COLLABORATIVE PROJECT: MAGIC - A multi-tiered approach to generating increased carbon dioxide in the chloroplast
Lead Research Organisation:
University of Glasgow
Department Name: Inst of Molecular Cell & Systems Biology
Abstract
Photosynthesis is at the core of virtually every aspect of society, from food production to industrial construction. Terrestrial photosynthesis is intimately connected with our use of other natural resources, and it exerts major controls on the water, mineral and carbon cycles of the world. For example, plant transpiration is thought to have contributed to recent changes in fresh-water availability associated with the global rise in CO2, and it is at the centre of a crisis in water availability expected over the next 20-30 years. Over this same period it is estimated that a 50% increase in global food production will be required to keep pace with the increase in human population. Crop yields have matched population growth until recently, but the gains from cereal cultivars bred in the Green Revolution were realised in full a decade ago. Thus it is vital that routes to further improvements in photosynthetic efficiency are sought now. In most species, CO2 is fixed by Ribulose Bisphosphate Carboxylase/Oxygenase (RuBisCO) in the Calvin-Benson cycle to generate a three-carbon compound. RuBisCO is remarkably poor in its substrate selectivity and promiscuously fixes both CO2 and O2, a fact that makes RuBisCO arguably the most inefficient step in photosynthesis. One way of reducing O2 use by RuBisCO is to raise the partial pressure of CO2 (pCO2). So-called carbon concentrating mechanisms (CCMs) have evolved multiple times in nature, albeit not as a feature of most common crop species. Thus, comparisons suggest roughly a 50% increase in overall yield might be realised if O2 use by RuBisCO were bypassed in crops. Significant resources have gone into engineering RuBisCO for increased CO2 selectivity and introducing a single-celled version of C4 photosynthesis in rice, but these approaches have yet to see a step change in photosynthetic efficiency. One new set of strategies yet to be explored is to co-opt light-driven pumps, anion exchange transport and substrate channelling to supply CO2 to RuBisCO. To date none of these processes is known to facilitate photosynthesis, although all three occur naturally and have been employed synthetically in biology. It is our goal to develop the equivalent of a 'two-stage pump': placing in series (1) a transport mechanism to concentrate HCO3- in the chloroplast powered by the light-driven ion pump halorhodopsin (hR) from the archeon Halobacterium halobium, and (2) substrate channelling within the chloroplast using one or more molecular 'building blocks' from Clostridium or cyanobacteria to carry HCO3- or a four-carbon intermediate to RuBisCO. This two-stage strategy is expected to maximise CCM gain driven independently with light energy absorbed by hR, and it has the added potential for engineering hR to tap the unused asset of light beyond the photosynthetic spectrum. Furthermore, an overarching feature of this approach is in its modular nature: it will be possible to develop each stage of the two-stage pump in parallel, and to assess its functionality separately at molecular, cellular and whole-organismal levels, combining the components thereafter for final validation. This modular approach ensures the maximum efficiency and speed in realising our goal within the three-year period.
Technical Summary
We will develop our two-stage pump making use of alternative strategies for both the first and second stages, and testing where appropriate in the photosynthetic model of cyanobacteria before translation to the chloroplasts of the C3 model plant Arabidopsis. For the first stage of engineering a HCO3- transport system driven by hR, two mechanistically-different strategies will be pursued. One strategy will take existing transport functionalities of hR and the mammalian Cl-/HCO3- exchange transporter AE1, each proven in independent heterologous expression studies, to generate a Cl- gradient across the chloroplast inner envelope membrane and to use this gradient to drive Cl-/HCO3- exchange. The second, simpler and possibly more elegant strategy is to engineer hR to select for HCO3- over Cl- or other anionic species in order to pump HCO3- directly across the membrane. For the second stage of the two-stage pump, we will engineer a set of scaffold proteins to capture carbon entering the chloroplast stroma either as HCO3- or as a four-carbon intermediate and deliver it for conversion to CO2 directly at the active site of RuBisCO. Scaffolding alternatives will include constructs positioned at the inner face of the envelope membrane as well as fixed to the soluble RuBisCO within the stroma, and we will make use of either proven building blocks derived from Clostridium or a new set of constructs derived from cyanobacterial carboxysomes. At each step of development we will be able to assess functionality and impact separately at molecular, cellular and whole-plant levels. Once we are satisfied that the components will work, we will then combine them for final validation.
Planned Impact
This proposal is for fundamental research to establish novel and synthetic approaches to increasing photosynthetic capacity through mechanisms for capturing CO2. The concepts behind the proposal are at the core of ideas emerging within the international cell and synthetic biology communities and should help stimulate thinking about approaches to the next Green Revolution as well as novel applications in other areas of science at the interfaces between biology, physics and systems analysis. Thus, the research is expected to benefit fundamental researchers as well as industry through conceptual developments as well as the introduction of new technologies for light harvesting and its applications in biology. The research will feed into higher education training programmes through research training at the postgraduate and postdoctoral levels, and through international exchange with our collaborators (JHG, CK) in the USA. Finally it will help guide future efforts in applications to agricultural/industrial systems. MRB and JMH have established links with industrial/technology transfer partners (Agrisera, Dualsystems, Plant Bioscience), research institutes (SCRI and JIC) and relevant international consortia (IRRI and the C4 Rice Consortium,) to take advantage of these developments. Further details of these, and additional impacts will be found in Part 1 of the Case for Support and in the attached Impact Pathways.
People |
ORCID iD |
Michael Blatt (Principal Investigator) |
Publications
Chen ZH
(2012)
Systems dynamic modeling of the stomatal guard cell predicts emergent behaviors in transport, signaling, and volume control.
in Plant physiology
Chen ZH
(2017)
Molecular Evolution of Grass Stomata.
in Trends in plant science
Cai S
(2017)
Speedy Grass Stomata: Emerging Molecular and Evolutionary Features.
in Molecular plant
Cai S
(2017)
Evolutionary Conservation of ABA Signaling for Stomatal Closure.
in Plant physiology
Caesar K
(2011)
A fast brassinolide-regulated response pathway in the plasma membrane of Arabidopsis thaliana.
in The Plant journal : for cell and molecular biology
Blatt MR
(2015)
Vigilante Science.
in Plant physiology
Blatt MR
(2018)
New Faces behind the Scenes.
in Plant physiology
Blatt MR
(2014)
Applications of fluorescent marker proteins in plant cell biology.
in Methods in molecular biology (Clifton, N.J.)
Blatt MR
(2018)
Plant Physiology Launches Associate Features Editors.
in Plant physiology
Blatt MR
(2014)
Exploring emergent properties in cellular homeostasis using OnGuard to model K+ and other ion transport in guard cells.
in Journal of plant physiology
Blatt MR
(2017)
Small Pores with a Big Impact.
in Plant physiology
Blatt MR
(2022)
What can mechanistic models tell us about guard cells, photosynthesis, and water use efficiency?
in Trends in plant science
Blatt MR
(2013)
The conceptual approach to quantitative modeling of guard cells.
in Plant signaling & behavior
Blatt M
(2014)
Focus on Water
in Plant Physiology
Besserer A
(2012)
Selective regulation of maize plasma membrane aquaporin trafficking and activity by the SNARE SYP121.
in The Plant cell
Description | The aim of this project was to establish a collaboration with a focus on prototype engineering of photosynthesis in plants. The longer-term target in this work was to improve the efficiency of photosynthesis through a synthetic approach. Our major discoveries centred on the spatial relations necessary for carbon capture in photosynthesis and on the need for quantitative data relevant to light harvesting by components proposed for synthetic enhancement. |
Exploitation Route | We have taken the findings forward in a second, three-year project to resolve aspects of light capture and turnover of our synthetic components. |
Sectors | Agriculture Food and Drink Energy Environment Manufacturing including Industrial Biotechology Other |
URL | http://psrg.org.uk |
Description | The outcomes in estimating gaseous diffusion have been used in determining the potential for manipulating gas exchange and stomatal responses that regulate these processes. To date, an important consequence has been to guide ongoing work to drive stomatal behaviour in models and now ongoing in crops for enchanced carbon fixation and water use efficiencies, work that is currently under patent application |
First Year Of Impact | 2019 |
Sector | Agriculture, Food and Drink,Education,Other |
Impact Types | Societal Economic |
Title | 2in1 vector systems |
Description | Synthetic biology vectors for transient and stable transformation with quantitative visual reporting on cell-by-cell basis |
Type Of Material | Technology assay or reagent |
Year Produced | 2009 |
Provided To Others? | Yes |
Impact | Multiple publications from my own research group and over 100 research groups worldwide Vector system distributions to more than 500 research groups worldwide |
URL | http://psrg.org.uk |
Title | EZ-Rhizo |
Description | Computer software tool for quantitative measurement and analysis of root growth/development |
Type Of Material | Physiological assessment or outcome measure |
Year Produced | 2010 |
Provided To Others? | Yes |
Impact | Multiple publications from my own research group and research groups worldwide Online distribution has been accessed through the laboratory website with site views at a rate of >500 per month |
URL | http://psrg.org.uk |
Title | Henry |
Description | Software for electrophysiology and imaging data aquisition and analysis |
Type Of Material | Technology assay or reagent |
Provided To Others? | Yes |
Impact | Multiple publications from my own research group and research groups worldwide Online distribution has been accessed through the laboratory website with site views at a rate of >500 per month |
URL | http://psrg.org.uk |
Title | Multicistronic vector systems |
Description | Synthetic biology vector systems for transient and stable transformation for expressing multiple, tagged proteins and for quantitative analysis of membrane traffic and transport |
Type Of Material | Technology assay or reagent |
Year Produced | 2010 |
Provided To Others? | Yes |
Impact | Multiple publications from my own research group and over 100 research groups worldwide Vector system distributions to more than 500 research groups worldwide |
URL | http://psrg.org.uk |
Title | OnGuard |
Description | Systems biology software for quantitative modelling of cellular transport and homeostasis |
Type Of Material | Physiological assessment or outcome measure |
Year Produced | 2012 |
Provided To Others? | Yes |
Impact | Multiple publications from my own research group and research groups worldwide Online distribution has been accessed through the laboratory website with site views at a rate of >500 per month |
URL | http://psrg.org.uk |
Title | SUS vector systems |
Description | Synthetic biological vector systems for protein-protein interaction screening |
Type Of Material | Technology assay or reagent |
Year Produced | 2010 |
Provided To Others? | Yes |
Impact | Multiple publications from my own research group and over 100 research groups worldwide Vector system distributions to more than 500 research groups worldwide |
URL | http://psrg.org.uk |
Title | Software tools for electrophysiology and imaging |
Description | The laboratory continues to develop and refine software/hardware tools for data acquisition and analysis relevant to electrophysiology, single-cell imaging and analysis. These activities are long-standing and open-ended, and develop in line with the current research activities and needs of the laboratory. All software and related packages are made freely available to the research community through the laboratory website at psrg.org.uk |
Type Of Material | Technology assay or reagent |
Provided To Others? | Yes |
Impact | The various software tools and packages have furthered the research activities of the laboratory since the 1990s and continue to provide key support and drivers for advancing much of current research. These tools and packages are disseminated, on average, to over 100 laboratories per year. |
URL | http://psrg.org.uk |
Title | EZ-Rhizo |
Description | Software for quantitative trait analysis and acquisition for root growth/development |
Type Of Material | Database/Collection of data |
Year Produced | 2010 |
Provided To Others? | Yes |
Impact | Multiple publications from my own research group and research groups worldwide Online distribution has been accessed through the laboratory website with site views at a rate of >500 per month |
URL | http://psrg.org.uk |
Title | Henry |
Description | Software package for electrophysiology and imaging data acquisition and analysis |
Type Of Material | Data handling & control |
Provided To Others? | Yes |
Impact | Multiple publications from my own research group and research groups worldwide Online distribution has been accessed through the laboratory website with site views at a rate of >500 per month |
URL | http://psrg.org.uk |
Title | OnGuard |
Description | Quantitative systems biology modelling of cellular transport and homeostasis |
Type Of Material | Computer model/algorithm |
Year Produced | 2012 |
Provided To Others? | Yes |
Impact | Multiple publications from my own research group and research groups worldwide Online distribution has been accessed through the laboratory website with site views at a rate of >500 per month |
URL | http://psrg.org.uk |
Title | SDM-assist |
Description | Software for molecular primer design that enables introduction of silent markers for molecular cloning |
Type Of Material | Data analysis technique |
Year Produced | 2013 |
Provided To Others? | Yes |
Impact | Multiple publications from my own research group and research groups worldwide Online distribution has been accessed through the laboratory website with site views at a rate of >500 per month |
URL | http://psrg.org.uk |
Description | PBL |
Organisation | Plant Bioscience Limited Technology |
Country | United Kingdom |
Sector | Private |
PI Contribution | IPR on ABA receptor technology and ABA signalling |
Collaborator Contribution | Funding related to IPR on ABA receptor technology and ABA signalling |
Impact | Multiple outcomes in publications and industrial contacts |
Description | PSG |
Organisation | POSCO - South Korea |
Country | Korea, Republic of |
Sector | Private |
PI Contribution | Base support for meetings and exchange of materials |
Collaborator Contribution | Base support for meetings and exchange of materials |
Impact | Base support for meetings and exchange of materials |
Title | Software tools and packages for electrophysiology and imaging |
Description | The laboratory continues to develop and refine software/hardware tools for data acquisition and analysis relevant to electrophysiology, single-cell imaging and analysis. These activities are long-standing and open-ended, and develop in line with the current research activities and needs of the laboratory. All software and related packages are made freely available to the research community through the laboratory website at psrg.org.uk |
Type Of Technology | Software |
Impact | The various software tools and packages have furthered the research activities of the laboratory since the 1990s and continue to provide key support and drivers for advancing much of current research. These tools and packages are disseminated, on average, to over 100 laboratories per year. |
URL | http://psrg.org.uk |
Description | International online services |
Form Of Engagement Activity | A press release, press conference or response to a media enquiry/interview |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Public/other audiences |
Results and Impact | Prof. Blatt and members of his laboratory have contributed to various media events over the years, including online interview contributions (e.g. People behind the Science, a US-based media program) |
Year(s) Of Engagement Activity | Pre-2006,2006,2008,2011,2015,2016,2017,2018 |
Description | Invited presentations |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Public/other audiences |
Results and Impact | I regularly speak to audiences, from small groups (5-20) to large audiences (>1000) in a variety of settings. In addition to teaching and extramural activities associated with the university, I also speak on invitation to national and international groups a number of times each year and in a variety of settings, academic as well as public. I also reach audiences through short video presentations mounted on the web, these primarily via my laboratory website and the ASPB websites. Anyone reading this entry is welcome to visit these sites to learn more. The impacts arising from my presentations are varied. For example, a common consequence of my speaking in academic settings is to attract potential researchers to visit my laboratory and, frequently, to interest potential collaborators and students/postdocs to my research group. At scientific meetings, my talks often attract interest also from researchers interested in the various tools and materials that my research has produced, including the various vector systems and software packages that I |
Year(s) Of Engagement Activity | Pre-2006,2006,2007,2008,2009,2010,2011,2012,2013,2014,2015,2016,2017,2018 |
URL | http://psrg.org.uk |
Description | Schools and displays |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | Yes |
Geographic Reach | International |
Primary Audience | Public/other audiences |
Results and Impact | As these were multiple events, this question is not informative or useful. Participants varied from numbers in the tens to several thousands Extensive training of participating laboratory members as well as broad scope reach to schools and communities, in the case of the GCC science days to the west of Scotland and in the case of the IFPD activities to audiences within and outside the UK |
Year(s) Of Engagement Activity | 2010,2011,2012,2013,2014,2015,2016,2017,2018 |
URL | http://psrg.org.uk |
Description | Teaching Tools |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | Yes |
Geographic Reach | International |
Primary Audience | Schools |
Results and Impact | The PI has supported the editor in developing these tools since their inception in 2009 and has contributed to recent tools relating to membranes and transport education The Tool received an international award in 2010 for excellence in education and has an acknowledged takeup worldwide in over 3000 institutions |
Year(s) Of Engagement Activity | 2009,2010,2011,2012,2013,2014,2015,2016,2017,2018 |
URL | http://psrg.org.uk |
Description | Teaching Tools |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | Yes |
Geographic Reach | International |
Primary Audience | Schools |
Results and Impact | The PI has supported the editor in developing these tools since their inception in 2009 and has contributed to recent tools relating to membranes and transport education The Tool received an international award in 2010 for excellence in education and has an acknowledged takeup worldwide in over 3000 institutions |
Year(s) Of Engagement Activity | 2009,2010,2011,2012,2013,2014,2015,2016,2017,2018 |
URL | http://psrg.org.uk |