NSFGEO-NERC An unexpected requirement for silicon in coccolithophore calcification: ecological and evolutionary implications.
Lead Research Organisation:
Marine Biological Association of the United Kingdom
Department Name: Marine Biology
Abstract
The oceans cover more than three quarters of the surface of the Earth and tiny algae in our seas are responsible for half of all photosynthesis on our planet. These single celled organisms, known as phytoplankton, form the basis of marine food webs and their activities can have an enormous impact on the geology of our planet. One group of phytoplankton known as the coccolithophores produce a covering of calcium carbonate plates (coccoliths) and can form vast blooms in the oceans. When the coccolithophores die, their coccoliths settle to the ocean floor, leading to the formation of sedimentary rocks, such as chalks and limestones.
In many parts of the ocean the low availability of nutrients (such as nitrogen and phosphorus) limits phytoplankton growth. Competition for nutrients plays an important role in determining which phytoplankton species can grow in different environments. One of the most successful phytoplankton groups in modern oceans is the diatoms, which are fast-growing, making it difficult for many other phytoplankton types to compete with them. However, diatoms need lots of dissolved silicon to make their silica cell walls. In some marine environments, the availability of silicon limits the growth of diatoms, allowing other phytoplankton (which do not need silicon) to grow in their place.
It is commonly thought that the calcifying coccolithophores have no requirement for silicon. However, we have recently discovered that some important coccolithophore species actually possess silicon transporters that are similar to those used by diatoms. Remarkably, we found that these coccolithophores use silicon to make their calcium carbonate coccoliths. Therefore the processes of silica formation in diatoms and calcite production in coccolithophores, which were previously believed to be distinct processes, show a completely unexpected link. These findings have important implications for the evolution of biomineralisation in phytoplankton and for the competitive interactions between coccolithophores and diatoms.
Not all coccolithophores show a requirement for silicon. We found that the species responsible for the massive coccolithophore blooms, Emiliania huxleyi, does not possess silicon transporters and exhibits no need for silicon in the calcification process. The absence of a requirement for silicon may have enabled bloom-forming species to grow better in areas where silicon is low (e.g. after a diatom bloom).
There is therefore a clear need to understand the role of silicon in coccolithophore biology.
In this proposal we will address this issue using a combination of laboratory experiments and computational modelling approaches. Firstly, we will use molecular genetic and laboratory experiments to determine which of the major coccolithophore species exhibit a requirement for silicon. We will then select species for detailed physiological analysis, to determine how silicon contributes to the formation of coccoliths and how coccolithophores take up silicon from the surrounding seawater. These studies will allow us to examine the evolutionary history of the requirement for silicon and determine when certain lineages appear to have lost this trait. Using parameters on Si uptake and usage derived from our experimental work, we will use computer simulations to model global coccolithophore distributions and identify environments where the requirement for Si appears to be playing an important role in coccolithophore ecology.
The research will provide novel insight into physiology, ecology and evolution of coccolithophores, including information on how and why coccoliths are produced, which is currently poorly understood. The research will also inform us on the evolution of coccolith formation, which will be vitally important if we are to understand how coccolithophores have been influenced by past changes in the Earth's climate and how they may respond to changes in the future.
In many parts of the ocean the low availability of nutrients (such as nitrogen and phosphorus) limits phytoplankton growth. Competition for nutrients plays an important role in determining which phytoplankton species can grow in different environments. One of the most successful phytoplankton groups in modern oceans is the diatoms, which are fast-growing, making it difficult for many other phytoplankton types to compete with them. However, diatoms need lots of dissolved silicon to make their silica cell walls. In some marine environments, the availability of silicon limits the growth of diatoms, allowing other phytoplankton (which do not need silicon) to grow in their place.
It is commonly thought that the calcifying coccolithophores have no requirement for silicon. However, we have recently discovered that some important coccolithophore species actually possess silicon transporters that are similar to those used by diatoms. Remarkably, we found that these coccolithophores use silicon to make their calcium carbonate coccoliths. Therefore the processes of silica formation in diatoms and calcite production in coccolithophores, which were previously believed to be distinct processes, show a completely unexpected link. These findings have important implications for the evolution of biomineralisation in phytoplankton and for the competitive interactions between coccolithophores and diatoms.
Not all coccolithophores show a requirement for silicon. We found that the species responsible for the massive coccolithophore blooms, Emiliania huxleyi, does not possess silicon transporters and exhibits no need for silicon in the calcification process. The absence of a requirement for silicon may have enabled bloom-forming species to grow better in areas where silicon is low (e.g. after a diatom bloom).
There is therefore a clear need to understand the role of silicon in coccolithophore biology.
In this proposal we will address this issue using a combination of laboratory experiments and computational modelling approaches. Firstly, we will use molecular genetic and laboratory experiments to determine which of the major coccolithophore species exhibit a requirement for silicon. We will then select species for detailed physiological analysis, to determine how silicon contributes to the formation of coccoliths and how coccolithophores take up silicon from the surrounding seawater. These studies will allow us to examine the evolutionary history of the requirement for silicon and determine when certain lineages appear to have lost this trait. Using parameters on Si uptake and usage derived from our experimental work, we will use computer simulations to model global coccolithophore distributions and identify environments where the requirement for Si appears to be playing an important role in coccolithophore ecology.
The research will provide novel insight into physiology, ecology and evolution of coccolithophores, including information on how and why coccoliths are produced, which is currently poorly understood. The research will also inform us on the evolution of coccolith formation, which will be vitally important if we are to understand how coccolithophores have been influenced by past changes in the Earth's climate and how they may respond to changes in the future.
Planned Impact
Economic and societal beneficiaries
This proposal aims to deliver mechanistic understanding of a fundamental aspect of marine phytoplankton physiology that will provide insight into competitive interactions between phytoplankton. We therefore expect it to deliver a lasting impact, not only to scientists but more widely to a variety of interested parties. As the research is likely to influence our understanding of marine ecosystem dynamics, the findings will be of relevance to a wide variety of stakeholders with interests in the marine environment. The research will have a wide impact in areas that are underpinned by marine productivity and the stability of marine ecosystems, from food production and tourism through to environmental management.
The proposed work represents cutting-edge blue-skies research and it can be hard to predict the wider impact of research of this nature. The impact of the research on a range of stakeholders may be indirect. It should be noted that an important aspect of the research is to examine how advances at the cellular level can be used to understand processes at the global ecosystem level. The proposed research therefore aims to build pathways where diverse stakeholders at the ecosystem level can benefit from fundamental scientific advances at a very different scale. Thus, a wider benefit of the research will be to facilitate the integration of environmental scientists to further the dissemination of blue skies research. This approach and its implementation are discussed in more detail in the Pathways to Impact attachment.
Beyond environmental science, the research also has applications in industrial biotechnology as there is enormous interest in the biotechnological potential of biomineralised phytoplankton. Applications from drug delivery through to enzyme immobilisation and microphotonics have all been investigated for biomineralised phytoplankton or biomimetic structures derived from these organisms. However, the ability of materials scientists to generate and manipulate biominerals for industrial biotechnology remains limited. There is a strong drive to learn from natural systems, where the diversity and complexity of form and function of biominerals is enormous. The research will provide insight into how Si may be used to modulate the formation of calcium carbonate structures, which may have direct applications for industrial biotechnology.
End users
Non-academic stakeholders include policy forming bodies such as Governmental Environment and Climate Change Departments (e.g. the European Union, the UK Met Office, UK Government Departments, including DECC and DEFRA) as well as international bodies and NGOs (IPCC, environmental and fisheries charities, pressure groups). All of these groups have a potential interest in the factors driving marine primary productivity. Improved quantitative understanding of marine ecosystem function will allow these policy forming bodies to address issues such as ecosystem management protection, and prediction and mitigation against any undesirable changes.
A major aim of this proposal is to build processes that enable researchers working on fundamental aspects of environmental research to engage with and inform end users. This forms the basis of the 'Genes to Ecosystems' workshop described in Pathways to Impact.
Development of UK skill base
The staff involved in this project will be trained to high level in both experimental and computational techniques. These clearly are of benefit to the academic research sector, but if these researchers do not choose to follow an academic career path, these skills will contribute significantly to the UK skill base within both the private and public sectors. Recent alumini from our laboratory are using skills relating to this research area in both the public sector (e.g. Knowledge Exchange for a research institute), and the private sector (e.g. development of educational software, the microscopy industry).
This proposal aims to deliver mechanistic understanding of a fundamental aspect of marine phytoplankton physiology that will provide insight into competitive interactions between phytoplankton. We therefore expect it to deliver a lasting impact, not only to scientists but more widely to a variety of interested parties. As the research is likely to influence our understanding of marine ecosystem dynamics, the findings will be of relevance to a wide variety of stakeholders with interests in the marine environment. The research will have a wide impact in areas that are underpinned by marine productivity and the stability of marine ecosystems, from food production and tourism through to environmental management.
The proposed work represents cutting-edge blue-skies research and it can be hard to predict the wider impact of research of this nature. The impact of the research on a range of stakeholders may be indirect. It should be noted that an important aspect of the research is to examine how advances at the cellular level can be used to understand processes at the global ecosystem level. The proposed research therefore aims to build pathways where diverse stakeholders at the ecosystem level can benefit from fundamental scientific advances at a very different scale. Thus, a wider benefit of the research will be to facilitate the integration of environmental scientists to further the dissemination of blue skies research. This approach and its implementation are discussed in more detail in the Pathways to Impact attachment.
Beyond environmental science, the research also has applications in industrial biotechnology as there is enormous interest in the biotechnological potential of biomineralised phytoplankton. Applications from drug delivery through to enzyme immobilisation and microphotonics have all been investigated for biomineralised phytoplankton or biomimetic structures derived from these organisms. However, the ability of materials scientists to generate and manipulate biominerals for industrial biotechnology remains limited. There is a strong drive to learn from natural systems, where the diversity and complexity of form and function of biominerals is enormous. The research will provide insight into how Si may be used to modulate the formation of calcium carbonate structures, which may have direct applications for industrial biotechnology.
End users
Non-academic stakeholders include policy forming bodies such as Governmental Environment and Climate Change Departments (e.g. the European Union, the UK Met Office, UK Government Departments, including DECC and DEFRA) as well as international bodies and NGOs (IPCC, environmental and fisheries charities, pressure groups). All of these groups have a potential interest in the factors driving marine primary productivity. Improved quantitative understanding of marine ecosystem function will allow these policy forming bodies to address issues such as ecosystem management protection, and prediction and mitigation against any undesirable changes.
A major aim of this proposal is to build processes that enable researchers working on fundamental aspects of environmental research to engage with and inform end users. This forms the basis of the 'Genes to Ecosystems' workshop described in Pathways to Impact.
Development of UK skill base
The staff involved in this project will be trained to high level in both experimental and computational techniques. These clearly are of benefit to the academic research sector, but if these researchers do not choose to follow an academic career path, these skills will contribute significantly to the UK skill base within both the private and public sectors. Recent alumini from our laboratory are using skills relating to this research area in both the public sector (e.g. Knowledge Exchange for a research institute), and the private sector (e.g. development of educational software, the microscopy industry).
Organisations
Publications
Marron AO
(2016)
The Evolution of Silicon Transport in Eukaryotes.
in Molecular biology and evolution
Flynn KJ
(2016)
The role of coccolithophore calcification in bioengineering their environment.
in Proceedings. Biological sciences
Lenhart K
(2016)
Evidence for methane production by the marine algae <i>Emiliania huxleyi</i>
in Biogeosciences
Milner S
(2016)
Ocean warming modulates the effects of acidification on Emiliania huxleyi calcification and sinking
in Limnology and Oceanography
Langer G
(2016)
Sr partitioning in the benthic foraminifera Ammonia aomoriensis and Amphistegina lessonii
in Chemical Geology
Jaya BN
(2016)
Coccospheres confer mechanical protection: New evidence for an old hypothesis.
in Acta biomaterialia
Rosas-Navarro A
(2016)
Temperature affects the morphology and calcification of <i>Emiliania huxleyi</i> strains
in Biogeosciences
Durak GM
(2017)
The role of the cytoskeleton in biomineralisation in haptophyte algae.
in Scientific reports
Taylor A
(2017)
Coccolithophore Cell Biology: Chalking Up Progress
in Annual Review of Marine Science
Langer G
(2018)
Relationship between mineralogy and minor element partitioning in limpets from an Ischia CO2 vent site provides new insights into their biomineralization pathway
in Geochimica et Cosmochimica Acta
Walker CE
(2018)
The requirement for calcification differs between ecologically important coccolithophore species.
in The New phytologist
Rosas-Navarro A
(2018)
Temperature effects on sinking velocity of different Emiliania huxleyi strains.
in PloS one
Walker C
(2018)
An Extracellular Polysaccharide-Rich Organic Layer Contributes to Organization of the Coccosphere in Coccolithophores
in Frontiers in Marine Science
Klintzsch T
(2019)
Methane production by three widespread marine phytoplankton species: release rates, precursor compounds, and potential relevance for the environment
in Biogeosciences
Klintzsch T
(2020)
Effects of Temperature and Light on Methane Production of Widespread Marine Phytoplankton
in Journal of Geophysical Research: Biogeosciences
Langer G
(2020)
Li Partitioning Into Coccoliths of Emiliania huxleyi : Evaluating the General Role of "Vital Effects" in Explaining Element Partitioning in Biogenic Carbonates
in Geochemistry, Geophysics, Geosystems
Meyer E
(2020)
Sr in coccoliths of Scyphosphaera apsteinii: Partitioning behavior and role in coccolith morphogenesis
in Geochimica et Cosmochimica Acta
De Vries J
(2020)
The haplo-diplontic life cycle expands niche space of coccolithophores
De Vries J
(2021)
Haplo-diplontic life cycle expands coccolithophore niche
in Biogeosciences
Walker JM
(2021)
Coccolith crystals: Pure calcite or organic-mineral composite structures?
in Acta biomaterialia
Brownlee C
(2021)
Coccolithophore calcification: Changing paradigms in changing oceans.
in Acta biomaterialia
Langer G
(2021)
Role of silicon in the development of complex crystal shapes in coccolithophores.
in The New phytologist
Langer G
(2022)
Distinct physiological responses of Coccolithus braarudii life cycle phases to light intensity and nutrient availability
in European Journal of Phycology
Description | The coccolithophores are an important group of marine phytoplankton that play an important role in ocean carbon cycling. We have identified key steps in the process of calcification by this group of algae, that allow us to understand how calcification may have initially developed. This knowledge should help us understand the role of calcification in the physiology and ecology of the coccolithophores both in current oceans, but also help us identify the conditions under which calcification may first have evolved. |
Exploitation Route | The outcomes will be useful to researchers with an interest in the ecology and physiology of coccolithophores. These range from geologists studying the formation of sedimentary rocks, palaeontologists examining the fossil record of coccolithophores in past oceans, through to biologists examining the role of coccolithophores in modern ecosystems. More broadly, the findings should help us understand how calcification came about in the coccolithophores and went on to play a major role in the ocean carbon cycle. |
Sectors | Environment |
Description | Travel Award for EMBO Aquatic Microeukaryotes Symposium, Heidelberg |
Amount | $1,164 (USD) |
Organisation | Gordon and Betty Moore Foundation |
Sector | Charity/Non Profit |
Country | United States |
Start | 03/2016 |
End | 03/2016 |
Title | NERC Grant NE/N011708/1. An unexpected requirement for silicon in coccolithophore calcification |
Description | Data associated with laboratory studies examining the response of coccolithophores to silicon |
Type Of Material | Database/Collection of data |
Year Produced | 2021 |
Provided To Others? | Yes |
Impact | n/a |
URL | https://www.dassh.ac.uk/doitool/data/1799 |
Description | Advances in Coccolithophores |
Organisation | Heriot-Watt University |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | We contributed to a network of like-minded researchers focusing on coccolithophore biology. The aim was develop a discussion group to identify big unknowns in the research area and examine potential solutions. We helped organise the fist 'Advances in Coccolithophores' workshop in Bergen June 2022. |
Collaborator Contribution | The other partners contributed to the organisation of this workshop. |
Impact | Advances in coccolithophore workshop, Bergen 2022 attended by 140 participants A similar workshop is planned for September 2023. |
Start Year | 2022 |
Description | Advances in Coccolithophores |
Organisation | Ruder Boskovic Institute |
Country | Croatia |
Sector | Public |
PI Contribution | We contributed to a network of like-minded researchers focusing on coccolithophore biology. The aim was develop a discussion group to identify big unknowns in the research area and examine potential solutions. We helped organise the fist 'Advances in Coccolithophores' workshop in Bergen June 2022. |
Collaborator Contribution | The other partners contributed to the organisation of this workshop. |
Impact | Advances in coccolithophore workshop, Bergen 2022 attended by 140 participants A similar workshop is planned for September 2023. |
Start Year | 2022 |
Description | Advances in Coccolithophores |
Organisation | University of Bristol |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | We contributed to a network of like-minded researchers focusing on coccolithophore biology. The aim was develop a discussion group to identify big unknowns in the research area and examine potential solutions. We helped organise the fist 'Advances in Coccolithophores' workshop in Bergen June 2022. |
Collaborator Contribution | The other partners contributed to the organisation of this workshop. |
Impact | Advances in coccolithophore workshop, Bergen 2022 attended by 140 participants A similar workshop is planned for September 2023. |
Start Year | 2022 |
Description | Weizmann Institute - collaborative award |
Organisation | Weizmann Institute of Science |
Country | Israel |
Sector | Academic/University |
PI Contribution | The research conducted during this award led to us being invited to contribution to a collaborative grant initiative between UK researchers and the Weizmann Institute, Israel. Together with Dr Assaf Gal (Weizmann), the lead PI (G. Wheeler) and PDRA (G. Langer) devised a research proposal to foster collaboration between the two organisations and develop further some of the research areas within the initial award that were of interest to both parties. The value of the collaborative award was $100000 USD split between the two organisations to support research activities and promote travel between the labs (although travel visits have been curtailed by Covid restrictions). |
Collaborator Contribution | We are currently directly involved in collaborative research activities between the two organisations, studying the mechanisms of calcification in a range of different coccolithophore species. |
Impact | Publication The role of silicon in the development of complex crystal shapes in coccolithophores Gerald Langer Alison R. Taylor Charlotte E. Walker Erin M. Meyer Oz Ben Joseph Assaf Gal Glenn M. Harper Ian Probert Colin Brownlee Glen L. Wheeler New Phytologist https://doi.org/10.1111/nph.17230 |
Start Year | 2019 |