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Wang G, Huang L, Zhuang S, Han F, Huang Q, Hao M, Lin G, Chen L, Shen B, Li F, Li X, Chen C, Gao Y, Mock T, Liang J. Resting cell formation in the marine diatom Thalassiosira pseudonana. THE NEW PHYTOLOGIST 2024. [PMID: 38402560 DOI: 10.1111/nph.19646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 02/08/2024] [Indexed: 02/26/2024]
Abstract
Resting cells represent a survival strategy employed by diatoms to endure prolonged periods of unfavourable conditions. In the oceans, many diatoms sink at the end of their blooming season and therefore need to endure cold and dark conditions in the deeper layers of the water column. How they survive these conditions is largely unknown. We conducted an integrative analysis encompassing methods from histology, physiology, biochemistry, and genetics to reveal the biological mechanism of resting-cell formation in the model diatom Thalassiosira pseudonana. Resting-cell formation was triggered by a decrease in light and temperature with subsequent catabolism of storage compounds. Resting cells were characterised by an acidic and viscous cytoplasm and altered morphology of the chloroplast ultrastructure. The formation of resting cells in T. pseudonana is an energy demanding process required for a biophysical alteration of the cytosol and chloroplasts to endure the unfavourable conditions of the deeper ocean as photosynthetic organisms. However, most resting cells (> 90%) germinate upon return to favorable growth conditions.
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Affiliation(s)
- Guangning Wang
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
| | - Lu Huang
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
| | - Shanshan Zhuang
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
| | - Fang Han
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
| | - Qianqian Huang
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
| | - Mengyuan Hao
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
| | - Guifang Lin
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
| | - Longnan Chen
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
| | - Biying Shen
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
| | - Feng Li
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
| | - Xuesong Li
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
| | - Changping Chen
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
| | - Yahui Gao
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
- State Key Laboratory of Marine Environment Science, Xiamen University, Xiamen, 361102, Fujian, China
| | - Thomas Mock
- School of Environmental Sciences, University of East Anglia (UEA), Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Junrong Liang
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
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Cell death responses to acute high light mediated by non-photochemical quenching in the dinoflagellate Karenia brevis. Sci Rep 2022; 12:14081. [PMID: 35982058 PMCID: PMC9388518 DOI: 10.1038/s41598-022-18056-4] [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: 03/31/2022] [Accepted: 08/04/2022] [Indexed: 11/09/2022] Open
Abstract
Programmed cell death (PCD) can be induced in microalgae by many abiotic challenges via generation of reactive oxygen species (ROS). Marine phytoplankton live in a highly variable light environment, yet the potential for excess photosynthetically available radiation to trigger PCD has not been examined. On the other hand, photoprotective non-photochemical quenching (NPQ) is hypothesized to counteract intracellular ROS, potentially preventing cell death. The main objective of this study is to investigate high-light-induced death processes and their relationship with photosynthesis in bloom-forming dinoflagellate Karenia brevis. Here, we characterized the prevalence of ROS, caspase-like enzyme activity and cell death as well as photosynthetic status under acute irradiance of 500, 750 or 1000 µmol m-2 s-1. PCD only occurred at the largest light shift. Although depressed photosynthetic capacities and oxidative stress were apparent across the stress gradient, they did not necessarily lead to cell death. NPQ exhibited dose-dependent activation with increasing light stress, which enabled cells to resist or delay PCD. These results highlight the important role of the balance between ROS generation and NPQ activation on determining cell fates in Karenia under acute irradiance stress. This research also provides insights into potential survival strategies and mechanisms of cell loss under a changeable light environment.
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Paidi MK, Polisetti V, Damarla K, Singh PS, Mandal SK, Ray P. 3D Natural Mesoporous Biosilica-Embedded Polysulfone Made Ultrafiltration Membranes for Application in Separation Technology. Polymers (Basel) 2022; 14:polym14091750. [PMID: 35566918 PMCID: PMC9101741 DOI: 10.3390/polym14091750] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 04/24/2022] [Accepted: 04/24/2022] [Indexed: 02/01/2023] Open
Abstract
Diatoms are the most abundant photosynthetic microalgae found in all aquatic habitats. In the extant study, the spent biomass (after lipid extraction) of the centric marine diatom Thalassiosira lundiana CSIRCSMCRI 001 was subjected to acid digestion for the extraction of micro composite inorganic biosilica. Then, the resulting three-dimensional mesoporous biosilica material (diatomite) was used as a filler in polysulfone (PSF) membrane preparation by phase inversion. The fabricated PSF/diatomite composite membranes were characterized by SEM-EDX, TGA, and ATR-IR, and their performances were evaluated. The number of pores and pore size were increased on the membrane surface with increased diatomite in the composite membranes as compared to the control. The diatomite composite membranes had high hydrophilicity and thermal stability, lower surface roughness, and excellent water permeability. Membranes with high % diatomite, i.e., PSF/Dia0.5, had a maximum water flux of 806.8 LMH (Liter/m2/h) at 20 psi operating pressure. High-diatomite content membranes also exhibited the highest rejection of BSA protein (98.5%) and rhodamine 6G (94.8%). Similarly, in biomedical rejection tests, the PSF/Dia0.5 membrane exhibited a maximum rejection of ampicillin (75.84%) and neomycin (85.88%) at 20 Psi pressure. In conclusion, the mesoporous inorganic biosilica material was extracted from spent biomass of diatom and successfully used in filtration techniques. The results of this study could enhance the application of natural biogenic porous silica materials in wastewater treatment for water recycling.
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Affiliation(s)
- Murali Krishna Paidi
- CSIR-Central Salt and Marine Chemicals Research Institute, Council of Scientific and Industrial Research (CSIR), GB Marg, Bhavnagar 364002, India; (M.K.P.); (K.D.); (P.S.S.)
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Veerababu Polisetti
- CSIR-Central Salt and Marine Chemicals Research Institute, Council of Scientific and Industrial Research (CSIR), GB Marg, Bhavnagar 364002, India; (M.K.P.); (K.D.); (P.S.S.)
- Department of Fibre and Polymer Technology, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden
- Correspondence: (V.P.); (S.K.M.); (P.R.)
| | - Krishnaiah Damarla
- CSIR-Central Salt and Marine Chemicals Research Institute, Council of Scientific and Industrial Research (CSIR), GB Marg, Bhavnagar 364002, India; (M.K.P.); (K.D.); (P.S.S.)
| | - Puyam Sobhindro Singh
- CSIR-Central Salt and Marine Chemicals Research Institute, Council of Scientific and Industrial Research (CSIR), GB Marg, Bhavnagar 364002, India; (M.K.P.); (K.D.); (P.S.S.)
| | - Subir Kumar Mandal
- CSIR-Central Salt and Marine Chemicals Research Institute, Council of Scientific and Industrial Research (CSIR), GB Marg, Bhavnagar 364002, India; (M.K.P.); (K.D.); (P.S.S.)
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
- Correspondence: (V.P.); (S.K.M.); (P.R.)
| | - Paramita Ray
- CSIR-Central Salt and Marine Chemicals Research Institute, Council of Scientific and Industrial Research (CSIR), GB Marg, Bhavnagar 364002, India; (M.K.P.); (K.D.); (P.S.S.)
- Correspondence: (V.P.); (S.K.M.); (P.R.)
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Seasonal mixed layer depth shapes phytoplankton physiology, viral production, and accumulation in the North Atlantic. Nat Commun 2021; 12:6634. [PMID: 34789722 PMCID: PMC8599477 DOI: 10.1038/s41467-021-26836-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 10/20/2021] [Indexed: 12/03/2022] Open
Abstract
Seasonal shifts in phytoplankton accumulation and loss largely follow changes in mixed layer depth, but the impact of mixed layer depth on cell physiology remains unexplored. Here, we investigate the physiological state of phytoplankton populations associated with distinct bloom phases and mixing regimes in the North Atlantic. Stratification and deep mixing alter community physiology and viral production, effectively shaping accumulation rates. Communities in relatively deep, early-spring mixed layers are characterized by low levels of stress and high accumulation rates, while those in the recently shallowed mixed layers in late-spring have high levels of oxidative stress. Prolonged stratification into early autumn manifests in negative accumulation rates, along with pronounced signatures of compromised membranes, death-related protease activity, virus production, nutrient drawdown, and lipid markers indicative of nutrient stress. Positive accumulation renews during mixed layer deepening with transition into winter, concomitant with enhanced nutrient supply and lessened viral pressure. Phytoplankton are important primary producers. Here the authors investigate phytoplankton physiological changes associated with bloom phases and mixing regimes in the North Atlantic, finding that stratification and deep mixing shape accumulation rates by altering physiology and viral production.
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Thangaraj S, Palanisamy SK, Zhang G, Sun J. Quantitative Proteomic Profiling of Marine Diatom Skeletonema dohrnii in Response to Temperature and Silicate Induced Environmental Stress. Front Microbiol 2021; 11:554832. [PMID: 33519723 PMCID: PMC7841394 DOI: 10.3389/fmicb.2020.554832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 12/23/2020] [Indexed: 11/17/2022] Open
Abstract
Global warming is expected to reduce the nutrient concentration in the upper ocean and affect the physiology of marine diatoms, but the underlying molecular mechanisms controlling these physiological changes are currently unknown. To understand these mechanisms, here we investigated iTRAQ based proteomic profiling of diatom Skeletonema dohrnii in a multifactorial experimental with a combining change of temperature and silicate concentrations. In total, 3369 differently abundant proteins were detected in four different environmental conditions, and the function of all proteins was identified using Gene Ontology and KEGG pathway analysis. For discriminating the proteome variation among samples, multivariate statistical analysis (PCA, PLS-DA) was performed by comparing the protein ratio differences. Further, performing pathway analysis on diatom proteomes, we here demonstrated downregulation of photosynthesis, carbon metabolism, and ribosome biogenesis in the cellular process that leads to decrease the oxidoreductase activity and affects the cell cycle of the diatom. Using PLS-DA VIP score plot analysis, we identified 15 protein biomarkers for discriminating studied samples. Of these, five proteins or gene (rbcL, PRK, atpB, DNA-binding, and signal transduction) identified as key biomarkers, induced by temperature and silicate stress in diatom metabolism. Our results show that proteomic finger-printing of S. dohrnii with different environmental conditions adds biological information that strengthens marine phytoplankton proteome analysis.
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Affiliation(s)
| | - Satheesh Kumar Palanisamy
- Department of Zoology, School of Natural Science, Ryan Institute, National University of Ireland, Galway, Ireland
| | - Guicheng Zhang
- Research Center for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, China.,Tianjin Key Laboratory of Marine Resources and Chemistry, Tianjin University of Science and Technology, Tianjin, China
| | - Jun Sun
- College of Marine Science and Technology, China University of Geosciences, Wuhan, China
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6
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Zhao Y, Tang X, Lv M, Liu Q, Li J, Zhang B, Li L, Zhang X, Zhao Y. The molecular response mechanisms of a diatom Thalassiosira pseudonana to the toxicity of BDE-47 based on whole transcriptome analysis. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2020; 229:105669. [PMID: 33142158 DOI: 10.1016/j.aquatox.2020.105669] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 10/16/2020] [Accepted: 10/21/2020] [Indexed: 06/11/2023]
Abstract
Polybrominated diphenyl ethers (PBDEs) are ubiquitously distributed persistent organic pollutants (POPs) in marine environments. Phytoplankton are the entrance of PBDEs entering to biotic environments from abiotic environments, while the responding mechanisms of phytoplankton to PBDEs have not been full established. Therefore, we chose the model diatom Thalassiosira pseudonana in this study, by integrating whole transcriptome analysis with physiological-biochemical data, to reveal the molecular responding mechanisms of T. pseudonana to the toxicity of BDE-47. Our results indicated the changes of genes expressions correlated to the physiological-biochemical changes, and there were multiple molecular mechanisms of T. pseudonana responding to the toxicity of BDE-47: Gene expressions evidence explained the suppression of light reaction and proved the occurrence of cellular oxidative stress; In the meanwhile, up-regulations of genes in pathways involving carbon metabolisms happened, including the Calvin cycle, glycolysis, TCA cycle, fatty acid synthesis, and triacylglycerol synthesis; Lastly, DNA damage was found and three outcome including DNA repair, cell cycle arrest and programmed cell death (PCD) happened, which could finally inhibit the cell division and population growth of T. pseudonana. This study presented the most complete molecular responding mechanisms of phytoplankton cells to PBDEs, and provided valuable information of various PBDEs-sensitive genes with multiple functions for further research involving organic pollutants and phytoplankton.
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Affiliation(s)
- Yirong Zhao
- College of Marine Life Sciences, Department of Marine Ecology, Ocean University of China, Qingdao, 266003, China
| | - Xuexi Tang
- College of Marine Life Sciences, Department of Marine Ecology, Ocean University of China, Qingdao, 266003, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China.
| | - Mengchen Lv
- College of Marine Life Sciences, Department of Marine Ecology, Ocean University of China, Qingdao, 266003, China
| | - Qian Liu
- College of Marine Life Sciences, Department of Marine Ecology, Ocean University of China, Qingdao, 266003, China
| | - Jun Li
- College of Marine Life Sciences, Department of Marine Ecology, Ocean University of China, Qingdao, 266003, China
| | - Bihan Zhang
- College of Marine Life Sciences, Department of Marine Ecology, Ocean University of China, Qingdao, 266003, China
| | - Luying Li
- College of Marine Life Sciences, Department of Marine Ecology, Ocean University of China, Qingdao, 266003, China
| | - Xinxin Zhang
- College of Marine Life Sciences, Department of Marine Ecology, Ocean University of China, Qingdao, 266003, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China
| | - Yan Zhao
- College of Marine Life Sciences, Department of Marine Ecology, Ocean University of China, Qingdao, 266003, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China.
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7
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Launay H, Huang W, Maberly SC, Gontero B. Regulation of Carbon Metabolism by Environmental Conditions: A Perspective From Diatoms and Other Chromalveolates. FRONTIERS IN PLANT SCIENCE 2020; 11:1033. [PMID: 32765548 PMCID: PMC7378808 DOI: 10.3389/fpls.2020.01033] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 06/23/2020] [Indexed: 05/08/2023]
Abstract
Diatoms belong to a major, diverse and species-rich eukaryotic clade, the Heterokonta, within the polyphyletic chromalveolates. They evolved as a result of secondary endosymbiosis with one or more Plantae ancestors, but their precise evolutionary history is enigmatic. Nevertheless, this has conferred them with unique structural and biochemical properties that have allowed them to flourish in a wide range of different environments and cope with highly variable conditions. We review the effect of pH, light and dark, and CO2 concentration on the regulation of carbon uptake and assimilation. We discuss the regulation of the Calvin-Benson-Bassham cycle, glycolysis, lipid synthesis, and carbohydrate synthesis at the level of gene transcripts (transcriptomics), proteins (proteomics) and enzyme activity. In contrast to Viridiplantae where redox regulation of metabolic enzymes is important, it appears to be less common in diatoms, based on the current evidence, but regulation at the transcriptional level seems to be widespread. The role of post-translational modifications such as phosphorylation, glutathionylation, etc., and of protein-protein interactions, has been overlooked and should be investigated further. Diatoms and other chromalveolates are understudied compared to the Viridiplantae, especially given their ecological importance, but we believe that the ever-growing number of sequenced genomes combined with proteomics, metabolomics, enzyme measurements, and the application of novel techniques will provide a better understanding of how this important group of algae maintain their productivity under changing conditions.
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Affiliation(s)
- Hélène Launay
- BIP, Aix Marseille Univ CNRS, BIP UMR 7281, Marseille, France
| | - Wenmin Huang
- BIP, Aix Marseille Univ CNRS, BIP UMR 7281, Marseille, France
- Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan, China
| | - Stephen C. Maberly
- UK Centre for Ecology & Hydrology, Lake Ecosystems Group, Lancaster Environment Centre, Lancaster, United Kingdom
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Jiang B, Xing Y, Li G, Zhang N, Lian L, Sun G, Zhang D. iTRAQ-Based Comparative Proteomic Analysis of Acinetobacter baylyi ADP1 Under DNA Damage in Relation to Different Carbon Sources. Front Microbiol 2020; 10:2906. [PMID: 31993023 PMCID: PMC6971185 DOI: 10.3389/fmicb.2019.02906] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 12/02/2019] [Indexed: 12/27/2022] Open
Abstract
DNA damage response allows microorganisms to repair or bypass DNA damage and maintain the genome integrity. It has attracted increasing attention but the underlying influential factors affecting DNA damage response are still unclear. In this work, isobaric tags for relative and absolute quantification (iTRAQ)-based proteomic analysis was used to investigate the influence of carbon sources on the translational response of Acinetobacter baylyi ADP1 to DNA damage. After cultivating in a nutrient-rich medium (LB) and defined media supplemented with four different carbon sources (acetate, citrate, pyruvate, and succinate), a total of 2807 proteins were identified. Among them, 84 proteins involved in stress response were significantly altered, indicating the strong influence of carbon source on the response of A. baylyi ADP1 to DNA damage and other stresses. As the first study on the comparative global proteomic changes in A. baylyi ADP1 under DNA damage across nutritional environments, our findings revealed that DNA damage response in A. baylyi ADP1 at the translational level is significantly altered by carbon source, providing an insight into the complex protein interactions across carbon sources and offering theoretical clues for further study to elucidate their general regulatory mechanism to adapt to different nutrient environments.
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Affiliation(s)
- Bo Jiang
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, China.,Beijing Key Laboratory of Resource-Oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing, China
| | - Yi Xing
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, China.,Beijing Key Laboratory of Resource-Oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing, China
| | - Guanghe Li
- School of Environment, Tsinghua University, Beijing, China.,State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing, China
| | - Nana Zhang
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, China.,Beijing Key Laboratory of Resource-Oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing, China
| | - Luning Lian
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, China.,Beijing Key Laboratory of Resource-Oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing, China
| | - Guangdong Sun
- School of Environment, Tsinghua University, Beijing, China.,State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing, China
| | - Dayi Zhang
- School of Environment, Tsinghua University, Beijing, China.,State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing, China
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Wang H, Chen F, Mi T, Liu Q, Yu Z, Zhen Y. Responses of Marine Diatom Skeletonema marinoi to Nutrient Deficiency: Programmed Cell Death. Appl Environ Microbiol 2020; 86:e02460-19. [PMID: 31757826 PMCID: PMC6974647 DOI: 10.1128/aem.02460-19] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 11/15/2019] [Indexed: 11/20/2022] Open
Abstract
Diatoms are important phytoplankton and contribute greatly to the primary productivity of marine ecosystems. Despite the ecological significance of diatoms and the importance of programmed cell death (PCD) in the fluctuation of diatom populations, little is known about the molecular mechanisms of PCD triggered by different nutrient stresses. Here we describe the physiological, morphological, biochemical, and molecular changes in response to low levels of nutrients in the ubiquitous diatom Skeletonema marinoi The levels of gene expression involved in oxidation resistance and PCD strongly increased upon nitrogen (N) or phosphorus (P) starvation. The enzymatic activity of caspase 3-like protein also increased. Differences in mRNA levels and protein activities were observed between the low-N and low-P treatments, suggesting that PCD could have a differential response to different nutrient stresses. When cultures were replete with N or P, the growth inhibition stopped. Meanwhile, the enzymatic activity of caspase 3-like protein and the number of cells with damaged membranes decreased. These results suggest that PCD is an important cell fate decision mechanism in the marine diatom S. marinoi Our results provide important insight into how diatoms adjust phenotypic and genotypic features of their cell-regulated death programs when stressed by nutrient limitations. Overall, this study could allow us to better understand the molecular mechanism behind the formation and termination of diatom blooms in the marine environment.IMPORTANCE Our study showed how the ubiquitous diatom S. marinoi responded to different nutrient limitations with PCD in terms of physiological, morphological, biochemical, and molecular characteristics. Some PCD-related genes (PDCD4, GOX, and HSP90) induced by N deficiency were relatively upregulated compared to those induced by P deficiency. In contrast, the expression of the TSG101 gene in S. marinoi showed a clear and constant increase during P limitation compared to N limitation. These findings suggest that PCD is a complex mechanism involving several different proteins. The systematic mRNA level investigations provide new insight into understanding the oxidative stress- and cell death-related functional genes of diatoms involved in the response to nutrient fluctuations (N or P stress) in the marine environment.
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Affiliation(s)
- Hualong Wang
- College of Marine Life Science, Ocean University of China, Qingdao, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, Baltimore, Maryland, USA
| | - Feng Chen
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, Baltimore, Maryland, USA
| | - Tiezhu Mi
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
- Key Laboratory of Marine Environment and Ecology, Ministry of Education, Qingdao, China
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, China
| | - Qian Liu
- College of Marine Life Science, Ocean University of China, Qingdao, China
| | - Zhigang Yu
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
- Key Laboratory of Marine Chemical Theory and Technology, Ministry of Education, Qingdao, China
| | - Yu Zhen
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
- Key Laboratory of Marine Environment and Ecology, Ministry of Education, Qingdao, China
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, China
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10
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Thangaraj S, Giordano M, Sun J. Comparative Proteomic Analysis Reveals New Insights Into the Common and Specific Metabolic Regulation of the Diatom Skeletonema dohrnii to the Silicate and Temperature Availability. FRONTIERS IN PLANT SCIENCE 2020; 11:578915. [PMID: 33224167 PMCID: PMC7674209 DOI: 10.3389/fpls.2020.578915] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 09/28/2020] [Indexed: 05/12/2023]
Abstract
Silicate (Si) and temperature are essential drivers for diatom growth and development in the ocean. Response of diatoms to these particular stress has been investigated; however, their common and specific responses to regulate intracellular development and growth are not known. Here, we investigated the combination of physiological characteristics and comparative proteomics of the diatom Skeletonema dohrnii grown in silicate- and temperature-limited conditions. Results show that cell carbon and lipid quotas were higher at lower-temperature cells, whereas cellular phosphate was higher in cells grown with lower Si. In silicate-limited cells, nitrate transporters were downregulated and resulted in lower nitrate assimilation, whereas the phosphate transporters and its assimilation were reduced in lower-temperature conditions. In photosynthesis, lower silicate caused impact in the linear electron flow and NADPH production, whereas cycling electron transport and ATP production were affected by the lower temperature. Concerning cell cycle, imbalances in the translation process were observed in lower-silicate cells, whereas impact in the transcription mechanism was observed in lower-temperature cells. However, proteins associated with carbon fixation and photorespiration were downregulated in both stress conditions, while the carbohydrate and lipid synthesis proteins were upregulated. Our results showed new insights into the common and specific responses on the proteome and physiology of S. dohrnii to silicate and temperature limitation, providing particular nutrient (Si)- and temperature-dependent mechanisms in diatoms.
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Affiliation(s)
- Satheeswaran Thangaraj
- College of Marine Science and Technology, China University of Geosciences (Wuhan), Wuhan, China
| | - Mario Giordano
- Dipartimento di Scienze della Vita e dell’Ambiente, Università Politecnica delle Marche, Ancona, Italy
| | - Jun Sun
- College of Marine Science and Technology, China University of Geosciences (Wuhan), Wuhan, China
- *Correspondence: Jun Sun,
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Thangaraj S, Shang X, Sun J, Liu H. Quantitative Proteomic Analysis Reveals Novel Insights into Intracellular Silicate Stress-Responsive Mechanisms in the Diatom Skeletonema dohrnii. Int J Mol Sci 2019; 20:E2540. [PMID: 31126124 PMCID: PMC6566588 DOI: 10.3390/ijms20102540] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 05/19/2019] [Accepted: 05/20/2019] [Indexed: 01/04/2023] Open
Abstract
Diatoms are a successful group of marine phytoplankton that often thrives under adverse environmental stress conditions. Members of the Skeletonema genus are ecologically important which may subsist during silicate stress and form a dense bloom following higher silicate concentration. However, our understanding of diatoms' underlying molecular mechanism involved in these intracellular silicate stress-responses are limited. Here an iTRAQ-based proteomic method was coupled with multiple physiological techniques to explore distinct cellular responses associated with oxidative stress in the diatom Skeletonema dohrnii to the silicate limitation. In total, 1768 proteins were detected; 594 proteins were identified as differentially expressed (greater than a two-fold change; p < 0.05). In Si-limited cells, downregulated proteins were mainly related to photosynthesis metabolism, light-harvesting complex, and oxidative phosphorylation, corresponding to inducing oxidative stress, and ROS accumulation. None of these responses were identified in Si-limited cells; in comparing with other literature, Si-stress cells showed that ATP-limited diatoms are unable to rely on photosynthesis, which will break down and reshuffle carbon metabolism to compensate for photosynthetic carbon fixation losses. Our findings have a good correlation with earlier reports and provides a new molecular level insight into the systematic intracellular responses employed by diatoms in response to silicate stress in the marine environment.
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Affiliation(s)
- Satheeswaran Thangaraj
- Tianjin Key Laboratory of Marine Resources and Chemistry, Tianjin University of Science and Technology, No 29, 13th Avenue, TEDA, Tianjin 300457, China.
- Research Center for Indian Ocean Ecosystem, Tianjin University of Science and Technology, No 29, 13th Avenue, TEDA, Tianjin 300457, China.
- Faculty of Food Engineering and Biotechnology, Tianjin University of Science and Technology, No 29, 13th Avenue, TEDA, Tianjin 300457, China.
| | - Xiaomei Shang
- Tianjin Key Laboratory of Marine Resources and Chemistry, Tianjin University of Science and Technology, No 29, 13th Avenue, TEDA, Tianjin 300457, China.
- Research Center for Indian Ocean Ecosystem, Tianjin University of Science and Technology, No 29, 13th Avenue, TEDA, Tianjin 300457, China.
| | - Jun Sun
- Tianjin Key Laboratory of Marine Resources and Chemistry, Tianjin University of Science and Technology, No 29, 13th Avenue, TEDA, Tianjin 300457, China.
- Research Center for Indian Ocean Ecosystem, Tianjin University of Science and Technology, No 29, 13th Avenue, TEDA, Tianjin 300457, China.
| | - Haijiao Liu
- Tianjin Key Laboratory of Marine Resources and Chemistry, Tianjin University of Science and Technology, No 29, 13th Avenue, TEDA, Tianjin 300457, China.
- Research Center for Indian Ocean Ecosystem, Tianjin University of Science and Technology, No 29, 13th Avenue, TEDA, Tianjin 300457, China.
- Institute of Marine Science and Technology, Shandong University, No 27, Shanda Nan Road, Jinan 250110, China.
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