1
|
Perdomo JA, Scales JC, Lee W, Kanyuka K, Carmo‐Silva E. Down-regulation of wheat Rubisco activase isoforms expression by virus-induced gene silencing. Plant Direct 2024; 8:e583. [PMID: 38628621 PMCID: PMC11018489 DOI: 10.1002/pld3.583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 03/17/2024] [Accepted: 03/21/2024] [Indexed: 04/19/2024]
Abstract
Rubisco activase (Rca) is an essential photosynthetic enzyme that removes inhibitors from the catalytic sites of the carboxylating enzyme Rubisco. In wheat, Rca is composed of one longer 46 kDa α-isoform and two shorter 42 kDa β-isoforms encoded by the genes TaRca1 and TaRca2. TaRca1 produces a single transcript from which a short 1β-isoform is expressed, whereas two alternative transcripts are generated from TaRca2 directing expression of either a long 2α-isoform or a short 2β-isoform. The 2β isoform is similar but not identical to 1β. Here, virus-induced gene silencing (VIGS) was used to silence the different TaRca transcripts. Abundance of the transcripts and the respective protein isoforms was then evaluated in the VIGS-treated and control plants. Remarkably, treatment with the construct specifically targeting TaRca1 efficiently decreased expression not only of TaRca1 but also of the two alternative TaRca2 transcripts. Similarly, specific targeting of the TaRca2 transcript encoding a long isoform TaRca2α resulted in silencing of both TaRca2 alternative transcripts. The corresponding protein isoforms decreased in abundance. These findings indicate concomitant down-regulation of TaRca1 and TaRca2 at both transcript and protein levels and may impact the feasibility of altering the relative abundance of Rca isoforms in wheat.
Collapse
Affiliation(s)
- Juan Alejandro Perdomo
- Lancaster Environment CentreLancaster UniversityLancasterUK
- School of Pharmacy and Biomedical SciencesUniversity of Central LancashirePrestonUK
| | | | - Wing‐Sham Lee
- Biointeractions and Crop ProtectionRothamsted ResearchHarpendenUK
| | - Kostya Kanyuka
- Biointeractions and Crop ProtectionRothamsted ResearchHarpendenUK
- NIABCambridgeUK
| | - Elizabete Carmo‐Silva
- Lancaster Environment CentreLancaster UniversityLancasterUK
- Plant Biology and Crop SciencesRothamsted ResearchHarpendenUK
| |
Collapse
|
2
|
Bloemers D, Carmo-Silva E. Antibody Design for the Quantification of Photosynthetic Proteins and Their Isoforms. Methods Mol Biol 2024; 2790:405-416. [PMID: 38649583 DOI: 10.1007/978-1-0716-3790-6_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2024]
Abstract
Antibodies are a valuable research tool, with uses including detection and quantification of specific proteins. By using peptide fragments to raise antibodies, they can be designed to differentiate between structurally similar proteins, or to bind conserved motifs in divergent proteins. Peptide sequence selection and antibody validation are crucial to ensure reliable results from antibody-based experiments. This chapter describes the steps for the identification of peptide sequences to produce protein- or isoform-specific antibodies using recombinant technologies as well as the subsequent validation of such antibodies. The photosynthetic protein Rubisco activase is used as a case study to explain the various steps involved and key aspects to take into consideration.
Collapse
Affiliation(s)
- Duncan Bloemers
- Lancaster Environment Centre, Lancaster University, Lancaster, UK
| | | |
Collapse
|
3
|
Aliakbari M, Tahmasebi S, Sisakht JN. Jasmonic acid improves barley photosynthetic efficiency through a possible regulatory module, MYC2-RcaA, under combined drought and salinity stress. Photosynth Res 2024; 159:69-78. [PMID: 38329704 DOI: 10.1007/s11120-023-01074-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Accepted: 12/28/2023] [Indexed: 02/09/2024]
Abstract
The combined stress of drought and salinity is prevalent in various regions of the world, affects several physiological and biochemical processes in crops, and causes their yield to decrease. Photosynthesis is one of the main processes that are disturbed by combined stress. Therefore, improving the photosynthetic efficiency of crops is one of the most promising strategies to overcome environmental stresses, making studying the molecular basis of regulation of photosynthesis a necessity. In this study, we sought a potential mechanism that regulated a major component of the combined stress response in the important crop barley (Hordeum vulgare L.), namely the Rubisco activase A (RcaA) gene. Promoter analysis of the RcaA gene led to identifying Jasmonic acid (JA)-responsive elements with a high occurrence. Specifically, a Myelocytomatosis oncogenes 2 (MYC2) transcription factor binding site was highlighted as a plausible functional promoter motif. We conducted a controlled greenhouse experiment with an abiotic stress-susceptible barley genotype and evaluated expression profiling of the RcaA and MYC2 genes, photosynthetic parameters, plant water status, and cell membrane damages under JA, combined drought and salinity stress (CS) and JA + CS treatments. Our results showed that applying JA enhances barley's photosynthetic efficiency and water relations and considerably compensates for the adverse effects of combined stress. Significant association was observed among gene expression profiles and evaluated physiochemical characteristics. The results showed a plausible regulatory route through the JA-dependent MYC2-RcaA module involved in photosynthesis regulation and combined stress tolerance. These findings provide valuable knowledge for further functional studies of the regulation of photosynthesis under abiotic stresses toward the development of multiple-stress-tolerant crops.
Collapse
Affiliation(s)
- Massume Aliakbari
- Department of Crop Production and Plant Breeding, Shiraz University, Shiraz, Iran.
| | - Sirous Tahmasebi
- Department of Seed and Plant Improvement Research, Fars Agriculture and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization (AREEO), Shiraz, Iran.
| | - Javad Nouripour Sisakht
- Department of Plant Production and Genetics, College of Agricultural Engineering, Isfahan University of Technology, Isfahan, Iran
| |
Collapse
|
4
|
Carmo-Silva E, Page R, Marsden CJ, Gjindali A, Orr DJ. Extraction of Soluble Proteins from Leaves. Methods Mol Biol 2024; 2790:391-404. [PMID: 38649582 DOI: 10.1007/978-1-0716-3790-6_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2024]
Abstract
Protein biochemistry can provide valuable answers to better understand plant performance and responses to the surrounding environment. In this chapter, we describe the process of extracting proteins from plant leaf samples. We highlight the key aspects to take into consideration to preserve protein integrity, from sample collection to extraction and preparation or storage for subsequent analysis of protein abundance and/or enzymatic activities.
Collapse
Affiliation(s)
| | - Rhiannon Page
- Lancaster Environment Centre, Lancaster University, Lancaster, UK
| | | | - Armida Gjindali
- Lancaster Environment Centre, Lancaster University, Lancaster, UK
| | - Douglas J Orr
- Lancaster Environment Centre, Lancaster University, Lancaster, UK
| |
Collapse
|
5
|
Amaral J, Lobo AKM, Carmo-Silva E. Regulation of Rubisco activity in crops. New Phytol 2024; 241:35-51. [PMID: 38058283 DOI: 10.1111/nph.19369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 09/18/2023] [Indexed: 12/08/2023]
Abstract
Efficient plant acclimation to changing environmental conditions relies on fast adjustments of the transcriptome, proteome, and metabolome. Regulation of enzyme activity depends on the activity of specific chaperones, chemical post-translational modifications (PTMs) of amino acid residues, and changes in the cellular and organellar microenvironment. Central to carbon assimilation, and thus plant growth and yield, Rubisco activity is regulated by its chaperone Rubisco activase (Rca) and by adjustments in the chloroplast stroma environment. Focused on crops, this review highlights the main PTMs and stromal ions and metabolites affecting Rubisco and Rca in response to environmental stimuli. Rca isoforms differ in regulatory properties and heat sensitivity, with expression changing according to the surrounding environment. Much of the physiological relevance of Rubisco and Rca PTMs is still poorly understood, though some PTMs have been associated with Rubisco regulation in response to stress. Ion and metabolite concentrations in the chloroplast change in response to variations in light and temperature. Some of these changes promote Rubisco activation while others inhibit activation, deactivate the enzyme, or change the rates of catalysis. Understanding these regulatory mechanisms will aid the development of strategies to improve carbon fixation by Rubisco under rapidly changing environments as experienced by crop plants.
Collapse
Affiliation(s)
- Joana Amaral
- Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, UK
| | - Ana K M Lobo
- Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, UK
| | | |
Collapse
|
6
|
Gionfriddo M, Zang K, Hayer-Hartl M. The challenge of engineering Rubisco for improving photosynthesis. FEBS Lett 2023. [PMID: 37334940 DOI: 10.1002/1873-3468.14678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 05/12/2023] [Accepted: 05/12/2023] [Indexed: 06/21/2023]
Abstract
Photosynthesis uses the energy of sunlight to convert water and atmospheric CO2 into sugars, providing food and oxygen for life. The fixation of atmospheric CO2 in this crucial biological process is mediated by the enzyme Rubisco. The inefficiencies of Rubisco have inspired researchers for decades to explore ways to improve its function with the goal of increasing crop yields [1-4], and more recently to combat global warming [5]. In this graphical review we highlight the challenges involved in engineering plant Rubisco, with a focus on the extensive chaperone requirement for its biogenesis. We discuss strategies for engineering the catalytic properties of Rubisco and for sequestering the enzyme in membraneless compartments to increase CO2 fixation.
Collapse
Affiliation(s)
- Matteo Gionfriddo
- Max Planck Institute of Biochemistry, Department of Cellular Biochemistry, Martinsried, 82152, Germany
| | - Kun Zang
- Max Planck Institute of Biochemistry, Department of Cellular Biochemistry, Martinsried, 82152, Germany
| | - Manajit Hayer-Hartl
- Max Planck Institute of Biochemistry, Department of Cellular Biochemistry, Martinsried, 82152, Germany
| |
Collapse
|
7
|
Sparrow-Muñoz I, Chen TC, Burgess SJ. Recent developments in the engineering of Rubisco activase for enhanced crop yield. Biochem Soc Trans 2023:BST20221281. [PMID: 36929563 DOI: 10.1042/BST20221281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 03/01/2023] [Accepted: 03/03/2023] [Indexed: 03/18/2023]
Abstract
Rubisco activase (RCA) catalyzes the release of inhibitory sugar phosphates from ribulose-1,6-biphosphate carboxylase/oxygenase (Rubisco) and can play an important role in biochemical limitations of photosynthesis under dynamic light and elevated temperatures. There is interest in increasing RCA activity to improve crop productivity, but a lack of understanding about the regulation of photosynthesis complicates engineering strategies. In this review, we discuss work relevant to improving RCA with a focus on advances in understanding the structural cause of RCA instability under heat stress and the regulatory interactions between RCA and components of photosynthesis. This reveals substantial variation in RCA thermostability that can be influenced by single amino acid substitutions, and that engineered variants can perform better in vitro and in vivo under heat stress. In addition, there are indications RCA activity is controlled by transcriptional, post-transcriptional, post-translational, and spatial regulation, which may be important for balancing between carbon fixation and light capture. Finally, we provide an overview of findings from recent field experiments and consider the requirements for commercial validation as part of efforts to increase crop yields in the face of global climate change.
Collapse
|
8
|
Waheeda K, Kitchel H, Wang Q, Chiu PL. Molecular mechanism of Rubisco activase: Dynamic assembly and Rubisco remodeling. Front Mol Biosci 2023; 10:1125922. [PMID: 36845545 PMCID: PMC9951593 DOI: 10.3389/fmolb.2023.1125922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 01/31/2023] [Indexed: 02/12/2023] Open
Abstract
Ribulose-1,5-bisphosphate (RuBP) carboxylase-oxygenase (Rubisco) enzyme is the limiting step of photosynthetic carbon fixation, and its activation is regulated by its co-evolved chaperone, Rubisco activase (Rca). Rca removes the intrinsic sugar phosphate inhibitors occupying the Rubisco active site, allowing RuBP to split into two 3-phosphoglycerate (3PGA) molecules. This review summarizes the evolution, structure, and function of Rca and describes the recent findings regarding the mechanistic model of Rubisco activation by Rca. New knowledge in these areas can significantly enhance crop engineering techniques used to improve crop productivity.
Collapse
Affiliation(s)
- Kazi Waheeda
- School of Molecular Sciences, Arizona State University, Tempe, AZ, United States,Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, AZ, United States
| | - Heidi Kitchel
- School of Molecular Sciences, Arizona State University, Tempe, AZ, United States,Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, AZ, United States
| | - Quan Wang
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Po-Lin Chiu
- School of Molecular Sciences, Arizona State University, Tempe, AZ, United States,Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, AZ, United States,*Correspondence: Po-Lin Chiu,
| |
Collapse
|
9
|
Qu Y, Mueller-Cajar O, Yamori W. Improving plant heat tolerance through modification of Rubisco activase in C3 plants to secure crop yield and food security in a future warming world. J Exp Bot 2023; 74:591-599. [PMID: 35981868 DOI: 10.1093/jxb/erac340] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 08/17/2022] [Indexed: 06/15/2023]
Abstract
The world's population may reach 10 billion by 2050, but 10% still suffer from food shortages. At the same time, global warming threatens food security by decreasing crop yields, so it is necessary to develop crops with enhanced resistance to high temperatures in order to secure the food supply. In this review, the role of Rubisco activase as an important factor in plant heat tolerance is summarized, based on the conclusions of recent findings. Rubisco activase is a molecular chaperone determining the activation of Rubisco, whose heat sensitivity causes reductions of photosynthesis at high temperatures. Thus, the thermostability of Rubisco activase is considered to be critical for improving plant heat tolerance. It has been shown that the introduction of thermostable Rubisco activase through gene editing into Arabidopsis thaliana and from heat-adapted wild Oryza species or C4Zea mays into Oryza sativa improves Rubisco activation, photosynthesis, and plant growth at high temperatures. We propose that developing a universal thermostable Rubisco activase could be a promising direction for further studies.
Collapse
Affiliation(s)
- Yuchen Qu
- Graduate School of Agricultural and Life Sciences, Institute for Sustainable Agri-ecosystem Services, The University of Tokyo, Tokyo, Japan
| | | | - Wataru Yamori
- Graduate School of Agricultural and Life Sciences, Institute for Sustainable Agri-ecosystem Services, The University of Tokyo, Tokyo, Japan
| |
Collapse
|
10
|
Orr DJ, Robijns AKJ, Baker CR, Niyogi KK, Carmo-Silva E. Dynamics of Rubisco regulation by sugar phosphate derivatives and their phosphatases. J Exp Bot 2023; 74:581-590. [PMID: 36173669 PMCID: PMC9833046 DOI: 10.1093/jxb/erac386] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 09/28/2022] [Indexed: 05/31/2023]
Abstract
Regulating the central CO2-fixing enzyme Rubisco is as complex as its ancient reaction mechanism and involves interaction with a series of cofactors and auxiliary proteins that activate catalytic sites and maintain activity. A key component among the regulatory mechanisms is the binding of sugar phosphate derivatives that inhibit activity. Removal of inhibitors via the action of Rubisco activase is required to restore catalytic competency. In addition, specific phosphatases dephosphorylate newly released inhibitors, rendering them incapable of binding to Rubisco catalytic sites. The best studied inhibitor is 2-carboxy-d-arabinitol 1-phosphate (CA1P), a naturally occurring nocturnal inhibitor that accumulates in most species during darkness and low light, progressively binding to Rubisco. As light increases, Rubisco activase removes CA1P from Rubisco, and the specific phosphatase CA1Pase dephosphorylates CA1P to CA, which cannot bind Rubisco. Misfire products of Rubisco's complex reaction chemistry can also act as inhibitors. One example is xylulose-1,5-bisphosphate (XuBP), which is dephosphorylated by XuBPase. Here we revisit key findings related to sugar phosphate derivatives and their specific phosphatases, highlighting outstanding questions and how further consideration of these inhibitors and their role is important for better understanding the regulation of carbon assimilation.
Collapse
Affiliation(s)
| | - Alice K J Robijns
- Present address: Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
| | - Christopher R Baker
- Howard Hughes Medical Institute, Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA
| | - Krishna K Niyogi
- Howard Hughes Medical Institute, Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | | |
Collapse
|
11
|
Carmo-Silva E, Sharwood RE. Rubisco and its regulation-major advances to improve carbon assimilation and productivity. J Exp Bot 2023; 74:507-509. [PMID: 36629907 PMCID: PMC9833034 DOI: 10.1093/jxb/erac475] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 11/30/2022] [Indexed: 06/17/2023]
|
12
|
Wang H, Hayer-Hartl M. Phase Separation of Rubisco by the Folded SSUL Domains of CcmM in Beta-Carboxysome Biogenesis. Methods Mol Biol 2023; 2563:269-296. [PMID: 36227479 DOI: 10.1007/978-1-0716-2663-4_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Carboxysomes are large, cytosolic bodies present in all cyanobacteria and many proteobacteria that function as the sites of photosynthetic CO2 fixation by the enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). The carboxysome lumen is enriched with Rubisco and carbonic anhydrase (CA). The polyhedral proteinaceous shell allows the passage of HCO3- ions into the carboxysome, where they are converted to CO2 by CA. Thus, the carboxysome functions as a CO2-concentrating mechanism (CCM), enhancing the efficiency of Rubisco in CO2 fixation. In β-cyanobacteria, carboxysome biogenesis first involves the aggregation of Rubisco by CcmM, a scaffolding protein that exists in two isoforms. Both isoforms contain a minimum of three Rubisco small subunit-like (SSUL) domains, connected by flexible linkers. Multivalent interaction between these linked SSUL domains with Rubisco results in phase separation and condensate formation. Here, we use Rubisco and the short isoform of CcmM (M35) of the β-cyanobacterium Synechococcus elongatus PCC7942 to describe the methods used for in vitro analysis of the mechanism of condensate formation driven by the SSUL domains. The methods include turbidity assays, bright-field and fluorescence microscopy, as well as transmission electron microscopy (TEM) in both negative staining and cryo-conditions.
Collapse
Affiliation(s)
- Huping Wang
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
- Membrane Protein Biosynthesis and Quality Control, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Manajit Hayer-Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany.
| |
Collapse
|
13
|
Harvey CM, Cavanagh AP, Kim SY, Wright DA, Edquilang RG, Shreeves KS, Perdomo JA, Spalding MH, Ort DR, Bernacchi CJ, Huber SC. Removal of redox-sensitive Rubisco Activase does not alter Rubisco regulation in soybean. Photosynth Res 2022; 154:169-182. [PMID: 36163583 DOI: 10.1007/s11120-022-00962-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 09/09/2022] [Indexed: 06/16/2023]
Abstract
Rubisco activase (Rca) facilitates the catalytic repair of Rubisco, the CO2-fixing enzyme of photosynthesis, following periods of darkness, low to high light transitions or stress. Removal of the redox-regulated isoform of Rubisco activase, Rca-α, enhances photosynthetic induction in Arabidopsis and has been suggested as a strategy for the improvement of crops, which may experience frequent light transitions in the field; however, this has never been tested in a crop species. Therefore, we used RNAi to reduce the Rca-α content of soybean (Glycine max cv. Williams 82) below detectable levels and then characterized the growth, photosynthesis, and Rubisco activity of the resulting transgenics, in both growth chamber and field conditions. Under a 16 h sine wave photoperiod, the reduction of Rca-α contents had no impact on morphological characteristics, leaf expansion rate, or total biomass. Photosynthetic induction rates were unaltered in both chamber-grown and field-grown plants. Plants with reduced Rca-α content maintained the ability to regulate Rubisco activity in low light just as in control plants. This result suggests that in soybean, Rca-α is not as centrally involved in the regulation of Rca oligomer activity as it is in Arabidopsis. The isoform stoichiometry supports this conclusion, as Rca-α comprises only ~ 10% of the Rubisco activase content of soybean, compared to ~ 50% in Arabidopsis. This is likely to hold true in other species that contain a low ratio of Rca-α to Rca-ß isoforms.
Collapse
Affiliation(s)
- Christopher M Harvey
- Agricultural Research Service, Global Change and Photosynthesis Research Unit, United States Department of Agriculture, Urbana, IL, USA.
| | - Amanda P Cavanagh
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- School of Life Sciences, University of Essex, Colchester, CO4 3SQ, UK
| | | | - David A Wright
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, USA
| | - Ron G Edquilang
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Departments of Plant Biology and Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Kayla S Shreeves
- Departments of Plant Biology and Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Juan Alejandro Perdomo
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- School of Pharmacy and Biomedical Sciences, University of Central Lancashire, Preston, PR1 2HE, UK
| | - Martin H Spalding
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, USA
| | - Donald R Ort
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Departments of Plant Biology and Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Carl J Bernacchi
- Agricultural Research Service, Global Change and Photosynthesis Research Unit, United States Department of Agriculture, Urbana, IL, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Departments of Plant Biology and Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Steven C Huber
- Agricultural Research Service, Global Change and Photosynthesis Research Unit, United States Department of Agriculture, Urbana, IL, USA
- Departments of Plant Biology and Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| |
Collapse
|
14
|
Phillips AL, Scafaro AP, Atwell BJ. Photosynthetic traits of Australian wild rice (Oryza australiensis) confer tolerance to extreme daytime temperatures. Plant Mol Biol 2022; 110:347-363. [PMID: 34997897 PMCID: PMC9646608 DOI: 10.1007/s11103-021-01210-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 10/27/2021] [Indexed: 05/08/2023]
Abstract
A wild relative of rice from the Australian savannah was compared with cultivated rice, revealing thermotolerance in growth and photosynthetic processes and a more robust carbon economy in extreme heat. Above ~ 32 °C, impaired photosynthesis compromises the productivity of rice. We compared leaf tissues from heat-tolerant wild rice (Oryza australiensis) with temperate-adapted O. sativa after sustained exposure to heat, as well as diurnal heat shock. Leaf elongation and shoot biomass in O. australiensis were unimpaired at 45 °C, and soluble sugar concentrations trebled during 10 h of a 45 °C shock treatment. By contrast, 45 °C slowed growth strongly in O. sativa. Chloroplastic CO2 concentrations eliminated CO2 supply to chloroplasts as the basis of differential heat tolerance. This directed our attention to carboxylation and the abundance of the heat-sensitive chaperone Rubisco activase (Rca) in each species. Surprisingly, O. australiensis leaves at 45 °C had 50% less Rca per unit Rubisco, even though CO2 assimilation was faster than at 30 °C. By contrast, Rca per unit Rubisco doubled in O. sativa at 45 °C while CO2 assimilation was slower, reflecting its inferior Rca thermostability. Plants grown at 45 °C were simultaneously exposed to 700 ppm CO2 to enhance the CO2 supply to Rubisco. Growth at 45 °C responded to CO2 enrichment in O. australiensis but not O. sativa, reflecting more robust carboxylation capacity and thermal tolerance in the wild rice relative.
Collapse
Affiliation(s)
- Aaron L Phillips
- Waite Research Institute and School of Agriculture, Food, and Wine, University of Adelaide, Adelaide, SA, Australia
- Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia
- ARC Centre of Excellence in Plant Energy Biology, School of Agriculture, Food, and Wine, The University of Adelaide, Adelaide, SA, Australia
| | - Andrew P Scafaro
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, The Australian National University, Canberra, ACT, Australia
| | - Brian J Atwell
- Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia.
| |
Collapse
|
15
|
Chen JH, Tang M, Jin XQ, Li H, Chen LS, Wang QL, Sun AZ, Yi Y, Guo FQ. Regulation of Calvin-Benson cycle enzymes under high temperature stress. aBIOTECH 2022; 3:65-77. [PMID: 36311539 DOI: 10.1007/s42994-022-00068-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 01/01/2022] [Indexed: 10/19/2022]
Abstract
The Calvin-Benson cycle (CBC) consists of three critical processes, including fixation of CO2 by Rubisco, reduction of 3-phosphoglycerate (3PGA) to triose phosphate (triose-P) with NADPH and ATP generated by the light reactions, and regeneration of ribulose 1,5-bisphosphate (RuBP) from triose-P. The activities of photosynthesis-related proteins, mainly from the CBC, were found more significantly affected and regulated in plants challenged with high temperature stress, including Rubisco, Rubisco activase (RCA) and the enzymes involved in RuBP regeneration, such as sedoheptulose-1,7-bisphosphatase (SBPase). Over the past years, the regulatory mechanism of CBC, especially for redox-regulation, has attracted major interest, because balancing flux at the various enzymatic reactions and maintaining metabolite levels in a range are of critical importance for the optimal operation of CBC under high temperature stress, providing insights into the genetic manipulation of photosynthesis. Here, we summarize recent progress regarding the identification of various layers of regulation point to the key enzymes of CBC for acclimation to environmental temperature changes along with open questions are also discussed.
Collapse
|
16
|
Chen T, Fang Y, Jiang Q, Dykes GF, Lin Y, Price GD, Long BM, Liu LN. Incorporation of Functional Rubisco Activases into Engineered Carboxysomes to Enhance Carbon Fixation. ACS Synth Biol 2022; 11:154-161. [PMID: 34664944 PMCID: PMC8787814 DOI: 10.1021/acssynbio.1c00311] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
![]()
The carboxysome is
a versatile paradigm of prokaryotic organelles
and is a proteinaceous self-assembling microcompartment that plays
essential roles in carbon fixation in all cyanobacteria and some chemoautotrophs.
The carboxysome encapsulates
the central CO2-fixing enzyme, ribulose-1,5-bisphosphate
carboxylase/oxygenase (Rubisco), using a polyhedral protein shell
that is selectively permeable to specific metabolites in favor of
Rubisco carboxylation. There is tremendous interest in repurposing
carboxysomes to boost carbon fixation in heterologous organisms. Here,
we develop the design and engineering of α-carboxysomes by coexpressing
the Rubisco activase components CbbQ and CbbO with α-carboxysomes
in Escherichia coli. Our results show
that CbbQ and CbbO could assemble into the reconstituted α-carboxysome
as intrinsic components. Incorporation of both CbbQ and CbbO within
the carboxysome promotes activation of Rubisco and enhances the CO2-fixation activities of recombinant carboxysomes. We also
show that the structural composition of these carboxysomes could be
modified in different expression systems, representing the plasticity
of the carboxysome architecture. In translational terms, our study
informs strategies for engineering and modulating carboxysomes in
diverse biotechnological applications.
Collapse
Affiliation(s)
- Taiyu Chen
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Crown Street, Liverpool L69 7ZB, U.K
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research, Huazhong Agricultural University, Wuhan 430070, China
| | - Yi Fang
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Crown Street, Liverpool L69 7ZB, U.K
| | - Qiuyao Jiang
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Crown Street, Liverpool L69 7ZB, U.K
| | - Gregory F. Dykes
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Crown Street, Liverpool L69 7ZB, U.K
| | - Yongjun Lin
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research, Huazhong Agricultural University, Wuhan 430070, China
| | - G. Dean Price
- Australian Research Council Centre of Excellence for Translational Photosynthesis, Research School of Biology, Australian National University, 134 Linnaeus Way, Acton, Australian Capital Territory 2601, Australia
| | - Benedict M. Long
- Australian Research Council Centre of Excellence for Translational Photosynthesis, Research School of Biology, Australian National University, 134 Linnaeus Way, Acton, Australian Capital Territory 2601, Australia
| | - Lu-Ning Liu
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Crown Street, Liverpool L69 7ZB, U.K
- College of Marine Life Sciences, and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao 266003, China
| |
Collapse
|
17
|
Iñiguez C, Aguiló-Nicolau P, Galmés J. Improving photosynthesis through the enhancement of Rubisco carboxylation capacity. Biochem Soc Trans 2021; 49:2007-2019. [PMID: 34623388 DOI: 10.1042/bst20201056] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 09/07/2021] [Accepted: 09/09/2021] [Indexed: 12/14/2022]
Abstract
Rising human population, along with the reduction in arable land and the impacts of global change, sets out the need for continuously improving agricultural resource use efficiency and crop yield (CY). Bioengineering approaches for photosynthesis optimization have largely demonstrated the potential for enhancing CY. This review is focused on the improvement of Rubisco functioning, which catalyzes the rate-limiting step of CO2 fixation required for plant growth, but also catalyzes the ribulose-bisphosphate oxygenation initiating the carbon and energy wasteful photorespiration pathway. Rubisco carboxylation capacity can be enhanced by engineering the Rubisco large and/or small subunit genes to improve its catalytic traits, or by engineering the mechanisms that provide enhanced Rubisco expression, activation and/or elevated [CO2] around the active sites to favor carboxylation over oxygenation. Recent advances have been made in the expression, assembly and activation of foreign (either natural or mutant) faster and/or more CO2-specific Rubisco versions. Some components of CO2 concentrating mechanisms (CCMs) from bacteria, algae and C4 plants has been successfully expressed in tobacco and rice. Still, none of the transformed plant lines expressing foreign Rubisco versions and/or simplified CCM components were able to grow faster than wild type plants under present atmospheric [CO2] and optimum conditions. However, the results obtained up to date suggest that it might be achievable in the near future. In addition, photosynthetic and yield improvements have already been observed when manipulating Rubisco quantity and activation degree in crops. Therefore, engineering Rubisco carboxylation capacity continues being a promising target for the improvement in photosynthesis and yield.
Collapse
Affiliation(s)
- Concepción Iñiguez
- Research Group on Plant Biology Under Mediterranean Conditions, Universitat de les Illes Balears-INAGEA, Palma, Balearic Islands, Spain
- Department of Ecology, Faculty of Sciences, University of Málaga, Málaga, Spain
| | - Pere Aguiló-Nicolau
- Research Group on Plant Biology Under Mediterranean Conditions, Universitat de les Illes Balears-INAGEA, Palma, Balearic Islands, Spain
| | - Jeroni Galmés
- Research Group on Plant Biology Under Mediterranean Conditions, Universitat de les Illes Balears-INAGEA, Palma, Balearic Islands, Spain
| |
Collapse
|
18
|
Wijewardene I, Shen G, Zhang H. Enhancing crop yield by using Rubisco activase to improve photosynthesis under elevated temperatures. Stress Biol 2021; 1:2. [PMID: 37676541 PMCID: PMC10429496 DOI: 10.1007/s44154-021-00002-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 06/29/2021] [Indexed: 09/08/2023]
Abstract
With the rapid growth of world population, it is essential to increase agricultural productivity to feed the growing population. Over the past decades, many methods have been used to increase crop yields. Despite the success in boosting the crop yield through these methods, global food production still needs to be increased to be on par with the increasing population and its dynamic consumption patterns. Additionally, given the prevailing environmental conditions pertaining to the global temperature increase, heat stress will likely be a critical factor that negatively affects plant biomass and crop yield. One of the key elements hindering photosynthesis and plant productivity under heat stress is the thermo-sensitivity of the Rubisco activase (RCA), a molecular chaperone that converts Rubisco back to active form after it becomes inactive. It would be an attractive and practical strategy to maintain photosynthetic activity under elevated temperatures by enhancing the thermo-stability of RCA. In this context, this review discusses the need to improve the thermo-tolerance of RCA under current climatic conditions and to further study RCA structure and regulation, and its limitations at elevated temperatures. This review summarizes successful results and provides a perspective on RCA research and its implication in improving crop yield under elevated temperature conditions in the future.
Collapse
Affiliation(s)
- Inosha Wijewardene
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, 79409, USA.
| | - Guoxin Shen
- Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang Province, China
| | - Hong Zhang
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, 79409, USA.
| |
Collapse
|
19
|
Wang Y, Chan KX, Long SP. Towards a dynamic photosynthesis model to guide yield improvement in C4 crops. Plant J 2021; 107:343-359. [PMID: 34087011 PMCID: PMC9291162 DOI: 10.1111/tpj.15365] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 05/19/2021] [Accepted: 05/22/2021] [Indexed: 05/22/2023]
Abstract
The most productive C4 food and biofuel crops, such as Saccharum officinarum (sugarcane), Sorghum bicolor (sorghum) and Zea mays (maize), all use NADP-ME-type C4 photosynthesis. Despite high productivities, these crops fall well short of the theoretical maximum solar conversion efficiency of 6%. Understanding the basis of these inefficiencies is key for bioengineering and breeding strategies to increase the sustainable productivity of these major C4 crops. Photosynthesis is studied predominantly at steady state in saturating light. In field stands of these crops light is continually changing, and often with rapid fluctuations. Although light may change in a second, the adjustment of photosynthesis may take many minutes, leading to inefficiencies. We measured the rates of CO2 uptake and stomatal conductance of maize, sorghum and sugarcane under fluctuating light regimes. The gas exchange results were combined with a new dynamic photosynthesis model to infer the limiting factors under non-steady-state conditions. The dynamic photosynthesis model was developed from an existing C4 metabolic model for maize and extended to include: (i) post-translational regulation of key photosynthetic enzymes and their temperature responses; (ii) dynamic stomatal conductance; and (iii) leaf energy balance. Testing the model outputs against measured rates of leaf CO2 uptake and stomatal conductance in the three C4 crops indicated that Rubisco activase, the pyruvate phosphate dikinase regulatory protein and stomatal conductance are the major limitations to the efficiency of NADP-ME-type C4 photosynthesis during dark-to-high light transitions. We propose that the level of influence of these limiting factors make them targets for bioengineering the improved photosynthetic efficiency of these key crops.
Collapse
Affiliation(s)
- Yu Wang
- Carl R Woese Institute for Genomic BiologyUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
- DOE Center for Advanced Bioenergy and Bioproducts InnovationUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
| | - Kher Xing Chan
- Carl R Woese Institute for Genomic BiologyUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
- DOE Center for Advanced Bioenergy and Bioproducts InnovationUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
| | - Stephen P. Long
- Carl R Woese Institute for Genomic BiologyUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
- DOE Center for Advanced Bioenergy and Bioproducts InnovationUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
- Departments of Plant Biology and of Crop SciencesUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
- Lancaster Environment CentreLancaster UniversityLancasterLA1 4YQUK
| |
Collapse
|
20
|
Perdomo JA, Buchner P, Carmo-Silva E. The relative abundance of wheat Rubisco activase isoforms is post-transcriptionally regulated. Photosynth Res 2021; 148:47-56. [PMID: 33796933 PMCID: PMC8154801 DOI: 10.1007/s11120-021-00830-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 03/11/2021] [Indexed: 06/06/2023]
Abstract
Diurnal rhythms and light availability affect transcription-translation feedback loops that regulate the synthesis of photosynthetic proteins. The CO2-fixing enzyme Rubisco is the most abundant protein in the leaves of major crop species and its activity depends on interaction with the molecular chaperone Rubisco activase (Rca). In Triticum aestivum L. (wheat), three Rca isoforms are present that differ in their regulatory properties. Here, we tested the hypothesis that the relative abundance of the redox-sensitive and redox-insensitive Rca isoforms could be differentially regulated throughout light-dark diel cycle in wheat. While TaRca1-β expression was consistently negligible throughout the day, transcript levels of both TaRca2-β and TaRca2-α were higher and increased at the start of the day, with peak levels occurring at the middle of the photoperiod. Abundance of TaRca-β protein was maximal 1.5 h after the peak in TaRca2-β expression, but the abundance of TaRca-α remained constant during the entire photoperiod. The redox-sensitive TaRca-α isoform was less abundant, representing 85% of the redox-insensitive TaRca-β at the transcript level and 12.5% at the protein level. Expression of Rubisco large and small subunit genes did not show a consistent pattern throughout the diel cycle, but the abundance of Rubisco decreased by up to 20% during the dark period in fully expanded wheat leaves. These results, combined with a lack of correlation between transcript and protein abundance for both Rca isoforms and Rubisco throughout the entire diel cycle, suggest that the abundance of these photosynthetic enzymes is post-transcriptionally regulated.
Collapse
Affiliation(s)
| | - Peter Buchner
- Plant Biology and Crop Science Department, Rothamsted Research, Harpenden, AL5 2JQ, UK
| | | |
Collapse
|
21
|
Degen GE, Orr DJ, Carmo-Silva E. Heat-induced changes in the abundance of wheat Rubisco activase isoforms. New Phytol 2021; 229:1298-1311. [PMID: 32964463 DOI: 10.1111/nph.16937] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 09/02/2020] [Indexed: 05/24/2023]
Abstract
The Triticum aestivum (wheat) genome encodes three isoforms of Rubisco activase (Rca) differing in thermostability, which could be exploited to improve the resilience of this crop to global warming. We hypothesized that elevated temperatures would cause an increase in the relative abundance of heat-stable Rca1β. Wheat plants were grown at 25° C : 18°C (day : night) and exposed to heat stress (38° C : 22°C) for up to 5 d at pre-anthesis. Carbon (C) assimilation, Rubisco activity, CA1Pase activity, transcripts of Rca1β, Rca2β, and Rca2α, and the quantities of the corresponding protein products were measured during and after heat stress. The transcript of Rca1β increased 40-fold in 4 h at elevated temperatures and returned to the original level after 4 h upon return of plants to control temperatures. Rca1β comprised up to 2% of the total Rca protein in unstressed leaves but increased three-fold in leaves exposed to elevated temperatures for 5 d and remained high at 4 h after heat stress. These results show that elevated temperatures cause rapid changes in Rca gene expression and adaptive changes in Rca isoform abundance. The improved understanding of the regulation of C assimilation under heat stress will inform efforts to improve wheat productivity and climate resilience.
Collapse
Affiliation(s)
- Gustaf E Degen
- Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, UK
| | - Douglas J Orr
- Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, UK
| | | |
Collapse
|
22
|
Ng J, Guo Z, Mueller-Cajar O. Rubisco activase requires residues in the large subunit N terminus to remodel inhibited plant Rubisco. J Biol Chem 2020; 295:16427-16435. [PMID: 32948656 PMCID: PMC7705312 DOI: 10.1074/jbc.ra120.015759] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 09/09/2020] [Indexed: 11/06/2022] Open
Abstract
The photosynthetic CO2 fixing enzyme ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) forms dead-end inhibited complexes while binding multiple sugar phosphates, including its substrate ribulose 1,5-bisphosphate. Rubisco can be rescued from this inhibited form by molecular chaperones belonging to the ATPases associated with diverse cellular activities (AAA+ proteins) termed Rubisco activases (Rcas). The mechanism of green-type Rca found in higher plants has proved elusive, in part because until recently higher-plant Rubiscos could not be expressed recombinantly. Identifying the interaction sites between Rubisco and Rca is critical to formulate mechanistic hypotheses. Toward that end here we purify and characterize a suite of 33 Arabidopsis Rubisco mutants for their ability to be activated by Rca. Mutation of 17 surface-exposed large subunit residues did not yield variants that were perturbed in their interaction with Rca. In contrast, we find that Rca activity is highly sensitive to truncations and mutations in the conserved N terminus of the Rubisco large subunit. Large subunits lacking residues 1-4 are functional Rubiscos but cannot be activated. Both T5A and T7A substitutions result in functional carboxylases that are poorly activated by Rca, indicating the side chains of these residues form a critical interaction with the chaperone. Many other AAA+ proteins function by threading macromolecules through a central pore of a disc-shaped hexamer. Our results are consistent with a model in which Rca transiently threads the Rubisco large subunit N terminus through the axial pore of the AAA+ hexamer.
Collapse
Affiliation(s)
- Jediael Ng
- School of Biological Sciences, Nanyang Technological University, Singapore
| | - Zhijun Guo
- School of Biological Sciences, Nanyang Technological University, Singapore
| | | |
Collapse
|
23
|
Gunn LH, Martin Avila E, Birch R, Whitney SM. The dependency of red Rubisco on its cognate activase for enhancing plant photosynthesis and growth. Proc Natl Acad Sci U S A 2020; 117:25890-25896. [PMID: 32989135 PMCID: PMC7568259 DOI: 10.1073/pnas.2011641117] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Plant photosynthesis and growth are often limited by the activity of the CO2-fixing enzyme Rubisco. The broad kinetic diversity of Rubisco in nature is accompanied by differences in the composition and compatibility of the ancillary proteins needed for its folding, assembly, and metabolic regulation. Variations in the protein folding needs of catalytically efficient red algae Rubisco prevent their production in plants. Here, we show this impediment does not extend to Rubisco from Rhodobacter sphaeroides (RsRubisco)-a red-type Rubisco able to assemble in plant chloroplasts. In transplastomic tobRsLS lines expressing a codon optimized Rs-rbcLS operon, the messenger RNA (mRNA) abundance was ∼25% of rbcL transcript and RsRubisco ∼40% the Rubisco content in WT tobacco. To mitigate the low activation status of RsRubisco in tobRsLS (∼23% sites active under ambient CO2), the metabolic repair protein RsRca (Rs-activase) was introduced via nuclear transformation. RsRca production in the tobRsLS::X progeny matched endogenous tobacco Rca levels (∼1 µmol protomer·m2) and enhanced RsRubisco activation to 75% under elevated CO2 (1%, vol/vol) growth. Accordingly, the rate of photosynthesis and growth in the tobRsLS::X lines were improved >twofold relative to tobRsLS. Other tobacco lines producing RsRubisco containing alternate diatom and red algae S-subunits were nonviable as CO2-fixation rates (kcatc) were reduced >95% and CO2/O2 specificity impaired 30-50%. We show differences in hybrid and WT RsRubisco biogenesis in tobacco correlated with assembly in Escherichia coli advocating use of this bacterium to preevaluate the kinetic and chloroplast compatibility of engineered RsRubisco, an isoform amenable to directed evolution.
Collapse
Affiliation(s)
- Laura H Gunn
- Plant Science Division, Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia
| | - Elena Martin Avila
- Plant Science Division, Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia
| | - Rosemary Birch
- Plant Science Division, Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia
| | - Spencer M Whitney
- Plant Science Division, Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia
| |
Collapse
|
24
|
Flecken M, Wang H, Popilka L, Hartl FU, Bracher A, Hayer-Hartl M. Dual Functions of a Rubisco Activase in Metabolic Repair and Recruitment to Carboxysomes. Cell 2020; 183:457-473.e20. [PMID: 32979320 DOI: 10.1016/j.cell.2020.09.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 07/13/2020] [Accepted: 09/01/2020] [Indexed: 01/19/2023]
Abstract
Rubisco, the key enzyme of CO2 fixation in photosynthesis, is prone to inactivation by inhibitory sugar phosphates. Inhibited Rubisco undergoes conformational repair by the hexameric AAA+ chaperone Rubisco activase (Rca) in a process that is not well understood. Here, we performed a structural and mechanistic analysis of cyanobacterial Rca, a close homolog of plant Rca. In the Rca:Rubisco complex, Rca is positioned over the Rubisco catalytic site under repair and pulls the N-terminal tail of the large Rubisco subunit (RbcL) into the hexamer pore. Simultaneous displacement of the C terminus of the adjacent RbcL opens the catalytic site for inhibitor release. An alternative interaction of Rca with Rubisco is mediated by C-terminal domains that resemble the small Rubisco subunit. These domains, together with the N-terminal AAA+ hexamer, ensure that Rca is packaged with Rubisco into carboxysomes. The cyanobacterial Rca is a dual-purpose protein with functions in Rubisco repair and carboxysome organization.
Collapse
Affiliation(s)
- Mirkko Flecken
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Huping Wang
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Leonhard Popilka
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - F Ulrich Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Andreas Bracher
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Manajit Hayer-Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany.
| |
Collapse
|
25
|
Acevedo‐Siaca LG, Coe R, Wang Y, Kromdijk J, Quick WP, Long SP. Variation in photosynthetic induction between rice accessions and its potential for improving productivity. New Phytol 2020; 227:1097-1108. [PMID: 32124982 PMCID: PMC7383871 DOI: 10.1111/nph.16454] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 01/13/2020] [Indexed: 05/18/2023]
Abstract
Photosynthetic induction describes the transient increase in leaf CO2 uptake with an increase in light. During induction, efficiency is lower than at steady state. Under field conditions of fluctuating light, this lower efficiency during induction may cost > 20% of potential crop assimilation. Accelerating induction would boost photosynthetic and resource-use efficiencies. Variation between rice accessions and potential for accelerating induction was analysed by gas exchange. Induction during shade to sun transitions of 14 accessions representing five subpopulations from the 3000 Rice Genome Project Panel (3K RGP) was analysed. Differences of 109% occurred in the CO2 fixed during the first 300 s of induction, 117% in the half-time to completion of induction, and 65% in intrinsic water-use efficiency during induction, between the highest and lowest performing accessions. Induction in three accessions with contrasting responses (AUS 278, NCS 771 A and IR64-21) was compared for a range of [CO2 ] to analyse limitations. This showed in vivo capacity for carboxylation at Rubisco (Vc,max ), and not stomata, as the primary limitation to induction, with significant differences between accessions. Variation in nonsteady-state efficiency greatly exceeded that at steady state, suggesting a new and more promising opportunity for selection of greater crop photosynthetic efficiency in this key food crop.
Collapse
Affiliation(s)
| | - Robert Coe
- C4 Rice CenterInternational Rice Research InstituteLos BañosLaguna4031Philippines
- High Resolution Plant Phenomics CentreCommonwealth Scientific and Industrial Research Organization (CSIRO)Plant IndustryCanberraACT2601Australia
| | - Yu Wang
- Carl R. Woese Institute for Genomic BiologyUniversity of Illinois at Urbana–ChampaignUrbanaIL61801USA
| | - Johannes Kromdijk
- Carl R. Woese Institute for Genomic BiologyUniversity of Illinois at Urbana–ChampaignUrbanaIL61801USA
- Department of Plant SciencesUniversity of CambridgeCambridgeCB2 3EAUK
| | - W. Paul Quick
- C4 Rice CenterInternational Rice Research InstituteLos BañosLaguna4031Philippines
- Department of Animal and Plant SciencesUniversity of SheffieldWestern BankSheffieldS10 2TNUK
| | - Stephen P. Long
- Department of Crop SciencesUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
- Carl R. Woese Institute for Genomic BiologyUniversity of Illinois at Urbana–ChampaignUrbanaIL61801USA
- Department of Plant BiologyUniversity of Illinois at Urbana–ChampaignUrbanaIL61801USA
- Lancaster Environment CentreLancaster UniversityLancasterLA1 4YQUK
| |
Collapse
|
26
|
Wijewardene I, Mishra N, Sun L, Smith J, Zhu X, Payton P, Shen G, Zhang H. Improving drought-, salinity-, and heat-tolerance in transgenic plants by co-overexpressing Arabidopsis vacuolar pyrophosphatase gene AVP1 and Larrea Rubisco activase gene RCA. Plant Sci 2020; 296:110499. [PMID: 32540017 DOI: 10.1016/j.plantsci.2020.110499] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Revised: 03/31/2020] [Accepted: 04/06/2020] [Indexed: 05/25/2023]
Abstract
The severity and frequency of many abiotic stresses such as drought, salinity and heat, cause substantial crop losses worldwide, which poses a serious challenge in food security. To increase crop production, new approaches are needed. Previous research has shown that overexpression of the tonoplast H+ pyrophosphatase gene AVP1 leads to improved drought and salt tolerance in transgenic plants. Other research showed that overexpression of thermotolerant ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) activase gene could maintain photosynthesis at higher temperatures, which contributes to higher heat tolerance in transgenic plants. In nature, abiotic stresses rarely come alone, instead these stresses often occur in various combinations. Therefore, it is desirable to make crops more tolerant to multiple stresses, which will likely lead to higher crop yield under various stress conditions. It is shown here that co-overexpression of the Arabidopsis gene AVP1 and the Larrea Rubisco activase gene RCA significantly increases drought, salinity and heat tolerance, resulting in higher biomass and seed yield than wild-type plants. AVP1/RCA co-overexpressing plants are as more drought- and salt-tolerant as AVP1-overexpressing plants, and as more heat-tolerant as RCA-overexpressing plants. More importantly, they produce higher seed yields than AVP1-overexpressing, RCA-overexpressing, and wild-type plants under combined drought and heat conditions.
Collapse
Affiliation(s)
- Inosha Wijewardene
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, 79409, USA
| | - Neelam Mishra
- St. Joseph's College Autonomous, Bengaluru, Karnataka, 560027, India
| | - Li Sun
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, 79409, USA
| | - Jennifer Smith
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, 79409, USA
| | - Xunlu Zhu
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, 79409, USA
| | - Paxton Payton
- USDA-ARS Cropping Systems Research Laboratory, Lubbock, TX, USA
| | - Guoxin Shen
- Zhejiang Academy of Agricultural Sciences, Hangzhou, China.
| | - Hong Zhang
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, 79409, USA.
| |
Collapse
|
27
|
Degen GE, Worrall D, Carmo-Silva E. An isoleucine residue acts as a thermal and regulatory switch in wheat Rubisco activase. Plant J 2020; 103:742-751. [PMID: 32363739 DOI: 10.1111/tpj.14766] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 02/21/2020] [Accepted: 03/24/2020] [Indexed: 05/25/2023]
Abstract
The regulation of Rubisco, the gatekeeper of carbon fixation into the biosphere, by its molecular chaperone Rubisco activase (Rca) is essential for photosynthesis and plant growth. Using energy from ATP hydrolysis, Rca promotes the release of inhibitors and restores catalytic competence to Rubisco-active sites. Rca is sensitive to moderate heat stress, however, and becomes progressively inhibited as the temperature increases above the optimum for photosynthesis. Here, we identify a single amino acid substitution (M159I) that fundamentally alters the thermal and regulatory properties of Rca in bread wheat (Triticum aestivum L.). Using site-directed mutagenesis, we demonstrate that the M159I substitution extends the temperature optimum of the most abundant Rca isoform by 5°C in vitro, while maintaining the efficiency of Rubisco activation by Rca. The results suggest that this single amino acid substitution acts as a thermal and regulatory switch in wheat Rca that can be exploited to improve the climate resilience and efficiency of carbon assimilation of this cereal crop as temperatures become warmer and more volatile.
Collapse
Affiliation(s)
- Gustaf E Degen
- Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, UK
| | - Dawn Worrall
- Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, UK
| | | |
Collapse
|
28
|
De Souza AP, Wang Y, Orr DJ, Carmo-Silva E, Long SP. Photosynthesis across African cassava germplasm is limited by Rubisco and mesophyll conductance at steady state, but by stomatal conductance in fluctuating light. New Phytol 2020; 225:2498-2512. [PMID: 31446639 PMCID: PMC7065220 DOI: 10.1111/nph.16142] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 08/15/2019] [Indexed: 05/18/2023]
Abstract
Sub-Saharan Africa is projected to see a 55% increase in food demand by 2035, where cassava (Manihot esculenta) is the most widely planted crop and a major calorie source. Yet, cassava yield in this region has not increased significantly for 13 yr. Improvement of genetic yield potential, the basis of the first Green Revolution, could be realized by improving photosynthetic efficiency. First, the factors limiting photosynthesis and their genetic variability within extant germplasm must be understood. Biochemical and diffusive limitations to leaf photosynthetic CO2 uptake under steady state and fluctuating light in 13 farm-preferred and high-yielding African cultivars were analyzed. A cassava leaf metabolic model was developed to quantify the value of overcoming limitations to leaf photosynthesis. At steady state, in vivo Rubisco activity and mesophyll conductance accounted for 84% of the limitation. Under nonsteady-state conditions of shade to sun transition, stomatal conductance was the major limitation, resulting in an estimated 13% and 5% losses in CO2 uptake and water use efficiency, across a diurnal period. Triose phosphate utilization, although sufficient to support observed rates, would limit improvement in leaf photosynthesis to 33%, unless improved itself. The variation of carbon assimilation among cultivars was three times greater under nonsteady state compared to steady state, pinpointing important overlooked breeding targets for improved photosynthetic efficiency in cassava.
Collapse
Affiliation(s)
- Amanda P. De Souza
- Carl R Woese Institute for Genomic Biology, University of
Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Yu Wang
- Carl R Woese Institute for Genomic Biology, University of
Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Douglas J. Orr
- Lancaster Environment Centre, Lancaster University,
Lancaster, LA1 4YQ, UK
| | | | - Stephen P. Long
- Carl R Woese Institute for Genomic Biology, University of
Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Lancaster Environment Centre, Lancaster University,
Lancaster, LA1 4YQ, UK
| |
Collapse
|
29
|
Wang Y, Burgess SJ, de Becker EM, Long SP. Photosynthesis in the fleeting shadows: an overlooked opportunity for increasing crop productivity? Plant J 2020; 101:874-884. [PMID: 31908116 PMCID: PMC7064922 DOI: 10.1111/tpj.14663] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 12/16/2019] [Accepted: 12/19/2019] [Indexed: 05/20/2023]
Abstract
Photosynthesis measurements are traditionally taken under steady-state conditions; however, leaves in crop fields experience frequent fluctuations in light and take time to respond. This slow response reduces the efficiency of carbon assimilation. Transitions from low to high light require photosynthetic induction, including the activation of Rubisco and the opening of stomata, whereas transitions from high to low light require the relaxation of dissipative energy processes, collectively known as non-photochemical quenching (NPQ). Previous attempts to assess the impact of these delays on net carbon assimilation have used simplified models of crop canopies, limiting the accuracy of predictions. Here, we use ray tracing to predict the spatial and temporal dynamics of lighting for a rendered mature Glycine max (soybean) canopy to review the relative importance of these delays on net cumulative assimilation over the course of both a sunny and a cloudy summer day. Combined limitations result in a 13% reduction in crop carbon assimilation on both sunny and cloudy days, with induction being more important on cloudy than on sunny days. Genetic variation in NPQ relaxation rates and photosynthetic induction in parental lines of a soybean nested association mapping (NAM) population was assessed. Short-term NPQ relaxation (<30 min) showed little variation across the NAM lines, but substantial variation was found in the speeds of photosynthetic induction, attributable to Rubisco activation. Over the course of a sunny and an intermittently cloudy day these would translate to substantial differences in total crop carbon assimilation. These findings suggest an unexplored potential for breeding improved photosynthetic potential in our major crops.
Collapse
Affiliation(s)
- Yu Wang
- Carl R Woese Institute for Genomic BiologyUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
| | - Steven J. Burgess
- Carl R Woese Institute for Genomic BiologyUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
| | - Elsa M. de Becker
- Carl R Woese Institute for Genomic BiologyUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
- Department of Plant BiologyUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
| | - Stephen P. Long
- Carl R Woese Institute for Genomic BiologyUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
- Department of Crop SciencesUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
- Lancaster Environment CentreLancaster UniversityLancasterLA1 4YQUK
| |
Collapse
|
30
|
Wang X, Li Z, Liu B, Zhou H, Elmongy MS, Xia Y. Combined Proteome and Transcriptome Analysis of Heat-Primed Azalea Reveals New Insights Into Plant Heat Acclimation Memory. Front Plant Sci 2020; 11:1278. [PMID: 32973837 PMCID: PMC7466565 DOI: 10.3389/fpls.2020.01278] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 08/05/2020] [Indexed: 05/21/2023]
Abstract
Plants can obtain superinduction of defense against unpredictable challenges based on prior acclimation, but the mechanisms involved in the acclimation memory are little known. The objective of this study was to characterize mechanisms of heat acclimation memory in Rhododendron hainanense, a thermotolerant wild species of azalea. Pretreatment of a 2-d recovery (25/18°C, day/night) after heat acclimation (37°C, 1 h) (AR-pt) did not weaken but enhanced acquired thermotolerance in R. hainanense with less damaged phenotype, net photosynthetic rate, and membrane stability than non-acclimation pretreated (NA-pt) plants. Combined transcriptome and proteome analysis revealed that a lot of heat-responsive genes still maintained high protein abundance rather than transcript level after the 2-d recovery. Photosynthesis-related genes were highly enriched and most decreased under heat stress (HS: 42°C, 1 h) with a less degree in AR-pt plants compared to NA-pt. Sustainably accumulated chloroplast-localized heat shock proteins (HSPs), Rubisco activase 1 (RCA1), beta-subunit of chaperonin-60 (CPN60β), and plastid transcriptionally active chromosome 5 (pTAC5) in the recovery period probably provided equipped protection of AR-pt plants against the subsequent HS, with less damaged photochemical efficiency and chloroplast structure. In addition, significant higher levels of RCA1 transcripts in AR-pt compared to NA-pt plants in early stage of HS showed a more important role of RCA1 than other chaperonins in heat acclimation memory. The novel heat-induced RCA1, rather than constitutively expressed RCA2 and RCA3, showed excellent thermostability after long-term HS (LHS: 42/35°C, 7 d) and maintained balanced Rubisco activation state in photosynthetic acclimation. This study provides new insights into plant heat acclimation memory and indicates candidate genes for genetic modification and molecular breeding in thermotolerance improvement.
Collapse
Affiliation(s)
- Xiuyun Wang
- Genomics and Genetic Engineering Laboratory of Ornamental Plants, Department of Horticulture, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
| | - Zheng Li
- Genomics and Genetic Engineering Laboratory of Ornamental Plants, Department of Horticulture, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
| | - Bing Liu
- Genomics and Genetic Engineering Laboratory of Ornamental Plants, Department of Horticulture, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
| | - Hong Zhou
- Genomics and Genetic Engineering Laboratory of Ornamental Plants, Department of Horticulture, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
| | - Mohamed S. Elmongy
- Genomics and Genetic Engineering Laboratory of Ornamental Plants, Department of Horticulture, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
- Department of Vegetable and Floriculture, Faculty of Agriculture, Mansoura University, Mansoura, Egypt
| | - Yiping Xia
- Genomics and Genetic Engineering Laboratory of Ornamental Plants, Department of Horticulture, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
- *Correspondence: Yiping Xia,
| |
Collapse
|
31
|
Corrigendum. New Phytol 2019; 225:1041. [PMID: 31854032 DOI: 10.1111/nph.16198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
|
32
|
Tsai YC, Ye F, Liew L, Liu D, Bhushan S, Gao YG, Mueller-Cajar O. Insights into the mechanism and regulation of the CbbQO-type Rubisco activase, a MoxR AAA+ ATPase. Proc Natl Acad Sci U S A 2020; 117:381-7. [PMID: 31848241 DOI: 10.1073/pnas.1911123117] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The vast majority of biological carbon dioxide fixation relies on the function of ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco). In most cases the enzyme exhibits a tendency to become inhibited by its substrate RuBP and other sugar phosphates. The inhibition is counteracted by diverse molecular chaperones known as Rubisco activases (Rcas). In some chemoautotrophic bacteria, the CbbQO-type Rca Q2O2 repairs inhibited active sites of hexameric form II Rubisco. The 2.2-Å crystal structure of the MoxR AAA+ protein CbbQ2 from Acidithiobacillus ferrooxidans reveals the helix 2 insert (H2I) that is critical for Rca function and forms the axial pore of the CbbQ hexamer. Negative-stain electron microscopy shows that the essential CbbO adaptor protein binds to the conserved, concave side of the CbbQ2 hexamer. Site-directed mutagenesis supports a model in which adenosine 5'-triphosphate (ATP)-powered movements of the H2I are transmitted to CbbO via the concave residue L85. The basal ATPase activity of Q2O2 Rca is repressed but strongly stimulated by inhibited Rubisco. The characterization of multiple variants where this repression is released indicates that binding of inhibited Rubisco to the C-terminal CbbO VWA domain initiates a signal toward the CbbQ active site that is propagated via elements that include the CbbQ α4-β4 loop, pore loop 1, and the presensor 1-β hairpin (PS1-βH). Detailed mechanistic insights into the enzyme repair chaperones of the highly diverse CO2 fixation machinery of Proteobacteria will facilitate their successful implementation in synthetic biology ventures.
Collapse
|
33
|
Shivhare D, Ng J, Tsai YC, Mueller-Cajar O. Probing the rice Rubisco- Rubisco activase interaction via subunit heterooligomerization. Proc Natl Acad Sci U S A 2019; 116:24041-8. [PMID: 31712424 DOI: 10.1073/pnas.1914245116] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
During photosynthesis the AAA+ protein and essential molecular chaperone Rubisco activase (Rca) constantly remodels inhibited active sites of the CO2-fixing enzyme Rubisco (ribulose 1,5-bisphosphate carboxylase/oxygenase) to release tightly bound sugar phosphates. Higher plant Rca is a crop improvement target, but its mechanism remains poorly understood. Here we used structure-guided mutagenesis to probe the Rubisco-interacting surface of rice Rca. Mutations in Ser-23, Lys-148, and Arg-321 uncoupled adenosine triphosphatase and Rca activity, implicating them in the Rubisco interaction. Mutant doping experiments were used to evaluate a suite of known Rubisco-interacting residues for relative importance in the context of the functional hexamer. Hexamers containing some subunits that lack the Rubisco-interacting N-terminal domain displayed a ∼2-fold increase in Rca function. Overall Rubisco-interacting residues located toward the rim of the hexamer were found to be less critical to Rca function than those positioned toward the axial pore. Rca is a key regulator of the rate-limiting CO2-fixing reactions of photosynthesis. A detailed functional understanding will assist the ongoing endeavors to enhance crop CO2 assimilation rate, growth, and yield.
Collapse
|
34
|
Perdomo JA, Degen GE, Worrall D, Carmo-Silva E. Rubisco activation by wheat Rubisco activase isoform 2β is insensitive to inhibition by ADP. Biochem J 2019; 476:2595-606. [PMID: 31471529 DOI: 10.1042/BCJ20190110] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 08/28/2019] [Accepted: 08/30/2019] [Indexed: 11/17/2022]
Abstract
Rubisco activase (Rca) is a catalytic chaperone that remodels the active site, promotes the release of inhibitors and restores catalytic competence to Rubisco. Rca activity and its consequent effect on Rubisco activation and photosynthesis are modulated by changes to the chloroplast environment induced by fluctuations in light levels that reach the leaf, including redox status and adenosine diphosphate (ADP)/adenosine triphosphate (ATP) ratio. The Triticum aestivum (wheat) genome encodes for three Rca protein isoforms: 1β (42.7 kDa), 2β (42.2 kDa) and 2α (46.0 kDa). The regulatory properties of these isoforms were characterised by measuring rates of Rubisco activation and ATP hydrolysis by purified recombinant Rca proteins in the presence of physiological ADP/ATP ratios. ATP hydrolysis by all three isoforms was sensitive to inhibition by increasing amounts of ADP in the assay. In contrast, Rubisco activation activity of Rca 2β was insensitive to ADP inhibition, while Rca 1β and 2α were inhibited. Two double and one quadruple site-directed mutants were designed to elucidate if differences in the amino acid sequences between Rca 1β and 2β could explain the differences in ADP sensitivity. Changing two amino acids in Rca 2β to the corresponding residues in 1β (T358K & Q362E) resulted in significant inhibition of Rubisco activation in presence of ADP. The results show that the wheat Rca isoforms differ in their regulatory properties and that amino acid changes in the C domain influence ADP sensitivity. Advances in the understanding of Rubisco regulation will aid efforts to improve the efficiency of photosynthetic CO2 assimilation.
Collapse
|
35
|
Mei Q, Yang Y, Ye S, Liang W, Wang X, Zhou J, Yu C, Yan C, Chen J. H 2O 2 Induces Association of RCA with the Thylakoid Membrane to Enhance Resistance of Oryza meyeriana to Xanthomonas oryzae pv. oryzae. Plants (Basel) 2019; 8:E351. [PMID: 31527548 DOI: 10.3390/plants8090351] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 09/04/2019] [Accepted: 09/10/2019] [Indexed: 11/17/2022]
Abstract
Oryza meyeriana is a wild species of rice with high resistance to Xanthomonas oryzae pv. oryzae (Xoo), but the detailed resistance mechanism is unclear. Ribulose-1, 5-bisphosphate carboxylase/oxygenase (Rubisco) activase (RCA) is an important enzyme that regulates photosynthesis by activating Rubisco. We have previously reported that Xoo infection induced the relocation of RCA from the chloroplast stroma to the thylakoid membrane in O. meyeriana, but the underlying regulating mechanism and physiological significance of this association remains unknown. In this study, "H2O2 burst" with rapid and large increase in the amount of H2O2 was found to be induced by Xoo invasion in the leaves of O. meyeriana. 3, 3-diaminobenzidine (DAB) and oxidative 2, 7-Dichlorodi-hydrofluorescein diacetate (H2DCFDA) staining experiments both showed that H2O2 was generated in the chloroplast of O. meyeriana, and that this H2O2 generation as well as Xoo resistance of the wild rice were dramatically dependent on light. H2O2, methyl viologen with light, and the xanthine-xanthine oxidase system all induced RCA to associate with the thylakoid membrane in vitro, which showed that H2O2 could induce the relocation of RCA. In vitro experiments also showed that H2O2 induced changes in both the RCA and thylakoid membrane that were required for them to associate and that this association only occurred in O. meyeriana and not in the susceptible cultivated rice. These results suggest that the association of RCA with the thylakoid membrane helps to protect the thylakoid membrane against oxidative damage from H2O2. Therefore, in addition to its universal function of activating Rubisco, RCA appears to play a novel role in the resistance of O. meyeriana to Xoo.
Collapse
|
36
|
Kim SY, Harvey CM, Giese J, Lassowskat I, Singh V, Cavanagh AP, Spalding MH, Finkemeier I, Ort DR, Huber SC. In vivo evidence for a regulatory role of phosphorylation of Arabidopsis Rubisco activase at the Thr78 site. Proc Natl Acad Sci U S A 2019; 116:18723-31. [PMID: 31451644 DOI: 10.1073/pnas.1812916116] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Arabidopsis Rubisco activase (Rca) is phosphorylated at threonine-78 (Thr78) in low light and in the dark, suggesting a potential regulatory role in photosynthesis, but this has not been directly tested. To do so, we transformed an rca-knockdown mutant largely lacking redox regulation with wild-type Rca-β or Rca-β with Thr78-to-Ala (T78A) or Thr78-to-Ser (T78S) site-directed mutations. Interestingly, the T78S mutant was hyperphosphorylated at the Ser78 site relative to Thr78 of the Rca-β wild-type control, as evidenced by immunoblotting with custom antibodies and quantitative mass spectrometry. Moreover, plants expressing the T78S mutation had reduced photosynthesis and quantum efficiency of photosystem II (ϕPSII) and reduced growth relative to control plants expressing wild-type Rca-β under all conditions tested. Gene expression was also altered in a manner consistent with reduced growth. In contrast, plants expressing Rca-β with the phospho-null T78A mutation had faster photosynthetic induction kinetics and increased ϕPSII relative to Rca-β controls. While expression of the wild-type Rca-β or the T78A mutant fully rescued the slow-growth phenotype of the rca-knockdown mutant grown in a square-wave light regime, the T78A mutants grew faster than the Rca-β control plants at low light (30 µmol photons m-2 s-1) and in a fluctuating low-light/high-light environment. Collectively, these results suggest that phosphorylation of Thr78 (or Ser78 in the T78S mutant) plays a negative regulatory role in vivo and provides an explanation for the absence of Ser at position 78 in terrestrial plant species.
Collapse
|
37
|
Salter WT, Merchant AM, Richards RA, Trethowan R, Buckley TN. Rate of photosynthetic induction in fluctuating light varies widely among genotypes of wheat. J Exp Bot 2019; 70:2787-2796. [PMID: 30821324 PMCID: PMC6506768 DOI: 10.1093/jxb/erz100] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 02/20/2019] [Indexed: 05/22/2023]
Abstract
Crop photosynthesis and yield are limited by slow photosynthetic induction in sunflecks. We quantified variation in induction kinetics across diverse genotypes of wheat for the first time. Following a preliminary study that hinted at wide variation in induction kinetics across 58 genotypes, we grew 10 genotypes with contrasting responses in a controlled environment and quantified induction kinetics of carboxylation capacity (Vcmax) from dynamic A versus ci curves after a shift from low to high light (from 50 µmol m-2 s-1 to 1500 µmol m-2 s-1), in five flag leaves per genotype. Within-genotype median time for 95% induction (t95) of Vcmax varied 1.8-fold, from 5.2 min to 9.5 min. Our simulations suggest that non-instantaneous induction reduces daily net carbon gain by up to 15%, and that breeding to speed up Vcmax induction in the slowest of our 10 genotypes to match that in the fastest genotype could increase daily net carbon gain by up to 3.4%, particularly for leaves in mid-canopy positions (cumulative leaf area index ≤1.5 m2 m-2), those that experience predominantly short-duration sunflecks, and those with high photosynthetic capacities.
Collapse
Affiliation(s)
- William T Salter
- School of Life and Environmental Sciences, Sydney Institute of Agriculture, The University of Sydney, Brownlow Hill, NSW, Australia
| | - Andrew M Merchant
- School of Life and Environmental Sciences, Sydney Institute of Agriculture, The University of Sydney, Brownlow Hill, NSW, Australia
| | | | - Richard Trethowan
- School of Life and Environmental Sciences, Sydney Institute of Agriculture, The University of Sydney, Brownlow Hill, NSW, Australia
| | - Thomas N Buckley
- Department of Plant Sciences, University of California, Davis, Davis, CA, USA
- Correspondence:
| |
Collapse
|
38
|
Wilson RH, Thieulin-Pardo G, Hartl FU, Hayer-Hartl M. Improved recombinant expression and purification of functional plant Rubisco. FEBS Lett 2019; 593:611-621. [PMID: 30815863 PMCID: PMC6593764 DOI: 10.1002/1873-3468.13352] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 02/24/2019] [Accepted: 02/25/2019] [Indexed: 12/22/2022]
Abstract
Improving the performance of the key photosynthetic enzyme Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) by protein engineering is a critical strategy for increasing crop yields. The extensive chaperone requirement of plant Rubisco for folding and assembly has long been an impediment to this goal. Production of plant Rubisco in Escherichia coli requires the coexpression of the chloroplast chaperonin and four assembly factors. Here, we demonstrate that simultaneous expression of Rubisco and chaperones from a T7 promotor produces high levels of functional enzyme. Expressing the small subunit of Rubisco with a C-terminal hexahistidine-tag further improved assembly, resulting in a ~ 12-fold higher yield than the previously published procedure. The expression system described here provides a platform for the efficient production and engineering of plant Rubisco.
Collapse
Affiliation(s)
- Robert H Wilson
- Chaperonin-assisted Protein Folding Group, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Gabriel Thieulin-Pardo
- Chaperonin-assisted Protein Folding Group, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Franz-Ulrich Hartl
- Cellular Biochemistry Group, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Manajit Hayer-Hartl
- Chaperonin-assisted Protein Folding Group, Max Planck Institute of Biochemistry, Martinsried, Germany
| |
Collapse
|
39
|
Tomimatsu H, Sakata T, Fukayama H, Tang Y. Short-term effects of high CO2 accelerate photosynthetic induction in Populus koreana × trichocarpa with always-open stomata regardless of phenotypic changes in high CO2 growth conditions. Tree Physiol 2019; 39:474-483. [PMID: 30053250 DOI: 10.1093/treephys/tpy078] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Revised: 05/28/2018] [Accepted: 06/18/2018] [Indexed: 05/21/2023]
Abstract
Long-term high CO2 exposure accelerates photosynthetic induction response due to rapid light increase. However, it is unclear whether the acceleration is caused by acclimation of photosynthetic components (long-term CO2 effect) and/or by the sufficient substrate under high CO2 at the measurement (short-term CO2 effect). Populus koreana × trichocarpa cv. Peace has wide-open stomata almost not responding to changes of photon flux density. Using this species, we examined the long- and short-term CO2 effects on photosynthetic induction by focusing on biochemical components. We grew the plants under [CO2] of 380, 700 and 1020 μmol CO2 mol-1 air and measured the photosynthetic induction response under [CO2] of 380 and 1020 μmol CO2 mol-1 air. Despite significant reduction in Rubisco content and light-saturated photosynthetic rate in the leaves from the high growth CO2, the photosynthetic induction time was similar in leaves from different growth CO2 plants when measurement [CO2] was the same. The induction, however, was significantly fast at the higher than at the lower measurement [CO2], regardless of growth CO2 of the plants. These results demonstrate that the acceleration of apparent photosynthetic induction under high CO2 environment was mainly contributed by a short-term CO2 effect rather than by a long-term acclimation effect when stomatal limitation is not the major factor.
Collapse
Affiliation(s)
- Hajime Tomimatsu
- Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies, Onogawa 16-2, Tsukuba, Japan
| | - Tsuyoshi Sakata
- Biological Laboratory, Center for Natural Sciences, Kitasato University, 1-15-1 Kitasato, Sagamihara, Japan
| | - Hiroshi Fukayama
- Graduate School of Agricultural Science, Kobe University, Nada-ku, Kobe, Japan
| | - Yanhong Tang
- Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies, Onogawa 16-2, Tsukuba, Japan
| |
Collapse
|
40
|
Fukayama H, Mizumoto A, Ueguchi C, Katsunuma J, Morita R, Sasayama D, Hatanaka T, Azuma T. Expression level of Rubisco activase negatively correlates with Rubisco content in transgenic rice. Photosynth Res 2018; 137:465-474. [PMID: 29846871 DOI: 10.1007/s11120-018-0525-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 05/25/2018] [Indexed: 05/24/2023]
Abstract
The relationship between ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and Rubisco activase (Rca) levels was studied using transgenic rice overexpressing maize Rca (OX-mRca) and knockdown transgenic rice expressing antisense Rca (KD-Rca). The ratio of Rubisco to total soluble protein was lower in OX-mRca, whereas it was higher in KD-Rca than in WT, indicating that Rca expression was negatively correlated with Rubisco content. The expressions of other Calvin-Benson-Bassham cycle enzymes such as sedoheptulose-1,7-bisphosphatase and phosphoribulokinase analyzed by immunoblotting did not show such a negative correlation with Rca, suggesting that the effect of Rca on protein expression may be specific for Rubisco. Although Rubisco content was decreased in OX-mRca, the transcript levels of the Rubisco large subunit (OsRbcL) and the Rubisco small subunit mostly increased in OX-mRca as well as in KD-Rca. Additionally, polysome loading of OsRbcL was slightly higher in OX-mRca than it was in WT, suggesting that the OsRbcL translation activity was likely stimulated by overexpression of Rca. 35S-methionine labeling experiments demonstrated that there was no significant difference in the stability of newly synthesized Rubisco among genotypes. However, 35S-methionine-labeled Rubisco was marginally decreased in OX-mRca and increased in KD-Rca compared to the WT. These results suggest that Rca negatively affects the Rubisco content, possibly in the synthesis step.
Collapse
Affiliation(s)
- Hiroshi Fukayama
- Laboratory of Tropical Crop Science, Graduate School of Agricultural Science, Kobe University, Kobe, 657-8501, Japan.
| | - Akina Mizumoto
- Laboratory of Tropical Crop Science, Graduate School of Agricultural Science, Kobe University, Kobe, 657-8501, Japan
| | - Chiaki Ueguchi
- Laboratory of Crop Science, Graduate School of Agricultural Science, Kobe University, Kobe, 657-8501, Japan
| | - Jun Katsunuma
- Laboratory of Crop Science, Faculty of Agriculture, Kobe University, Kobe, 657-8501, Japan
| | - Ryutaro Morita
- Laboratory of Tropical Crop Science, Graduate School of Agricultural Science, Kobe University, Kobe, 657-8501, Japan
| | - Daisuke Sasayama
- Laboratory of Crop Science, Graduate School of Agricultural Science, Kobe University, Kobe, 657-8501, Japan
| | - Tomoko Hatanaka
- Laboratory of Crop Science, Graduate School of Agricultural Science, Kobe University, Kobe, 657-8501, Japan
| | - Tetsushi Azuma
- Laboratory of Tropical Crop Science, Graduate School of Agricultural Science, Kobe University, Kobe, 657-8501, Japan
| |
Collapse
|
41
|
Andralojc PJ, Carmo-Silva E, Degen GE, Parry MAJ. Increasing metabolic potential: C-fixation. Essays Biochem 2018; 62:109-18. [PMID: 29653967 DOI: 10.1042/EBC20170014] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 02/17/2018] [Accepted: 02/18/2018] [Indexed: 01/30/2023]
Abstract
Due to the growing world population, crop yields must increase to meet the rising demand. Crop plants also require adaptation to optimize performance in the changing environments caused by climate change. Improving photosynthetic carbon fixation is a promising, albeit technically challenging, strategy whose potential has only just begun to be considered in breeding programmes. Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), a fundamental enzyme of carbon fixation, is extremely inefficient and many strategies to improve photosynthesis focus on overcoming the limitations of this enzyme, either by improving Rubisco activity and regulation or by improving the supply of substrates. Although progress is being made, the need to tailor solutions for each crop and their respective environments has been highlighted. Even so, continuing research will be required to achieve these objectives and to grow crops more sustainably in the future.
Collapse
|
42
|
Taylor SH, Long SP. Slow induction of photosynthesis on shade to sun transitions in wheat may cost at least 21% of productivity. Philos Trans R Soc Lond B Biol Sci 2018; 372:rstb.2016.0543. [PMID: 28808109 PMCID: PMC5566890 DOI: 10.1098/rstb.2016.0543] [Citation(s) in RCA: 128] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/02/2017] [Indexed: 12/02/2022] Open
Abstract
Wheat is the second most important direct source of food calories in the world. After considerable improvement during the Green Revolution, increase in genetic yield potential appears to have stalled. Improvement of photosynthetic efficiency now appears a major opportunity in addressing the sustainable yield increases needed to meet future food demand. Effort, however, has focused on increasing efficiency under steady-state conditions. In the field, the light environment at the level of individual leaves is constantly changing. The speed of adjustment of photosynthetic efficiency can have a profound effect on crop carbon gain and yield. Flag leaves of wheat are the major photosynthetic organs supplying the grain of wheat, and will be intermittently shaded throughout a typical day. Here, the speed of adjustment to a shade to sun transition in these leaves was analysed. On transfer to sun conditions, the leaf required about 15 min to regain maximum photosynthetic efficiency. In vivo analysis based on the responses of leaf CO2 assimilation (A) to intercellular CO2 concentration (ci) implied that the major limitation throughout this induction was activation of the primary carboxylase of C3 photosynthesis, ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). This was followed in importance by stomata, which accounted for about 20% of the limitation. Except during the first few seconds, photosynthetic electron transport and regeneration of the CO2 acceptor molecule, ribulose-1,5-bisphosphate (RubP), did not affect the speed of induction. The measured kinetics of Rubisco activation in the sun and de-activation in the shade were predicted from the measurements. These were combined with a canopy ray tracing model that predicted intermittent shading of flag leaves over the course of a June day. This indicated that the slow adjustment in shade to sun transitions could cost 21% of potential assimilation. This article is part of the themed issue ‘Enhancing photosynthesis in crop plants: targets for improvement’.
Collapse
Affiliation(s)
- Samuel H Taylor
- Lancaster Environment Centre, Lancaster University, Lancaster, Lancashire LA1 4YQ, UK
| | - Stephen P Long
- Lancaster Environment Centre, Lancaster University, Lancaster, Lancashire LA1 4YQ, UK .,Department of Crop Sciences, University of Illinois, Urbana, IL 61801, USA.,Department of Plant Biology, University of Illinois, Urbana, IL 61801, USA
| |
Collapse
|
43
|
Morales A, Kaiser E, Yin X, Harbinson J, Molenaar J, Driever SM, Struik PC. Dynamic modelling of limitations on improving leaf CO 2 assimilation under fluctuating irradiance. Plant Cell Environ 2018; 41:589-604. [PMID: 29243271 DOI: 10.1111/pce.13119] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 11/24/2017] [Accepted: 12/01/2017] [Indexed: 05/21/2023]
Abstract
A dynamic model of leaf CO2 assimilation was developed as an extension of the canonical steady-state model, by adding the effects of energy-dependent non-photochemical quenching (qE), chloroplast movement, photoinhibition, regulation of enzyme activity in the Calvin cycle, metabolite concentrations, and dynamic CO2 diffusion. The model was calibrated and tested successfully using published measurements of gas exchange and chlorophyll fluorescence on Arabidopsis thaliana ecotype Col-0 and several photosynthetic mutants and transformants affecting the regulation of Rubisco activity (rca-2 and rwt43), non-photochemical quenching (npq4-1 and npq1-2), and sucrose synthesis (spsa1). The potential improvements on CO2 assimilation under fluctuating irradiance that can be achieved by removing the kinetic limitations on the regulation of enzyme activities, electron transport, and stomatal conductance were calculated in silico for different scenarios. The model predicted that the rates of activation of enzymes in the Calvin cycle and stomatal opening were the most limiting (up to 17% improvement) and that effects varied with the frequency of fluctuations. On the other hand, relaxation of qE and chloroplast movement had a strong effect on average low-irradiance CO2 assimilation (up to 10% improvement). Strong synergies among processes were found, such that removing all kinetic limitations simultaneously resulted in improvements of up to 32%.
Collapse
Affiliation(s)
- Alejandro Morales
- Centre for Crop Systems Analysis, Wageningen University & Research, Wageningen, The Netherlands
| | - Elias Kaiser
- Horticulture and Product Physiology, Wageningen University & Research, Wageningen, The Netherlands
| | - Xinyou Yin
- Centre for Crop Systems Analysis, Wageningen University & Research, Wageningen, The Netherlands
| | - Jeremy Harbinson
- Horticulture and Product Physiology, Wageningen University & Research, Wageningen, The Netherlands
| | - Jaap Molenaar
- Biometris, Mathematical and Statistical Methods Group, Wageningen University & Research, Wageningen, The Netherlands
| | - Steven M Driever
- Centre for Crop Systems Analysis, Wageningen University & Research, Wageningen, The Netherlands
| | - Paul C Struik
- Centre for Crop Systems Analysis, Wageningen University & Research, Wageningen, The Netherlands
| |
Collapse
|
44
|
Jurczyk B, Grzesiak M, Pociecha E, Wlazło M, Rapacz M. Diverse Stomatal Behaviors Mediating Photosynthetic Acclimation to Low Temperatures in Hordeum vulgare. Front Plant Sci 2018; 9:1963. [PMID: 30687360 PMCID: PMC6333868 DOI: 10.3389/fpls.2018.01963] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 12/18/2018] [Indexed: 05/21/2023]
Abstract
Photosynthetic acclimation to cold conditions is an important factor influencing freezing tolerance of plants. Photosynthetic enzyme activities increase as part of a photochemical mechanism underlying photosynthetic acclimation to low temperatures. Additionally, a non-photochemical mechanism may be activated to minimize photooxidative damage. The aim of this study was to test the hypothesis that differences in stomatal conductance in Hordeum vulgare plants with contrasting freezing tolerances induce various strategies for photosynthetic acclimation to cold stress. Different stomatal behaviors during the prehardening step resulted in diverse plant reactions to low-temperature stress. Plants with a relatively low freezing tolerance exhibited decreased stomatal conductance, resulting in decreased photochemical activity, faster induction of the non-photochemical mechanism, and downregulated expression of two Rubisco activase (RcaA) splicing variants. In contrast, plants with a relatively high freezing tolerance that underwent a prehardening step maintained the stomatal conductance at control level and exhibited delayed photochemical activity and RcaA expression decrease, and increased Rubisco activity, which increased net photosynthetic rate. Thus, in barley, the induction of photoinhibition avoidance (i.e., non-photochemical photoacclimation mechanism) is insufficient for an effective cold acclimation. An increase in cold-induced net photosynthetic rate due to open stomata is also necessary.
Collapse
Affiliation(s)
- Barbara Jurczyk
- Department of Plant Physiology, Faculty of Agriculture and Economics, University of Agriculture in Kraków, Kraków, Poland
- *Correspondence: Barbara Jurczyk, ;
| | - Maciej Grzesiak
- Institute of Plant Physiology, Polish Academy of Sciences, Kraków, Poland
| | - Ewa Pociecha
- Department of Plant Physiology, Faculty of Agriculture and Economics, University of Agriculture in Kraków, Kraków, Poland
| | - Magdalena Wlazło
- Department of Plant Physiology, Faculty of Agriculture and Economics, University of Agriculture in Kraków, Kraków, Poland
| | - Marcin Rapacz
- Department of Plant Physiology, Faculty of Agriculture and Economics, University of Agriculture in Kraków, Kraków, Poland
| |
Collapse
|
45
|
Abstract
Rubisco activase of plants evolved in a stepwise manner without losing its function to adapt to the major evolutionary events including endosymbiosis and land colonization. Rubisco activase is an essential enzyme for photosynthesis, which removes inhibitory sugar phosphates from the active sites of Rubisco, a process necessary for Rubisco activation and carbon fixation. The gene probably evolved in cyanobacteria as different species differ for its presence. However, the gene is present in all other plant species. At least a single gene copy was maintained throughout plant evolution; but various genome and gene duplication events, which occurred during plant evolution, increased its copy number in some species. The exons and exon-intron junctions of present day higher plant's Rca, which is conserved in most species seem to have evolved in charophytes. A unique tandem duplication of Rca gene occurred in a common grass ancestor, and the two genes evolved differently for gene structure, sequence, and expression pattern. At the protein level, starting with a primitive form in cyanobacteria, RCA of chlorophytes evolved by integrating chloroplast transit peptide (cTP), and N-terminal domains to the ATPase, Rubisco recognition and C-terminal domains. The redox regulated C-terminal extension (CTE) and the associated alternate splicing mechanism, which splices the RCA-α and RCA-β isoforms were probably gained from another gene in charophytes, conserved in most species except the members of Solanaceae family.
Collapse
Affiliation(s)
- Ragupathi Nagarajan
- Department of Crop and Soil Sciences, Washington State University, Pullman, WA, 99164, USA
| | - Kulvinder S Gill
- Department of Crop and Soil Sciences, Washington State University, Pullman, WA, 99164, USA.
| |
Collapse
|
46
|
Bayramov S. Changes in protein quantities of phosphoenolpyruvate carboxylase and Rubisco activase in various wheat genotypes. Saudi J Biol Sci 2017; 24:1529-1533. [PMID: 30294222 PMCID: PMC6169427 DOI: 10.1016/j.sjbs.2015.09.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 09/02/2015] [Accepted: 09/06/2015] [Indexed: 11/16/2022] Open
Abstract
In early seedlings of wheat genotypes two isoforms of Rubisco activase with molecular weights of 42 and 46 kDa are expressed. Amounts of both isoforms significantly increase in early seedlings of the durum wheat genotype Barakatli-95 exposed to salt stress. But at the beginning of the tillering stage, the changes in quantities of both RCA isoforms are different in durum and bread wheat genotypes subjected to a 3-day drought stress. In the leaves of the early seedlings of the studied wheat genotypes exposed to drought stress quantities of PEPC subunits increase compared to the control but they remain relatively stable in early roots and germinating seeds. However, quantities of its subunits decrease sharply in roots and germinating seeds of early seedlings under the influence of 100 mM NaCl. In flag leaves and ear elements of the Barakatli-95 genotype grown under normal water supply conditions protein quantities of PEPC subunits change differently depending on time. Changes in protein quantities of RCA, PEPC and Rubisco enzymes have been studied comparatively in ear elements and flag leaves after the fourth day of anthesis.
Collapse
Affiliation(s)
- Shahniyar Bayramov
- Institute of Botany, Azerbaijan National Academy of Sciences, 40 Patamdar Shosse, AZ-1073 Baku, Azerbaijan
| |
Collapse
|
47
|
Hayer-Hartl M. From chaperonins to Rubisco assembly and metabolic repair. Protein Sci 2017; 26:2324-2333. [PMID: 28960553 DOI: 10.1002/pro.3309] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 09/21/2017] [Accepted: 09/25/2017] [Indexed: 01/13/2023]
Abstract
Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) mediates the fixation of atmospheric CO2 in photosynthesis by catalyzing the carboxylation of the 5-carbon sugar ribulose-1,5-bisphosphate (RuBP). Despite its pivotal role, Rubisco is an inefficient enzyme and thus has been a key target for bioengineering. However, efforts to increase crop yields by Rubisco engineering remain unsuccessful, due in part to the complex machinery of molecular chaperones required for Rubisco biogenesis and metabolic repair. While the large subunit of Rubisco generally requires the chaperonin system for folding, the evolution of the hexadecameric Rubisco from its dimeric precursor resulted in the dependence on an array of additional factors required for assembly. Moreover, Rubisco function can be inhibited by a range of sugar-phosphate ligands. Metabolic repair of Rubisco depends on remodeling by the ATP-dependent Rubisco activase and hydrolysis of inhibitors by specific phosphatases. This review highlights our work toward understanding the structure and mechanism of these auxiliary machineries.
Collapse
Affiliation(s)
- Manajit Hayer-Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
| |
Collapse
|
48
|
Bhat JY, Miličić G, Thieulin-Pardo G, Bracher A, Maxwell A, Ciniawsky S, Mueller-Cajar O, Engen JR, Hartl FU, Wendler P, Hayer-Hartl M. Mechanism of Enzyme Repair by the AAA + Chaperone Rubisco Activase. Mol Cell 2017; 67:744-756.e6. [PMID: 28803776 DOI: 10.1016/j.molcel.2017.07.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 06/07/2017] [Accepted: 07/01/2017] [Indexed: 01/16/2023]
Abstract
How AAA+ chaperones conformationally remodel specific target proteins in an ATP-dependent manner is not well understood. Here, we investigated the mechanism of the AAA+ protein Rubisco activase (Rca) in metabolic repair of the photosynthetic enzyme Rubisco, a complex of eight large (RbcL) and eight small (RbcS) subunits containing eight catalytic sites. Rubisco is prone to inhibition by tight-binding sugar phosphates, whose removal is catalyzed by Rca. We engineered a stable Rca hexamer ring and analyzed its functional interaction with Rubisco. Hydrogen/deuterium exchange and chemical crosslinking showed that Rca structurally destabilizes elements of the Rubisco active site with remarkable selectivity. Cryo-electron microscopy revealed that Rca docks onto Rubisco over one active site at a time, positioning the C-terminal strand of RbcL, which stabilizes the catalytic center, for access to the Rca hexamer pore. The pulling force of Rca is fine-tuned to avoid global destabilization and allow for precise enzyme repair.
Collapse
Affiliation(s)
- Javaid Y Bhat
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Goran Miličić
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Gabriel Thieulin-Pardo
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Andreas Bracher
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Andrew Maxwell
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Susanne Ciniawsky
- Gene Center Munich, Ludwig-Maximilians-Universität München, Feodor-Lynen-Strasse 25, 81377 Munich, Germany
| | - Oliver Mueller-Cajar
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - John R Engen
- Department of Chemistry and Chemical Biology, Northeastern University, 360 Huntington Avenue, Boston, MA 02115-5000, USA
| | - F Ulrich Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Petra Wendler
- Gene Center Munich, Ludwig-Maximilians-Universität München, Feodor-Lynen-Strasse 25, 81377 Munich, Germany.
| | - Manajit Hayer-Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany.
| |
Collapse
|
49
|
Abstract
Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) mediates the fixation of atmospheric CO2 in photosynthesis by catalyzing the carboxylation of the 5-carbon sugar ribulose-1,5-bisphosphate (RuBP). Rubisco is a remarkably inefficient enzyme, fixing only 2-10 CO2 molecules per second. Efforts to increase crop yields by bioengineering Rubisco remain unsuccessful, owing in part to the complex cellular machinery required for Rubisco biogenesis and metabolic maintenance. The large subunit of Rubisco requires the chaperonin system for folding, and recent studies have shown that assembly of hexadecameric Rubisco is mediated by specific assembly chaperones. Moreover, Rubisco function can be inhibited by a range of sugar-phosphate ligands, including RuBP. Metabolic repair depends on remodeling of Rubisco by the ATP-dependent Rubisco activase and hydrolysis of inhibitory sugar phosphates by specific phosphatases. Here, we review our present understanding of the structure and function of these auxiliary factors and their utilization in efforts to engineer more catalytically efficient Rubisco enzymes.
Collapse
Affiliation(s)
- Andreas Bracher
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany ; , ,
| | - Spencer M Whitney
- Research School of Biology, Australian National University, Acton, Australian Capital Territory 2601, Australia;
| | - F Ulrich Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany ; , ,
| | - Manajit Hayer-Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany ; , ,
| |
Collapse
|
50
|
Perdomo JA, Capó-Bauçà S, Carmo-Silva E, Galmés J. Rubisco and Rubisco Activase Play an Important Role in the Biochemical Limitations of Photosynthesis in Rice, Wheat, and Maize under High Temperature and Water Deficit. Front Plant Sci 2017; 8:490. [PMID: 28450871 PMCID: PMC5390490 DOI: 10.3389/fpls.2017.00490] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 03/21/2017] [Indexed: 05/19/2023]
Abstract
To understand the effect of heat and drought on three major cereal crops, the physiological and biochemical (i.e., metabolic) factors affecting photosynthesis were examined in rice, wheat, and maize plants grown under long-term water deficit (WD), high temperature (HT) and the combination of both stresses (HT-WD). Diffusional limitations to photosynthesis prevailed under WD for the C3 species, rice and wheat. Conversely, biochemical limitations prevailed under WD for the C4 species, maize, under HT for all three species, and under HT-WD in rice and maize. These biochemical limitations to photosynthesis were associated with Rubisco activity that was highly impaired at HT and under HT-WD in the three species. Decreases in Rubisco activation were unrelated to the amount of Rubisco and Rubisco activase (Rca), but were probably caused by inhibition of Rca activity, as suggested by the mutual decrease and positive correlation between Rubisco activation state and the rate of electron transport. Decreased Rubisco activation at HT was associated with biochemical limitation of net CO2 assimilation rate (AN). Overall, the results highlight the importance of Rubisco as a target for improving the photosynthetic performance of these C3 (wheat and rice) and C4 (maize) cereal crops under increasingly variable and warmer climates.
Collapse
Affiliation(s)
- Juan A. Perdomo
- Plant Biology and Crop Science, Rothamsted Research (BBSRC)Harpenden, UK
| | - Sebastià Capó-Bauçà
- Research Group on Plant Biology under Mediterranean Conditions, Universitat de les Illes Balears-INAGEAPalma de Mallorca, Spain
| | | | - Jeroni Galmés
- Research Group on Plant Biology under Mediterranean Conditions, Universitat de les Illes Balears-INAGEAPalma de Mallorca, Spain
| |
Collapse
|