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Le VV, Tran QG, Ko SR, Oh HM, Ahn CY. Insights into cyanobacterial blooms through the lens of omics. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 934:173028. [PMID: 38723963 DOI: 10.1016/j.scitotenv.2024.173028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 05/04/2024] [Accepted: 05/04/2024] [Indexed: 05/20/2024]
Abstract
Cyanobacteria are oxygen-producing photosynthetic bacteria that convert carbon dioxide into biomass upon exposure to sunlight. However, favorable conditions cause harmful cyanobacterial blooms (HCBs), which are the dense accumulation of biomass at the water surface or subsurface, posing threats to freshwater ecosystems and human health. Understanding the mechanisms underlying cyanobacterial bloom formation is crucial for effective management. In this regard, recent advancements in omics technologies have provided valuable insights into HCBs, which have raised expectations to develop more effective control methods in the near future. This literature review aims to present the genomic architecture, adaptive mechanisms, microbial interactions, and ecological impacts of HCBs through the lens of omics. Genomic analysis indicates that the genome plasticity of cyanobacteria has enabled their resilience and effective adaptation to environmental changes. Transcriptomic investigations have revealed that cyanobacteria use various strategies for adapting to environmental stress. Additionally, metagenomic and metatranscriptomic analyses have emphasized the significant role of the microbial community in regulating HCBs. Finally, we offer perspectives on potential opportunities for further research in this field.
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Affiliation(s)
- Ve Van Le
- Cell factory Research Centre, Korea Research Institute of Bioscience & Biotechnology, 125 Gwahak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | | | - So-Ra Ko
- Cell factory Research Centre, Korea Research Institute of Bioscience & Biotechnology, 125 Gwahak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Hee-Mock Oh
- Cell factory Research Centre, Korea Research Institute of Bioscience & Biotechnology, 125 Gwahak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea; Department of Environmental Biotechnology, KRIBB School of Biotechnology, University of Science and Technology, Daejeon 34113, Republic of Korea
| | - Chi-Yong Ahn
- Cell factory Research Centre, Korea Research Institute of Bioscience & Biotechnology, 125 Gwahak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea; Department of Environmental Biotechnology, KRIBB School of Biotechnology, University of Science and Technology, Daejeon 34113, Republic of Korea.
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Singh PR, Gupta A, Singh AP, Jaiswal J, Sinha RP. Effects of ultraviolet radiation on cellular functions of the cyanobacterium Synechocystis sp. PCC 6803 and its recovery under photosynthetically active radiation. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2024; 252:112866. [PMID: 38364711 DOI: 10.1016/j.jphotobiol.2024.112866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 01/27/2024] [Accepted: 02/07/2024] [Indexed: 02/18/2024]
Abstract
Cyanobacteria are photosynthetic organisms and challenged by large number of stresses, especially by ultraviolet radiation (UVR). UVR primarily impacts lipids, proteins, DNA, photosynthetic performance, which lowers the fitness and production of cyanobacteria. UVR has a catastrophic effect on cyanobacterial cells and eventually leads to cell death. UVR tolerance in the Synechocystis was poorly studied. Therefore, we irradiated Synechocystis sp. PCC 6803 to varying hours of photosynthetically active radiations (PAR), PAR + UV-A (PA), and PAR + UV-A + UV-B (PAB) for 48 h. To study the tolerance of Synechocystis sp. PCC 6803 against different UVR. The study shows that Chl a and total carotenoids content increased up to 36 h in PAR and PA, after 36 h a decrease was observed. PC increased up to 4-fold in 48 h of PA irradiation compared to 12 h. Maximum increase in ROS was observed under 48 h PAB i.e., 5.8-fold. Flowcytometry (FCM) based analysis shows that 25% of cells do not give fluorescence of Chl a and H2DCFH. In case of cell viability 10% cells were found to be non-viable in 48 h of PAB irradiance compared to 12 h. From the above study it was found that FCM-based approaches would provide a better understanding of the variations that occurred within the Synechocystis cells compared to fluorescence microscopy-based methods.
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Affiliation(s)
- Prashant R Singh
- Laboratory of Photobiology and Molecular Microbiology, Department of Botany, Institute of Science, Banaras Hindu University, Varanasi 221005, India
| | - Amit Gupta
- Laboratory of Photobiology and Molecular Microbiology, Department of Botany, Institute of Science, Banaras Hindu University, Varanasi 221005, India
| | - Ashish P Singh
- Laboratory of Photobiology and Molecular Microbiology, Department of Botany, Institute of Science, Banaras Hindu University, Varanasi 221005, India
| | - Jyoti Jaiswal
- Laboratory of Photobiology and Molecular Microbiology, Department of Botany, Institute of Science, Banaras Hindu University, Varanasi 221005, India
| | - Rajeshwar P Sinha
- Laboratory of Photobiology and Molecular Microbiology, Department of Botany, Institute of Science, Banaras Hindu University, Varanasi 221005, India.
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Singh PR, Pathak J, Rajneesh, Ahmed H, Häder DP, Sinha RP. Physiological responses of the cyanobacterium Synechocystis sp. PCC 6803 under rhythmic light variations. Photochem Photobiol Sci 2023; 22:2055-2069. [PMID: 37227683 DOI: 10.1007/s43630-023-00429-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 04/26/2023] [Indexed: 05/26/2023]
Abstract
Cyanobacteria are challenged by daily fluctuations of light intensities and photoperiod in their natural habitats, which affect the physiology and fitness of cyanobacteria. Circadian rhythms (CRs), an important endogenous process found in all organisms including cyanobacteria, control their physiological activities and helps in coping with 24-h light/dark (LD) cycle. In cyanobacteria, physiological responses under rhythmic ultraviolet radiation (UVR) are poorly studied. Therefore, we studied the changes in photosynthetic pigments, and physiological parameters of Synechocystis sp. PCC 6803 under UVR and photosynthetically active radiation (PAR) of light/dark (LD) oscillations having the combinations of 0, 4:20, 8:16, 12:12, 16:8, 20:4, and 24:24 h. The LD 16:8 enhanced the growth, pigments, proteins, photosynthetic efficiency, and physiology of Synechocystis sp. PCC6803. Continuous light (LL 24) of UVR and PAR exerted negative impact on the photosynthetic pigments, and chlorophyll fluorescence. Significant increase in reactive oxygen species (ROS) resulted in loss of plasma membrane integrity followed by decreased viability of cells. The dark phase played a significant role in Synechocystis to withstand the LL 24 under PAR and UVR. This study offers detailed understanding of the physiological responses of the cyanobacterium to changing light environment.
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Affiliation(s)
- Prashant R Singh
- Laboratory of Photobiology and Molecular Microbiology, Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi, 221005, India
| | - Jainendra Pathak
- Laboratory of Photobiology and Molecular Microbiology, Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi, 221005, India
- Department of Botany, Pt. Jawaharlal Nehru College (Affiliated to Bundelkhand University, Jhansi), Banda, 210001, India
| | - Rajneesh
- Laboratory of Photobiology and Molecular Microbiology, Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi, 221005, India
| | - Haseen Ahmed
- Laboratory of Photobiology and Molecular Microbiology, Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi, 221005, India
| | - Donat-P Häder
- Department of Biology, Emeritus From Friedrich-Alexander University, Neue Str. 9, 91096, Möhrendorf, Germany
| | - Rajeshwar P Sinha
- Laboratory of Photobiology and Molecular Microbiology, Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi, 221005, India.
- University Center for Research and Development (UCRD), Chandigarh University, Chandigarh, India.
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Singh VK, Jha S, Rana P, Mishra S, Kumari N, Singh SC, Anand S, Upadhye V, Sinha RP. Resilience and Mitigation Strategies of Cyanobacteria under Ultraviolet Radiation Stress. Int J Mol Sci 2023; 24:12381. [PMID: 37569755 PMCID: PMC10419127 DOI: 10.3390/ijms241512381] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 07/31/2023] [Accepted: 07/31/2023] [Indexed: 08/13/2023] Open
Abstract
Ultraviolet radiation (UVR) tends to damage key cellular machinery. Cells may adapt by developing several defence mechanisms as a response to such damage; otherwise, their destiny is cell death. Since cyanobacteria are primary biotic components and also important biomass producers, any drastic effects caused by UVR may imbalance the entire ecosystem. Cyanobacteria are exposed to UVR in their natural habitats. This exposure can cause oxidative stress which affects cellular morphology and vital processes such as cell growth and differentiation, pigmentation, photosynthesis, nitrogen metabolism, and enzyme activity, as well as alterations in the native structure of biomolecules such as proteins and DNA. The high resilience and several mitigation strategies adopted by a cyanobacterial community in the face of UV stress are attributed to the activation of several photo/dark repair mechanisms, avoidance, scavenging, screening, antioxidant systems, and the biosynthesis of UV photoprotectants, such as mycosporine-like amino acids (MAAs), scytonemin (Scy), carotenoids, and polyamines. This knowledge can be used to develop new strategies for protecting other organisms from the harmful effects of UVR. The review critically reports the latest updates on various resilience and defence mechanisms employed by cyanobacteria to withstand UV-stressed environments. In addition, recent developments in the field of the molecular biology of UV-absorbing compounds such as mycosporine-like amino acids and scytonemin and the possible role of programmed cell death, signal perception, and transduction under UVR stress are discussed.
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Affiliation(s)
- Varsha K. Singh
- Laboratory of Photobiology and Molecular Microbiology, Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi 221005, India; (V.K.S.); (S.J.); (P.R.); (S.M.); (N.K.)
| | - Sapana Jha
- Laboratory of Photobiology and Molecular Microbiology, Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi 221005, India; (V.K.S.); (S.J.); (P.R.); (S.M.); (N.K.)
| | - Palak Rana
- Laboratory of Photobiology and Molecular Microbiology, Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi 221005, India; (V.K.S.); (S.J.); (P.R.); (S.M.); (N.K.)
| | - Sonal Mishra
- Laboratory of Photobiology and Molecular Microbiology, Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi 221005, India; (V.K.S.); (S.J.); (P.R.); (S.M.); (N.K.)
| | - Neha Kumari
- Laboratory of Photobiology and Molecular Microbiology, Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi 221005, India; (V.K.S.); (S.J.); (P.R.); (S.M.); (N.K.)
| | - Suresh C. Singh
- Taurmed Technologies Pvt Ltd., 304, Pearl’s Business Park, Netaji Subhash Place, New Delhi 110034, India; (S.C.S.); (S.A.)
| | - Shekhar Anand
- Taurmed Technologies Pvt Ltd., 304, Pearl’s Business Park, Netaji Subhash Place, New Delhi 110034, India; (S.C.S.); (S.A.)
| | - Vijay Upadhye
- Department of Microbiology, Parul Institute of Applied Science, Center of Research for Development, Parul University, Vadodara 391760, India;
| | - Rajeshwar P. Sinha
- Laboratory of Photobiology and Molecular Microbiology, Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi 221005, India; (V.K.S.); (S.J.); (P.R.); (S.M.); (N.K.)
- University Center for Research & Development (UCRD), Chandigarh University, Chandigarh 140413, India
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Bai F, Jia Y, Li J, Wu Z, Li L, Song L. Paraquat induces different programmed cell death patterns in Microcystis aeruginosa and Chlorella luteoviridis. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 249:114429. [PMID: 36516625 DOI: 10.1016/j.ecoenv.2022.114429] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 12/10/2022] [Accepted: 12/11/2022] [Indexed: 06/17/2023]
Abstract
Although programmed cell death (PCD) has been reported in phytoplankton, knowledge of the characterization of the PCD pathway and cascade process in different phytoplankton species is still limited. In this study, PCD progression in cyanobacterium Microcystis aeruginosa and green algae Chlorella luteoviridis by paraquat-induced oxidative stress was monitored. The results showed that paraquat-induced PCD in the two species belonged to the caspase-dependent pathway. Dose- and time-dependent PCD characteristics in the two strains under paraquat included the increase in caspase-like activity, DNA fragmentation, and chromatin condensation. However, the signaling pathway and cascade events of PCD in M. aeruginosa and C. luteoviridis differed. In M. aeruginosa, the free Ca2+ concentration was rapidly increased at 8 h, followed by a significant elevation of the reactive oxygen species (ROS) level at 24 h, and eventual cell death. In C. luteoviridis, the mitochondrial apoptosis pathway, revealed by the depolarization of the mitochondrial membrane potential at 1 h and increase in the ROS level and caspase-like activity at 8 h, might contribute to cell death. In addition, the dynamics of ROS levels and metacaspase activity were synchronized, suggesting that paraquat-triggered PCD was ROS-mediated in both M. aeruginosa and C. luteoviridis. These results provide insights into PCD patterns in prokaryotic cyanobacteria and eukaryotic green algae under similar stress.
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Affiliation(s)
- Fang Bai
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Yunlu Jia
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
| | - Jie Li
- School of Life Sciences, Central South University, Changsha 410013, China
| | - Zhongxing Wu
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources Research in Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing 400715, China
| | - Lin Li
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Lirong Song
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
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To Die or Not to Die—Regulated Cell Death and Survival in Cyanobacteria. Microorganisms 2022; 10:microorganisms10081657. [PMID: 36014075 PMCID: PMC9415839 DOI: 10.3390/microorganisms10081657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 08/06/2022] [Accepted: 08/12/2022] [Indexed: 11/24/2022] Open
Abstract
Regulated cell death (RCD) is central to the development, integrity, and functionality of multicellular organisms. In the last decade, evidence has accumulated that RCD is a universal phenomenon in all life domains. Cyanobacteria are of specific interest due to their importance in aquatic and terrestrial habitats and their role as primary producers in global nutrient cycling. Current knowledge on cyanobacterial RCD is based mainly on biochemical and morphological observations, often by methods directly transferred from vertebrate research and with limited understanding of the molecular genetic basis. However, the metabolism of different cyanobacteria groups relies on photosynthesis and nitrogen fixation, whereas mitochondria are the central executioner of cell death in vertebrates. Moreover, cyanobacteria chosen as biological models in RCD studies are mainly colonial or filamentous multicellular organisms. On the other hand, unicellular cyanobacteria have regulated programs of cellular survival (RCS) such as chlorosis and post-chlorosis resuscitation. The co-existence of different genetically regulated programs in cyanobacterial populations may have been a top engine in life diversification. Development of cyanobacteria-specific methods for identification and characterization of RCD and wider use of single-cell analysis combined with intelligent image-based cell sorting and metagenomics would shed more light on the underlying molecular mechanisms and help us to address the complex colonial interactions during these events. In this review, we focus on the functional implications of RCD in cyanobacterial communities.
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In silico insight of cell-death-related proteins in photosynthetic cyanobacteria. Arch Microbiol 2022; 204:511. [PMID: 35864385 DOI: 10.1007/s00203-022-03130-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 07/05/2022] [Accepted: 07/07/2022] [Indexed: 11/02/2022]
Abstract
Cyanobacteria are a large group of ubiquitously found photosynthetic prokaryotes that are constantly exposed to different kinds of stressors of varying intensities and seem to overcome these in a precise and regulated manner. However, a high dose and duration of given stress induce cell death in a few select cyanobacteria, mainly to protect other cells (altruism). Despite the recent findings for the presence of biochemical and molecular hallmarks of cell death in cyanobacteria, it is yet a sketchily understood phenomenon. Regulation of metacaspase-like genes during Programmed Cell Death suggests it to be a genetically controlled mechanism like other eukaryotes. In addition to providing a comprehensive understanding of the current status of cell death in cyanobacteria, this review has used in silico analyses to directly compare the existence of some important molecular players operating in the intrinsic and extrinsic apoptotic pathways. Phylogenetic trees for all sequences indicate a cluster with a common ancestry and also a divergence from sequences of eukaryotic origin. To the best of our knowledge, such a comparison (except for orthocaspases) has not been attempted earlier and hopes to encourage workers in the field to investigate this altruistic phenomenon in detail.
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Yu J, Zhu H, Shutes B, Wang X. Salt-alkalization may potentially promote Microcystis aeruginosa blooms and the production of microcystin-LR. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 301:118971. [PMID: 35167928 DOI: 10.1016/j.envpol.2022.118971] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 01/30/2022] [Accepted: 02/06/2022] [Indexed: 06/14/2023]
Abstract
The development of saline-alkali lands has contributed to the increasing discharge of alkaline salt-laden wastewater, which poses a threat to aquatic organisms. However, the comprehensive effect of alkaline salt on Microcystis aeruginosa, a harmful cyanobacterium, remains unclear. In this study, the growth, physiology, cell ultrastructure and production of microcystin-LR (MC-LR) in Microcystis aeruginosa exposed to four levels of alkaline salt stress were evaluated. The growth of Microcystis aeruginosa was stimulated at an electrical conductivity (EC) of 2.5 mS/cm compared to the control, as supported by the increased cell density, photosynthetic pigment and protein contents. Microcystis aeruginosa could tolerate a certain level of alkaline salt (i.e., EC of 5 mS/cm) via increasing photosynthetic pigment contents to protect cells from alkaline salt stress, but the antioxidant defence system and cell ultrastructure were not affected. When EC increased to 7.5 mS/cm, alkaline salt caused oxidative stress and toxicity in Microcystis aeruginosa, as evidenced by analysis of the integrated biomarker response (IBR). Furthermore, the photosynthetic pigment and protein contents decreased, and cell apoptosis associated with ultrastructural changes was observed. Therefore, we propose that EC of 7.5 mS/cm is a threshold for growth of Microcystis aeruginosa. Additionally, the intracellular MC-LR content was stimulated by alkaline salt, and the highest value was observed at EC of 2.5 mS/cm. The extracellular MC-LR content increased with the increasing alkaline salt concentration. When EC was 7.5 mS/cm, the extracellular MC-LR content was significantly higher than in the control and was associated with the upregulated mcyH gene. This study recommends that more attention should be paid to the risk of Microcystis aeruginosa bloom and microcystin-LR pollution in lakes located in salinization regions.
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Affiliation(s)
- Jing Yu
- School of Water Resources and Environment, China University of Geosciences (Beijing), Beijing, 100083, China; Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, 130102, China
| | - Hui Zhu
- Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, 130102, China; Jilin Provincial Engineering Center of CWs Design in Cold Region & Beautiful Country Construction, Changchun, 130102, China.
| | - Brian Shutes
- Department of Natural Sciences, Middlesex University, Hendon, London, NW4 4BT, UK
| | - Xinyi Wang
- Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, 130102, China; Jilin Provincial Engineering Center of CWs Design in Cold Region & Beautiful Country Construction, Changchun, 130102, China
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Aguilera A, Berdun F, Bartoli C, Steelheart C, Alegre M, Bayir H, Tyurina YY, Kagan VE, Salerno G, Pagnussat G, Martin MV. C-ferroptosis is an iron-dependent form of regulated cell death in cyanobacteria. J Cell Biol 2022; 221:212878. [PMID: 34817556 PMCID: PMC8624678 DOI: 10.1083/jcb.201911005] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 09/29/2021] [Accepted: 11/05/2021] [Indexed: 12/30/2022] Open
Abstract
Ferroptosis is an oxidative and iron-dependent form of regulated cell death (RCD) recently described in eukaryotic organisms like animals, plants, and parasites. Here, we report that a similar process takes place in the photosynthetic prokaryote Synechocystis sp. PCC 6803 in response to heat stress. After a heat shock, Synechocystis sp. PCC 6803 cells undergo a cell death pathway that can be suppressed by the canonical ferroptosis inhibitors, CPX, vitamin E, Fer-1, liproxstatin-1, glutathione (GSH), or ascorbic acid (AsA). Moreover, as described for eukaryotic ferroptosis, this pathway is characterized by an early depletion of the antioxidants GSH and AsA, and by lipid peroxidation. These results indicate that all of the hallmarks described for eukaryotic ferroptosis are conserved in photosynthetic prokaryotes and suggest that ferroptosis might be an ancient cell death program.
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Affiliation(s)
- Anabella Aguilera
- Instituto de Investigaciones en Biodiversidad y Biotecnología (INBIOTEC-CONICET), Fundación para Investigaciones Biológicas Aplicadas (CIB-FIBA), Mar del Plata, Argentina
| | - Federico Berdun
- Instituto de Investigaciones en Biodiversidad y Biotecnología (INBIOTEC-CONICET), Fundación para Investigaciones Biológicas Aplicadas (CIB-FIBA), Mar del Plata, Argentina
| | - Carlos Bartoli
- Instituto de Fisiología Vegetal (INFIVE), Facultades de Ciencias Agrarias y Forestales y de Ciencias Naturales y Museo, Universidad Nacional de La Plata, CCT-CONICET La Plata, La Plata, Argentina
| | - Charlotte Steelheart
- Instituto de Fisiología Vegetal (INFIVE), Facultades de Ciencias Agrarias y Forestales y de Ciencias Naturales y Museo, Universidad Nacional de La Plata, CCT-CONICET La Plata, La Plata, Argentina
| | - Matías Alegre
- Instituto de Fisiología Vegetal (INFIVE), Facultades de Ciencias Agrarias y Forestales y de Ciencias Naturales y Museo, Universidad Nacional de La Plata, CCT-CONICET La Plata, La Plata, Argentina
| | - Hülya Bayir
- Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA.,Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA.,Children's Neuroscience Institute, University of Pittsburgh, Pittsburgh, PA.,Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, PA.,Departments of Environmental and Occupational Health, Chemistry, Pharmacology and Chemical Biology, Radiation Oncology, University of Pittsburgh, Pittsburgh, PA
| | - Yulia Y Tyurina
- Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, PA.,Departments of Environmental and Occupational Health, Chemistry, Pharmacology and Chemical Biology, Radiation Oncology, University of Pittsburgh, Pittsburgh, PA
| | - Valerian E Kagan
- Children's Neuroscience Institute, University of Pittsburgh, Pittsburgh, PA.,Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, PA.,Departments of Environmental and Occupational Health, Chemistry, Pharmacology and Chemical Biology, Radiation Oncology, University of Pittsburgh, Pittsburgh, PA.,Institute for Regenerative Medicine, IM Sechenov Moscow State Medical University, Moscow, Russia
| | - Graciela Salerno
- Instituto de Investigaciones en Biodiversidad y Biotecnología (INBIOTEC-CONICET), Fundación para Investigaciones Biológicas Aplicadas (CIB-FIBA), Mar del Plata, Argentina
| | - Gabriela Pagnussat
- Instituto de investigaciones Biológicas IIB-CONICET, Universidad Nacional de Mar del Plata, Mar del Plata, Argentina
| | - María Victoria Martin
- Instituto de Investigaciones en Biodiversidad y Biotecnología (INBIOTEC-CONICET), Fundación para Investigaciones Biológicas Aplicadas (CIB-FIBA), Mar del Plata, Argentina
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10
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Swapnil P, Meena M, Rai AK. Molecular interaction of nitrate transporter proteins with recombinant glycinebetaine results in efficient nitrate uptake in the cyanobacterium Anabaena PCC 7120. PLoS One 2021; 16:e0257870. [PMID: 34793479 PMCID: PMC8601584 DOI: 10.1371/journal.pone.0257870] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Accepted: 09/14/2021] [Indexed: 11/18/2022] Open
Abstract
Nitrate transport in cyanobacteria is mediated by ABC-transporter, which consists of a highly conserved ATP binding cassette (ABC) and a less conserved transmembrane domain (TMD). Under salt stress, recombinant glycinebetaine (GB) not only protected the rate of nitrate transport in transgenic Anabaena PCC 7120, rather stimulated the rate by interacting with the ABC-transporter proteins. In silico analyses revealed that nrtA protein consisted of 427 amino acids, the majority of which were hydrophobic and contained a Tat (twin-arginine translocation) signal profile of 34 amino acids (1-34). The nrtC subunit of 657 amino acids contained two hydrophobic distinct domains; the N-terminal (5-228 amino acids), which was 59% identical to nrtD (the ATP-binding subunit) and the C-terminal (268-591), 28.2% identical to nrtA, suggesting C-terminal as a solute binding domain and N-terminal as ATP binding domain. Subunit nrtD consisted of 277 amino acids and its N-terminal (21-254) was an ATP binding motif. Phylogenetic analysis revealed that nitrate-ABC-transporter proteins are highly conserved among the cyanobacterial species, though variation existed in sequences resulting in several subclades. Nostoc PCC 7120 was very close to Anabaena variabilis ATCC 29413, Anabaena sp. 4-3 and Anabaena sp. CA = ATCC 33047. On the other, Nostoc spp. NIES-3756 and PCC 7524 were often found in the same subclade suggesting more work before referring it to Anabaena PCC 7120 or Nostoc PCC 7120. The molecular interaction of nitrate with nrtA was hydrophilic, while hydrophobic with nrtC and nrtD. GB interaction with nrtACD was hydrophobic and showed higher affinity compared to nitrate.
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Affiliation(s)
- Prashant Swapnil
- Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi, India
- Department of Botany, University of Delhi, New Delhi, India
| | - Mukesh Meena
- Laboratory of Phytopathology and Microbial Biotechnology, Department of Botany, Mohanlal Sukhadia University, Udaipur, Rajasthan, India
| | - Ashwani K. Rai
- Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi, India
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11
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Swapnil P, Meena M, Rai AK. Molecular interaction of nitrate transporter proteins with recombinant glycinebetaine results in efficient nitrate uptake in the cyanobacterium Anabaena PCC 7120. PLoS One 2021; 16:e0257870. [DOI: https:/doi.org/10.1371/journal.pone.0257870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/18/2023] Open
Abstract
Nitrate transport in cyanobacteria is mediated by ABC-transporter, which consists of a highly conserved ATP binding cassette (ABC) and a less conserved transmembrane domain (TMD). Under salt stress, recombinant glycinebetaine (GB) not only protected the rate of nitrate transport in transgenic Anabaena PCC 7120, rather stimulated the rate by interacting with the ABC-transporter proteins. In silico analyses revealed that nrtA protein consisted of 427 amino acids, the majority of which were hydrophobic and contained a Tat (twin-arginine translocation) signal profile of 34 amino acids (1–34). The nrtC subunit of 657 amino acids contained two hydrophobic distinct domains; the N-terminal (5–228 amino acids), which was 59% identical to nrtD (the ATP-binding subunit) and the C-terminal (268–591), 28.2% identical to nrtA, suggesting C-terminal as a solute binding domain and N-terminal as ATP binding domain. Subunit nrtD consisted of 277 amino acids and its N-terminal (21–254) was an ATP binding motif. Phylogenetic analysis revealed that nitrate-ABC-transporter proteins are highly conserved among the cyanobacterial species, though variation existed in sequences resulting in several subclades. Nostoc PCC 7120 was very close to Anabaena variabilis ATCC 29413, Anabaena sp. 4–3 and Anabaena sp. CA = ATCC 33047. On the other, Nostoc spp. NIES-3756 and PCC 7524 were often found in the same subclade suggesting more work before referring it to Anabaena PCC 7120 or Nostoc PCC 7120. The molecular interaction of nitrate with nrtA was hydrophilic, while hydrophobic with nrtC and nrtD. GB interaction with nrtACD was hydrophobic and showed higher affinity compared to nitrate.
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Cui J, Sun T, Chen L, Zhang W. Salt-Tolerant Synechococcus elongatus UTEX 2973 Obtained via Engineering of Heterologous Synthesis of Compatible Solute Glucosylglycerol. Front Microbiol 2021; 12:650217. [PMID: 34084156 PMCID: PMC8168540 DOI: 10.3389/fmicb.2021.650217] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 03/25/2021] [Indexed: 01/08/2023] Open
Abstract
The recently isolated cyanobacterium Synechococcus elongatus UTEX 2973 (Syn2973) is characterized by a faster growth rate and greater tolerance to high temperature and high light, making it a good candidate chassis for autotrophic photosynthetic microbial cell factories. However, Syn2973 is sensitive to salt stress, making it urgently important to improve the salt tolerance of Syn2973 for future biotechnological applications. Glucosylglycerol, a compatible solute, plays an important role in resisting salt stress in moderate and marine halotolerant cyanobacteria. In this study, the salt tolerance of Syn2973 was successfully improved by introducing the glucosylglycerol (GG) biosynthetic pathway (OD750 improved by 24% at 60 h). In addition, the salt tolerance of Syn2973 was further enhanced by overexpressing the rate-limiting step of glycerol-3-phosphate dehydrogenase and downregulating the gene rfbA, which encodes UDP glucose pyrophosphorylase. Taken together, these results indicate that the growth of the end-point strain M-2522-GgpPS-drfbA was improved by 62% compared with the control strain M-pSI-pSII at 60 h under treatment with 0.5 M NaCl. Finally, a comparative metabolomic analysis between strains M-pSI-pSII and M-2522-GgpPS-drfbA was performed to characterize the carbon flux in the engineered M-2522-GgpPS-drfbA strain, and the results showed that more carbon flux was redirected from ADP-GLC to GG synthesis. This study provides important engineering strategies to improve salt tolerance and GG production in Syn2973 in the future.
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Affiliation(s)
- Jinyu Cui
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, China.,Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering, Tianjin University, Tianjin, China.,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, China
| | - Tao Sun
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, China.,Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering, Tianjin University, Tianjin, China.,Center for Biosafety Research and Strategy, Tianjin University, Tianjin, China
| | - Lei Chen
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, China.,Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering, Tianjin University, Tianjin, China.,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, China
| | - Weiwen Zhang
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, China.,Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering, Tianjin University, Tianjin, China.,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, China.,Center for Biosafety Research and Strategy, Tianjin University, Tianjin, China
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13
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Aguilera A, Klemenčič M, Sueldo DJ, Rzymski P, Giannuzzi L, Martin MV. Cell Death in Cyanobacteria: Current Understanding and Recommendations for a Consensus on Its Nomenclature. Front Microbiol 2021; 12:631654. [PMID: 33746925 PMCID: PMC7965980 DOI: 10.3389/fmicb.2021.631654] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 02/11/2021] [Indexed: 01/31/2023] Open
Abstract
Cyanobacteria are globally widespread photosynthetic prokaryotes and are major contributors to global biogeochemical cycles. One of the most critical processes determining cyanobacterial eco-physiology is cellular death. Evidence supports the existence of controlled cellular demise in cyanobacteria, and various forms of cell death have been described as a response to biotic and abiotic stresses. However, cell death research in this phylogenetic group is a relatively young field and understanding of the underlying mechanisms and molecular machinery underpinning this fundamental process remains largely elusive. Furthermore, no systematic classification of modes of cell death has yet been established for cyanobacteria. In this work, we analyzed the state of knowledge in the field of cyanobacterial cell death. Based on that, we propose unified criterion for the definition of accidental, regulated, and programmed forms of cell death in cyanobacteria based on molecular, biochemical, and morphologic aspects following the directions of the Nomenclature Committee on Cell Death (NCCD). With this, we aim to provide a guide to standardize the nomenclature related to this topic in a precise and consistent manner, which will facilitate further ecological, evolutionary, and applied research in the field of cyanobacterial cell death.
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Affiliation(s)
- Anabella Aguilera
- Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), Linnaeus University, Kalmar, Sweden
| | - Marina Klemenčič
- Department of Chemistry and Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Daniela J. Sueldo
- School of Life Sciences, University of Warwick, Coventry, United Kingdom
| | - Piotr Rzymski
- Department of Environmental Medicine, Poznan University of Medical Sciences, Poznan´, Poland
- Integrated Science Association (ISA), Universal Scientific Education and Research Network (USERN), Poznan´, Poland
| | - Leda Giannuzzi
- Centro de Investigación y Desarrollo en Criotecnología de Alimentos, Consejo Nacional de Investigaciones Científicas y Tecnológicas, Universidad Nacional de La Plata, La Plata, Argentina
- Área de Toxicología General, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, La Plata, Argentina
| | - María Victoria Martin
- Instituto de Investigaciones en Biodiversidad y Biotecnología (INBIOTEC-CONICET), Fundación para Investigaciones Biológicas Aplicadas (CIB-FIBA), Mar del Plata, Argentina
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14
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Zhu Y, Zhong X, Wang Y, Zhao Q, Huang H. Growth Performance and Antioxidative Response of Chlorella pyrenoidesa, Dunaliella salina, and Anabaena cylindrica to Four Kinds of Ionic Liquids. Appl Biochem Biotechnol 2021; 193:1945-1966. [PMID: 33528747 DOI: 10.1007/s12010-021-03515-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 01/18/2021] [Indexed: 01/15/2023]
Abstract
Ionic liquids are widely used for lipid and pigment extractions from microalgae. It is possible that ionic liquids are discharged into environments. The evaluation of growth performance and antioxidative response of ionic liquids to microalgae is helpful to explore the stress regulation mechanism and investigate possible environmental risk. Ionic liquids induce production of reactive oxygen species (ROS) to microalgae. These oxidative stresses are possible from cations, anions, and salinity. In this study, the growth inhibitions of [BMIM]Br, [BMIM]Cl, [EMIM]Cl, and [EMIM]EtOSO3 to Anabaena cylindrica, Chlorella pyrenoidesa, and Dunaliella salina were evaluated. It was interesting that Br- and two kinds of cations, [BMIM] and [EMIM], had significant effects on growth inhibitions of these microalgae. IC50 values of these ionic liquids for A. cylindrica, C. pyrenoidesa, and D. salina were also estimated based on the results of growth inhibitions. It was proved that [EMIM]Cl is relatively harmless to C. pyrenoidesa and D. salina, and [EMIM]EtOSO3 is relatively or practically harmless to C. pyrenoidesa. [BMIM]Br and [BMIM]Cl are practically harmless to A. cylindrica and C. pyrenoidesa, and relatively harmless to D. salina. More than 0.8 g/L [EMIM]EtOSO3 led to bleaching of both A. cylindrica and D. salina at 48 h which was shown that the anion, EtOSO3-, had higher inhibition to A. cylindrica and D. salina than Cl-. In addition, high concentration of ionic liquids led to reductions of chlorophyll content in these three kinds of microalgae, increase of ROS levels and malondialdehyde contents for most of the cases. High concentration of ionic liquids also increased the activities of superoxide dismutase in three kinds of microalgae. There were positive correlations between ROS levels or MDA content, and inhibitions ratios of these ionic liquids to microalgae except [EMIM]Cl to A. cylindrica. These antioxidant enzymes were beneficial for reducing the ROS induced by ionic liquids.
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Affiliation(s)
- Yali Zhu
- School of Pharmaceutical Science, Nanjing Tech University, No. 30 Puzhu South Road, Nanjing, 211816, People's Republic of China
| | - Xueqing Zhong
- School of Pharmaceutical Science, Nanjing Tech University, No. 30 Puzhu South Road, Nanjing, 211816, People's Republic of China
| | - Yujiao Wang
- School of Pharmaceutical Science, Nanjing Tech University, No. 30 Puzhu South Road, Nanjing, 211816, People's Republic of China
| | - Quanyu Zhao
- School of Pharmaceutical Science, Nanjing Tech University, No. 30 Puzhu South Road, Nanjing, 211816, People's Republic of China.
| | - He Huang
- School of Pharmaceutical Science, Nanjing Tech University, No. 30 Puzhu South Road, Nanjing, 211816, People's Republic of China. .,Jiangsu National Synergetic Innovation Centre for Advanced Materials (SICAM), Nanjing, People's Republic of China. .,State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, No. 5 Xinmofan Road, Nanjing, 210009, People's Republic of China. .,School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, 2 Xuelin Road, Nanjing, 210023, People's Republic of China.
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15
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Bhattacharjee S, Mishra AK. The tale of caspase homologues and their evolutionary outlook: deciphering programmed cell death in cyanobacteria. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:4639-4657. [PMID: 32369588 PMCID: PMC7475262 DOI: 10.1093/jxb/eraa213] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 04/28/2020] [Indexed: 06/11/2023]
Abstract
Programmed cell death (PCD), a genetically orchestrated mechanism of cellular demise, is paradoxically required to support life. As in lower eukaryotes and bacteria, PCD in cyanobacteria is poorly appreciated, despite recent biochemical and molecular evidence that supports its existence. Cyanobacterial PCD is an altruistic reaction to stressful conditions that significantly enhances genetic diversity and inclusive fitness of the population. Recent bioinformatic analysis has revealed an abundance of death-related proteases, i.e. orthocaspases (OCAs) and their mutated variants, in cyanobacteria, with the larger genomes of morphologically complex strains harbouring most of them. Sequence analysis has depicted crucial accessory domains along with the proteolytic p20-like sub-domain in OCAs, predicting their functional versatility. However, the cascades involved in sensing death signals, their transduction, and the downstream expression and activation of OCAs remain to be elucidated. Here, we provide a comprehensive description of the attempts to identify mechanisms of PCD and the existence and importance of OCAs based on in silico approaches. We also review the evolutionary and ecological significance of PCD in cyanobacteria. In the future, the analysis of cyanobacterial PCD will identify novel proteins that have varied functional roles in signalling cascades and also help in understanding the incipient mechanism of PCD morphotype(s) from where eukaryotic PCD might have originated.
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Affiliation(s)
- Samujjal Bhattacharjee
- Laboratory of Microbial Genetics, Department of Botany, Banaras Hindu University, Varanasi, India
| | - Arun Kumar Mishra
- Laboratory of Microbial Genetics, Department of Botany, Banaras Hindu University, Varanasi, India
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16
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Engineering salt tolerance of photosynthetic cyanobacteria for seawater utilization. Biotechnol Adv 2020; 43:107578. [PMID: 32553809 DOI: 10.1016/j.biotechadv.2020.107578] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Revised: 05/17/2020] [Accepted: 06/05/2020] [Indexed: 02/04/2023]
Abstract
Photosynthetic cyanobacteria are capable of utilizing sunlight and CO2 as sole energy and carbon sources, respectively. With genetically modified cyanobacteria being used as a promising chassis to produce various biofuels and chemicals in recent years, future large-scale cultivation of cyanobacteria would have to be performed in seawater, since freshwater supplies of the earth are very limiting. However, high concentration of salt is known to inhibit the growth of cyanobacteria. This review aims at comparing the mechanisms that different cyanobacteria respond to salt stress, and then summarizing various strategies of developing salt-tolerant cyanobacteria for seawater cultivation, including the utilization of halotolerant cyanobacteria and the engineering of salt-tolerant freshwater cyanobacteria. In addition, the challenges and potential strategies related to further improving salt tolerance in cyanobacteria are also discussed.
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17
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Campos FV, Oliveira JA, Pereira MG, Farnese FS. Nitric oxide and phytohormone interactions in the response of Lactuca sativa to salinity stress. PLANTA 2019; 250:1475-1489. [PMID: 31327043 DOI: 10.1007/s00425-019-03236-w] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 07/06/2019] [Indexed: 05/26/2023]
Abstract
MAIN CONCLUSION Nitric oxide increased lettuce's tolerance to salinity by restoring its hormonal balance, consequently reducing Na + accumulation and activating defense mechanisms that allowed the attenuation of ionic, oxidative, and osmotic stresses. Agricultural crops are continually threatened by soil salinity. The plant's ability to tolerate soil salinity can be increased by treatment with the signaling molecule nitric oxide (NO). Involvement of NO in plant metabolism and its interactions with phytohormones have not been fully described, so knowledge about the role of this radical in signaling pathways remains fragmented. In this work, Lactuca sativa (lettuce) plants were subjected to four treatments: (1) control (nutrient solution); (2) SNP [nutrient solution containing 70 μM sodium nitroprusside (SNP), an NO donor]; (3) NaCl (nutrient solution containing 80 mM NaCl); or (4) SNP + NaCl (nutrient solution containing SNP and NaCl). The plants were exposed to these conditions for 24 h, and then, the roots and leaves were collected and used to evaluate biochemical parameters (reactive oxygen species (ROS) production, cell membrane damage, cell death, antioxidant enzymes activities, and proline concentration), physiological parameters (pigments' concentration and gas-exchange measurements), and phytohormone content. To evaluate growth, tolerance index, and nutrient concentration, the plants were exposed to the treatments for 3 days. L sativa exposure to NaCl triggered ionic, osmotic, and oxidative stress, which resulted in hormone imbalance, cell death, and decreased growth. These deleterious changes were correlated with Na+ content in the vegetative tissues. Adding NO decreased Na+ accumulation and stabilized the mineral nutrient concentration, which maintained the photosynthetic rate and re-established growth. NO-signaling action also re-established the phytohormones balance and resulted in antioxidant system activation and osmotic regulation, with consequent increase in plants tolerance to the salt.
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Affiliation(s)
- Fernanda V Campos
- Instituto Federal Fluminense/Campus Avançado São João da Barra, São João da Barra, RJ, 28200-00, Brazil
| | - Juraci A Oliveira
- Departamento de Biologia Geral, Universidade Federal de Viçosa, Viçosa, MG, 36570-000, Brazil.
| | - Mayara G Pereira
- Departamento de Biologia Geral, Universidade Federal de Viçosa, Viçosa, MG, 36570-000, Brazil
| | - Fernanda S Farnese
- Instituto Federal Goiano, Campus Rio Verde, Rio Verde, GO, 75.901-970, Brazil
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18
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Wang X, Zhang D, Chen W, Tao J, Xu M, Guo P. Effects of fulvic acid and fulvic ions on Escherichia coli survival in river under repeated freeze-thaw cycles. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 247:1100-1109. [PMID: 30823339 DOI: 10.1016/j.envpol.2019.01.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 01/02/2019] [Accepted: 01/03/2019] [Indexed: 06/09/2023]
Abstract
The effects of fulvic acid (FA) and ions on mesophilic pathogenic bacteria survival under freeze-thaw (FT) stress in natural water and its resistant mechanisms are rarely understood. Therefore, survival patterns of Escherichia coli in river water added with various concentrations of FA or FA-ion under FT stress were studied in this work. Meanwhile, cell surface hydrophobicity (CSH), unit activities of superoxide dismutase (SOD) and catalase (CAT) were determined and Escherichia coli morphologies were observed to explore the bacterial resistant mechanisms against FT stress. The results demonstrated that FT cycles significantly reduced bacterial quantities as sampling time, i.e. freeze-thaw cycle time increased. And the biggest reducing rate was observed after the first FT cycle in every system. Ttd values, time needed to reach detection limit under FT stress decreased under FT stress as FA was added into water, while the changes of ttd values were quite complicated when FA and various ions existed together. Generally, the ttd values of FA-cation systems exceeded that of FA system except FA-Ca2+ systems, but it was opposite for FA-anion systems. CSH was heightened after FT cycles and reached peak value at last sampling time in every system. Mechanical constraint from extracellular ice crystals and high CSH induced bacterial aggregation, which protect inner cells of aggregation from extracellular ice crystals. And the unit activities of SOD were significantly higher than those of CAT. Unit activities of SOD and CAT in large part of tested systems increased with sampling time under FT stress, which reduced reactive oxygen species produced from repeated FT cycles. Thus, these could improve the resistance of Escherichia coli to freeze-thaw stress and promote their survival. This work explored the survival pattern and strategy of Escherichia coli in natural water under FT stress.
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Affiliation(s)
- Xu Wang
- Key Laboratory of Groundwater Resources and Environment Ministry of Education, College of Environment and Resources, Jilin University, Changchun, 130012, China
| | - Dongyan Zhang
- The First Hospital of Jilin University, Changchun, 130021, China
| | - Weiwei Chen
- Key Laboratory of Groundwater Resources and Environment Ministry of Education, College of Environment and Resources, Jilin University, Changchun, 130012, China
| | - Jiahui Tao
- Key Laboratory of Groundwater Resources and Environment Ministry of Education, College of Environment and Resources, Jilin University, Changchun, 130012, China
| | - Meng Xu
- Key Laboratory of Groundwater Resources and Environment Ministry of Education, College of Environment and Resources, Jilin University, Changchun, 130012, China
| | - Ping Guo
- Key Laboratory of Groundwater Resources and Environment Ministry of Education, College of Environment and Resources, Jilin University, Changchun, 130012, China.
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19
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Ross C, Warhurst BC, Brown A, Huff C, Ochrietor JD. Mesohaline conditions represent the threshold for oxidative stress, cell death and toxin release in the cyanobacterium Microcystis aeruginosa. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2019; 206:203-211. [PMID: 30500607 DOI: 10.1016/j.aquatox.2018.11.019] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 11/20/2018] [Accepted: 11/21/2018] [Indexed: 06/09/2023]
Abstract
As aquatic ecosystems become increasingly affected by hydrologic alterations, drought and sea level rise a need exists to better understand the biological effects of elevated salinity on toxigenic cyanobacteria such as Microcystis aeruginosa. This study investigated the impacts of oligohaline/low mesohaline conditions and exposure time on selected physiological and biochemical responses in M. aeruginosa including cell viability, oxidative stress, antioxidant responses, in addition to microcystin synthesis and release into the surrounding environment. M. aeruginosa was able to grow in most test salinity treatments (1.4-10 ppt), as supported by cell abundance data and chlorophyll-a (chl-a) concentrations. Physiological data showed that after certain salinity thresholds (∼7ppt) were surpassed, salt stress had cascading effects, such as increased ROS production and lipid peroxidation, potentiating the decline in cellular viability. Furthermore, elevated salinity induced oxidative stress which was concomitant with a decrease in cell abundance, chl-a concentration and photochemical efficiency in the 7-10 ppt treatments. M. aeruginosa did not synthesize microcystins (MCs) in response to increased saline conditions, and mcy-D expression was not correlated with either salinity treatment or extracellular MC concentrations, indicating that salinity stress could inhibit toxin production and that released toxins were likely synthesized prior to exposure. Additionally, extracellular MC concentrations were not correlated with decreased cellular integrity, as evidenced by SYTOX analyses, suggesting that toxins may be released through mechanisms other than cellular lysis. Results from this study support that M. aeruginosa can survive with limited negative impacts to cellular structure and function up to a certain threshold between 7-10 ppt. However, after these thresholds are surpassed, there is radical decline in cell health and viability leading to toxin release. This work underscores the importance of understanding the balance between ROS production and antioxidant capacities when assessing the fate of M. aeruginosa under mesohaline conditions.
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Affiliation(s)
- Cliff Ross
- Department of Biology, University of North Florida, 1 UNF Drive, Jacksonville, FL, 32224, USA.
| | - B Christopher Warhurst
- Department of Biology, University of North Florida, 1 UNF Drive, Jacksonville, FL, 32224, USA
| | - Amber Brown
- Department of Biology, University of North Florida, 1 UNF Drive, Jacksonville, FL, 32224, USA
| | - Chase Huff
- Department of Biology, University of North Florida, 1 UNF Drive, Jacksonville, FL, 32224, USA
| | - Judith D Ochrietor
- Department of Biology, University of North Florida, 1 UNF Drive, Jacksonville, FL, 32224, USA
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20
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Swapnil P, Rai AK. Physiological responses to salt stress of salt-adapted and directly salt (NaCl and NaCl+Na 2SO 4 mixture)-stressed cyanobacterium Anabaena fertilissima. PROTOPLASMA 2018; 255:963-976. [PMID: 29352355 DOI: 10.1007/s00709-018-1205-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 01/10/2018] [Indexed: 05/13/2023]
Abstract
Soil salinity in nature is generally mixed type; however, most of the studies on salt toxicity are performed with NaCl and little is known about sulfur type of salinity (Na2SO4). Present study discerns the physiologic mechanisms responsible for salt tolerance in salt-adapted Anabaena fertilissima, and responses of directly stressed parent cells to NaCl and NaCl+Na2SO4 mixture. NaCl at 500 mM was lethal to the cyanobacterium, whereas salt-adapted cells grew luxuriantly. Salinity impaired gross photosynthesis, electron transport activities, and respiration in parent cells, but not in the salt-adapted cells, except a marginal increase in PSI activity. Despite higher Na+ concentration in the salt mixture, equimolar NaCl appeared more inhibitive to growth. Sucrose and trehalose content and antioxidant activities were maximal in 250 mM NaCl-treated cells, followed by salt mixture and was almost identical in salt-adapted (exposed to 500 mm NaCl) and control cells, except a marginal increase in ascorbate peroxidase activity and an additional fourth superoxide dismutase isoform. Catalase isoform of 63 kDa was induced only in salt-stressed cells. Salinity increased the uptake of intracellular Na+ and Ca2+ and leakage of K+ in parent cells, while cation level in salt-adapted cells was comparable to control. Though there was differential increase in intracellular Ca2+ under different salt treatments, ratio of Ca2+/Na+ remained the same. It is inferred that stepwise increment in the salt concentration enabled the cyanobacterium to undergo priming effect and acquire robust and efficient defense system involving the least energy.
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Affiliation(s)
- Prashant Swapnil
- Department of Botany, Banaras Hindu University, Varanasi, 221005, India
| | - Ashwani K Rai
- Department of Botany, Banaras Hindu University, Varanasi, 221005, India.
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21
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Kruk C, Segura AM, Nogueira L, Alcántara I, Calliari D, Martínez de la Escalera G, Carballo C, Cabrera C, Sarthou F, Scavone P, Piccini C. A multilevel trait-based approach to the ecological performance of Microcystis aeruginosa complex from headwaters to the ocean. HARMFUL ALGAE 2017; 70:23-36. [PMID: 29169566 DOI: 10.1016/j.hal.2017.10.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 10/16/2017] [Accepted: 10/16/2017] [Indexed: 06/07/2023]
Abstract
The Microcystis aeruginosa complex (MAC) clusters cosmopolitan and conspicuous harmful bloom-forming cyanobacteria able to produce cyanotoxins. It is hypothesized that low temperatures and brackish salinities are the main barriers to MAC proliferation. Here, patterns at multiple levels of organization irrespective of taxonomic identity (i.e. a trait-based approach) were analyzed. MAC responses from the intracellular (e.g. respiratory activity) to the ecosystem level (e.g. blooms) were evaluated in wide environmental gradients. Experimental results on buoyancy and respiratory activity in response to increased salinity (0-35) and a literature review of maximum growth rates under different temperatures and salinities were combined with field sampling from headwaters (800km upstream) to the marine end of the Rio de la Plata estuary (Uruguay-South America). Salinity and temperature were the major variables affecting MAC responses. Experimentally, freshwater MAC cells remained active for 24h in brackish waters (salinity=15) while colonies increased their flotation velocity. At the population level, maximum growth rate decreased with salinity and presented a unimodal exponential response with temperature, showing an optimum at 27.5°C and a rapid decrease thereafter. At the community and ecosystem levels, MAC occurred from fresh to marine waters (salinity 30) with a sustained relative increase of large mucilaginous colonies biovolume with respect to individual cells. Similarly, total biomass and, specific and morphological richness decreased with salinity while blooms were only detected in freshwater both at high (33°C) and low (11°C) temperatures. In brackish waters, large mucilaginous colonies presented advantages under osmotic restrictive conditions. These traits values have also been associated with higher toxicity potential. This suggest salinity or low temperatures would not represent effective barriers for the survival and transport of potentially toxic MAC under likely near future scenarios of increasing human impacts (i.e. eutrophication, dam construction and climate change).
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Affiliation(s)
- Carla Kruk
- Ecología Funcional de Sistemas Acuáticos, Centro Universitario Regional Este-Rocha, Universidad de la República, Uruguay; Sección Limnología, IECA, Facultad de Ciencias, Universidad de la República, Uruguay.
| | - Angel M Segura
- Modelización y Análisis de Recursos Naturales, Centro Universitario Regional Este-Rocha, Universidad de la República, Uruguay
| | - Lucía Nogueira
- Sección Limnología, IECA, Facultad de Ciencias, Universidad de la República, Uruguay
| | - Ignacio Alcántara
- Sección Limnología, IECA, Facultad de Ciencias, Universidad de la República, Uruguay; Departamento de Microbiología, Instituto de Investigaciones Biológicas Clemente Estable, MEC, Uruguay
| | - Danilo Calliari
- Ecología Funcional de Sistemas Acuáticos, Centro Universitario Regional Este-Rocha, Universidad de la República, Uruguay; Oceanografía, IECA, Facultad de Ciencias, Universidad de la República, Uruguay
| | | | - Carmela Carballo
- Ecología Funcional de Sistemas Acuáticos, Centro Universitario Regional Este-Rocha, Universidad de la República, Uruguay; Sección Limnología, IECA, Facultad de Ciencias, Universidad de la República, Uruguay
| | - Carolina Cabrera
- Ecología Funcional de Sistemas Acuáticos, Centro Universitario Regional Este-Rocha, Universidad de la República, Uruguay; Sección Limnología, IECA, Facultad de Ciencias, Universidad de la República, Uruguay
| | - Florencia Sarthou
- Ecología Funcional de Sistemas Acuáticos, Centro Universitario Regional Este-Rocha, Universidad de la República, Uruguay; Sección Limnología, IECA, Facultad de Ciencias, Universidad de la República, Uruguay
| | - Paola Scavone
- Departamento de Microbiología, Instituto de Investigaciones Biológicas Clemente Estable, MEC, Uruguay
| | - Claudia Piccini
- Departamento de Microbiología, Instituto de Investigaciones Biológicas Clemente Estable, MEC, Uruguay
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