1
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Stirbet A, Guo Y, Lazár D, Govindjee G. From leaf to multiscale models of photosynthesis: applications and challenges for crop improvement. PHOTOSYNTHESIS RESEARCH 2024; 161:21-49. [PMID: 38619700 DOI: 10.1007/s11120-024-01083-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Accepted: 01/29/2024] [Indexed: 04/16/2024]
Abstract
To keep up with the growth of human population and to circumvent deleterious effects of global climate change, it is essential to enhance crop yield to achieve higher production. Here we review mathematical models of oxygenic photosynthesis that are extensively used, and discuss in depth a subset that accounts for diverse approaches providing solutions to our objective. These include models (1) to study different ways to enhance photosynthesis, such as fine-tuning antenna size, photoprotection and electron transport; (2) to bioengineer carbon metabolism; and (3) to evaluate the interactions between the process of photosynthesis and the seasonal crop dynamics, or those that have included statistical whole-genome prediction methods to quantify the impact of photosynthesis traits on the improvement of crop yield. We conclude by emphasizing that the results obtained in these studies clearly demonstrate that mathematical modelling is a key tool to examine different approaches to improve photosynthesis for better productivity, while effective multiscale crop models, especially those that also include remote sensing data, are indispensable to verify different strategies to obtain maximized crop yields.
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Affiliation(s)
| | - Ya Guo
- Key Laboratory of Advanced Process Control for Light Industry, Ministry of Education Jiangnan University, Wuxi, 214122, China
| | - Dušan Lazár
- Department of Biophysics, Faculty of Science, Palacký Univesity, Šlechtitelů 27, 78371, Olomouc, Czech Republic
| | - Govindjee Govindjee
- Department of Biochemistry, Department of Plant Biology, and the Center of Biophysics & Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
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2
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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] [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.
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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
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3
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Recent developments in the engineering of Rubisco activase for enhanced crop yield. Biochem Soc Trans 2023; 51:627-637. [PMID: 36929563 DOI: 10.1042/bst20221281] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [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.
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4
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Murchie EH, Reynolds M, Slafer GA, Foulkes MJ, Acevedo-Siaca L, McAusland L, Sharwood R, Griffiths S, Flavell RB, Gwyn J, Sawkins M, Carmo-Silva E. A 'wiring diagram' for source strength traits impacting wheat yield potential. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:72-90. [PMID: 36264277 PMCID: PMC9786870 DOI: 10.1093/jxb/erac415] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 10/18/2022] [Indexed: 05/06/2023]
Abstract
Source traits are currently of great interest for the enhancement of yield potential; for example, much effort is being expended to find ways of modifying photosynthesis. However, photosynthesis is but one component of crop regulation, so sink activities and the coordination of diverse processes throughout the crop must be considered in an integrated, systems approach. A set of 'wiring diagrams' has been devised as a visual tool to integrate the interactions of component processes at different stages of wheat development. They enable the roles of chloroplast, leaf, and whole-canopy processes to be seen in the context of sink development and crop growth as a whole. In this review, we dissect source traits both anatomically (foliar and non-foliar) and temporally (pre- and post-anthesis), and consider the evidence for their regulation at local and whole-plant/crop levels. We consider how the formation of a canopy creates challenges (self-occlusion) and opportunities (dynamic photosynthesis) for components of photosynthesis. Lastly, we discuss the regulation of source activity by feedback regulation. The review is written in the framework of the wiring diagrams which, as integrated descriptors of traits underpinning grain yield, are designed to provide a potential workspace for breeders and other crop scientists that, along with high-throughput and precision phenotyping data, genetics, and bioinformatics, will help build future dynamic models of trait and gene interactions to achieve yield gains in wheat and other field crops.
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Affiliation(s)
| | - Matthew Reynolds
- International Maize and Wheat Improvement Center (CIMMYT), Km. 45, Carretera Mexico-Veracruz, El Batan, Texcoco, Mexico
| | - Gustavo A Slafer
- Department of Crop and Forest Sciences, University of Lleida–AGROTECNIO-CERCA Center, Av. R. Roure 191, 25198 Lleida, Spain
- ICREA (Catalonian Institution for Research and Advanced Studies), Barcelona, Spain
| | - M John Foulkes
- Division of Plant and Crop Science, School of Biosciences, University of Nottingham, Sutton Bonington LE12 5RD, UK
| | - Liana Acevedo-Siaca
- International Maize and Wheat Improvement Center (CIMMYT), Km. 45, Carretera Mexico-Veracruz, El Batan, Texcoco, Mexico
| | - Lorna McAusland
- Division of Plant and Crop Science, School of Biosciences, University of Nottingham, Sutton Bonington LE12 5RD, UK
| | - Robert Sharwood
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond NSW 2753, Australia
| | - Simon Griffiths
- John Innes Centre, Norwich Research Park, Colney Ln, Norwich NR4 7UH, UK
| | - Richard B Flavell
- International Wheat Yield Partnership, 1500 Research Parkway, College Station, TX 77843, USA
| | - Jeff Gwyn
- International Wheat Yield Partnership, 1500 Research Parkway, College Station, TX 77843, USA
| | - Mark Sawkins
- International Wheat Yield Partnership, 1500 Research Parkway, College Station, TX 77843, USA
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5
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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. PHOTOSYNTHESIS RESEARCH 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] [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.
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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
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6
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Song C, Fan Q, Tang Y, Sun Y, Wang L, Wei M, Chang Y. Overexpression of DfRaf from Fragrant Woodfern (Dryopteris fragrans) Enhances High-Temperature Tolerance in Tobacco (Nicotiana tabacum). Genes (Basel) 2022; 13:genes13071212. [PMID: 35885995 PMCID: PMC9321628 DOI: 10.3390/genes13071212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 06/03/2022] [Accepted: 06/27/2022] [Indexed: 01/25/2023] Open
Abstract
Heat stress seriously affects medicinal herbs’ growth and yield. Rubisco accumulation factor (Raf) is a key mediator regulating the activity of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), which plays important roles in carbon assimilation and the Calvin cycle in plants. Raf has been studied in many plants, but has rarely been studied in the important medicinal plant fragrant woodfern (Dryopteris fragrans). The aim of this study was to analyze the effects of Raf on carbohydrate metabolism and the response to heat stress in medicinal plants. In this study, high temperature treatment upregulated the expression of DfRaf, which was significantly higher than that of phosphoribokinase (DfPRK), Rubisco small subunits (DfRbcS), Rubisco large subunits (DfRbcL) and Rubisco activase (DfRCA). The subcellular localization showed that the DfRaf proteins were primarily located in the nucleus; DfPRK, DfRbcS, DfRbcL and DfRCA proteins were primarily located in the chloroplast. We found that overexpression of DfRaf led to increased activity of Rubisco, RCA and PRK under high-temperature stress. The H2O2, O2− and MDA content of the DfRaf-OV-L2 and DfRaf-OV-L6 transgenic lines were significantly lower than those of WT and VC plants under high-temperature stress. The photosynthetic pigments, proline, soluble sugar content and ROS-scavenging ability of the DfRaf-OV-L2 and DfRaf-OV-L6 transgenic lines were higher than those of WT and VC plants under high-temperature stress. The results showed that overexpression of the DfRaf gene increased the Rubisco activity, which enhanced the high-temperature tolerance of plants.
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Affiliation(s)
| | | | | | | | | | | | - Ying Chang
- Correspondence: ; Tel.: +86-(0451)-5519-0410
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7
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Long SP, Taylor SH, Burgess SJ, Carmo-Silva E, Lawson T, De Souza AP, Leonelli L, Wang Y. Into the Shadows and Back into Sunlight: Photosynthesis in Fluctuating Light. ANNUAL REVIEW OF PLANT BIOLOGY 2022; 73:617-648. [PMID: 35595290 DOI: 10.1146/annurev-arplant-070221-024745] [Citation(s) in RCA: 48] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Photosynthesis is an important remaining opportunity for further improvement in the genetic yield potential of our major crops. Measurement, analysis, and improvement of leaf CO2 assimilation (A) have focused largely on photosynthetic rates under light-saturated steady-state conditions. However, in modern crop canopies of several leaf layers, light is rarely constant, and the majority of leaves experience marked light fluctuations throughout the day. It takes several minutes for photosynthesis to regain efficiency in both sun-shade and shade-sun transitions, costing a calculated 10-40% of potential crop CO2 assimilation. Transgenic manipulations to accelerate the adjustment in sun-shade transitions have already shown a substantial productivity increase in field trials. Here, we explore means to further accelerate these adjustments and minimize these losses through transgenic manipulation, gene editing, and exploitation of natural variation. Measurement andanalysis of photosynthesis in sun-shade and shade-sun transitions are explained. Factors limiting speeds of adjustment and how they could be modified to effect improved efficiency are reviewed, specifically nonphotochemical quenching (NPQ), Rubisco activation, and stomatal responses.
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Affiliation(s)
- Stephen P Long
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA;
- Departments of Plant Biology and Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
- Lancaster Environment Centre, Lancaster University, Lancaster, United Kingdom
| | - Samuel H Taylor
- Lancaster Environment Centre, Lancaster University, Lancaster, United Kingdom
| | - Steven J Burgess
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA;
| | | | - Tracy Lawson
- School of Life Sciences, University of Essex, Colchester, United Kingdom
| | - Amanda P De Souza
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA;
| | - Lauriebeth Leonelli
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA;
- Department of Agricultural and Biological Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Yu Wang
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA;
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8
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Wijewardene I, Shen G, Zhang H. Enhancing crop yield by using Rubisco activase to improve photosynthesis under elevated temperatures. STRESS BIOLOGY 2021; 1:2. [PMID: 37676541 PMCID: PMC10429496 DOI: 10.1007/s44154-021-00002-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [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.
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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.
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9
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Perdomo JA, Buchner P, Carmo-Silva E. The relative abundance of wheat Rubisco activase isoforms is post-transcriptionally regulated. PHOTOSYNTHESIS RESEARCH 2021; 148:47-56. [PMID: 33796933 PMCID: PMC8154801 DOI: 10.1007/s11120-021-00830-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [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.
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Affiliation(s)
| | - Peter Buchner
- Plant Biology and Crop Science Department, Rothamsted Research, Harpenden, AL5 2JQ, UK
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10
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Degen GE, Orr DJ, Carmo-Silva E. Heat-induced changes in the abundance of wheat Rubisco activase isoforms. THE NEW PHYTOLOGIST 2021; 229:1298-1311. [PMID: 32964463 DOI: 10.1111/nph.16937] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [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.
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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
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11
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Sales CRG, da Silva AB, Carmo-Silva E. Measuring Rubisco activity: challenges and opportunities of NADH-linked microtiter plate-based and 14C-based assays. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:5302-5312. [PMID: 32728715 PMCID: PMC7501812 DOI: 10.1093/jxb/eraa289] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 06/22/2020] [Indexed: 05/28/2023]
Abstract
Rubisco is central to carbon assimilation, and efforts to improve the efficiency and sustainability of crop production have spurred interest in phenotyping Rubisco activity. We tested the hypothesis that microtiter plate-based methods provide comparable results to those obtained with the radiometric assay that measures the incorporation of 14CO2 into 3-phosphoglycerate (3-PGA). Three NADH-linked assays were tested that use alternative coupling enzymes: glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and glycerolphosphate dehydrogenase (GlyPDH); phosphoenolpyruvate carboxylase (PEPC) and malate dehydrogenase (MDH); and pyruvate kinase (PK) and lactate dehydrogenase (LDH). To date there has been no thorough evaluation of their reliability by comparison with the 14C-based method. The three NADH-linked assays were used in parallel to estimate (i) the 3-PGA concentration-response curve of NADH oxidation, (ii) the Michaelis-Menten constant for ribulose-1,5-bisphosphate, (iii) fully active and inhibited Rubisco activities, and (iv) Rubisco initial and total activities in fully illuminated and shaded leaves. All three methods correlated strongly with the 14C-based method, and the PK-LDH method showed a strong correlation and was the cheapest method. PEPC-MDH would be a suitable option for situations in which ADP/ATP might interfere with the assay. GAPDH-GlyPDH proved more laborious than the other methods. Thus, we recommend the PK-LDH method as a reliable, cheaper, and higher throughput method to phenotype Rubisco activity for crop improvement efforts.
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Affiliation(s)
- Cristina R G Sales
- Lancaster Environment Centre, Lancaster University, Library Avenue, Lancaster, UK
| | - Anabela Bernardes da Silva
- BioISI - Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisbon, Lisbon, Portugal
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12
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Oliveira FDBD, Miranda RDS, Araújo GDS, Coelho DG, Lobo MDP, Paula-Marinho SDO, Lopes LDS, Monteiro-Moreira ACO, Carvalho HHD, Gomes-Filho E. New insights into molecular targets of salt tolerance in sorghum leaves elicited by ammonium nutrition. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2020; 154:723-734. [PMID: 32763797 DOI: 10.1016/j.plaphy.2020.06.051] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 06/09/2020] [Accepted: 06/29/2020] [Indexed: 06/11/2023]
Abstract
This study investigated the proteome modulation and physiological responses of Sorghum bicolor plants grown in nutrient solutions containing nitrate (NO3-) or ammonium (NH4+) at 5.0 mM, and subjected to salinity with 75 mM NaCl for ten days. Salinity promoted significant reductions in leaf area, root and shoot dry mass of sorghum plants, regardless of nitrogen source; however, higher growth was observed in ammonium-grown plants. The better performance of ammonium-fed stressed plants was associated with low hydrogen peroxide accumulation, and improved CO2 assimilation and K+/Na+ homeostasis under salinity. Proteomic study revealed a nitrogen source-induced differential modulation in proteins related to photosynthesis/carbon metabolism, energy metabolism, response to stress and other cellular processes. Nitrate-fed plants induced thylakoidal electron transport chain proteins and structural and carbon assimilation enzymes, but these mechanisms seemed to be insufficient to mitigate salt damage in photosynthetic performance. In contrast, the greater tolerance to salinity of ammonium-grown plants may have arisen from: i.) de novo synthesis or upregulation of enzymes from photosynthetic/carbon metabolism, which resulted in better CO2 assimilation rates under NaCl-stress; ii.) activation of proteins involved in energy metabolism which made available energy for salt responses, most likely by proton pumps and Na+/H+ antiporters; and iii.) reprogramming of proteins involved in response to stress and other metabolic processes, constituting intricate pathways of salt responses. Overall, our findings not only provide new insights of molecular basis of salt tolerance in sorghum plants induced by ammonium nutrition, but also give new perspectives to develop biotechnological strategies to generate more salt-tolerant crops.
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Affiliation(s)
| | - Rafael de Souza Miranda
- Programa de Pós-graduação em Ciências Agrárias, Campus Professora Cinobelina Elvas, Universidade Federal do Piauí, Bom Jesus, Brazil.
| | - Gyedre Dos Santos Araújo
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Fortaleza, Brazil
| | - Daniel Gomes Coelho
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Fortaleza, Brazil
| | | | | | - Lineker de Sousa Lopes
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Fortaleza, Brazil
| | | | | | - Enéas Gomes-Filho
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará and Instituto Nacional de Ciência e Tecnologia em Salinidade (INCTSal), Fortaleza, Brazil.
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Degen GE, Worrall D, Carmo-Silva E. An isoleucine residue acts as a thermal and regulatory switch in wheat Rubisco activase. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 103:742-751. [PMID: 32363739 DOI: 10.1111/tpj.14766] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [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.
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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
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14
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Wang Y, Burgess SJ, de Becker EM, Long SP. Photosynthesis in the fleeting shadows: an overlooked opportunity for increasing crop productivity? THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 101:874-884. [PMID: 31908116 PMCID: PMC7064922 DOI: 10.1111/tpj.14663] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [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.
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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
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