from a filamentous cyanobacterium Anabaena variabilis and single cellular green alga Parachlorella kessleri. Nitrogen-fixing cells in A. variabilis, heterocysts, are mostly visualized as cells in which short-lived fluorescence (≤0.1 ns) characteristic of PSI is predominant. The other cells in A. variabilis (vegetative cells) and P. kessleri cells show a transition in the status of PSII from an open state with the maximal charge separation rate at a weak excitation limit to a closed state in which charge separation is temporarily prohibited by previous excitation(s) at a relatively high laser power. This transition is successfully reproduced by a computer simulation with a high fidelity to the actual imaging conditions. More details in the fluorescence from heterocysts were examined to assess possible functions of PSII in the anaerobic environment inside the heterocysts for the nitrogen-fixing enzyme, nitrogenase. Photochemically active PSII:PSI ratio in heterocysts is tentatively estimated to be typically below our detection limit or at most about 5% in limited heterocysts in comparison with that in vegetative cells.
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Affiliation(s)
- Shuho Nozue
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Akira Mukuno
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Yumi Tsuda
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Takashi Shiina
- Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Sakyo-ku, Kyoto 606-8522, Japan
| | - Masahide Terazima
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Shigeichi Kumazaki
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.
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Sandh G, Ramström M, Stensjö K. Analysis of the early heterocyst Cys-proteome in the multicellular cyanobacterium Nostoc punctiforme reveals novel insights into the division of labor within diazotrophic filaments. BMC Genomics 2014; 15:1064. [PMID: 25476978 PMCID: PMC4363197 DOI: 10.1186/1471-2164-15-1064] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Accepted: 11/12/2014] [Indexed: 01/30/2023] Open
Abstract
Background In the filamentous cyanobacterium Nostoc punctiforme ATCC 29133, removal of combined nitrogen induces the differentiation of heterocysts, a cell-type specialized in N2 fixation. The differentiation involves genomic, structural and metabolic adaptations. In cyanobacteria, changes in the availability of carbon and nitrogen have also been linked to redox regulated posttranslational modifications of protein bound thiol groups. We have here employed a thiol targeting strategy to relatively quantify the putative redox proteome in heterocysts as compared to N2-fixing filaments, 24 hours after combined nitrogen depletion. The aim of the study was to expand the coverage of the cell-type specific proteome and metabolic landscape of heterocysts. Results Here we report the first cell-type specific proteome of newly formed heterocysts, compared to N2-fixing filaments, using the cysteine-specific selective ICAT methodology. The data set defined a good quantitative accuracy of the ICAT reagent in complex protein samples. The relative abundance levels of 511 proteins were determined and 74% showed a cell-type specific differential abundance. The majority of the identified proteins have not previously been quantified at the cell-type specific level. We have in addition analyzed the cell-type specific differential abundance of a large section of proteins quantified in both newly formed and steady-state diazotrophic cultures in N. punctiforme. The results describe a wide distribution of members of the putative redox regulated Cys-proteome in the central metabolism of both vegetative cells and heterocysts of N. punctiforme. Conclusions The data set broadens our understanding of heterocysts and describes novel proteins involved in heterocyst physiology, including signaling and regulatory proteins as well as a large number of proteins with unknown function. Significant differences in cell-type specific abundance levels were present in the cell-type specific proteomes of newly formed diazotrophic filaments as compared to steady-state cultures. Therefore we conclude that by using our approach we are able to analyze a synchronized fraction of newly formed heterocysts, which enabled a better detection of proteins involved in the heterocyst specific physiology. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-1064) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | - Karin Stensjö
- Microbial Chemistry, Department of Chemistry - Ångström Laboratory, Science for Life Laboratory, Uppsala University, Box 523, SE-751 20 Uppsala, Sweden.
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