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Diesel J, Molano G, Montecinos GJ, DeWeese K, Calhoun S, Kuo A, Lipzen A, Salamov A, Grigoriev IV, Reed DC, Miller RJ, Nuzhdin SV, Alberto F. A scaffolded and annotated reference genome of giant kelp (Macrocystis pyrifera). BMC Genomics 2023; 24:543. [PMID: 37704968 PMCID: PMC10498591 DOI: 10.1186/s12864-023-09658-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 09/07/2023] [Indexed: 09/15/2023] Open
Abstract
Macrocystis pyrifera (giant kelp), is a brown macroalga of great ecological importance as a primary producer and structure-forming foundational species that provides habitat for hundreds of species. It has many commercial uses (e.g. source of alginate, fertilizer, cosmetics, feedstock). One of the limitations to exploiting giant kelp's economic potential and assisting in giant kelp conservation efforts is a lack of genomic tools like a high quality, contiguous reference genome with accurate gene annotations. Reference genomes attempt to capture the complete genomic sequence of an individual or species, and importantly provide a universal structure for comparison across a multitude of genetic experiments, both within and between species. We assembled the giant kelp genome of a haploid female gametophyte de novo using PacBio reads, then ordered contigs into chromosome level scaffolds using Hi-C. We found the giant kelp genome to be 537 MB, with a total of 35 scaffolds and 188 contigs. The assembly N50 is 13,669,674 with GC content of 50.37%. We assessed the genome completeness using BUSCO, and found giant kelp contained 94% of the BUSCO genes from the stramenopile clade. Annotation of the giant kelp genome revealed 25,919 genes. Additionally, we present genetic variation data based on 48 diploid giant kelp sporophytes from three different Southern California populations that confirms the population structure found in other studies of these populations. This work resulted in a high-quality giant kelp genome that greatly increases the genetic knowledge of this ecologically and economically vital species.
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Affiliation(s)
- Jose Diesel
- Department of Molecular and Computational Biology, University of Southern California, Los Angeles, CA, USA
| | - Gary Molano
- Department of Molecular and Computational Biology, University of Southern California, Los Angeles, CA, USA
| | - Gabriel J Montecinos
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - Kelly DeWeese
- Department of Molecular and Computational Biology, University of Southern California, Los Angeles, CA, USA
| | - Sara Calhoun
- U.S. Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Alan Kuo
- U.S. Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Anna Lipzen
- U.S. Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Asaf Salamov
- U.S. Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Igor V Grigoriev
- U.S. Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA, USA
| | - Daniel C Reed
- Marine Science Institute, University of California at Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Robert J Miller
- Marine Science Institute, University of California at Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Sergey V Nuzhdin
- Department of Molecular and Computational Biology, University of Southern California, Los Angeles, CA, USA
| | - Filipe Alberto
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI, USA.
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Insight into the genome data of commercially important giant kelp Macrocystis pyrifera. Data Brief 2022; 42:108068. [PMID: 35356318 PMCID: PMC8958530 DOI: 10.1016/j.dib.2022.108068] [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: 02/08/2022] [Revised: 03/01/2022] [Accepted: 03/14/2022] [Indexed: 11/23/2022] Open
Abstract
Kelps or brown algae are a wide group of marine macroalgae that play an important role in aquatic ecosystems and generally have high commercial value. To facilitate brown algal studies, we report the complete genome sequence of the largest kelp Macrocystis pyrifera. The whole genome is ∼428 Mb in size, comprises 44,307 scaffolds with an average GC content of 47%, and is predicted to contain a total of 24,778 genes. 18S sequence-based phylogenetic analysis revealed that littoral brown seaweed Scytosiphon lomentaria is the closest species of M. pyrifera. Numerous genes identified in this dataset are involved in genetic information processing, signaling, and cellular processes, carbohydrate metabolism, and terpenoids biosynthesis.
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Florez JZ, Camus C, Hengst MB, Buschmann AH. A mesocosm study on bacteria-kelp interactions: Importance of nitrogen availability and kelp genetics. JOURNAL OF PHYCOLOGY 2021; 57:1777-1791. [PMID: 34570392 DOI: 10.1111/jpy.13213] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 06/12/2021] [Accepted: 08/15/2021] [Indexed: 06/13/2023]
Abstract
Macroalgal holobiont studies involve understanding interactions between the host, its microbiota, and the environment. We analyzed the effect of bacteria-kelp interactions on phenotypic responses of two genetically distinct populations of giant kelp, Macrocystis pyrifera (north and south), exposed to different nitrogen (N) concentrations. In co-culture experiments with different N concentration treatments, we evaluated kelp growth responses and changes in three specific molecular markers associated with the N cycle, both in epiphytic bacteria (relative abundance of nrfA-gene: cytochrome c nitrite reductase) and macroalgae (expression of NR-gene: nitrate reductase; GluSyn-gene: glutamate synthase). Both kelp populations responded differently to N limitation, with M. pyrifera-south sporophytes having a lower specific growth rate (SGR) under N-limiting conditions than the northern population; M. pyrifera-north sporophytes showed no significant differences in SGR when exposed to low-N and high-N concentrations. This corresponded to a higher GluSyn-gene expression in the M. pyrifera-north sporophytes and the co-occurrence of specific nrfA bacterial taxa. These bacteria may increase ammonium availability under low-N concentrations, allowing M. pyrifera-north to optimize nutrient assimilation by increasing the expression of GluSyn. We conclude that bacteria-kelp interactions are important in enhancing kelp growth rates under low N availability, although this effect may be regulated by the genetic background of kelp populations.
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Affiliation(s)
- July Z Florez
- Programa de Doctorado en Ciencias mención Conservación y Manejo de Recursos Naturales, Universidad de Los Lagos, Puerto Montt, Chile
- Centro i˜mar and CeBiB, Universidad de Los Lagos, Puerto Montt, Chile
- Departamento de Ciencias Farmacéuticas, Universidad Católica del Norte, Antofagasta, Chile
| | - Carolina Camus
- Centro i˜mar and CeBiB, Universidad de Los Lagos, Puerto Montt, Chile
| | - Martha B Hengst
- Departamento de Ciencias Farmacéuticas, Universidad Católica del Norte, Antofagasta, Chile
- Centro de Biotecnología y Bioingeniería (CeBiB), Santiago, Chile
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Zhang X, Fan X, Wang Y, Xu D, Zhang J, Ye N. Exploring Core Response Mechanisms to Multiple Environmental Stressors Via A Genome-Wide Study in the Brown Alga Saccharina japonica (Laminariales, Phaeophyceae). JOURNAL OF PHYCOLOGY 2021; 57:345-354. [PMID: 33211355 DOI: 10.1111/jpy.13108] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 09/22/2020] [Accepted: 10/23/2020] [Indexed: 06/11/2023]
Abstract
Saccharina japonica is an important large brown alga and a major component of productive beds on the northwest coast of the Pacific Ocean. Abiotic stress response mechanisms are receiving considerable attention because global climate change is increasing their abiotic stress levels. However, our knowledge of how S. japonica broadly responds to stress is limited. In this study, we investigated the S. japonica responsive genes underlying acclimation to diverse stressors of acidification, high light, high temperature, hypersalinity, and hyposalinity and identified 408 core genes constantly and differentially expressed in response to all stressors. Our results confirm that stressors had strong effects on genes participating in photosynthesis, amino acid metabolism, carbohydrate metabolism, halogen metabolism, and reactive oxygen species defense. These findings will improve our understanding of brown algal response mechanisms linked to environmental stress and provide a list of candidate genes for improving algal stress tolerance in light of environmental stress in future studies.
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Affiliation(s)
- Xiaowen Zhang
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, 266071, China
- Laboratory for Marine Fisheries and Aquaculture, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266200, China
| | - Xiao Fan
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, 266071, China
- Laboratory for Marine Fisheries and Aquaculture, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266200, China
| | - Yitao Wang
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, 266071, China
- Laboratory for Marine Fisheries and Aquaculture, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266200, China
| | - Dong Xu
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, 266071, China
- Laboratory for Marine Fisheries and Aquaculture, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266200, China
| | - Jian Zhang
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, 266071, China
- Laboratory for Marine Fisheries and Aquaculture, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266200, China
| | - Naihao Ye
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, 266071, China
- Laboratory for Marine Fisheries and Aquaculture, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266200, China
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Effect of environmental history on the habitat-forming kelp Macrocystis pyrifera responses to ocean acidification and warming: a physiological and molecular approach. Sci Rep 2021; 11:2510. [PMID: 33510300 PMCID: PMC7843619 DOI: 10.1038/s41598-021-82094-7] [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: 08/23/2020] [Accepted: 01/15/2021] [Indexed: 01/30/2023] Open
Abstract
The capacity of marine organisms to adapt and/or acclimate to climate change might differ among distinct populations, depending on their local environmental history and phenotypic plasticity. Kelp forests create some of the most productive habitats in the world, but globally, many populations have been negatively impacted by multiple anthropogenic stressors. Here, we compare the physiological and molecular responses to ocean acidification (OA) and warming (OW) of two populations of the giant kelp Macrocystis pyrifera from distinct upwelling conditions (weak vs strong). Using laboratory mesocosm experiments, we found that juvenile Macrocystis sporophyte responses to OW and OA did not differ among populations: elevated temperature reduced growth while OA had no effect on growth and photosynthesis. However, we observed higher growth rates and NO3- assimilation, and enhanced expression of metabolic-genes involved in the NO3- and CO2 assimilation in individuals from the strong upwelling site. Our results suggest that despite no inter-population differences in response to OA and OW, intrinsic differences among populations might be related to their natural variability in CO2, NO3- and seawater temperatures driven by coastal upwelling. Further work including additional populations and fluctuating climate change conditions rather than static values are needed to precisely determine how natural variability in environmental conditions might influence a species' response to climate change.
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Wang S, Lin L, Shi Y, Qian W, Li N, Yan X, Zou H, Wu M. First Draft Genome Assembly of the Seaweed Sargassum fusiforme. Front Genet 2020; 11:590065. [PMID: 33193728 PMCID: PMC7644962 DOI: 10.3389/fgene.2020.590065] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 09/17/2020] [Indexed: 11/13/2022] Open
Affiliation(s)
- Shengqin Wang
- National and Local Joint Engineering Research Center of Ecological Treatment Technology for Urban Water Pollution, Wenzhou University, Wenzhou, China
- College of Life and Environmental Science, Wenzhou University, Wenzhou, China
| | - Lidong Lin
- College of Life and Environmental Science, Wenzhou University, Wenzhou, China
- Dongtou Fisheries Science and Technology Research Institute, Wenzhou, China
| | - Yijian Shi
- College of Electrical and Electronic Engineering, Wenzhou University, Wenzhou, China
| | - Weiguo Qian
- College of Life and Environmental Science, Wenzhou University, Wenzhou, China
| | - Nan Li
- National and Local Joint Engineering Research Center of Ecological Treatment Technology for Urban Water Pollution, Wenzhou University, Wenzhou, China
- College of Life and Environmental Science, Wenzhou University, Wenzhou, China
| | - Xiufeng Yan
- National and Local Joint Engineering Research Center of Ecological Treatment Technology for Urban Water Pollution, Wenzhou University, Wenzhou, China
- College of Life and Environmental Science, Wenzhou University, Wenzhou, China
| | - Huixi Zou
- National and Local Joint Engineering Research Center of Ecological Treatment Technology for Urban Water Pollution, Wenzhou University, Wenzhou, China
- College of Life and Environmental Science, Wenzhou University, Wenzhou, China
| | - Mingjiang Wu
- National and Local Joint Engineering Research Center of Ecological Treatment Technology for Urban Water Pollution, Wenzhou University, Wenzhou, China
- College of Life and Environmental Science, Wenzhou University, Wenzhou, China
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Machado Monteiro CM, Li H, Bischof K, Bartsch I, Valentin KU, Corre E, Collén J, Harms L, Glöckner G, Heinrich S. Is geographical variation driving the transcriptomic responses to multiple stressors in the kelp Saccharina latissima? BMC PLANT BIOLOGY 2019; 19:513. [PMID: 31775614 PMCID: PMC6881991 DOI: 10.1186/s12870-019-2124-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 11/07/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND Kelps (Laminariales, Phaeophyceae) are brown macroalgae of utmost ecological, and increasingly economic, importance on temperate to polar rocky shores. Omics approaches in brown algae are still scarce and knowledge of their acclimation mechanisms to the changing conditions experienced in coastal environments can benefit from the application of RNA-sequencing. Despite evidence of ecotypic differentiation, transcriptomic responses from distinct geographical locations have, to our knowledge, never been studied in the sugar kelp Saccharina latissima so far. RESULTS In this study we investigated gene expression responses using RNA-sequencing of S. latissima from environments with contrasting temperature and salinity conditions - Roscoff, in temperate eastern Atlantic, and Spitsbergen in the Arctic. Juvenile sporophytes derived from uniparental stock cultures from both locations were pre-cultivated at 8 °C and SA 30. Sporophytes acclimated to 0 °C, 8 °C and 15 °C were exposed to a low salinity treatment (SA 20) for 24 h. Hyposalinity had a greater impact at the transcriptomic level than the temperature alone, and its effects were modulated by temperature. Namely, photosynthesis and pigment synthesis were extensively repressed by low salinity at low temperatures. Although some responses were shared among sporophytes from the different sites, marked differences were revealed by principal component analysis, differential expression and GO enrichment. The interaction between low temperature and low salinity drove the largest changes in gene expression in sporophytes from Roscoff while specimens from Spitsbergen required more metabolic adjustment at higher temperatures. Moreover, genes related to cell wall adjustment were differentially expressed between Spitsbergen and Roscoff control samples. CONCLUSIONS Our study reveals interactive effects of temperature and salinity on transcriptomic profiles in S. latissima. Moreover, our data suggest that under identical culture conditions sporophytes from different locations diverge in their transcriptomic responses. This is probably connected to variations in temperature and salinity in their respective environment of origin. The current transcriptomic results support the plastic response pattern in sugar kelp which is a species with several reported ecotypes. Our data provide the baseline for a better understanding of the underlying processes of physiological plasticity and may help in the future to identify strains adapted to specific environments and its genetic control.
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Affiliation(s)
- Cátia Marina Machado Monteiro
- Marine Botany, Faculty Biology/Chemistry, University of Bremen, Bremen, Germany
- Station Biologique de Roscoff, plateforme ABiMS, CNRS: FR2424, Sorbonne Université (UPMC), 29680 Roscoff, France
- Sorbonne Université, CNRS, Integrative Biology of Marine Models (LBI2M), Station Biologique de Roscoff, 29680 Roscoff, France
| | - Huiru Li
- Marine Botany, Faculty Biology/Chemistry, University of Bremen, Bremen, Germany
- Fisheries College, Ocean University of China, Qingdao, China
| | - Kai Bischof
- Marine Botany, Faculty Biology/Chemistry, University of Bremen, Bremen, Germany
| | - Inka Bartsch
- Alfred-Wegener-Institute, Helmholtz Centre for Marine and Polar Research, Bremerhaven, Germany
| | - Klaus Ulrich Valentin
- Alfred-Wegener-Institute, Helmholtz Centre for Marine and Polar Research, Bremerhaven, Germany
| | - Erwan Corre
- Station Biologique de Roscoff, plateforme ABiMS, CNRS: FR2424, Sorbonne Université (UPMC), 29680 Roscoff, France
| | - Jonas Collén
- Sorbonne Université, CNRS, Integrative Biology of Marine Models (LBI2M), Station Biologique de Roscoff, 29680 Roscoff, France
| | - Lars Harms
- Alfred-Wegener-Institute, Helmholtz Centre for Marine and Polar Research, Bremerhaven, Germany
| | - Gernot Glöckner
- Institute for Biochemistry I, Medical Faculty, University of Cologne, Cologne, Germany
| | - Sandra Heinrich
- Institute for Plant Science and Microbiology, University of Hamburg, Hamburg, Germany
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Gaubert J, Greff S, Thomas OP, Payri CE. Metabolomic variability of four macroalgal species of the genus Lobophora using diverse approaches. PHYTOCHEMISTRY 2019; 162:165-172. [PMID: 30925377 DOI: 10.1016/j.phytochem.2019.03.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2018] [Revised: 02/27/2019] [Accepted: 03/02/2019] [Indexed: 05/26/2023]
Abstract
Among comparative metabolomic studies used in marine sciences, only few of them are dedicated to macroalgae despite their ecological importance in marine ecosystems. Therefore, experimental data are needed to assess the scopes and limitations of different metabolomic techniques applied to macroalgal models. Species of the genus Lobophora belong to marine brown algae (Family: Dictyotaceae) and are widely distributed, especially in tropical coral reefs. The species richness of this genus has only been unveiled recently and it includes species of diverse morphologies and habitats, with some species interacting with corals. This study aims to assess the potential of different metabolomic fingerprinting approaches in the discrimination of four well known Lobophora species (L. rosacea, L. sonderii, L. obscura and L. monticola). These species present distinct morphologies and are found in various habitats in the New Caledonian lagoon (South-Western Pacific). We compared and combined different untargeted metabolomic techniques: liquid chromatography-mass spectrometry (LC-MS), nuclear magnetic resonance (1H-NMR) and gas chromatography (GC-MS). Metabolomic separations were observed between each Lobophora species, with significant differences according to the techniques used. LC-MS was the best approach for metabotype distinction but a combination of approaches was also useful and allowed identification of chemomarkers for some species. These comparisons provide important data on the use of metabolomic approaches in the Lobophora genus and will pave the way for further studies on the sources of metabolomic variations for this ecologically important macroalgae.
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Affiliation(s)
- Julie Gaubert
- Sorbonne Universités, Collège Doctoral, F-75005 Paris, France; UMR ENTROPIE (IRD, UR, CNRS), Institut de Recherche pour le Développement, B.P. A5, 98848 Nouméa Cedex, Nouvelle-Calédonie, France
| | - Stéphane Greff
- Institut Méditerranéen de Biodiversité et d'Ecologie Marine et Continentale (IMBE), UMR 7263 CNRS, IRD, Aix Marseille Université, Avignon Université, Station Marine d'Endoume, rue de la Batterie des Lions, 13007 Marseille, France
| | - Olivier P Thomas
- Marine Biodiscovery, School of Chemistry and Ryan Institute, National University of Ireland Galway (NUI Galway), University Road, H91 TK33 Galway, Ireland.
| | - Claude E Payri
- UMR ENTROPIE (IRD, UR, CNRS), Institut de Recherche pour le Développement, B.P. A5, 98848 Nouméa Cedex, Nouvelle-Calédonie, France.
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Küpper FC, Carrano CJ. Key aspects of the iodine metabolism in brown algae: a brief critical review. Metallomics 2019; 11:756-764. [PMID: 30834917 DOI: 10.1039/c8mt00327k] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Brown algae include the strongest accumulators of iodine known among living systems. This paper reviews the current state of bioinorganic research in the field, focusing on the models Laminaria digitata, Macrocystis pyrifera and Ectocarpus siliculosus, and covering uptake and efflux, localization and biological significance of storage, as well as marine and atmospheric chemistry of iodine.
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Affiliation(s)
- Frithjof C Küpper
- School of Biological Sciences, University of Aberdeen, Cruickshank Building, St. Machar Drive, Aberdeen AB24 3UU, Scotland, UK
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Wurch LL, Alexander H, Frischkorn KR, Haley ST, Gobler CJ, Dyhrman ST. Transcriptional Shifts Highlight the Role of Nutrients in Harmful Brown Tide Dynamics. Front Microbiol 2019; 10:136. [PMID: 30809203 PMCID: PMC6379262 DOI: 10.3389/fmicb.2019.00136] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 01/21/2019] [Indexed: 11/13/2022] Open
Abstract
Harmful algal blooms (HABs) threaten ecosystems and human health worldwide. Controlling nitrogen inputs to coastal waters is a common HAB management strategy, as nutrient concentrations often suggest coastal blooms are nitrogen-limited. However, defining best nutrient management practices is a long-standing challenge: in part, because of difficulties in directly tracking the nutritional physiology of harmful species in mixed communities. Using metatranscriptome sequencing and incubation experiments, we addressed this challenge by assaying the in situ physiological ecology of the ecosystem destructive alga, Aureococcus anophagefferens. Here we show that gene markers of phosphorus deficiency were expressed in situ, and modulated by the enrichment of phosphorus, which was consistent with the observed growth rate responses. These data demonstrate the importance of phosphorus in controlling brown-tide dynamics, suggesting that phosphorus, in addition to nitrogen, should be evaluated in the management and mitigation of these blooms. Given that nutrient concentrations alone were suggestive of a nitrogen-limited ecosystem, this study underscores the value of directly assaying harmful algae in situ for the development of management strategies.
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Affiliation(s)
- Louie L Wurch
- Department of Biology, James Madison University, Harrisonburg, VA, United States
| | - Harriet Alexander
- Department of Biology, Woods Hole Oceanographic Institution, Woods Hole, MA, United States
| | - Kyle R Frischkorn
- Department of Earth and Environmental Sciences, Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, United States
| | - Sheean T Haley
- Department of Earth and Environmental Sciences, Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, United States
| | - Christopher J Gobler
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY, United States
| | - Sonya T Dyhrman
- Department of Earth and Environmental Sciences, Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, United States
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The evolution of the photoprotective antenna proteins in oxygenic photosynthetic eukaryotes. Biochem Soc Trans 2018; 46:1263-1277. [DOI: 10.1042/bst20170304] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 07/02/2018] [Accepted: 07/04/2018] [Indexed: 12/24/2022]
Abstract
Photosynthetic organisms require rapid and reversible down-regulation of light harvesting to avoid photodamage. Response to unpredictable light fluctuations is achieved by inducing energy-dependent quenching, qE, which is the major component of the process known as non-photochemical quenching (NPQ) of chlorophyll fluorescence. qE is controlled by the operation of the xanthophyll cycle and accumulation of specific types of proteins, upon thylakoid lumen acidification. The protein cofactors so far identified to modulate qE in photosynthetic eukaryotes are the photosystem II subunit S (PsbS) and light-harvesting complex stress-related (LHCSR/LHCX) proteins. A transition from LHCSR- to PsbS-dependent qE took place during the evolution of the Viridiplantae (also known as ‘green lineage’ organisms), such as green algae, mosses and vascular plants. Multiple studies showed that LHCSR and PsbS proteins have distinct functions in the mechanism of qE. LHCX(-like) proteins are closely related to LHCSR proteins and found in ‘red lineage’ organisms that contain secondary red plastids, such as diatoms. Although LHCX proteins appear to control qE in diatoms, their role in the mechanism remains poorly understood. Here, we present the current knowledge on the functions and evolution of these crucial proteins, which evolved in photosynthetic eukaryotes to optimise light harvesting.
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Lin JD, Lemay MA, Parfrey LW. Diverse Bacteria Utilize Alginate Within the Microbiome of the Giant Kelp Macrocystis pyrifera. Front Microbiol 2018; 9:1914. [PMID: 30177919 PMCID: PMC6110156 DOI: 10.3389/fmicb.2018.01914] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2018] [Accepted: 07/30/2018] [Indexed: 11/13/2022] Open
Abstract
Bacteria are integral to marine carbon cycling. They transfer organic carbon to higher trophic levels and remineralise it into inorganic forms. Kelp forests are among the most productive ecosystems within the global oceans, yet the diversity and metabolic capacity of bacteria that transform kelp carbon is poorly understood. Here, we use 16S amplicon and metagenomic shotgun sequencing to survey bacterial communities associated with the surfaces of the giant kelp Macrocystis pyrifera and assess the capacity of these bacteria for carbohydrate metabolism. We find that Macrocystis-associated communities are distinct from the water column, and that they become more diverse and shift in composition with blade depth, which is a proxy for tissue age. These patterns are also observed in metagenomic functional profiles, though the broader functional groups—carbohydrate active enzyme families—are largely consistent across samples and depths. Additionally, we assayed more than 250 isolates cultured from Macrocystis blades and the surrounding water column for the ability to utilize alginate, the primary polysaccharide in Macrocystis tissue. The majority of cultured bacteria (66%) demonstrated this capacity; we find that alginate utilization is patchily distributed across diverse genera in the Bacteroidetes and Proteobacteria, yet can also vary between isolates with identical 16S rRNA sequences. The genes encoding enzymes involved in alginate metabolism were detected in metagenomic data across taxonomically diverse bacterial communities, further indicating this capacity is likely widespread amongst bacteria in kelp forests. Overall, the M. pyrifera epibiota shifts across a depth gradient, demonstrating a connection between bacterial assemblage and host tissue state.
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Affiliation(s)
- Jordan D Lin
- Department of Botany, Biodiversity Research Centre, The University of British Columbia, Vancouver, BC, Canada
| | - Matthew A Lemay
- Department of Botany, Biodiversity Research Centre, The University of British Columbia, Vancouver, BC, Canada.,Hakai Institute, Heriot Bay, BC, Canada
| | - Laura W Parfrey
- Department of Botany, Biodiversity Research Centre, The University of British Columbia, Vancouver, BC, Canada.,Hakai Institute, Heriot Bay, BC, Canada.,Department of Zoology, University of British Columbia, Vancouver, BC, Canada
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Tymon TM, Miller EP, Gonzales JL, Raab A, Küpper FC, Carrano CJ. Some aspects of the iodine metabolism of the giant kelp Macrocystis pyrifera (phaeophyceae). J Inorg Biochem 2017; 177:82-88. [PMID: 28926758 DOI: 10.1016/j.jinorgbio.2017.09.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 09/04/2017] [Accepted: 09/06/2017] [Indexed: 11/16/2022]
Abstract
Despite its paramount role in the functioning of coastal ecosystems, relatively little is known about halogen metabolism in giant kelp (Macrocystis pyrifera). This is an important shortcoming given the potential implications for marine and atmospheric chemical processes in the wide distribution range of Macrocystis. The work presented here constitutes the first in depth investigation of the uptake, efflux, and of the physiological function of iodide in this important kelp species. Iodide uptake and efflux rates were measured in adult sporophytes of Macrocystis under normal and stressed (exogenous hydrogen peroxide and an elicitor-triggered oxidative burst) conditions. Kelp tissue took up iodide according to Michaelis-Menten type kinetics when incubated in seawater enriched with various concentrations of iodide. Upon the addition of exogenous hydrogen peroxide, simulating oxidative stress, a marked efflux of iodide occurred. In situ generation of hydrogen peroxide was elicited in Macrocystis upon the addition of oligomeric degradation products of alginate as well as arachidonic acid and methyl jasmonate constituting a defensive oxidative burst that could be linked to iodine accumulation. H2O2 was detected at the single cell level using dichlorohydrofluorescein diacetate, a fluorogenic probe capable of detecting intracellular H2O2. When assayed for vanadium haloperoxidase activity, several bromoperoxidase isoforms were detected as well as a single iodoperoxidase. Altogether, the results of this study show that Macrocystis has an elaborate iodine metabolism, which is likely significant for impacting iodine speciation in seawater around kelp beds and for volatile halogen emissions into the coastal atmosphere.
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Affiliation(s)
- Teresa M Tymon
- Department of Chemistry and Biochemistry, San Diego State University, San Diego, CA 92182-1030, USA
| | - Eric P Miller
- Department of Chemistry and Biochemistry, San Diego State University, San Diego, CA 92182-1030, USA
| | - Jennifer L Gonzales
- Department of Chemistry and Biochemistry, San Diego State University, San Diego, CA 92182-1030, USA
| | - Andrea Raab
- Department of Chemistry, University of Aberdeen, Aberdeen AB24 3FX, UK
| | | | - Carl J Carrano
- Department of Chemistry and Biochemistry, San Diego State University, San Diego, CA 92182-1030, USA.
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14
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Haley ST, Alexander H, Juhl AR, Dyhrman ST. Transcriptional response of the harmful raphidophyte Heterosigma akashiwo to nitrate and phosphate stress. HARMFUL ALGAE 2017; 68:258-270. [PMID: 28962986 DOI: 10.1016/j.hal.2017.07.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Revised: 06/30/2017] [Accepted: 07/01/2017] [Indexed: 06/07/2023]
Abstract
The marine eukaryotic alga Heterosigma akashiwo (Raphidophyceae) is known for forming ichthyotoxic harmful algal blooms (HABs). In the past 50 years, H. akashiwo blooms have increased, occurring globally in highly eutrophic coastal and estuarine systems. These systems often incur dramatic physicochemical changes, including macronutrient (nitrogen and phosphorus) enrichment and depletion, on short timescales. Here, H. akashiwo cultures grown under nutrient replete, low N and low P growth conditions were examined for changes in biochemical and physiological characteristics in concert with transcriptome sequencing to provide a mechanistic perspective on the metabolic processes involved in responding to N and P stress. There was a marked difference in the overall transcriptional pattern between low N and low P transcriptomes. Both nutrient stresses led to significant changes in the abundance of thousands of contigs related to a wide diversity of metabolic pathways, with limited overlap between the transcriptomic responses to low N and low P. Enriched contigs under low N included many related to nitrogen metabolism, acquisition, and transport. In addition, metabolic modules like photosynthesis and carbohydrate metabolism changed significantly under low N, coincident with treatment-specific changes in photosynthetic efficiency and particulate carbohydrate content. P-specific contigs responsible for P transport and organic P use were more enriched in the low P treatment than in the replete control and low N treatment. These results provide new insight into the genetic mechanisms that distinguish how this HAB species responds to these two common nutrient stresses, and the results can inform future field studies, linking transcriptional patterns to the physiological ecology of H. akashiwo in situ.
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Affiliation(s)
- Sheean T Haley
- Columbia University, Lamont-Doherty Earth Observatory, Palisades, NY, USA
| | - Harriet Alexander
- Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, CA, USA
| | - Andrew R Juhl
- Columbia University, Lamont-Doherty Earth Observatory, Palisades, NY, USA; Columbia University, Department of Earth and Environmental Sciences, Palisades, NY, USA
| | - Sonya T Dyhrman
- Columbia University, Lamont-Doherty Earth Observatory, Palisades, NY, USA; Columbia University, Department of Earth and Environmental Sciences, Palisades, NY, USA.
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15
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Harke MJ, Juhl AR, Haley ST, Alexander H, Dyhrman ST. Conserved Transcriptional Responses to Nutrient Stress in Bloom-Forming Algae. Front Microbiol 2017; 8:1279. [PMID: 28769884 PMCID: PMC5513979 DOI: 10.3389/fmicb.2017.01279] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 06/26/2017] [Indexed: 11/13/2022] Open
Abstract
The concentration and composition of bioavailable nitrogen (N) and phosphorus (P) in the upper ocean shape eukaryotic phytoplankton communities and influence their physiological responses. Phytoplankton are known to exhibit similar physiological responses to limiting N and P conditions such as decreased growth rates, chlorosis, and increased assimilation of N and P. Are these responses similar at the molecular level across multiple species? To interrogate this question, five species from biogeochemically important, bloom-forming taxa (Bacillariophyta, Dinophyta, and Haptophyta) were grown under similar low N, low P, and replete nutrient conditions to identify transcriptional patterns and associated changes in biochemical pools related to N and P stress. Metabolic profiles, revealed through the transcriptomes of these taxa, clustered together based on species rather than nutrient stressor, suggesting that the global metabolic response to nutrient stresses was largely, but not exclusively, species-specific. Nutrient stress led to few transcriptional changes in the two dinoflagellates, consistent with other research. An orthologous group analysis examined functionally conserved (i.e., similarly changed) responses to nutrient stress and therefore focused on the diatom and haptophytes. Most conserved ortholog changes were specific to a single nutrient treatment, but a small number of orthologs were similarly changed under both N and P stress in 2 or more species. Many of these orthologs were related to photosynthesis and may represent generalized stress responses. A greater number of orthologs were conserved across more than one species under low P compared to low N. Screening the conserved orthologs for functions related to N and P metabolism revealed increased relative abundance of orthologs for nitrate, nitrite, ammonium, and amino acid transporters under N stress, and increased relative abundance of orthologs related to acquisition of inorganic and organic P substrates under P stress. Although the global transcriptional responses were dominated by species-specific changes, the analysis of conserved responses revealed functional similarities in resource acquisition pathways among different phytoplankton taxa. This overlap in nutrient stress responses observed among species may be useful for tracking the physiological ecology of phytoplankton field populations.
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Affiliation(s)
- Matthew J Harke
- Lamont-Doherty Earth Observatory, Columbia UniversityPalisades, NY, United States
| | - Andrew R Juhl
- Lamont-Doherty Earth Observatory, Columbia UniversityPalisades, NY, United States.,Department of Earth and Environmental Sciences, Columbia UniversityPalisades, NY, United States
| | - Sheean T Haley
- Lamont-Doherty Earth Observatory, Columbia UniversityPalisades, NY, United States
| | - Harriet Alexander
- Department of Population Health and Reproduction, University of California, DavisDavis, CA, United States
| | - Sonya T Dyhrman
- Lamont-Doherty Earth Observatory, Columbia UniversityPalisades, NY, United States.,Department of Earth and Environmental Sciences, Columbia UniversityPalisades, NY, United States
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16
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Bína D, Bouda K, Litvín R. A two-component nonphotochemical fluorescence quenching in eustigmatophyte algae. PHOTOSYNTHESIS RESEARCH 2017; 131:65-77. [PMID: 27485797 DOI: 10.1007/s11120-016-0299-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 07/27/2016] [Indexed: 06/06/2023]
Abstract
Eustigmatophyte algae represent an interesting model system for the study of the regulation of the excitation energy flow due to their use of violaxanthin both as a major light-harvesting pigment and as the basis of xanthophyll cycle. Fluorescence induction kinetics was studied in an oleaginous marine alga Nannochloropsis oceanica. Nonphotochemical fluorescence quenching was analyzed in detail with respect to the state of the cellular xanthophyll pool. Two components of nonphotochemical fluorescence quenching (NPQ), both dependent on the presence of zeaxanthin, were clearly resolved, denoted as slow and fast NPQ based on kinetics of their formation. The slow component was shown to be in direct proportion to the amount of zeaxanthin, while the fast NPQ component was transiently induced in the presence of membrane potential on subsecond timescales. The applicability of these observations to other eustigmatophyte species is demonstrated by measurements of other representatives of this algal group, both marine and freshwater.
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Affiliation(s)
- David Bína
- Institute of Plant Molecular Biology, Biology Centre CAS, Branišovská 31, 370 05, České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05, České Budějovice, Czech Republic
| | - Karel Bouda
- Institute of Plant Molecular Biology, Biology Centre CAS, Branišovská 31, 370 05, České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05, České Budějovice, Czech Republic
| | - Radek Litvín
- Institute of Plant Molecular Biology, Biology Centre CAS, Branišovská 31, 370 05, České Budějovice, Czech Republic.
- Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05, České Budějovice, Czech Republic.
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17
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Stephens TA, Hepburn CD. A kelp with integrity: Macrocystis pyrifera prioritises tissue maintenance in response to nitrogen fertilisation. Oecologia 2016; 182:71-84. [PMID: 27170330 DOI: 10.1007/s00442-016-3641-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 04/20/2016] [Indexed: 10/21/2022]
Abstract
Our understanding of the response of vascular, terrestrial plants to nitrogen (N) addition is advanced and provides the foundation for modern agriculture. In comparison, information on responses of marine macroalgae to increased nitrogen is far less developed. We investigated how in situ pulses of nitrate (NO3 (-)) affected the growth and N physiology of Macrocystis pyrifera by adding N using potassium nitrate dissolution blocks during a period of low seawater N concentration. Multiple parameters (e.g. growth, pigments, soluble NO3 (-)) were measured in distinct tissues throughout entire fronds (apical meristem, stipe, adult blade, mature blade, sporophyll, and holdfast). Unexpectedly, N fertilisation did not enhance elongation rates within the frond, but instead thickness (biomass per unit area) increased in adult blades. Increased blade thickness may have enhanced tissue integrity as fertilised kelp had lower rates of blade erosion. Tissue chemistry also responded to enrichment; pigmentation, soluble NO3 (-), and % N were higher throughout fertilised fronds. Labelled (15)N traced N uptake and translocation from N sources in the kelp canopy to sinks in the holdfast, 10 m below. This is the first evidence of long-distance (>1 m) transport of N in macroalgae. Patterns in physiological parameters suggest that M. pyrifera displays functional differentiation between canopy and basal tissues that may aid in nutrient-tolerance strategies, similar to those seen in higher plants and unlike those seen in more simple algae (i.e. non-kelps). This study highlights how little we know about N additions and N-use strategies within kelp compared to the wealth of literature available for higher plants.
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Affiliation(s)
- Tiffany A Stephens
- Department of Marine Science, University of Otago, P.O. Box 56, Dunedin, 9054, New Zealand.
| | - Christopher D Hepburn
- Department of Marine Science, University of Otago, P.O. Box 56, Dunedin, 9054, New Zealand
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18
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Kumar M, Kuzhiumparambil U, Pernice M, Jiang Z, Ralph PJ. Metabolomics: an emerging frontier of systems biology in marine macrophytes. ALGAL RES 2016. [DOI: 10.1016/j.algal.2016.02.033] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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19
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Miller EP, Wu Y, Carrano CJ. Boron uptake, localization, and speciation in marine brown algae. Metallomics 2016; 8:161-9. [PMID: 26679972 DOI: 10.1039/c5mt00238a] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023]
Abstract
In contrast to the generally boron-poor terrestrial environment, the concentration of boron in the marine environment is relatively high (0.4 mM) and while there has been extensive interest in its use as a surrogate of pH in paleoclimate studies in the context of climate change-related questions, the relatively depth independent, and the generally non-nutrient-like concentration profile of this element have led to boron being neglected as a potentially biologically relevant element in the ocean. Among the marine plant-like organisms the brown algae (Phaeophyta) are one of only five lineages of photosynthetic eukaryotes to have evolved complex multicellularity. Many of unusual and often unique features of brown algae are attributable to this singular evolutionary history. These adaptations are a reflection of the marine coastal environment which brown algae dominate in terms of biomass. Consequently, brown algae are of fundamental importance to oceanic ecology, geochemistry, and coastal industry. Our results indicate that boron is taken up by a facilitated diffusion mechanism against a considerable concentration gradient. Furthermore, in both Ectocarpus and Macrocystis some boron is most likely bound to cell wall constituent alginate and the photoassimilate mannitol located in sieve cells. Herein, we describe boron uptake, speciation, localization and possible biological function in two species of brown algae, Macrocystis pyrifera and Ectocarpus siliculosus.
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Affiliation(s)
- Eric P Miller
- Department of Chemistry and Biochemistry, San Diego State University, San Diego, CA 92182-1030, USA.
| | - Youxian Wu
- Department of Civil, Construction, and Environmental Engineering, San Diego State University, San Diego, CA 92182-1030, USA
| | - Carl J Carrano
- Department of Chemistry and Biochemistry, San Diego State University, San Diego, CA 92182-1030, USA.
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20
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Strittmatter M, Grenville-Briggs LJ, Breithut L, Van West P, Gachon CMM, Küpper FC. Infection of the brown alga Ectocarpus siliculosus by the oomycete Eurychasma dicksonii induces oxidative stress and halogen metabolism. PLANT, CELL & ENVIRONMENT 2016; 39:259-71. [PMID: 25764246 PMCID: PMC4949667 DOI: 10.1111/pce.12533] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Revised: 11/03/2014] [Accepted: 02/07/2015] [Indexed: 05/24/2023]
Abstract
Pathogens are increasingly being recognized as key evolutionary and ecological drivers in marine ecosystems. Defence mechanisms of seaweeds, however, have mostly been investigated by mimicking infection using elicitors. We have established an experimental pathosystem between the genome brown model seaweed Ectocarpus siliculosus and the oomycete Eurychasma dicksonii as a powerful new tool to investigate algal responses to infection. Using proteomics, we identified 21 algal proteins differentially accumulated in response to Eu. dicksonii infection. These include classical algal stress response proteins such as a manganese superoxide dismutase, heat shock proteins 70 and a vanadium bromoperoxidase. Transcriptional profiling by qPCR confirmed the induction of the latter during infection. The accumulation of hydrogen peroxide was observed at different infection stages via histochemical staining. Inhibitor studies confirmed that the main source of hydrogen peroxide is superoxide converted by superoxide dismutase. Our data give an unprecedented global overview of brown algal responses to pathogen infection, and highlight the importance of oxidative stress and halogen metabolism in these interactions. This suggests overlapping defence pathways with herbivores and abiotic stresses. We also identify previously unreported actors, in particular a Rad23 and a plastid-lipid-associated protein, providing novel insights into the infection and defence processes in brown algae.
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Affiliation(s)
- Martina Strittmatter
- The Scottish Association for Marine Science, Scottish Marine Institute, Oban, Argyll, Scotland, PA37 1QA, UK
- Aberdeen Oomycete Laboratory, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, Scotland, AB25 2ZD, UK
| | - Laura J Grenville-Briggs
- Aberdeen Oomycete Laboratory, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, Scotland, AB25 2ZD, UK
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, 230 53, Sweden
| | - Lisa Breithut
- Fachbereich Biologie, Universität Konstanz, Konstanz, D-78457, Germany
| | - Pieter Van West
- Aberdeen Oomycete Laboratory, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, Scotland, AB25 2ZD, UK
| | - Claire M M Gachon
- The Scottish Association for Marine Science, Scottish Marine Institute, Oban, Argyll, Scotland, PA37 1QA, UK
| | - Frithjof C Küpper
- The Scottish Association for Marine Science, Scottish Marine Institute, Oban, Argyll, Scotland, PA37 1QA, UK
- Oceanlab, University of Aberdeen, Main Street, Newburgh, Scotland, AB41 6AA, UK
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21
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Bonin P, Groisillier A, Raimbault A, Guibert A, Boyen C, Tonon T. Molecular and biochemical characterization of mannitol-1-phosphate dehydrogenase from the model brown alga Ectocarpus sp. PHYTOCHEMISTRY 2015; 117:509-520. [PMID: 26232554 DOI: 10.1016/j.phytochem.2015.07.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Revised: 07/16/2015] [Accepted: 07/20/2015] [Indexed: 06/04/2023]
Abstract
The sugar alcohol mannitol is important in the food, pharmaceutical, medical and chemical industries. It is one of the most commonly occurring polyols in nature, with the exception of Archaea and animals. It has a range of physiological roles, including as carbon storage, compatible solute, and osmolyte. Mannitol is present in large amounts in brown algae, where its synthesis involved two steps: a mannitol-1-phosphate dehydrogenase (M1PDH) catalyzes a reversible reaction between fructose-6-phosphate (F6P) and mannitol-1-phosphate (M1P) (EC 1.1.1.17), and a mannitol-1-phosphatase hydrolyzes M1P to mannitol (EC 3.1.3.22). Analysis of the model brown alga Ectocarpus sp. genome provided three candidate genes for M1PDH activities. We report here the sequence analysis of Ectocarpus M1PDHs (EsM1PDHs), and the biochemical characterization of the recombinant catalytic domain of EsM1PDH1 (EsM1PDH1cat). Ectocarpus M1PDHs are representatives of a new type of modular M1PDHs among the polyol-specific long-chain dehydrogenases/reductases (PSLDRs). The N-terminal domain of EsM1PDH1 was not necessary for enzymatic activity. Determination of kinetic parameters indicated that EsM1PDH1cat displayed higher catalytic efficiency for F6P reduction compared to M1P oxidation. Both activities were influenced by NaCl concentration and inhibited by the thioreactive compound pHMB. These observations were completed by measurement of endogenous M1PDH activity and of EsM1PDH gene expression during one diurnal cycle. No significant changes in enzyme activity were monitored between day and night, although transcription of two out of three genes was altered, suggesting different levels of regulation for this key metabolic pathway in brown algal physiology.
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Affiliation(s)
- Patricia Bonin
- Sorbonne Université, UPMC Univ Paris 06, CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, F-29688 Roscoff cedex, France.
| | - Agnès Groisillier
- Sorbonne Université, UPMC Univ Paris 06, CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, F-29688 Roscoff cedex, France.
| | - Alice Raimbault
- Sorbonne Université, UPMC Univ Paris 06, CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, F-29688 Roscoff cedex, France.
| | - Anaïs Guibert
- Sorbonne Université, UPMC Univ Paris 06, CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, F-29688 Roscoff cedex, France.
| | - Catherine Boyen
- Sorbonne Université, UPMC Univ Paris 06, CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, F-29688 Roscoff cedex, France.
| | - Thierry Tonon
- Sorbonne Université, UPMC Univ Paris 06, CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, F-29688 Roscoff cedex, France.
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22
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Goss R, Lepetit B. Biodiversity of NPQ. JOURNAL OF PLANT PHYSIOLOGY 2015; 172:13-32. [PMID: 24854581 DOI: 10.1016/j.jplph.2014.03.004] [Citation(s) in RCA: 239] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Revised: 03/10/2014] [Accepted: 03/11/2014] [Indexed: 05/21/2023]
Abstract
In their natural environment plants and algae are exposed to rapidly changing light conditions and light intensities. Illumination with high light intensities has the potential to overexcite the photosynthetic pigments and the electron transport chain and thus induce the production of toxic reactive oxygen species (ROS). To prevent damage by the action of ROS, plants and algae have developed a multitude of photoprotection mechanisms. One of the most important protection mechanisms is the dissipation of excessive excitation energy as heat in the light-harvesting complexes of the photosystems. This process requires a structural change of the photosynthetic antenna complexes that are normally optimized with regard to efficient light-harvesting. Enhanced heat dissipation in the antenna systems is accompanied by a strong quenching of the chlorophyll a fluorescence and has thus been termed non-photochemical quenching of chlorophyll a fluorescence, NPQ. The general importance of NPQ for the photoprotection of plants and algae is documented by its wide distribution in the plant kingdom. In the present review we will summarize the present day knowledge about NPQ in higher plants and different algal groups with a special focus on the molecular mechanisms that lead to the structural rearrangements of the antenna complexes and enhanced heat dissipation. We will present the newest models for NPQ in higher plants and diatoms and will compare the features of NPQ in different algae with those of NPQ in higher plants. In addition, we will briefly address evolutionary aspects of NPQ, i.e. how the requirements of NPQ have changed during the transition of plants from the aquatic habitat to the land environment. We will conclude with a presentation of open questions regarding the mechanistic basis of NPQ and suggestions for future experiments that may serve to obtain this missing information.
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Affiliation(s)
- Reimund Goss
- Institut für Biologie, Universität Leipzig, Johannisallee 21-23, D-04103 Leipzig, Germany.
| | - Bernard Lepetit
- Institut für Biologie, Universität Konstanz, Universitätsstrasse 10, D-78457 Konstanz, Germany
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23
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Abstract
Biomass derived from marine microalgae and macroalgae is globally recognized as a source of valuable chemical constituents with applications in the agri-horticultural sector (including animal feeds and health and plant stimulants), as human food and food ingredients as well as in the nutraceutical, cosmeceutical, and pharmaceutical industries. Algal biomass supply of sufficient quality and quantity however remains a concern with increasing environmental pressures conflicting with the growing demand. Recent attempts in supplying consistent, safe and environmentally acceptable biomass through cultivation of (macro- and micro-) algal biomass have concentrated on characterizing natural variability in bioactives, and optimizing cultivated materials through strain selection and hybridization, as well as breeding and, more recently, genetic improvements of biomass. Biotechnological tools including metabolomics, transcriptomics, and genomics have recently been extended to algae but, in comparison to microbial or plant biomass, still remain underdeveloped. Current progress in algal biotechnology is driven by an increased demand for new sources of biomass due to several global challenges, new discoveries and technologies available as well as an increased global awareness of the many applications of algae. Algal diversity and complexity provides significant potential provided that shortages in suitable and safe biomass can be met, and consumer demands are matched by commercial investment in product development.
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Affiliation(s)
- Dagmar B Stengel
- Botany and Plant Science, School of Natural Science, Ryan Institute for Environmental, Marine and Energy Research, National University of Ireland Galway, University Road, Galway, Ireland,
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24
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Frischkorn KR, Harke MJ, Gobler CJ, Dyhrman ST. De novo assembly of Aureococcus anophagefferens transcriptomes reveals diverse responses to the low nutrient and low light conditions present during blooms. Front Microbiol 2014; 5:375. [PMID: 25104951 PMCID: PMC4109616 DOI: 10.3389/fmicb.2014.00375] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Accepted: 07/03/2014] [Indexed: 12/23/2022] Open
Abstract
Transcriptome profiling was performed on the harmful algal bloom-forming pelagophyte Aureococcus anophagefferens strain CCMP 1850 to assess responses to common stressors for dense phytoplankton blooms: low inorganic nitrogen concentrations, low inorganic phosphorus concentrations, low light levels, and a replete control. The de novo assemblies of pooled reads from all treatments reconstructed ~54,000 transcripts using Trinity, and ~31,000 transcripts using ABySS. Comparison to the strain CCMP 1984 genome showed that the majority of the gene models were present in both de novo assemblies and that roughly 95% of contigs from both assemblies mapped to the genome, with Trinity capturing slightly more genome content. Sequence reads were mapped back to the de novo assemblies as well as the gene models and differential expression was analyzed using a Bayesian approach called Analysis of Sequence Counts (ASC). On average, 93% of significantly upregulated transcripts recovered by genome mapping were present in the significantly upregulated pool from both de novo assembly methods. Transcripts related to the transport and metabolism of nitrogen were upregulated in the low nitrogen treatment, transcripts encoding enzymes that hydrolyze organic phosphorus or relieve arsenic toxicity were upregulated in the low phosphorus treatment, and transcripts for enzymes that catabolize organic compounds, restructure lipid membranes, or are involved in sulfolipid biosynthesis were upregulated in the low light treatment. A comparison of this transcriptome to the nutrient regulated transcriptional response of CCMP 1984 identified conserved responses between these two strains. These analyses reveal the transcriptional underpinnings of physiological shifts that could contribute to the ecological success of this species in situ: organic matter processing, metal detoxification, lipid restructuring, and photosynthetic apparatus turnover.
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Affiliation(s)
- Kyle R Frischkorn
- Department of Earth and Environmental Sciences and the Lamont-Doherty Earth Observatory, Columbia University Palisades, NY, USA
| | - Matthew J Harke
- School of Marine and Atmospheric Sciences, Stony Brook University Southampton, NY, USA
| | - Christopher J Gobler
- School of Marine and Atmospheric Sciences, Stony Brook University Southampton, NY, USA
| | - Sonya T Dyhrman
- Department of Earth and Environmental Sciences and the Lamont-Doherty Earth Observatory, Columbia University Palisades, NY, USA
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25
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Lin H, Qin S. Tipping points in seaweed genetic engineering: scaling up opportunities in the next decade. Mar Drugs 2014; 12:3025-45. [PMID: 24857961 PMCID: PMC4052329 DOI: 10.3390/md12053025] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2014] [Revised: 04/04/2014] [Accepted: 04/25/2014] [Indexed: 12/30/2022] Open
Abstract
Seaweed genetic engineering is a transgenic expression system with unique features compared with those of heterotrophic prokaryotes and higher plants. This study discusses several newly sequenced seaweed nuclear genomes and the necessity that research on vector design should consider endogenous promoters, codon optimization, and gene copy number. Seaweed viruses and artificial transposons can be applied as transformation methods after acquiring a comprehensive understanding of the mechanism of viral infections in seaweeds and transposon patterns in seaweed genomes. After cultivating transgenic algal cells and tissues in a photobioreactor, a biosafety assessment of genetically modified (GM) seaweeds must be conducted before open-sea application. We propose a set of programs for the evaluation of gene flow from GM seaweeds to local/geographical environments. The effective implementation of such programs requires fundamentally systematic and interdisciplinary studies on algal physiology and genetics, marine hydrology, reproductive biology, and ecology.
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Affiliation(s)
- Hanzhi Lin
- Environmental Biophysics and Molecular Ecology Program, Institute of Marine and Coastal Sciences, Rutgers University, 71 Dudley Road, New Brunswick, NJ 08901, USA.
| | - Song Qin
- Key Lab of Coastal Biology and Bio-resource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, 17 Chunhui Road, Yantai 264003, China.
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Lavaud J, Goss R. The Peculiar Features of Non-Photochemical Fluorescence Quenching in Diatoms and Brown Algae. ADVANCES IN PHOTOSYNTHESIS AND RESPIRATION 2014. [DOI: 10.1007/978-94-017-9032-1_20] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
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