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Karthick PV, Senthil A, Djanaguiraman M, Anitha K, Kuttimani R, Boominathan P, Karthikeyan R, Raveendran M. Improving Crop Yield through Increasing Carbon Gain and Reducing Carbon Loss. PLANTS (BASEL, SWITZERLAND) 2024; 13:1317. [PMID: 38794389 PMCID: PMC11124956 DOI: 10.3390/plants13101317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 04/07/2024] [Accepted: 04/10/2024] [Indexed: 05/26/2024]
Abstract
Photosynthesis is a process where solar energy is utilized to convert atmospheric CO2 into carbohydrates, which forms the basis for plant productivity. The increasing demand for food has created a global urge to enhance yield. Earlier, the plant breeding program was targeting the yield and yield-associated traits to enhance the crop yield. However, the yield cannot be further improved without improving the leaf photosynthetic rate. Hence, in this review, various strategies to enhance leaf photosynthesis were presented. The most promising strategies were the optimization of Rubisco carboxylation efficiency, the introduction of a CO2 concentrating mechanism in C3 plants, and the manipulation of photorespiratory bypasses in C3 plants, which are discussed in detail. Improving Rubisco's carboxylation efficiency is possible by engineering targets such as Rubisco subunits, chaperones, and Rubisco activase enzyme activity. Carbon-concentrating mechanisms can be introduced in C3 plants by the adoption of pyrenoid and carboxysomes, which can increase the CO2 concentration around the Rubisco enzyme. Photorespiration is the process by which the fixed carbon is lost through an oxidative process. Different approaches to reduce carbon and nitrogen loss were discussed. Overall, the potential approaches to improve the photosynthetic process and the way forward were discussed in detail.
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Affiliation(s)
- Palanivelu Vikram Karthick
- Department of Crop Physiology, Tamil Nadu Agricultural University, Coimbatore 641003, India; (P.V.K.); (M.D.); (K.A.); (R.K.); (P.B.)
| | - Alagarswamy Senthil
- Department of Crop Physiology, Tamil Nadu Agricultural University, Coimbatore 641003, India; (P.V.K.); (M.D.); (K.A.); (R.K.); (P.B.)
| | - Maduraimuthu Djanaguiraman
- Department of Crop Physiology, Tamil Nadu Agricultural University, Coimbatore 641003, India; (P.V.K.); (M.D.); (K.A.); (R.K.); (P.B.)
| | - Kuppusamy Anitha
- Department of Crop Physiology, Tamil Nadu Agricultural University, Coimbatore 641003, India; (P.V.K.); (M.D.); (K.A.); (R.K.); (P.B.)
| | - Ramalingam Kuttimani
- Department of Crop Physiology, Tamil Nadu Agricultural University, Coimbatore 641003, India; (P.V.K.); (M.D.); (K.A.); (R.K.); (P.B.)
| | - Parasuraman Boominathan
- Department of Crop Physiology, Tamil Nadu Agricultural University, Coimbatore 641003, India; (P.V.K.); (M.D.); (K.A.); (R.K.); (P.B.)
| | - Ramasamy Karthikeyan
- Directorate of Crop Management, Tamil Nadu Agricultural University, Coimbatore 641003, India;
| | - Muthurajan Raveendran
- Directorate of Research, Tamil Nadu Agricultural University, Coimbatore 641003, India;
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Schulz-Mirbach H, Dronsella B, He H, Erb TJ. Creating new-to-nature carbon fixation: A guide. Metab Eng 2024; 82:12-28. [PMID: 38160747 DOI: 10.1016/j.ymben.2023.12.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 12/23/2023] [Accepted: 12/27/2023] [Indexed: 01/03/2024]
Abstract
Synthetic biology aims at designing new biological functions from first principles. These new designs allow to expand the natural solution space and overcome the limitations of naturally evolved systems. One example is synthetic CO2-fixation pathways that promise to provide more efficient ways for the capture and conversion of CO2 than natural pathways, such as the Calvin Benson Bassham (CBB) cycle of photosynthesis. In this review, we provide a practical guideline for the design and realization of such new-to-nature CO2-fixation pathways. We introduce the concept of "synthetic CO2-fixation", and give a general overview over the enzymology and topology of synthetic pathways, before we derive general principles for their design from their eight naturally evolved analogs. We provide a comprehensive summary of synthetic carbon-assimilation pathways and derive a step-by-step, practical guide from the theoretical design to their practical implementation, before ending with an outlook on new developments in the field.
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Affiliation(s)
- Helena Schulz-Mirbach
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Str. 10, 35043, Marburg, Germany
| | - Beau Dronsella
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Str. 10, 35043, Marburg, Germany; Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam, Germany
| | - Hai He
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Str. 10, 35043, Marburg, Germany
| | - Tobias J Erb
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Str. 10, 35043, Marburg, Germany; Center for Synthetic Microbiology (SYNMIKRO), Karl-von-Frisch-Str. 16, D-35043, Marburg, Germany.
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3
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Zhao L, Cai Z, Li Y, Zhang Y. Engineering Rubisco to enhance CO 2 utilization. Synth Syst Biotechnol 2024; 9:55-68. [PMID: 38273863 PMCID: PMC10809010 DOI: 10.1016/j.synbio.2023.12.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 12/15/2023] [Accepted: 12/25/2023] [Indexed: 01/27/2024] Open
Abstract
Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) is a pivotal enzyme that mediates the fixation of CO2. As the most abundant protein on earth, Rubisco has a significant impact on global carbon, water, and nitrogen cycles. However, the significantly low carboxylation activity and competing oxygenase activity of Rubisco greatly impede high carbon fixation efficiency. This review first summarizes the current efforts in directly or indirectly modifying plant Rubisco, which has been challenging due to its high conservation and limitations in chloroplast transformation techniques. However, recent advancements in understanding Rubisco biogenesis with the assistance of chaperones have enabled successful heterologous expression of all Rubisco forms, including plant Rubisco, in microorganisms. This breakthrough facilitates the acquisition and evaluation of modified proteins, streamlining the measurement of their activity. Moreover, the establishment of a screening system in E. coli opens up possibilities for obtaining high-performance mutant enzymes through directed evolution. Finally, this review emphasizes the utilization of Rubisco in microorganisms, not only expanding their carbon-fixing capabilities but also holding significant potential for enhancing biotransformation processes.
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Affiliation(s)
- Lei Zhao
- CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhen Cai
- CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Yin Li
- CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Yanping Zhang
- CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
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4
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Matsushima A, Matsuo K. Removal of plant endogenous proteins from tobacco leaf extract by freeze-thaw treatment for purification of recombinant proteins. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2024; 339:111953. [PMID: 38072330 DOI: 10.1016/j.plantsci.2023.111953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 12/05/2023] [Accepted: 12/06/2023] [Indexed: 01/13/2024]
Abstract
Plants are useful as a low-cost source for producing biopharmaceutical proteins. A significant hurdle in the production of recombinant proteins in plants, however, is the complicated process of removing plant-derived components. Removing endogenous plant proteins, including ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO), a major photosynthetic plant enzyme that catalyzes photosynthesis through carboxylation and oxygenation, is important for the purification of recombinant plant proteins. In particular, RuBisCO accounts for 50% of the soluble leaf protein; thus, the removal of RuBisCO is critical for the purification of recombinant proteins from plant materials. An effective conventional method, known as freeze-thaw treatment, was developed for the removal of RuBisCO from Nicotiana benthamiana, which expresses recombinant green fluorescent protein (GFP). Crude extracts or supernatants were frozen at - 30 °C. Upon thawing, most of the RuBisCO was precipitated by centrifugation without significant inactivation and/or yield reduction of GFP. Based on the proteomics analysis, using this method, RuBisCO large and small subunits were reduced to approximately 10% and 20% of those of the unfrozen supernatant solutions, respectively, without the need for specific reagents or equipment. The proteomic analysis also revealed that many ribosomal proteins were removed from the extracts. This method improves the purification process of recombinant proteins from plant materials. Prolonged freezing damaged recombinant β-glucuronidase (GUS), suggesting that the applicability of this treatment should be carefully considered for each recombinant protein.
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Affiliation(s)
- Akito Matsushima
- Frontier Business Division, Chiyoda Corporation, 4-6-2 Minatomirai, Nishi-ku, Yokohama 220-8765, Japan
| | - Kouki Matsuo
- National Institute of Advanced Industrial Science and Technology (AIST), Bioproduction Research Institute, 2-17-2-1 Tsukisamu-Higashi, Toyohira-ku, Sapporo 062-8517, Japan.
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5
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Jin K, Chen G, Yang Y, Zhang Z, Lu T. Strategies for manipulating Rubisco and creating photorespiratory bypass to boost C 3 photosynthesis: Prospects on modern crop improvement. PLANT, CELL & ENVIRONMENT 2023; 46:363-378. [PMID: 36444099 DOI: 10.1111/pce.14500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 11/25/2022] [Accepted: 11/26/2022] [Indexed: 06/16/2023]
Abstract
Photosynthesis is a process that uses solar energy to fix CO2 in the air and converts it into sugar, and ultimately powers almost all life activities on the earth. C3 photosynthesis is the most common form of photosynthesis in crops. Current efforts of increasing crop yields in response to growing global food requirement are mostly focused on improving C3 photosynthesis. In this review, we summarized the strategies of C3 photosynthesis improvement in terms of Rubisco properties and photorespiratory limitation. Potential engineered targets include Rubisco subunits and their catalytic sites, Rubisco assembly chaperones, and Rubisco activase. In addition, we reviewed multiple photorespiratory bypasses built by strategies of synthetic biology to reduce the release of CO2 and ammonia and minimize energy consumption by photorespiration. The potential strategies are suggested to enhance C3 photosynthesis and boost crop production.
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Affiliation(s)
- Kaining Jin
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, P. R. China
- Department of Plant Sciences, Centre for Crop Systems Analysis, Wageningen University & Research, Wageningen, The Netherlands
| | - Guoxin Chen
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, P. R. China
| | - Yirong Yang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, P. R. China
| | - Zhiguo Zhang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, P. R. China
| | - Tiegang Lu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, P. R. China
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6
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Oh ZG, Askey B, Gunn LH. Red Rubiscos and opportunities for engineering green plants. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:520-542. [PMID: 36055563 PMCID: PMC9833100 DOI: 10.1093/jxb/erac349] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 09/01/2022] [Indexed: 06/15/2023]
Abstract
Nature's vital, but notoriously inefficient, CO2-fixing enzyme Rubisco often limits the growth of photosynthetic organisms including crop species. Form I Rubiscos comprise eight catalytic large subunits and eight auxiliary small subunits and can be classified into two distinct lineages-'red' and 'green'. While red-type Rubiscos (Form IC and ID) are found in rhodophytes, their secondary symbionts, and certain proteobacteria, green-type Rubiscos (Form IA and IB) exist in terrestrial plants, chlorophytes, cyanobacteria, and other proteobacteria. Eukaryotic red-type Rubiscos exhibit desirable kinetic properties, namely high specificity and high catalytic efficiency, with certain isoforms outperforming green-type Rubiscos. However, it is not yet possible to functionally express a high-performing red-type Rubisco in chloroplasts to boost photosynthetic carbon assimilation in green plants. Understanding the molecular and evolutionary basis for divergence between red- and green-type Rubiscos could help us to harness the superior CO2-fixing power of red-type Rubiscos. Here we review our current understanding about red-type Rubisco distribution, biogenesis, and sequence-structure, and present opportunities and challenges for utilizing red-type Rubisco kinetics towards crop improvements.
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Affiliation(s)
- Zhen Guo Oh
- Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, USA
| | - Bryce Askey
- Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, USA
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Buck S, Rhodes T, Gionfriddo M, Skinner T, Yuan D, Birch R, Kapralov MV, Whitney SM. Escherichia coli expressing chloroplast chaperones as a proxy to test heterologous Rubisco production in leaves. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:664-676. [PMID: 36322613 DOI: 10.1093/jxb/erac435] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 10/31/2022] [Indexed: 06/16/2023]
Abstract
Rubisco is a fundamental enzyme in photosynthesis and therefore for life. Efforts to improve plant Rubisco performance have been hindered by the enzymes' complex chloroplast biogenesis requirements. New Synbio approaches, however, now allow the production of some plant Rubisco isoforms in Escherichia coli. While this enhances opportunities for catalytic improvement, there remain limitations in the utility of the expression system. Here we generate, optimize, and test a robust Golden Gate cloning E. coli expression system incorporating the protein folding machinery of tobacco chloroplasts. By comparing the expression of different plant Rubiscos in both E. coli and plastome-transformed tobacco, we show that the E. coli expression system can accurately predict high level Rubisco production in chloroplasts but poorly forecasts the biogenesis potential of isoforms with impaired production in planta. We reveal that heterologous Rubisco production in E. coli and tobacco plastids poorly correlates with Rubisco large subunit phylogeny. Our findings highlight the need to fully understand the factors governing Rubisco biogenesis if we are to deliver an efficient, low-cost screening tool that can accurately emulate chloroplast expression.
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Affiliation(s)
- Sally Buck
- ARC Centre of Excellence in Translational Photosynthesis, Australian National University, Canberra 2000, Australia
| | - Tim Rhodes
- ARC Centre of Excellence in Translational Photosynthesis, Australian National University, Canberra 2000, Australia
| | - Matteo Gionfriddo
- ARC Centre of Excellence in Translational Photosynthesis, Australian National University, Canberra 2000, Australia
| | - Tanya Skinner
- ARC Centre of Excellence in Translational Photosynthesis, Australian National University, Canberra 2000, Australia
| | - Ding Yuan
- ARC Centre of Excellence in Translational Photosynthesis, Australian National University, Canberra 2000, Australia
| | - Rosemary Birch
- ARC Centre of Excellence in Translational Photosynthesis, Australian National University, Canberra 2000, Australia
| | - Maxim V Kapralov
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
| | - Spencer M Whitney
- ARC Centre of Excellence in Translational Photosynthesis, Australian National University, Canberra 2000, Australia
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8
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Manning T, Birch R, Stevenson T, Nugent G, Whitney S. Bacterial Form II Rubisco can support wild-type growth and productivity in Solanum tuberosum cv. Desiree (potato) under elevated CO 2. PNAS NEXUS 2023; 2:pgac305. [PMID: 36743474 PMCID: PMC9896143 DOI: 10.1093/pnasnexus/pgac305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Accepted: 12/22/2022] [Indexed: 02/05/2023]
Abstract
The last decade has seen significant advances in the development of approaches for improving both the light harvesting and carbon fixation pathways of photosynthesis by nuclear transformation, many involving multigene synthetic biology approaches. As efforts to replicate these accomplishments from tobacco into crops gather momentum, similar diversification is needed in the range of transgenic options available, including capabilities to modify crop photosynthesis by chloroplast transformation. To address this need, here we describe the first transplastomic modification of photosynthesis in a crop by replacing the native Rubisco in potato with the faster, but lower CO2-affinity and poorer CO2/O2 specificity Rubisco from the bacterium Rhodospirillum rubrum. High level production of R. rubrum Rubisco in the potRr genotype (8 to 10 µmol catalytic sites m2) allowed it to attain wild-type levels of productivity, including tuber yield, in air containing 0.5% (v/v) CO2. Under controlled environment growth at 25°C and 350 µmol photons m2 PAR, the productivity and leaf biochemistry of wild-type potato at 0.06%, 0.5%, or 1.5% (v/v) CO2 and potRr at 0.5% or 1.5% (v/v) CO2 were largely indistinguishable. These findings suggest that increasing the scope for enhancing productivity gains in potato by improving photosynthate production will necessitate improvement to its sink-potential, consistent with current evidence productivity gains by eCO2 fertilization for this crop hit a ceiling around 560 to 600 ppm CO2.
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Affiliation(s)
- Tahnee Manning
- School of Science, RMIT University, Bundoora, VIC 3083, Australia
| | - Rosemary Birch
- Australian Research Council Centre of Excellence for Translational Photosynthesis, Research School of Biology, The Australian National University, 134 Linnaeus Way, Acton, ACT 0200, Australia
| | - Trevor Stevenson
- School of Science, RMIT University, Bundoora, VIC 3083, Australia
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Tcherkez G, Farquhar GD. Rubisco catalytic adaptation is mostly driven by photosynthetic conditions - Not by phylogenetic constraints. JOURNAL OF PLANT PHYSIOLOGY 2021; 267:153554. [PMID: 34749030 DOI: 10.1016/j.jplph.2021.153554] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Revised: 10/19/2021] [Accepted: 10/19/2021] [Indexed: 06/13/2023]
Abstract
The prevalence of phylogenetic constraints in Rubisco evolution has been emphasised recently by (Bouvier et al., 2021), who argued that phylogenetic inheritance limits Rubisco adaptation much more than the biochemical trade-off between specificity, CO2 affinity and turn-over. In this Opinion, we have critically examined how a phylogenetic signal can be computed with Rubisco kinetic properties and phylogenetic trees, and we arrive at a different conclusion. In particular, Rubisco's adaptation is partly driven by C4 vs. C3 photosynthetic conditions in Angiosperms, apparent phylogenetic signals being mostly due to either homoplasy, computation artefacts or the use of nearly identical sister species. While phylogenetic inheritance of an ancestral enzyme form probably has some role in Rubisco's adaptation landscape, it is a minor player, at least compared to microenvironmental conditions such as CO2 and O2 concentrations.
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Affiliation(s)
- Guillaume Tcherkez
- Institut de Recherche and Horticulture et Semences, INRAe Angers, Université D'Angers, 42 Rue Georges Morel, 49070, Beaucouzé, France; Research School of Biology, ANU College of Science, Australian National University, 2601, Canberra ACT, Australia.
| | - Graham D Farquhar
- Research School of Biology, ANU College of Science, Australian National University, 2601, Canberra ACT, Australia
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Gupta D, Sharma G, Saraswat P, Ranjan R. Synthetic Biology in Plants, a Boon for Coming Decades. Mol Biotechnol 2021; 63:1138-1154. [PMID: 34420149 DOI: 10.1007/s12033-021-00386-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Accepted: 08/16/2021] [Indexed: 02/01/2023]
Abstract
Recently an enormous expansion of knowledge is seen in various disciplines of science. This surge of information has given rise to concept of interdisciplinary fields, which has resulted in emergence of newer research domains, one of them is 'Synthetic Biology' (SynBio). It captures basics from core biology and integrates it with concepts from the other areas of study such as chemical, electrical, and computational sciences. The essence of synthetic biology is to rewire, re-program, and re-create natural biological pathways, which are carried through genetic circuits. A genetic circuit is a functional assembly of basic biological entities (DNA, RNA, proteins), created using typical design, built, and test cycles. These circuits allow scientists to engineer nearly all biological systems for various useful purposes. The development of sophisticated molecular tools, techniques, genomic programs, and ease of nucleic acid synthesis have further fueled several innovative application of synthetic biology in areas like molecular medicines, pharmaceuticals, biofuels, drug discovery, metabolomics, developing plant biosensors, utilization of prokaryotic systems for metabolite production, and CRISPR/Cas9 in the crop improvement. These applications have largely been dominated by utilization of prokaryotic systems. However, newer researches have indicated positive growth of SynBio for the eukaryotic systems as well. This paper explores advances of synthetic biology in the plant field by elaborating on its core components and potential applications. Here, we have given a comprehensive idea of designing, development, and utilization of synthetic biology in the improvement of the present research state of plant system.
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Affiliation(s)
- Dipinte Gupta
- Plant Biotechnology Lab, Department of Botany, Faculty of Science, Dayalbagh Educational Institute (Deemed to be University), Dayalbagh, Agra, 282005, India
| | - Gauri Sharma
- Plant Biotechnology Lab, Department of Botany, Faculty of Science, Dayalbagh Educational Institute (Deemed to be University), Dayalbagh, Agra, 282005, India
| | - Pooja Saraswat
- Plant Biotechnology Lab, Department of Botany, Faculty of Science, Dayalbagh Educational Institute (Deemed to be University), Dayalbagh, Agra, 282005, India
| | - Rajiv Ranjan
- Plant Biotechnology Lab, Department of Botany, Faculty of Science, Dayalbagh Educational Institute (Deemed to be University), Dayalbagh, Agra, 282005, India.
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Whitney SM, Sharwood RE. Rubisco Engineering by Plastid Transformation and Protocols for Assessing Expression. Methods Mol Biol 2021; 2317:195-214. [PMID: 34028770 DOI: 10.1007/978-1-0716-1472-3_10] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The assimilation of CO2 within chloroplasts is catalyzed by the bifunctional enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase, Rubisco. Within higher plants the Rubisco large subunit gene, rbcL, is encoded in the plastid genome, while the Rubisco small subunit gene, RbcS is coded in the nucleus by a multigene family. Rubisco is considered a poor catalyst due to its slow turnover rate and its additional fixation of O2 that can result in wasteful loss of carbon through the energy requiring photorespiratory cycle. Improving the carboxylation efficiency and CO2/O2 selectivity of Rubisco within higher plants has been a long term goal which has been greatly advanced in recent times using plastid transformation techniques. Here we present experimental methodologies for efficiently engineering Rubisco in the plastids of a tobacco master line and analyzing leaf Rubisco content.
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Affiliation(s)
- Spencer M Whitney
- Plant Sciences, Research School of Biology, College of Science, The Australian National University, Acton, ACT, Australia.
| | - Robert E Sharwood
- Plant Sciences, Research School of Biology, College of Science, The Australian National University, Acton, ACT, Australia
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12
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Emerging research in plant photosynthesis. Emerg Top Life Sci 2020; 4:137-150. [PMID: 32573736 DOI: 10.1042/etls20200035] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 06/03/2020] [Accepted: 06/05/2020] [Indexed: 12/27/2022]
Abstract
Photosynthesis involves capturing light energy and, most often, converting it to chemical energy stored as reduced carbon. It is the source of food, fuel, and fiber and there is a resurgent interest in basic research on photosynthesis. Plants make excellent use of visible light energy; leaves are ideally suited to optimize light use by having a large area per amount of material invested and also having leaf angles to optimize light utilization. It is thought that plants do not use green light but in fact they use green light better than blue light under some conditions. Leaves also have mechanisms to protect against excess light and how these work in a stochastic light environment is currently a very active area of current research. The speed at which photosynthesis can begin when leaves are first exposed to light and the speed of induction of protective mechanisms, as well as the speed at which protective mechanisms dissipate when light levels decline, have recently been explored. Research is also focused on reducing wasteful processes such as photorespiration, when oxygen instead of carbon dioxide is used. Some success has been reported in altering the path of carbon in photorespiration but on closer inspection there appears to be unforeseen effects contributing to the good news. The stoichiometry of interaction of light reactions with carbon metabolism is rigid and the time constants vary tremendously presenting large challenges to regulatory mechanisms. Regulatory mechanisms will be the topic of photosynthesis research for some time to come.
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13
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Davidi D, Shamshoum M, Guo Z, Bar‐On YM, Prywes N, Oz A, Jablonska J, Flamholz A, Wernick DG, Antonovsky N, de Pins B, Shachar L, Hochhauser D, Peleg Y, Albeck S, Sharon I, Mueller‐Cajar O, Milo R. Highly active rubiscos discovered by systematic interrogation of natural sequence diversity. EMBO J 2020; 39:e104081. [PMID: 32500941 PMCID: PMC7507306 DOI: 10.15252/embj.2019104081] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2019] [Revised: 04/30/2020] [Accepted: 05/07/2020] [Indexed: 11/09/2022] Open
Abstract
CO2 is converted into biomass almost solely by the enzyme rubisco. The poor carboxylation properties of plant rubiscos have led to efforts that made it the most kinetically characterized enzyme, yet these studies focused on < 5% of its natural diversity. Here, we searched for fast-carboxylating variants by systematically mining genomic and metagenomic data. Approximately 33,000 unique rubisco sequences were identified and clustered into ≈ 1,000 similarity groups. We then synthesized, purified, and biochemically tested the carboxylation rates of 143 representatives, spanning all clusters of form-II and form-II/III rubiscos. Most variants (> 100) were active in vitro, with the fastest having a turnover number of 22 ± 1 s-1 -sixfold faster than the median plant rubisco and nearly twofold faster than the fastest measured rubisco to date. Unlike rubiscos from plants and cyanobacteria, the fastest variants discovered here are homodimers and exhibit a much simpler folding and activation kinetics. Our pipeline can be utilized to explore the kinetic space of other enzymes of interest, allowing us to get a better view of the biosynthetic potential of the biosphere.
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Affiliation(s)
- Dan Davidi
- Department of Plant and Environmental SciencesWeizmann Institute of ScienceRehovotIsrael
- Present address:
Department of GeneticsHarvard Medical SchoolBostonMAUSA
| | - Melina Shamshoum
- Department of Plant and Environmental SciencesWeizmann Institute of ScienceRehovotIsrael
| | - Zhijun Guo
- School of Biological SciencesNanyang Technological UniversitySingaporeSingapore
| | - Yinon M Bar‐On
- Department of Plant and Environmental SciencesWeizmann Institute of ScienceRehovotIsrael
| | - Noam Prywes
- Department of Molecular and Cell BiologyUniversity of CaliforniaBerkeleyCAUSA
| | - Aia Oz
- Migal Galilee Research InstituteKiryat ShmonaIsrael
- Tel Hai CollegeUpper GalileeIsrael
| | - Jagoda Jablonska
- Department of Biomolecular SciencesWeizmann Institute of ScienceRehovotIsrael
| | - Avi Flamholz
- Department of Molecular and Cell BiologyUniversity of CaliforniaBerkeleyCAUSA
| | - David G Wernick
- Department of Plant and Environmental SciencesWeizmann Institute of ScienceRehovotIsrael
- Present address:
BASF Enzymes LLCSan DiegoCAUSA
| | - Niv Antonovsky
- Department of Plant and Environmental SciencesWeizmann Institute of ScienceRehovotIsrael
- Present address:
Laboratory of Genetically Encoded Small MoleculesThe Rockefeller UniversityNew YorkNYUSA
| | - Benoit de Pins
- Department of Plant and Environmental SciencesWeizmann Institute of ScienceRehovotIsrael
| | - Lior Shachar
- Department of Plant and Environmental SciencesWeizmann Institute of ScienceRehovotIsrael
| | - Dina Hochhauser
- Department of Molecular GeneticsWeizmann Institute of ScienceRehovotIsrael
| | - Yoav Peleg
- Department of Life Sciences Core FacilitiesWeizmann Institute of ScienceRehovotIsrael
| | - Shira Albeck
- Department of Life Sciences Core FacilitiesWeizmann Institute of ScienceRehovotIsrael
| | - Itai Sharon
- Migal Galilee Research InstituteKiryat ShmonaIsrael
- Tel Hai CollegeUpper GalileeIsrael
| | | | - Ron Milo
- Department of Plant and Environmental SciencesWeizmann Institute of ScienceRehovotIsrael
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von Caemmerer S. Rubisco carboxylase/oxygenase: From the enzyme to the globe: A gas exchange perspective. JOURNAL OF PLANT PHYSIOLOGY 2020; 252:153240. [PMID: 32707452 DOI: 10.1016/j.jplph.2020.153240] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 07/12/2020] [Indexed: 05/28/2023]
Abstract
Rubisco is the primary carboxylase of the photosynthetic process, the most abundant enzyme in the biosphere, and also one of the best-characterized enzymes. Rubisco also functions as an oxygenase, a discovery made 50 years ago by Bill Ogren. Carboxylation of ribulose bisphosphate (RuBP) is the first step of the photosynthetic carbon reduction cycle and leads to the assimilation of CO2, whereas the oxygenase activity necessitates the recycling of phosphoglycolate through the photorespiratory carbon oxidation cycle with concomitant loss of CO2. Since the discovery of Rubisco's dual function, the biochemical properties of Rubisco have underpinned the mechanistic mathematical models of photosynthetic CO2 fixation which link Rubisco kinetic properties to gas exchange of leaves. This has allowed assessments of global CO2 exchange and predictions of how Rubisco has and will shape the environmental responses of crop and global photosynthesis in future climates. Rubisco's biochemical properties, including its slow catalytic turnover and poor affinity for CO2, constrain crop growth and therefore improving its activity and regulation and minimising photorespiration are key targets for crop improvement.
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Affiliation(s)
- Susanne von Caemmerer
- Australian Research Council Centre of Excellence for Translational Photosynthesis, Division of Plant Science, Research School of Biology, The Australian National University, Acton, Australian Capital Territory, 2601, Australia.
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15
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Orr DJ, Worrall D, Lin MT, Carmo-Silva E, Hanson MR, Parry MAJ. Hybrid Cyanobacterial-Tobacco Rubisco Supports Autotrophic Growth and Procarboxysomal Aggregation. PLANT PHYSIOLOGY 2020; 182:807-818. [PMID: 31744936 PMCID: PMC6997680 DOI: 10.1104/pp.19.01193] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 11/05/2019] [Indexed: 05/22/2023]
Abstract
Much of the research aimed at improving photosynthesis and crop productivity attempts to overcome shortcomings of the primary CO2-fixing enzyme Rubisco. Cyanobacteria utilize a CO2-concentrating mechanism (CCM), which encapsulates Rubisco with poor specificity but a relatively fast catalytic rate within a carboxysome microcompartment. Alongside the active transport of bicarbonate into the cell and localization of carbonic anhydrase within the carboxysome shell with Rubisco, cyanobacteria are able to overcome the limitations of Rubisco via localization within a high-CO2 environment. As part of ongoing efforts to engineer a β-cyanobacterial CCM into land plants, we investigated the potential for Rubisco large subunits (LSU) from the β-cyanobacterium Synechococcus elongatus (Se) to form aggregated Rubisco complexes with the carboxysome linker protein CcmM35 within tobacco (Nicotiana tabacum) chloroplasts. Transplastomic plants were produced that lacked cognate Se Rubisco small subunits (SSU) and expressed the Se LSU in place of tobacco LSU, with and without CcmM35. Plants were able to form a hybrid enzyme utilizing tobacco SSU and the Se LSU, allowing slow autotrophic growth in high CO2 CcmM35 was able to form large Rubisco aggregates with the Se LSU, and these incorporated small amounts of native tobacco SSU. Plants lacking the Se SSU showed delayed growth, poor photosynthetic capacity, and significantly reduced Rubisco activity compared with both wild-type tobacco and lines expressing the Se SSU. These results demonstrate the ability of the Se LSU and CcmM35 to form large aggregates without the cognate Se SSU in planta, harboring active Rubisco that enables plant growth, albeit at a much slower pace than plants expressing the cognate Se SSU.
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Affiliation(s)
- Douglas J Orr
- Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, United Kingdom
| | - Dawn Worrall
- Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, United Kingdom
| | - Myat T Lin
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14850
| | - Elizabete Carmo-Silva
- Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, United Kingdom
| | - Maureen R Hanson
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14850
| | - Martin A J Parry
- Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, United Kingdom
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16
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Conlan B, Birch R, Kelso C, Holland S, De Souza AP, Long SP, Beck JL, Whitney SM. BSD2 is a Rubisco-specific assembly chaperone, forms intermediary hetero-oligomeric complexes, and is nonlimiting to growth in tobacco. PLANT, CELL & ENVIRONMENT 2019; 42:1287-1301. [PMID: 30375663 DOI: 10.1111/pce.13473] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 09/30/2018] [Accepted: 10/22/2018] [Indexed: 05/28/2023]
Abstract
The folding and assembly of Rubisco large and small subunits into L8 S8 holoenzyme in chloroplasts involves many auxiliary factors, including the chaperone BSD2. Here we identify apparent intermediary Rubisco-BSD2 assembly complexes in the model C3 plant tobacco. We show BSD2 and Rubisco content decrease in tandem with leaf age with approximately half of the BSD2 in young leaves (~70 nmol BSD2 protomer.m2 ) stably integrated in putative intermediary Rubisco complexes that account for <0.2% of the L8 S8 pool. RNAi-silencing BSD2 production in transplastomic tobacco producing bacterial L2 Rubisco had no effect on leaf photosynthesis, cell ultrastructure, or plant growth. Genetic crossing the same RNAi-bsd2 alleles into wild-type tobacco however impaired L8 S8 Rubisco production and plant growth, indicating the only critical function of BSD2 is in Rubisco biogenesis. Agrobacterium mediated transient expression of tobacco, Arabidopsis, or maize BSD2 reinstated Rubisco biogenesis in BSD2-silenced tobacco. Overexpressing BSD2 in tobacco chloroplasts however did not alter Rubisco content, activation status, leaf photosynthesis rate, or plant growth in the field or in the glasshouse at 20°C or 35°C. Our findings indicate BSD2 functions exclusively in Rubisco biogenesis, can efficiently facilitate heterologous plant Rubisco assembly, and is produced in amounts nonlimiting to tobacco growth.
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Affiliation(s)
- Brendon Conlan
- Research School of Biology, The Australian National University, Acton, Australian Capital Territory, Australia
| | - Rosemary Birch
- Research School of Biology, The Australian National University, Acton, Australian Capital Territory, Australia
| | - Celine Kelso
- School of Chemistry, Molecular Horizons, University of Wollongong, New South Wales, Australia
| | - Sophie Holland
- Research School of Biology, The Australian National University, Acton, Australian Capital Territory, Australia
| | - Amanda P De Souza
- Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, Illinois, USA
| | - Stephen P Long
- Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, Illinois, USA
- Lancaster Environment Centre, Lancaster University, Lancaster, UK
| | - Jennifer L Beck
- School of Chemistry, Molecular Horizons, University of Wollongong, New South Wales, Australia
| | - Spencer M Whitney
- Research School of Biology, The Australian National University, Acton, Australian Capital Territory, Australia
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17
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Kubis A, Bar-Even A. Synthetic biology approaches for improving photosynthesis. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:1425-1433. [PMID: 30715460 PMCID: PMC6432428 DOI: 10.1093/jxb/erz029] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 01/08/2019] [Indexed: 05/10/2023]
Abstract
The phenomenal increase in agricultural yields that we have witnessed in the last century has slowed down as we approach the limits of selective breeding and optimization of cultivation techniques. To support the yield increase required to feed an ever-growing population, we will have to identify new ways to boost the efficiency with which plants convert light into biomass. This challenge could potentially be tackled using state-of-the-art synthetic biology techniques to rewrite plant carbon fixation. In this review, we use recent studies to discuss and demonstrate different approaches for enhancing carbon fixation, including engineering Rubisco for higher activity, specificity, and activation; changing the expression level of enzymes within the Calvin cycle to avoid kinetic bottlenecks; introducing carbon-concentrating mechanisms such as inorganic carbon transporters, carboxysomes, and C4 metabolism; and rewiring photorespiration towards more energetically efficient routes or pathways that do not release CO2. We conclude by noting the importance of prioritizing and combining different approaches towards continuous and sustainable increase of plant productivities.
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Affiliation(s)
- Armin Kubis
- Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, Germany
| | - Arren Bar-Even
- Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, Germany
- Correspondence:
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18
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Smith-Moore CM, Grunden AM. Bacteria and archaea as the sources of traits for enhanced plant phenotypes. Biotechnol Adv 2018; 36:1900-1916. [DOI: 10.1016/j.biotechadv.2018.07.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Revised: 07/12/2018] [Accepted: 07/24/2018] [Indexed: 10/28/2022]
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19
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Long BM, Hee WY, Sharwood RE, Rae BD, Kaines S, Lim YL, Nguyen ND, Massey B, Bala S, von Caemmerer S, Badger MR, Price GD. Carboxysome encapsulation of the CO 2-fixing enzyme Rubisco in tobacco chloroplasts. Nat Commun 2018; 9:3570. [PMID: 30177711 PMCID: PMC6120970 DOI: 10.1038/s41467-018-06044-0] [Citation(s) in RCA: 141] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 08/12/2018] [Indexed: 12/30/2022] Open
Abstract
A long-term strategy to enhance global crop photosynthesis and yield involves the introduction of cyanobacterial CO2-concentrating mechanisms (CCMs) into plant chloroplasts. Cyanobacterial CCMs enable relatively rapid CO2 fixation by elevating intracellular inorganic carbon as bicarbonate, then concentrating it as CO2 around the enzyme Rubisco in specialized protein micro-compartments called carboxysomes. To date, chloroplastic expression of carboxysomes has been elusive, requiring coordinated expression of almost a dozen proteins. Here we successfully produce simplified carboxysomes, isometric with those of the source organism Cyanobium, within tobacco chloroplasts. We replace the endogenous Rubisco large subunit gene with cyanobacterial Form-1A Rubisco large and small subunit genes, along with genes for two key α-carboxysome structural proteins. This minimal gene set produces carboxysomes, which encapsulate the introduced Rubisco and enable autotrophic growth at elevated CO2. This result demonstrates the formation of α-carboxysomes from a reduced gene set, informing the step-wise construction of fully functional α-carboxysomes in chloroplasts.
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Affiliation(s)
- Benedict M Long
- Realizing Increased Photosynthetic Efficiency (RIPE), The Australian National University, 134 Linnaeus Way, Acton, ACT, 2601, Australia.
| | - Wei Yih Hee
- Realizing Increased Photosynthetic Efficiency (RIPE), The Australian National University, 134 Linnaeus Way, Acton, ACT, 2601, Australia
| | - Robert E Sharwood
- Australian Research Council Centre of Excellence for Translational Photosynthesis, Research School of Biology, The Australian National University, 134 Linnaeus Way, Acton, ACT, 2601, Australia
| | - Benjamin D Rae
- Australian Research Council Centre of Excellence for Translational Photosynthesis, Research School of Biology, The Australian National University, 134 Linnaeus Way, Acton, ACT, 2601, Australia
| | - Sarah Kaines
- Realizing Increased Photosynthetic Efficiency (RIPE), The Australian National University, 134 Linnaeus Way, Acton, ACT, 2601, Australia
| | - Yi-Leen Lim
- Realizing Increased Photosynthetic Efficiency (RIPE), The Australian National University, 134 Linnaeus Way, Acton, ACT, 2601, Australia
| | - Nghiem D Nguyen
- Australian Research Council Centre of Excellence for Translational Photosynthesis, Research School of Biology, The Australian National University, 134 Linnaeus Way, Acton, ACT, 2601, Australia
| | - Baxter Massey
- Realizing Increased Photosynthetic Efficiency (RIPE), The Australian National University, 134 Linnaeus Way, Acton, ACT, 2601, Australia
| | - Soumi Bala
- Australian Research Council Centre of Excellence for Translational Photosynthesis, Research School of Biology, The Australian National University, 134 Linnaeus Way, Acton, ACT, 2601, Australia
| | - Susanne von Caemmerer
- Realizing Increased Photosynthetic Efficiency (RIPE), The Australian National University, 134 Linnaeus Way, Acton, ACT, 2601, Australia
- Australian Research Council Centre of Excellence for Translational Photosynthesis, Research School of Biology, The Australian National University, 134 Linnaeus Way, Acton, ACT, 2601, Australia
| | - Murray R Badger
- Realizing Increased Photosynthetic Efficiency (RIPE), The Australian National University, 134 Linnaeus Way, Acton, ACT, 2601, Australia
- Australian Research Council Centre of Excellence for Translational Photosynthesis, Research School of Biology, The Australian National University, 134 Linnaeus Way, Acton, ACT, 2601, Australia
| | - G Dean Price
- Realizing Increased Photosynthetic Efficiency (RIPE), The Australian National University, 134 Linnaeus Way, Acton, ACT, 2601, Australia
- Australian Research Council Centre of Excellence for Translational Photosynthesis, Research School of Biology, The Australian National University, 134 Linnaeus Way, Acton, ACT, 2601, Australia
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20
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Ren W, Xie J, Hou X, Li X, Guo H, Hu N, Kong L, Zhang J, Chang C, Wu Z. Potential molecular mechanisms of overgrazing-induced dwarfism in sheepgrass (Leymus chinensis) analyzed using proteomic data. BMC PLANT BIOLOGY 2018; 18:81. [PMID: 29739327 PMCID: PMC5941328 DOI: 10.1186/s12870-018-1304-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 04/30/2018] [Indexed: 06/01/2023]
Abstract
BACKGROUND This study was designed to reveal potential molecular mechanisms of long-term overgrazing-induced dwarfism in sheepgrass (Leymus chinensis). METHODS An electrospray ionisation mass spectrometry system was used to generate proteomic data of dwarf sheepgrass from a long-term overgrazed rangeland and normal sheepgrass from a long-term enclosed rangeland. Differentially expressed proteins (DEPs) between dwarf and normal sheepgrass were identified, after which their potential functions and interactions with each other were predicted. The expression of key DEPs was confirmed by high-performance liquid chromatography mass spectrometry (HPLC-MS) using a multiple reaction monitoring method. RESULTS Compared with normal sheepgrass, a total of 51 upregulated and 53 downregulated proteins were identified in dwarf sheepgrass. The amino acids biosynthesis pathway was differentially enriched between the two conditions presenting DEPs, such as SAT5_ARATH and DAPA_MAIZE. The protein-protein interaction (PPI) network revealed a possible interaction between RPOB2_LEPTE, A0A023H9M8_9STRA, ATPB_DIOEL, RBL_AMOTI and DNAK_GRATL. Four modules were also extracted from the PPI network. The HPLC-MS analysis confirmed the upregulation and downregulation of ATPB_DIOEL and DNAK_GRATL, respectively in dwarf samples compared with in the controls. CONCLUSIONS The upregulated ATPB_DIOEL and downregulated DNAK_GRATL as well as proteins that interact with them, such as RPOB2_LEPTE, A0A023H9M8_9STRA and RBL_AMOTI, may be associated with the long-term overgrazing-induced dwarfism in sheepgrass.
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Affiliation(s)
- Weibo Ren
- Institute of Grassland Research, Chinese Academy of Agriculture Sciences, No.120 East Wulanchabu Road, Hohhot, 010010, Inner Mongolia, China
| | - Jihong Xie
- Institute of Grassland Research, Chinese Academy of Agriculture Sciences, No.120 East Wulanchabu Road, Hohhot, 010010, Inner Mongolia, China
| | - Xiangyang Hou
- Institute of Grassland Research, Chinese Academy of Agriculture Sciences, No.120 East Wulanchabu Road, Hohhot, 010010, Inner Mongolia, China
| | - Xiliang Li
- Institute of Grassland Research, Chinese Academy of Agriculture Sciences, No.120 East Wulanchabu Road, Hohhot, 010010, Inner Mongolia, China
| | - Huiqin Guo
- Faculty of life sciences, Inner Mongolia Agriculture University, Hohhot, 010018, Inner Mongolia, China
| | - Ningning Hu
- Institute of Grassland Research, Chinese Academy of Agriculture Sciences, No.120 East Wulanchabu Road, Hohhot, 010010, Inner Mongolia, China
| | - Lingqi Kong
- Institute of Grassland Research, Chinese Academy of Agriculture Sciences, No.120 East Wulanchabu Road, Hohhot, 010010, Inner Mongolia, China
| | - Jize Zhang
- Institute of Grassland Research, Chinese Academy of Agriculture Sciences, No.120 East Wulanchabu Road, Hohhot, 010010, Inner Mongolia, China
| | - Chun Chang
- Institute of Grassland Research, Chinese Academy of Agriculture Sciences, No.120 East Wulanchabu Road, Hohhot, 010010, Inner Mongolia, China
| | - Zinian Wu
- Institute of Grassland Research, Chinese Academy of Agriculture Sciences, No.120 East Wulanchabu Road, Hohhot, 010010, Inner Mongolia, China.
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21
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Lin MT, Hanson MR. Red algal Rubisco fails to accumulate in transplastomic tobacco expressing Griffithsia monilis RbcL and RbcS genes. PLANT DIRECT 2018; 2:e00045. [PMID: 31245711 PMCID: PMC6508576 DOI: 10.1002/pld3.45] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 01/28/2018] [Accepted: 01/30/2018] [Indexed: 05/03/2023]
Abstract
In C3 plants, the carbon fixation step catalyzed by ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) represents a major rate-limiting step due to the competing oxygenation reaction, which leads to the energy-intensive photorespiration and lowers the overall photosynthetic efficiency. Hence, there is great biotechnological interest in replacing the Rubisco in C3 crops with a more efficient enzyme. The Rubisco enzymes from red algae are among the most attractive choices due to their remarkable preference for carboxylation over oxygenation reaction. However, the biogenesis of Rubisco is extremely complex. The Rubisco enzymes in plants, algae, and cyanobacteria are made up of eight large and eight small subunits. The folding of the large subunits and the assembly of the large subunits with the small subunits to form a functional holoenzyme require specific chaperonin complexes and assembly factors. As a result, previous success in expressing foreign Rubisco in plants has been limited to Rubisco large subunits from closely related plant species and simpler bacterial enzymes. In our previous work, we successfully replaced the Rubisco in tobacco with a cyanobacterial enzyme, which was able to support the phototrophic growth of the transgenic plants. In this work, we used the same approach to express the Rubisco subunits from the red alga Griffithsia monilis in tobacco chloroplasts in the absence of the tobacco Rubisco large subunit. Although the red algal Rubisco genes are being transcribed in tobacco chloroplasts, the transgenic plants lack functional Rubisco and can only grow in a medium containing sucrose. Our results suggest that co-expression of compatible chaperones will be necessary for successful assembly of red algal Rubisco in plants.
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Affiliation(s)
- Myat T. Lin
- Department of Molecular Biology and GeneticsCornell UniversityIthacaNYUSA
| | - Maureen R. Hanson
- Department of Molecular Biology and GeneticsCornell UniversityIthacaNYUSA
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22
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Liu D, Ramya RCS, Mueller-Cajar O. Surveying the expanding prokaryotic Rubisco multiverse. FEMS Microbiol Lett 2018; 364:3983162. [PMID: 28854711 DOI: 10.1093/femsle/fnx156] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Accepted: 07/19/2017] [Indexed: 11/12/2022] Open
Abstract
The universal, but catalytically modest, CO2-fixing enzyme Rubisco is currently experiencing intense interest by researchers aiming to enhance crop photosynthesis. These efforts are mostly focused on the highly conserved hexadecameric enzyme found in land plants. In comparison, prokaryotic organisms harbor a far greater diversity in Rubisco forms. Recent work towards improving our appreciation of microbial Rubisco properties and harnessing their potential is surveyed. New structural models are providing informative glimpses into catalytic subtleties and diverse oligomeric states. Ongoing characterization is informing us about the conservation of constraints, such as sugar phosphate inhibition and the associated dependence on Rubisco activase helper proteins. Prokaryotic Rubiscos operate under a far wider range of metabolic contexts than the photosynthetic function of higher plant enzymes. Relaxed selection pressures may have resulted in the exploration of a larger volume of sequence space than permitted in organisms performing oxygenic photosynthesis. To tap into the potential of microbial Rubiscos, in vivo selection systems are being used to discover functional metagenomic Rubiscos. Various directed evolution systems to optimize their function have been developed. It is anticipated that this approach will provide access to biotechnologically valuable enzymes that cannot be encountered in the higher plant Rubisco space.
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Affiliation(s)
- Di Liu
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| | | | - Oliver Mueller-Cajar
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
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23
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Giessen TW, Silver PA. Engineering carbon fixation with artificial protein organelles. Curr Opin Biotechnol 2017; 46:42-50. [DOI: 10.1016/j.copbio.2017.01.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 01/05/2017] [Indexed: 10/20/2022]
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Mueller-Cajar O. The Diverse AAA+ Machines that Repair Inhibited Rubisco Active Sites. Front Mol Biosci 2017; 4:31. [PMID: 28580359 PMCID: PMC5437159 DOI: 10.3389/fmolb.2017.00031] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 04/29/2017] [Indexed: 11/13/2022] Open
Abstract
Gaseous carbon dioxide enters the biosphere almost exclusively via the active site of the enzyme ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco). This highly conserved catalyst has an almost universal propensity to non-productively interact with its substrate ribulose 1,5-bisphosphate, leading to the formation of dead-end inhibited complexes. In diverse autotrophic organisms this tendency has been counteracted by the recruitment of dedicated AAA+ (ATPases associated with various cellular activities) proteins that all use the energy of ATP hydrolysis to remodel inhibited Rubisco active sites leading to release of the inhibitor. Three evolutionarily distinct classes of these Rubisco activases (Rcas) have been discovered so far. Green and red-type Rca are mostly found in photosynthetic eukaryotes of the green and red plastid lineage respectively, whereas CbbQO is associated with chemoautotrophic bacteria. Ongoing mechanistic studies are elucidating how the various motors are utilizing both similar and contrasting strategies to ultimately perform their common function of cracking the inhibited Rubisco active site. The best studied mechanism utilized by red-type Rca appears to involve transient threading of the Rubisco large subunit C-terminal peptide, reminiscent of the action performed by Clp proteases. As well as providing a fascinating example of convergent molecular evolution, Rca proteins can be considered promising crop-improvement targets. Approaches aiming to replace Rubisco in plants with improved enzymes will need to ensure the presence of a compatible Rca protein. The thermolability of the Rca protein found in crop plants provides an opportunity to fortify photosynthesis against high temperature stress. Photosynthesis also appears to be limited by Rca when light conditions are fluctuating. Synthetic biology strategies aiming to enhance the autotrophic CO2 fixation machinery will need to take into consideration the requirement for Rubisco activases as well as their properties.
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Affiliation(s)
- Oliver Mueller-Cajar
- School of Biological Sciences, Nanyang Technological UniversitySingapore, Singapore
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25
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Sharwood RE. Engineering chloroplasts to improve Rubisco catalysis: prospects for translating improvements into food and fiber crops. THE NEW PHYTOLOGIST 2017; 213:494-510. [PMID: 27935049 DOI: 10.1111/nph.14351] [Citation(s) in RCA: 101] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 09/10/2016] [Indexed: 05/19/2023]
Abstract
494 I. 495 II. 496 III. 496 IV. 499 V. 499 VI. 501 VII. 501 VIII. 502 IX. 505 X. 506 507 References 507 SUMMARY: The uncertainty of future climate change is placing pressure on cropping systems to continue to provide stable increases in productive yields. To mitigate future climates and the increasing threats against global food security, new solutions to manipulate photosynthesis are required. This review explores the current efforts available to improve carbon assimilation within plant chloroplasts by engineering Rubisco, which catalyzes the rate-limiting step of CO2 fixation. Fixation of CO2 and subsequent cycling of 3-phosphoglycerate through the Calvin cycle provides the necessary carbohydrate building blocks for maintaining plant growth and yield, but has to compete with Rubisco oxygenation, which results in photorespiration that is energetically wasteful for plants. Engineering improvements in Rubisco is a complex challenge and requires an understanding of chloroplast gene regulatory pathways, and the intricate nature of Rubisco catalysis and biogenesis, to transplant more efficient forms of Rubisco into crops. In recent times, major advances in Rubisco engineering have been achieved through improvement of our knowledge of Rubisco synthesis and assembly, and identifying amino acid catalytic switches in the L-subunit responsible for improvements in catalysis. Improving the capacity of CO2 fixation in crops such as rice will require further advances in chloroplast bioengineering and Rubisco biogenesis.
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Affiliation(s)
- Robert E Sharwood
- ARC Center of Excellence for Translational Photosynthesis, Research School of Biology, Australian National University, Canberra, ACT, 2601, Australia
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26
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Sharwood RE, Ghannoum O, Kapralov MV, Gunn LH, Whitney SM. Temperature responses of Rubisco from Paniceae grasses provide opportunities for improving C 3 photosynthesis. NATURE PLANTS 2016; 2:16186. [PMID: 27892943 DOI: 10.1038/nplants.2016.186] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 10/27/2016] [Indexed: 05/03/2023]
Abstract
Enhancing the catalytic properties of the CO2-fixing enzyme Rubisco is a target for improving agricultural crop productivity. Here, we reveal extensive diversity in the kinetic response between 10 and 37 °C by Rubisco from C3 and C4 species within the grass tribe Paniceae. The CO2 fixation rate (kcatc) for Rubisco from the C4 grasses with nicotinamide adenine dinucleotide (NAD) phosphate malic enzyme (NADP-ME) and phosphoenolpyruvate carboxykinase (PCK) photosynthetic pathways was twofold greater than the kcatc of Rubisco from NAD-ME species across all temperatures. The declining response of CO2/O2 specificity with increasing temperature was less pronounced for PCK and NADP-ME Rubisco, which would be advantageous in warmer climates relative to the NAD-ME grasses. Modelled variation in the temperature kinetics of Paniceae C3 Rubisco and PCK Rubisco differentially stimulated C3 photosynthesis relative to tobacco above and below 25 °C under current and elevated CO2. Amino acid substitutions in the large subunit that could account for the catalytic variation among Paniceae Rubisco are identified; however, incompatibilities with Paniceae Rubisco biogenesis in tobacco hindered their mutagenic testing by chloroplast transformation. Circumventing these bioengineering limitations is critical to tailoring the properties of crop Rubisco to suit future climates.
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Affiliation(s)
- Robert E Sharwood
- Research School of Biology, Australian National University, Canberra Australian Capital Territory 2601, Australia
- ARC Centre of Excellence for Translational Photosynthesis, Australian National University, Canberra Australian Capital Territory 2601, Australia
| | - Oula Ghannoum
- ARC Centre of Excellence for Translational Photosynthesis, Australian National University, Canberra Australian Capital Territory 2601, Australia
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, New South Wales 2753, Australia
| | - Maxim V Kapralov
- School of Natural Sciences and Psychology, Liverpool John Moores University, Liverpool L3 3AF, UK
| | - Laura H Gunn
- Research School of Biology, Australian National University, Canberra Australian Capital Territory 2601, Australia
| | - Spencer M Whitney
- Research School of Biology, Australian National University, Canberra Australian Capital Territory 2601, Australia
- ARC Centre of Excellence for Translational Photosynthesis, Australian National University, Canberra Australian Capital Territory 2601, Australia
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27
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Flexas J. Genetic improvement of leaf photosynthesis and intrinsic water use efficiency in C3 plants: Why so much little success? PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2016; 251:155-161. [PMID: 27593473 DOI: 10.1016/j.plantsci.2016.05.002] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2016] [Revised: 04/28/2016] [Accepted: 05/03/2016] [Indexed: 05/07/2023]
Abstract
There is an urgent need for simultaneously increasing photosynthesis/yields and water use efficiency (WUE) in C3 crops. Potentially, this can be achieved by genetic manipulation of the key traits involved. However, despite significant efforts in the past two decades very limited success has been achieved. Here I argue that this is mostly due to the fact that single gene/single trait approaches have been used thus far. Photosynthesis models demonstrate that only limited improving of photosynthesis can be expected by large improvements of any of its single limiting factors, i.e. stomatal conductance, mesophyll conductance, and the biochemical capacity for photosynthesis, the latter co-limited by Rubisco and the orchestrated activity of thylakoid electron transport and the Calvin cycle enzymes. Accordingly, only limited improvements of photosynthesis have been obtained by genetic manipulation of any of these single factors. In addition, improving photosynthesis by genetic manipulation in general reduced WUE, and vice-versa, and in many cases pleiotropic effects appear that cancel out some of the expected benefits. I propose that success in genetic manipulation for simultaneous improvement of photosynthesis and WUE efficiency may take longer than suggested in previous reports, and that it can be achieved only by joint projects addressing multi-gene manipulation for simultaneous alterations of all the limiting factors of photosynthesis, including the often neglected phloem capacity for loading and transport the expected surplus of carbohydrates in plants with improved photosynthesis.
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Affiliation(s)
- J Flexas
- Research Group on Plant Biology under Mediterranean Conditions, Departament de Biologia, Universitat de les Illes Balears, Carretera de Valldemossa Km 7.5, 07122 Palma de Mallorca, Illes Balears, Spain.
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28
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Erb TJ, Zarzycki J. Biochemical and synthetic biology approaches to improve photosynthetic CO 2-fixation. Curr Opin Chem Biol 2016; 34:72-79. [PMID: 27400232 DOI: 10.1016/j.cbpa.2016.06.026] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 06/20/2016] [Accepted: 06/21/2016] [Indexed: 01/08/2023]
Abstract
There is an urgent need to improve agricultural productivity to secure future food and biofuel supply. Here, we summarize current approaches that aim at improving photosynthetic CO2-fixation. We critically review, compare and comment on the four major lines of research towards this aim, which focus on (i) improving RubisCO, the CO2-fixing enzyme in photosynthesis, (ii) implementing CO2-concentrating mechanisms, (iii) establishing synthetic photorespiration bypasses, and (iv) engineering synthetic CO2-fixation pathways.
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Affiliation(s)
- Tobias J Erb
- Max Planck Institute for Terrestrial Microbiology, Biochemistry & Synthetic Biology of Microbial Metabolism Group, Karl-von-Frisch-Str. 10, 35043 Marburg, Germany; LOEWE Center for Synthetic Microbiology (SYNMIKRO), Philipps University Marburg, 35043 Marburg, Germany.
| | - Jan Zarzycki
- Max Planck Institute for Terrestrial Microbiology, Biochemistry & Synthetic Biology of Microbial Metabolism Group, Karl-von-Frisch-Str. 10, 35043 Marburg, Germany
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29
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Flexas J, Díaz-Espejo A, Conesa MA, Coopman RE, Douthe C, Gago J, Gallé A, Galmés J, Medrano H, Ribas-Carbo M, Tomàs M, Niinemets Ü. Mesophyll conductance to CO2 and Rubisco as targets for improving intrinsic water use efficiency in C3 plants. PLANT, CELL & ENVIRONMENT 2016; 39:965-82. [PMID: 26297108 DOI: 10.1111/pce.12622] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Revised: 07/09/2015] [Accepted: 07/26/2015] [Indexed: 05/20/2023]
Abstract
Water limitation is a major global constraint for plant productivity that is likely to be exacerbated by climate change. Hence, improving plant water use efficiency (WUE) has become a major goal for the near future. At the leaf level, WUE is the ratio between photosynthesis and transpiration. Maintaining high photosynthesis under water stress, while improving WUE requires either increasing mesophyll conductance (gm ) and/or improving the biochemical capacity for CO2 assimilation-in which Rubisco properties play a key role, especially in C3 plants at current atmospheric CO2 . The goals of the present analysis are: (1) to summarize the evidence that improving gm and/or Rubisco can result in increased WUE; (2) to review the degree of success of early attempts to genetically manipulate gm or Rubisco; (3) to analyse how gm , gsw and the Rubisco's maximum velocity (Vcmax ) co-vary across different plant species in well-watered and drought-stressed conditions; (4) to examine how these variations cause differences in WUE and what is the overall extent of variation in individual determinants of WUE; and finally, (5) to use simulation analysis to provide a theoretical framework for the possible control of WUE by gm and Rubisco catalytic constants vis-à-vis gsw under water limitations.
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Affiliation(s)
- J Flexas
- Research Group on Plant Biology under Mediterranean Conditions, Departament de Biologia, Universitat de les Illes Balears, Carretera de Valldemossa Km 7.5, 07122, Palma de Mallorca, Illes Balears, Spain
| | - A Díaz-Espejo
- Irrigation and Crop Ecophysiology Group, Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS, CSIC), Avenida Reina Mercedes 10, 41012, Sevilla, Spain
| | - M A Conesa
- Research Group on Plant Biology under Mediterranean Conditions, Departament de Biologia, Universitat de les Illes Balears, Carretera de Valldemossa Km 7.5, 07122, Palma de Mallorca, Illes Balears, Spain
| | - R E Coopman
- Ecophysiology Laboratory for Forest Conservation, Instituto de Conservación, Biodiversidad y Territorio, Facultad de Ciencias Forestales y Recursos Naturales, Universidad Austral de Chile, Casilla 567, 5110566, Valdivia, Chile
| | - C Douthe
- Research Group on Plant Biology under Mediterranean Conditions, Departament de Biologia, Universitat de les Illes Balears, Carretera de Valldemossa Km 7.5, 07122, Palma de Mallorca, Illes Balears, Spain
| | - J Gago
- Research Group on Plant Biology under Mediterranean Conditions, Departament de Biologia, Universitat de les Illes Balears, Carretera de Valldemossa Km 7.5, 07122, Palma de Mallorca, Illes Balears, Spain
- Applied Plant and Soil Biology, Faculty of Biology, University of Vigo, 36310, Vigo, Spain
| | - A Gallé
- Bayer CropScience NV, Innovation Center, Technologiepark 38, 9052, Zwijnaarde, Belgium
| | - J Galmés
- Research Group on Plant Biology under Mediterranean Conditions, Departament de Biologia, Universitat de les Illes Balears, Carretera de Valldemossa Km 7.5, 07122, Palma de Mallorca, Illes Balears, Spain
| | - H Medrano
- Research Group on Plant Biology under Mediterranean Conditions, Departament de Biologia, Universitat de les Illes Balears, Carretera de Valldemossa Km 7.5, 07122, Palma de Mallorca, Illes Balears, Spain
| | - M Ribas-Carbo
- Research Group on Plant Biology under Mediterranean Conditions, Departament de Biologia, Universitat de les Illes Balears, Carretera de Valldemossa Km 7.5, 07122, Palma de Mallorca, Illes Balears, Spain
| | - M Tomàs
- Research Group on Plant Biology under Mediterranean Conditions, Departament de Biologia, Universitat de les Illes Balears, Carretera de Valldemossa Km 7.5, 07122, Palma de Mallorca, Illes Balears, Spain
| | - Ü Niinemets
- Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 1, Tartu, 51014, Estonia
- Estonian Academy of Sciences, Kohtu 6, 10130, Tallinn, Estonia
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30
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Occhialini A, Lin MT, Andralojc PJ, Hanson MR, Parry MAJ. Transgenic tobacco plants with improved cyanobacterial Rubisco expression but no extra assembly factors grow at near wild-type rates if provided with elevated CO2. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2016; 85:148-60. [PMID: 26662726 PMCID: PMC4718753 DOI: 10.1111/tpj.13098] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Revised: 11/16/2015] [Accepted: 11/26/2015] [Indexed: 05/18/2023]
Abstract
Introducing a carbon-concentrating mechanism and a faster Rubisco enzyme from cyanobacteria into higher plant chloroplasts may improve photosynthetic performance by increasing the rate of CO2 fixation while decreasing losses caused by photorespiration. We previously demonstrated that tobacco plants grow photoautotrophically using Rubisco from Synechococcus elongatus, although the plants exhibited considerably slower growth than wild-type and required supplementary CO2 . Because of concerns that vascular plant assembly factors may not be adequate for assembly of a cyanobacterial Rubisco, prior transgenic plants included the cyanobacterial chaperone RbcX or the carboxysomal protein CcmM35. Here we show that neither RbcX nor CcmM35 is needed for assembly of active cyanobacterial Rubisco. Furthermore, by altering the gene regulatory sequences on the Rubisco transgenes, cyanobacterial Rubisco expression was enhanced and the transgenic plants grew at near wild-type growth rates, although still requiring elevated CO2 . We performed detailed kinetic characterization of the enzymes produced with and without the RbcX and CcmM35 cyanobacterial proteins. These transgenic plants exhibit photosynthetic characteristics that confirm the predicted benefits of introduction of non-native forms of Rubisco with higher carboxylation rate constants in vascular plants and the potential nitrogen-use efficiency that may be achieved provided that adequate CO2 is available near the enzyme.
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Affiliation(s)
| | - Myat T. Lin
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853 USA
| | - P. John Andralojc
- Plant Biology and Crop Science, Rothamsted Research, Harpenden, Herts, AL5 2JQ, UK
| | - Maureen R. Hanson
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853 USA
| | - Martin A. J. Parry
- Plant Biology and Crop Science, Rothamsted Research, Harpenden, Herts, AL5 2JQ, UK
- Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster LA1 4YW, UK
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31
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Whitney SM, Birch R, Kelso C, Beck JL, Kapralov MV. Improving recombinant Rubisco biogenesis, plant photosynthesis and growth by coexpressing its ancillary RAF1 chaperone. Proc Natl Acad Sci U S A 2015; 112:3564-9. [PMID: 25733857 PMCID: PMC4371954 DOI: 10.1073/pnas.1420536112] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Enabling improvements to crop yield and resource use by enhancing the catalysis of the photosynthetic CO2-fixing enzyme Rubisco has been a longstanding challenge. Efforts toward realization of this goal have been greatly assisted by advances in understanding the complexities of Rubisco's biogenesis in plastids and the development of tailored chloroplast transformation tools. Here we generate transplastomic tobacco genotypes expressing Arabidopsis Rubisco large subunits (AtL), both on their own (producing tob(AtL) plants) and with a cognate Rubisco accumulation factor 1 (AtRAF1) chaperone (producing tob(AtL-R1) plants) that has undergone parallel functional coevolution with AtL. We show AtRAF1 assembles as a dimer and is produced in tob(AtL-R1) and Arabidopsis leaves at 10-15 nmol AtRAF1 monomers per square meter. Consistent with a postchaperonin large (L)-subunit assembly role, the AtRAF1 facilitated two to threefold improvements in the amount and biogenesis rate of hybrid L8(A)S8(t) Rubisco [comprising AtL and tobacco small (S) subunits] in tob(AtL-R1) leaves compared with tob(AtL), despite >threefold lower steady-state Rubisco mRNA levels in tob(AtL-R1). Accompanying twofold increases in photosynthetic CO2-assimilation rate and plant growth were measured for tob(AtL-R1) lines. These findings highlight the importance of ancillary protein complementarity during Rubisco biogenesis in plastids, the possible constraints this has imposed on Rubisco adaptive evolution, and the likely need for such interaction specificity to be considered when optimizing recombinant Rubisco bioengineering in plants.
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Affiliation(s)
- Spencer M Whitney
- Research School of Biology, Australian National University, Acton, ACT 2601, Australia; and
| | - Rosemary Birch
- Research School of Biology, Australian National University, Acton, ACT 2601, Australia; and
| | - Celine Kelso
- School of Chemistry, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Jennifer L Beck
- School of Chemistry, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Maxim V Kapralov
- Research School of Biology, Australian National University, Acton, ACT 2601, Australia; and
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32
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Chen J, Han G, Shang C, Li J, Zhang H, Liu F, Wang J, Liu H, Zhang Y. Proteomic analyses reveal differences in cold acclimation mechanisms in freezing-tolerant and freezing-sensitive cultivars of alfalfa. FRONTIERS IN PLANT SCIENCE 2015; 6:105. [PMID: 25774161 PMCID: PMC4343008 DOI: 10.3389/fpls.2015.00105] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 02/09/2015] [Indexed: 05/11/2023]
Abstract
Cold acclimation in alfalfa (Medicago sativa L.) plays a crucial role in cold tolerance to harsh winters. To examine the cold acclimation mechanisms in freezing-tolerant alfalfa (ZD) and freezing-sensitive alfalfa (W5), holoproteins, and low-abundance proteins (after the removal of RuBisCO) from leaves were extracted to analyze differences at the protein level. A total of 84 spots were selected, and 67 spots were identified. Of these, the abundance of 49 spots and 24 spots in ZD and W5, respectively, were altered during adaptation to chilling stress. Proteomic results revealed that proteins involved in photosynthesis, protein metabolism, energy metabolism, stress and redox and other proteins were mobilized in adaptation to chilling stress. In ZD, a greater number of changes were observed in proteins, and autologous metabolism and biosynthesis were slowed in response to chilling stress, thereby reducing consumption, allowing for homeostasis. The capability for protein folding and protein biosynthesis in W5 was enhanced, which allows protection against chilling stress. The ability to perceive low temperatures was more sensitive in freezing-tolerant alfalfa compared to freezing-sensitive alfalfa. This proteomics study provides new insights into the cold acclimation mechanism in alfalfa.
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Affiliation(s)
- Jing Chen
- College of Life Sciences and Technology, Harbin Normal UniversityHarbin, China
| | - Guiqing Han
- College of Life Sciences and Technology, Harbin Normal UniversityHarbin, China
- Institute of Grass Research, Heilongjiang Academy of Agricultural SciencesHarbin, China
| | - Chen Shang
- Institute of Grass Research, Heilongjiang Academy of Agricultural SciencesHarbin, China
| | - Jikai Li
- Institute of Grass Research, Heilongjiang Academy of Agricultural SciencesHarbin, China
| | - Hailing Zhang
- Institute of Grass Research, Heilongjiang Academy of Agricultural SciencesHarbin, China
| | - Fengqi Liu
- Institute of Grass Research, Heilongjiang Academy of Agricultural SciencesHarbin, China
| | - Jianli Wang
- Institute of Grass Research, Heilongjiang Academy of Agricultural SciencesHarbin, China
| | - Huiying Liu
- Institute of Grass Research, Heilongjiang Academy of Agricultural SciencesHarbin, China
| | - Yuexue Zhang
- Institute of Grass Research, Heilongjiang Academy of Agricultural SciencesHarbin, China
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33
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Durão P, Aigner H, Nagy P, Mueller-Cajar O, Hartl FU, Hayer-Hartl M. Opposing effects of folding and assembly chaperones on evolvability of Rubisco. Nat Chem Biol 2015; 11:148-55. [PMID: 25558973 DOI: 10.1038/nchembio.1715] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 10/27/2014] [Indexed: 12/29/2022]
Abstract
Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) catalyzes the fixation of CO2 in photosynthesis. Despite its pivotal role, Rubisco is an inefficient enzyme and thus is a key target for directed evolution. Rubisco biogenesis depends on auxiliary factors, including the GroEL/ES-type chaperonin for folding and the chaperone RbcX for assembly. Here we performed directed evolution of cyanobacterial form I Rubisco using a Rubisco-dependent Escherichia coli strain. Overexpression of GroEL/ES enhanced Rubisco solubility and tended to expand the range of permissible mutations. In contrast, the specific assembly chaperone RbcX had a negative effect on evolvability by preventing a subset of mutants from forming holoenzyme. Mutation F140I in the large Rubisco subunit, isolated in the absence of RbcX, increased carboxylation efficiency approximately threefold without reducing CO2 specificity. The F140I mutant resulted in a ∼55% improved photosynthesis rate in Synechocystis PCC6803. The requirement of specific biogenesis factors downstream of chaperonin may have retarded the natural evolution of Rubisco.
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Affiliation(s)
- Paulo Durão
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Harald Aigner
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Péter Nagy
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Oliver Mueller-Cajar
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - F Ulrich Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Manajit Hayer-Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
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34
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Hassan SW, Waheed MT, Müller M, Clarke JL, Shinwari ZK, Lössl AG. Expression of HPV-16 L1 capsomeres with glutathione-S-transferase as a fusion protein in tobacco plastids: an approach for a capsomere-based HPV vaccine. Hum Vaccin Immunother 2014; 10:2975-82. [PMID: 25483463 PMCID: PMC5443053 DOI: 10.4161/21645515.2014.970973] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Revised: 07/11/2014] [Accepted: 07/21/2014] [Indexed: 12/20/2022] Open
Abstract
Human Papillomavirus (HPV) is the main cause of cervical cancer, which is the second most severe cancer of women worldwide, particularly in developing countries. Although vaccines against HPV infection are commercially available, they are neither affordable nor accessible to women in low income countries e.g. Africa. Thus, alternative cost-effective vaccine production approaches need to be developed. This study uses tobacco plants to express pentameric capsomeres of HPV that have been reported to generate elevated immune responses against HPV. A modified HPV-16 L1 (L1_2xCysM) protein has been expressed as a fusion protein with glutathione-S-transferase (GST) in tobacco chloroplasts following biolistic transformation. In total 7 transplastomic lines with healthy phenotypes were generated. Site specific integration of the GST-L1_2xCysM and aadA genes was confirmed by PCR. Southern blot analysis verified homogenous transformation of all transplastomic lines. Antigen capture ELISA with the conformation-specific antibody Ritti01, showed protein expression as well as the retention of immunogenic epitopes of L1 protein. In their morphology, GST-L1 expressing tobacco plants were identical to wild type plants and yielded fertile flowers. Taken together, these data enrich knowledge for future development of cost-effective plant-made vaccines against HPV.
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Affiliation(s)
- Syed Waqas Hassan
- Department of Biotechnology; Quaid-i-Azam University; Islamabad, Pakistan
| | | | - Martin Müller
- Deutsches Krebsforschungszentrum; Heidelberg, Germany
| | - Jihong Liu Clarke
- Bioforsk-Norwegian Institute for Agricultural and Environmental Research; Aas, Norway
| | | | - Andreas Günter Lössl
- Department of Crop Sciences; University of Natural Resources and Applied Life Sciences; Tulln an der Donau, Austria
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35
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Ho SH, Ye X, Hasunuma T, Chang JS, Kondo A. Perspectives on engineering strategies for improving biofuel production from microalgae--a critical review. Biotechnol Adv 2014; 32:1448-59. [PMID: 25285758 DOI: 10.1016/j.biotechadv.2014.09.002] [Citation(s) in RCA: 145] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Revised: 09/18/2014] [Accepted: 09/19/2014] [Indexed: 10/24/2022]
Abstract
Although the potential for biofuel production from microalgae via photosynthesis has been intensively investigated, information on the selection of a suitable operation strategy for microalgae-based biofuel production is lacking. Many published reports describe competitive strains and optimal culture conditions for use in biofuel production; however, the major impediment to further improvements is the absence of effective engineering strategies for microalgae cultivation and biofuel production. This comprehensive review discusses recent advances in understanding the effects of major environmental stresses and the characteristics of various engineering operation strategies on the production of biofuels (mainly biodiesel and bioethanol) using microalgae. The performances of microalgae-based biofuel-producing systems under various environmental stresses (i.e., irradiance, temperature, pH, nitrogen depletion, and salinity) and cultivation strategies (i.e., fed-batch, semi-continuous, continuous, two-stage, and salinity-gradient) are compared. The reasons for variations in performance and the underlying theories of the various production strategies are also critically discussed. The aim of this review is to provide useful information to facilitate development of innovative and feasible operation technologies for effectively increasing the commercial viability of microalgae-based biofuel production.
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Affiliation(s)
- Shih-Hsin Ho
- Organization of Advanced Science and Technology, Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan
| | - Xiaoting Ye
- Organization of Advanced Science and Technology, Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan
| | - Tomohisa Hasunuma
- Organization of Advanced Science and Technology, Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan
| | - Jo-Shu Chang
- Department of Chemical Engineering, National Cheng Kung University, Tainan 701, Taiwan; Research Center for Energy Technology and Strategy, National Cheng Kung University, Tainan 701, Taiwan; Center for Bioscience and Biotechnology, National Cheng Kung University, Tainan 701, Taiwan.
| | - Akihiko Kondo
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan; Biomass Engineering Program, RIKEN, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan.
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36
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Lin MT, Occhialini A, Andralojc PJ, Parry MAJ, Hanson MR. A faster Rubisco with potential to increase photosynthesis in crops. Nature 2014; 513:547-50. [PMID: 25231869 PMCID: PMC4176977 DOI: 10.1038/nature13776] [Citation(s) in RCA: 268] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Accepted: 08/14/2014] [Indexed: 01/20/2023]
Abstract
In photosynthetic organisms, D-ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) is the major enzyme assimilating atmospheric CO2 into the biosphere. Owing to the wasteful oxygenase activity and slow turnover of Rubisco, the enzyme is among the most important targets for improving the photosynthetic efficiency of vascular plants. It has been anticipated that introducing the CO2-concentrating mechanism (CCM) from cyanobacteria into plants could enhance crop yield. However, the complex nature of Rubisco's assembly has made manipulation of the enzyme extremely challenging, and attempts to replace it in plants with the enzymes from cyanobacteria and red algae have not been successful. Here we report two transplastomic tobacco lines with functional Rubisco from the cyanobacterium Synechococcus elongatus PCC7942 (Se7942). We knocked out the native tobacco gene encoding the large subunit of Rubisco by inserting the large and small subunit genes of the Se7942 enzyme, in combination with either the corresponding Se7942 assembly chaperone, RbcX, or an internal carboxysomal protein, CcmM35, which incorporates three small subunit-like domains. Se7942 Rubisco and CcmM35 formed macromolecular complexes within the chloroplast stroma, mirroring an early step in the biogenesis of cyanobacterial β-carboxysomes. Both transformed lines were photosynthetically competent, supporting autotrophic growth, and their respective forms of Rubisco had higher rates of CO2 fixation per unit of enzyme than the tobacco control. These transplastomic tobacco lines represent an important step towards improved photosynthesis in plants and will be valuable hosts for future addition of the remaining components of the cyanobacterial CCM, such as inorganic carbon transporters and the β-carboxysome shell proteins.
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Affiliation(s)
- Myat T Lin
- 1] Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853, USA [2]
| | - Alessandro Occhialini
- 1] Plant Biology and Crop Science, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK [2]
| | - P John Andralojc
- Plant Biology and Crop Science, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK
| | - Martin A J Parry
- Plant Biology and Crop Science, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK
| | - Maureen R Hanson
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853, USA
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37
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Galmés J, Conesa MÀ, Díaz-Espejo A, Mir A, Perdomo JA, Niinemets U, Flexas J. Rubisco catalytic properties optimized for present and future climatic conditions. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2014; 226:61-70. [PMID: 25113451 DOI: 10.1016/j.plantsci.2014.01.008] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Revised: 12/06/2013] [Accepted: 01/20/2014] [Indexed: 05/19/2023]
Abstract
Because of its catalytic inefficiencies, Rubisco is the most obvious target for improvement to enhance the photosynthetic capacity of plants. Two hypotheses are tested in the present work: (1) existing Rubiscos have optimal kinetic properties to maximize photosynthetic carbon assimilation in existing higher plants; (2) current knowledge allows proposal of changes to kinetic properties to make Rubiscos more suited to changed conditions in chloroplasts that are likely to occur with climate change. The catalytic mechanism of Rubisco results in higher catalytic rates of carboxylation being associated with decreased affinity for CO2, so that selection for different environments involves a trade-off between these two properties. The simulations performed in this study confirm that the optimality of Rubisco kinetics depends on the species and the environmental conditions. In particular, environmental drivers affecting the CO2 availability for carboxylation (Cc) or directly shifting the photosynthetic limitations between Rubisco and RuBP regeneration determine to what extend Rubisco kinetics are optimally suited to maximize CO2 assimilation rate. In general, modeled values for optimal kinetic reflect the predominant environmental conditions currently encountered by the species in the field. Under future climatic conditions, photosynthetic CO2 assimilation will be limited by RuBP-regeneration, especially in the absence of water stress, the largest rise in [CO2] and the lowest increases in temperature. Under these conditions, the model predicts that optimal Rubisco should have high Sc/o and low kcat(c).
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Affiliation(s)
- J Galmés
- Research Group in Plant Biology under Mediterranean Conditions, Department of Biology, Universitat de les Illes Balears, Carretera de Valldemossa km 7.5, 07122 Palma, Illes Balears, Spain.
| | - M À Conesa
- Research Group in Plant Biology under Mediterranean Conditions, Department of Biology, Universitat de les Illes Balears, Carretera de Valldemossa km 7.5, 07122 Palma, Illes Balears, Spain
| | - A Díaz-Espejo
- Irrigation and Crop Ecophysiology Group, Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS, CSIC), Avenida Reina Mercedes 10, 41012 Sevilla, Spain
| | - A Mir
- Computational Biology and Bioinformatics Research Group, Department of Mathematics and Computer Science, Universitat de les Illes Balears, Carretera de Valldemossa km 7.5, 07122 Palma, Illes Balears, Spain
| | - J A Perdomo
- Research Group in Plant Biology under Mediterranean Conditions, Department of Biology, Universitat de les Illes Balears, Carretera de Valldemossa km 7.5, 07122 Palma, Illes Balears, Spain
| | - U Niinemets
- Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 1, Tartu 51014, Estonia
| | - J Flexas
- Research Group in Plant Biology under Mediterranean Conditions, Department of Biology, Universitat de les Illes Balears, Carretera de Valldemossa km 7.5, 07122 Palma, Illes Balears, Spain
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von Caemmerer S, Tazoe Y, Evans JR, Whitney SM. Exploiting transplastomically modified Rubisco to rapidly measure natural diversity in its carbon isotope discrimination using tuneable diode laser spectroscopy. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:3759-67. [PMID: 24687980 PMCID: PMC4085952 DOI: 10.1093/jxb/eru036] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Carbon isotope discrimination (Δ) during C3 photosynthesis is dominated by the fractionation occurring during CO2-fixation by the enzyme Rubisco. While knowing the fractionation by enzymes is pivotal to fully understanding plant carbon metabolism, little is known about variation in the discrimination factor of Rubisco (b) as it is difficult to measure using existing in vitro methodologies. Tuneable diode laser absorption spectroscopy has improved the ability to make rapid measurements of Δ concurrently with photosynthetic gas exchange. This study used this technique to estimate b in vivo in five tobacco (Nicotiana tabacum L. cv Petit Havana [N,N]) genotypes expressing alternative Rubisco isoforms. For transplastomic tobacco producing Rhodospirillum rubrum Rubisco b was 23.8±0.7‰, while Rubisco containing the large subunit Leu-335-Val mutation had a b-value of 13.9±0.7‰. These values were significantly less than that for Rubisco from wild-type tobacco (b=29‰), a C3 species. Transplastomic tobacco producing chimeric Rubisco comprising tobacco Rubisco small subunits and the catalytic large subunits from either the C4 species Flaveria bidentis or the C3-C4 species Flaveria floridana had b-values of 27.8±0.8 and 28.6±0.6‰, respectively. These values were not significantly different from tobacco Rubisco.
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Affiliation(s)
- Susanne von Caemmerer
- Research School of Biology, The Australian National University, Canberra ACT 0200, Australia
| | - Youshi Tazoe
- Research School of Biology, The Australian National University, Canberra ACT 0200, Australia
| | - John R Evans
- Research School of Biology, The Australian National University, Canberra ACT 0200, Australia
| | - Spencer M Whitney
- Research School of Biology, The Australian National University, Canberra ACT 0200, Australia
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Whitney SM, Sharwood RE. Plastid transformation for Rubisco engineering and protocols for assessing expression. Methods Mol Biol 2014; 1132:245-62. [PMID: 24599858 DOI: 10.1007/978-1-62703-995-6_15] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The assimilation of CO2 within chloroplasts is catalyzed by the bi-functional enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase, Rubisco. Within higher plants the Rubisco large subunit gene, rbcL, is encoded in the plastid genome, while the Rubisco small subunit gene, RbcS is coded in the nucleus by a multi-gene family. Rubisco is considered a poor catalyst due to its slow turnover rate and its additional fixation of O2 that can result in wasteful loss of carbon through the energy requiring photorespiratory cycle. Improving the carboxylation efficiency and CO2/O2 selectivity of Rubisco within higher plants has been a long-term goal which has been greatly advanced in recent times using plastid transformation techniques. Here we present experimental methodologies for efficiently engineering Rubisco in the plastids of a tobacco master-line and analyzing leaf Rubisco content.
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Affiliation(s)
- Spencer M Whitney
- College of Medicine, Biology and Ecology, Research School of Biology, The Australian National University, Canberra, ACT, Australia
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40
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von Caemmerer S. Steady-state models of photosynthesis. PLANT, CELL & ENVIRONMENT 2013; 36:1617-30. [PMID: 23496792 DOI: 10.1111/pce.12098] [Citation(s) in RCA: 102] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Revised: 03/07/2013] [Accepted: 03/12/2013] [Indexed: 05/19/2023]
Abstract
In the challenge to increase photosynthetic rate per leaf area mathematical models of photosynthesis can be used to help interpret gas exchange measurements made under different environmental conditions and predict underlying photosynthetic biochemistry. To do this successfully it is important to improve the modelling of temperature dependencies of CO₂ assimilation and gain better understanding of internal CO₂ diffusion limitations. Despite these shortcomings steady-state models of photosynthesis provide simple easy to use tools for thought experiments to explore photosynthetic pathway changes such as redirecting photorespiratory CO₂, inserting bicarbonate pumps into C₃ chloroplasts or inserting C₄ photosynthesis into rice. Here a number of models derived from the C₃ model by Farquhar, von Caemmerer and Berry are discussed and compared.
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Affiliation(s)
- Susanne von Caemmerer
- Plant Science Division, Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia.
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Galmés J, Perdomo JA, Flexas J, Whitney SM. Photosynthetic characterization of Rubisco transplantomic lines reveals alterations on photochemistry and mesophyll conductance. PHOTOSYNTHESIS RESEARCH 2013; 115:153-66. [PMID: 23703453 DOI: 10.1007/s11120-013-9848-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Accepted: 05/10/2013] [Indexed: 06/02/2023]
Abstract
Improving Rubisco catalysis is considered a promising way to enhance C3-photosynthesis and photosynthetic water use efficiency (WUE) provided the introduced changes have little or no impact on other processes affecting photosynthesis such as leaf photochemistry or leaf CO2 diffusion conductances. However, the extent to which the factors affecting photosynthetic capacity are co-regulated is unclear. The aim of the present study was to characterize the photochemistry and CO2 transport processes in the leaves of three transplantomic tobacco genotypes expressing hybrid Rubisco isoforms comprising different Flaveria L-subunits that show variations in catalysis and differing trade-offs between the amount of Rubisco and its activation state. Stomatal conductance (g s) in each transplantomic tobacco line matched wild-type, while their photochemistry showed co-regulation with the variations in Rubisco catalysis. A tight co-regulation was observed between Rubisco activity and mesophyll conductance (g m) that was independent of g s thus producing plants with varying g m/g s ratios. Since the g m/g s ratio has been shown to positively correlate with intrinsic WUE, the present results suggest that altering photosynthesis by modifying Rubisco catalysis may also be useful for targeting WUE.
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Affiliation(s)
- Jeroni Galmés
- Research Group on Plant Biology under Mediterranean Conditions, Universitat de les Illes Balears, Ctra. de Valldemossa Km.7.5, 07122 Palma, Spain.
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42
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Hanson MR, Gray BN, Ahner BA. Chloroplast transformation for engineering of photosynthesis. JOURNAL OF EXPERIMENTAL BOTANY 2013; 64:731-42. [PMID: 23162121 DOI: 10.1093/jxb/ers325] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Many efforts are underway to engineer improvements in photosynthesis to meet the challenges of increasing demands for food and fuel in rapidly changing environmental conditions. Various transgenes have been introduced into either the nuclear or plastid genomes in attempts to increase photosynthetic efficiency. We examine the current knowledge of the critical features that affect levels of expression of plastid transgenes and protein accumulation in transplastomic plants, such as promoters, 5' and 3' untranslated regions, RNA-processing sites, translation signals and amino acid sequences that affect protein turnover. We review the prior attempts to manipulate the properties of ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco) through plastid transformation. We illustrate how plastid operons could be created for expression of the multiple genes needed to introduce new pathways or enzymes to enhance photosynthetic rates or reduce photorespiration. We describe here the past accomplishments and future prospects for manipulating plant enzymes and pathways to enhance carbon assimilation through plastid transformation.
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Affiliation(s)
- Maureen R Hanson
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA.
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Leakey ADB, Lau JA. Evolutionary context for understanding and manipulating plant responses to past, present and future atmospheric [CO2]. Philos Trans R Soc Lond B Biol Sci 2012; 367:613-29. [PMID: 22232771 PMCID: PMC3248707 DOI: 10.1098/rstb.2011.0248] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Variation in atmospheric [CO(2)] is a prominent feature of the environmental history over which vascular plants have evolved. Periods of falling and low [CO(2)] in the palaeo-record appear to have created selective pressure for important adaptations in modern plants. Today, rising [CO(2)] is a key component of anthropogenic global environmental change that will impact plants and the ecosystem goods and services they deliver. Currently, there is limited evidence that natural plant populations have evolved in response to contemporary increases in [CO(2)] in ways that increase plant productivity or fitness, and no evidence for incidental breeding of crop varieties to achieve greater yield enhancement from rising [CO(2)]. Evolutionary responses to elevated [CO(2)] have been studied by applying selection in controlled environments, quantitative genetics and trait-based approaches. Findings to date suggest that adaptive changes in plant traits in response to future [CO(2)] will not be consistently observed across species or environments and will not be large in magnitude compared with physiological and ecological responses to future [CO(2)]. This lack of evidence for strong evolutionary effects of elevated [CO(2)] is surprising, given the large effects of elevated [CO(2)] on plant phenotypes. New studies under more stressful, complex environmental conditions associated with climate change may revise this view. Efforts are underway to engineer plants to: (i) overcome the limitations to photosynthesis from today's [CO(2)] and (ii) benefit maximally from future, greater [CO(2)]. Targets range in scale from manipulating the function of a single enzyme (e.g. Rubisco) to adding metabolic pathways from bacteria as well as engineering the structural and functional components necessary for C(4) photosynthesis into C(3) leaves. Successfully improving plant performance will depend on combining the knowledge of the evolutionary context, cellular basis and physiological integration of plant responses to varying [CO(2)].
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Affiliation(s)
- Andrew D B Leakey
- Department of Plant Biology and Institute for Genomic Biology, University of Illinois, Urbana-Champaign, 1201 W. Gregory Drive, Urbana, IL 61801, USA.
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Ainsworth EA, Yendrek CR, Skoneczka JA, Long SP. Accelerating yield potential in soybean: potential targets for biotechnological improvement. PLANT, CELL & ENVIRONMENT 2012; 35:38-52. [PMID: 21689112 DOI: 10.1111/j.1365-3040.2011.02378.x] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Soybean (Glycine max Merr.) is the world's most widely grown legume and provides an important source of protein and oil. Global soybean production and yield per hectare increased steadily over the past century with improved agronomy and development of cultivars suited to a wide range of latitudes. In order to meet the needs of a growing world population without unsustainable expansion of the land area devoted to this crop, yield must increase at a faster rate than at present. Here, the historical basis for the yield gains realized in the past 90 years are examined together with potential metabolic targets for achieving further improvements in yield potential. These targets include improving photosynthetic efficiency, optimizing delivery and utilization of carbon, more efficient nitrogen fixation and altering flower initiation and abortion. Optimization of investment in photosynthetic enzymes, bypassing photorespiratory metabolism, engineering the electron transport chain and engineering a faster recovery from the photoprotected state are different strategies to improve photosynthesis in soybean. These potential improvements in photosynthetic carbon gain will need to be matched by increased carbon and nitrogen transport to developing soybean pods and seeds in order to maximize the benefit. Better understanding of control of carbon and nitrogen transport along with improved knowledge of the regulation of flower initiation and abortion will be needed to optimize sink capacity in soybean. Although few single targets are likely to deliver a quantum leap in yields, biotechnological advances in molecular breeding techniques that allow for alteration of the soybean genome and transcriptome promise significant yield gains.
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Affiliation(s)
- Elizabeth A Ainsworth
- USDA ARS Global Change and Photosynthesis Research Unit, 1201 W. Gregory Drive, Urbana, IL 61801, USA.
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Whitney SM, Sharwood RE, Orr D, White SJ, Alonso H, Galmés J. Isoleucine 309 acts as a C4 catalytic switch that increases ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) carboxylation rate in Flaveria. Proc Natl Acad Sci U S A 2011; 108:14688-93. [PMID: 21849620 PMCID: PMC3167554 DOI: 10.1073/pnas.1109503108] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Improving global yields of important agricultural crops is a complex challenge. Enhancing yield and resource use by engineering improvements to photosynthetic carbon assimilation is one potential solution. During the last 40 million years C(4) photosynthesis has evolved multiple times, enabling plants to evade the catalytic inadequacies of the CO(2)-fixing enzyme, ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco). Compared with their C(3) ancestors, C(4) plants combine a faster rubisco with a biochemical CO(2)-concentrating mechanism, enabling more efficient use of water and nitrogen and enhanced yield. Here we show the versatility of plastome manipulation in tobacco for identifying sequences in C(4)-rubisco that can be transplanted into C(3)-rubisco to improve carboxylation rate (V(C)). Using transplastomic tobacco lines expressing native and mutated rubisco large subunits (L-subunits) from Flaveria pringlei (C(3)), Flaveria floridana (C(3)-C(4)), and Flaveria bidentis (C(4)), we reveal that Met-309-Ile substitutions in the L-subunit act as a catalytic switch between C(4) ((309)Ile; faster V(C), lower CO(2) affinity) and C(3) ((309)Met; slower V(C), higher CO(2) affinity) catalysis. Application of this transplastomic system permits further identification of other structural solutions selected by nature that can increase rubisco V(C) in C(3) crops. Coengineering a catalytically faster C(3) rubisco and a CO(2)-concentrating mechanism within C(3) crop species could enhance their efficiency in resource use and yield.
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Affiliation(s)
- Spencer M Whitney
- Research School of Biology, Australian National University, Canberra ACT 2601, Australia.
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Tungsuchat-Huang T, Slivinski KM, Sinagawa-Garcia SR, Maliga P. Visual spectinomycin resistance (aadA(au)) gene for facile identification of transplastomic sectors in tobacco leaves. PLANT MOLECULAR BIOLOGY 2011; 76:453-61. [PMID: 21193947 DOI: 10.1007/s11103-010-9724-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2010] [Accepted: 12/19/2010] [Indexed: 05/28/2023]
Abstract
Identification of a genetically stable Nicotiana tabacum (tobacco) plant with a uniform population of transformed plastid genomes (ptDNA) takes two cycles of plant regeneration from chimeric leaves and analysis of multiple shoots by Southern probing in each cycle. Visual detection of transgenic sectors facilitates identification of transformed shoots in the greenhouse, complementing repeated cycles of blind purification in culture. In addition, it provides a tool to monitor the maintenance of transplastomic state. Our current visual marker system requires two genes: the aurea bar (bar(au)) gene that confers a golden leaf phenotype and a spectinomycin resistance (aadA) gene that is necessary for the introduction of the bar(au) gene in the plastid genome. We developed a novel aadA gene that fulfills both functions: it is a conventional selectable aadA gene in culture, and allows detection of transplastomic sectors in the greenhouse by leaf color. Common causes of pigment deficiency in leaves are mutations in photosynthetic genes, which affect chlorophyll accumulation. We use a different approach to achieve pigment deficiency: post-transcriptional interference with the expression of the clpP1 plastid gene by aurea aadA(au) transgene. This interference produces plants with reduced growth and a distinct color, but maintains a wild-type gene set and the capacity for photosynthesis. Importantly, when the aurea gene is removed, green pigmentation and normal growth rate are restored. Because the aurea plants are viable, the new aadA(au) genes are useful to query rare events in large populations and for in planta manipulation of the plastid genome.
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Affiliation(s)
- Tarinee Tungsuchat-Huang
- Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, 190 Frelinghuysen Road, Piscataway, NJ 08854-8020, USA
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Zhang XH, Webb J, Huang YH, Lin L, Tang RS, Liu A. Hybrid Rubisco of tomato large subunits and tobacco small subunits is functional in tobacco plants. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2011; 180:480-8. [PMID: 21421395 DOI: 10.1016/j.plantsci.2010.11.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2010] [Revised: 11/07/2010] [Accepted: 11/09/2010] [Indexed: 05/08/2023]
Abstract
Biogenesis of functional ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) in plants requires specific assembly in the chloroplast of the imported, cytosol-synthesized small subunits (SS) with the chloroplast-made large subunits (LS). Accumulating evidence indicates that chloroplasts (plastids) generally have a low tolerance for assembling foreign or modified Rubisco. To explore Rubisco engineering, we created two lines of transplastomic tobacco plants whose rbcL gene was replaced by tomato-derived rbcL: plant LLS2 with Rubisco composed of tobacco SS and Q437R LS and plant LLS4 with a hybrid Rubisco of tobacco SS and tomato LS (representing four substitutions of Y226F, A230T, S279T and Q437R from tobacco LS). Plant LLS2 exhibited similar phenotypes as the wild type. Plant LLS4 showed lower chlorophyll and Rubisco levels particularly in young emerging leaves, lower photosynthesis rates and biomass during early stages of development, but was able to reach reproductive maturity and somewhat wild type-like phenotype under ambient CO₂ condition. In vitro assays detected similar carboxylase activity and RuBP affinity in LLS2 and LLS4 plants as in wild type. Our studies demonstrated that tomato LS was sufficiently assembled with tobacco SS into functional Rubisco. The hybrid Rubisco of tomato LS and tobacco SS can drive photosynthesis that supports photoautotrophic growth and reproduction of tobacco plants under ambient CO₂ and light conditions. We discuss the effect of these residue substitutions on Rubisco activity and the possible attribution of chlorophyll deficiency to the in planta photosynthesis performance in the hybrid Rubisco plants.
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Affiliation(s)
- Xing-Hai Zhang
- Department of Biological Sciences, Florida Atlantic University, 777 Glades Road, Boca Raton, FL 33431, USA.
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48
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Whitney SM, Houtz RL, Alonso H. Advancing our understanding and capacity to engineer nature's CO2-sequestering enzyme, Rubisco. PLANT PHYSIOLOGY 2011; 155:27-35. [PMID: 20974895 PMCID: PMC3075749 DOI: 10.1104/pp.110.164814] [Citation(s) in RCA: 287] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2010] [Accepted: 10/18/2010] [Indexed: 05/18/2023]
Affiliation(s)
- Spencer M Whitney
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory 2601, Australia.
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49
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Maliga P, Svab Z. Engineering the plastid genome of Nicotiana sylvestris, a diploid model species for plastid genetics. Methods Mol Biol 2011; 701:37-50. [PMID: 21181523 DOI: 10.1007/978-1-61737-957-4_2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The plastids of higher plants have their own ∼120-160-kb genome that is present in 1,000-10,000 copies per cell. Engineering of the plastid genome (ptDNA) is based on homologous recombination between the plastid genome and cloned ptDNA sequences in the vector. A uniform population of engineered ptDNA is obtained by selection for marker genes encoded in the vectors. Manipulations of ptDNA include (1) insertion of transgenes in intergenic regions; (2) posttransformation excision of marker genes to obtain marker-free plants; (3) gene knockouts and gene knockdowns, and (4) cotransformation with multiple plasmids to introduce nonselected genes without physical linkage to marker genes. Most experiments on plastome engineering have been carried out in the allotetraploid Nicotiana tabacum. We report here for the first time plastid transformation in Nicotiana sylvestris, a diploid ornamental species. We demonstrate that the protocols and vectors developed for plastid transformation in N. tabacum are directly applicable to N. sylvestris with the advantage that the N. sylvestris transplastomic lines are suitable for mutant screens.
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Affiliation(s)
- Pal Maliga
- Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, Piscataway, NJ, USA.
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