1
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Bellasio C, Lundgren MR. The operation of PEPCK increases light harvesting plasticity in C 4 NAD-ME and NADP-ME photosynthetic subtypes: A theoretical study. Plant Cell Environ 2024; 47:2288-2309. [PMID: 38494958 DOI: 10.1111/pce.14869] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 02/15/2024] [Accepted: 02/18/2024] [Indexed: 03/19/2024]
Abstract
The repeated emergence of NADP-malic enzyme (ME), NAD-ME and phosphoenolpyruvate carboxykinase (PEPCK) subtypes of C4 photosynthesis are iconic examples of convergent evolution, which suggests that these biochemistries do not randomly assemble, but are instead specific adaptations resulting from unknown evolutionary drivers. Theoretical studies that are based on the classic biochemical understanding have repeatedly proposed light-use efficiency as a possible benefit of the PEPCK subtype. However, quantum yield measurements do not support this idea. We explore this inconsistency here via an analytical model that features explicit descriptions across a seamless gradient between C4 biochemistries to analyse light harvesting and dark photosynthetic metabolism. Our simulations show that the NADP-ME subtype, operated by the most productive crops, is the most efficient. The NAD-ME subtype has lower efficiency, but has greater light harvesting plasticity (the capacity to assimilate CO2 in the broadest combination of light intensity and spectral qualities). In both NADP-ME and NAD-ME backgrounds, increasing PEPCK activity corresponds to greater light harvesting plasticity but likely imposed a reduction in photosynthetic efficiency. We draw the first mechanistic links between light harvesting and C4 subtypes, providing the theoretical basis for future investigation.
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Affiliation(s)
- Chandra Bellasio
- Laboratory of Theoretical and Applied Crop Ecophysiology, School of Biology and Environmental Science, University College Dublin, Dublin, Ireland
- Department of Chemistry, Biology ond Biotechnology, Università Degli Studi Di Perugia, Perugia, Italy
- Department of Biology, University of the Balearic Islands, Palma, Illes Balears, Spain
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia
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2
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Dennis G, Posewitz MC. Advances in light system engineering across the phototrophic spectrum. Front Plant Sci 2024; 15:1332456. [PMID: 38410727 PMCID: PMC10895028 DOI: 10.3389/fpls.2024.1332456] [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] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 01/24/2024] [Indexed: 02/28/2024]
Abstract
Current work in photosynthetic engineering is progressing along the lines of cyanobacterial, microalgal, and plant research. These are interconnected through the fundamental mechanisms of photosynthesis and advances in one field can often be leveraged to improve another. It is worthwhile for researchers specializing in one or more of these systems to be aware of the work being done across the entire research space as parallel advances of techniques and experimental approaches can often be applied across the field of photosynthesis research. This review focuses on research published in recent years related to the light reactions of photosynthesis in cyanobacteria, eukaryotic algae, and plants. Highlighted are attempts to improve photosynthetic efficiency, and subsequent biomass production. Also discussed are studies on cross-field heterologous expression, and related work on augmented and novel light capture systems. This is reviewed in the context of translatability in research across diverse photosynthetic organisms.
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Affiliation(s)
- Galen Dennis
- Department of Chemistry, Colorado School of Mines, Golden, CO, United States
| | - Matthew C Posewitz
- Department of Chemistry, Colorado School of Mines, Golden, CO, United States
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3
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Hu C, Elias E, Nawrocki WJ, Croce R. Drought affects both photosystems in Arabidopsis thaliana. New Phytol 2023; 240:663-675. [PMID: 37530066 DOI: 10.1111/nph.19171] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Accepted: 07/14/2023] [Indexed: 08/03/2023]
Abstract
Drought is a major abiotic stress that impairs plant growth and development. Despite this, a comprehensive understanding of drought effects on the photosynthetic apparatus is lacking. In this work, we studied the consequences of 14-d drought treatment on Arabidopsis thaliana. We used biochemical and spectroscopic methods to examine photosynthetic membrane composition and functionality. Drought led to the disassembly of PSII supercomplexes and the degradation of PSII core. The light-harvesting complexes (LHCII) instead remain in the membrane but cannot act as an antenna for active PSII, thus representing a potential source of photodamage. This effect can also be observed during nonphotochemical quenching (NPQ) induction when even short pulses of saturating light can lead to photoinhibition. At a later stage, under severe drought stress, the PSI antenna size is also reduced and the PSI-LHCI supercomplexes disassemble. Surprisingly, although we did not observe changes in the PSI core protein content, the functionality of PSI is severely affected, suggesting the accumulation of nonfunctional PSI complexes. We conclude that drought affects both photosystems, although at a different stage, and that the operative quantum efficiency of PSII (ΦPSII ) is very sensitive to drought and can thus be used as a parameter for early detection of drought stress.
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Affiliation(s)
- Chen Hu
- Biophysics of Photosynthesis, Department of Physics and Astronomy and Institute for Lasers, Life and Biophotonics, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, the Netherlands
| | - Eduard Elias
- Biophysics of Photosynthesis, Department of Physics and Astronomy and Institute for Lasers, Life and Biophotonics, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, the Netherlands
| | - Wojciech J Nawrocki
- Biophysics of Photosynthesis, Department of Physics and Astronomy and Institute for Lasers, Life and Biophotonics, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, the Netherlands
| | - Roberta Croce
- Biophysics of Photosynthesis, Department of Physics and Astronomy and Institute for Lasers, Life and Biophotonics, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, the Netherlands
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4
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Li R, He Y, Chen J, Zheng S, Zhuang C. Research Progress in Improving Photosynthetic Efficiency. Int J Mol Sci 2023; 24:ijms24119286. [PMID: 37298238 DOI: 10.3390/ijms24119286] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 05/23/2023] [Accepted: 05/24/2023] [Indexed: 06/12/2023] Open
Abstract
Photosynthesis is the largest mass- and energy-conversion process on Earth, and it is the material basis for almost all biological activities. The efficiency of converting absorbed light energy into energy substances during photosynthesis is very low compared to theoretical values. Based on the importance of photosynthesis, this article summarizes the latest progress in improving photosynthesis efficiency from various perspectives. The main way to improve photosynthetic efficiency is to optimize the light reactions, including increasing light absorption and conversion, accelerating the recovery of non-photochemical quenching, modifying enzymes in the Calvin cycle, introducing carbon concentration mechanisms into C3 plants, rebuilding the photorespiration pathway, de novo synthesis, and changing stomatal conductance. These developments indicate that there is significant room for improvement in photosynthesis, providing support for improving crop yields and mitigating changes in climate conditions.
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Affiliation(s)
- Ruiqi Li
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China
| | - Ying He
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China
| | - Junyu Chen
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China
| | - Shaoyan Zheng
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China
| | - Chuxiong Zhuang
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China
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5
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Ghosh D, Mohapatra S, Dogra V. Improving photosynthetic efficiency by modulating non-photochemical quenching. Trends Plant Sci 2023; 28:264-266. [PMID: 36581517 DOI: 10.1016/j.tplants.2022.12.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [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: 11/10/2022] [Revised: 12/17/2022] [Accepted: 12/19/2022] [Indexed: 06/17/2023]
Abstract
High light exposure rapidly activates non-photochemical quenching (NPQ), protecting plants from photooxidative damage. Contrarily, its relaxation upon transition to normal light occurs quite slowly, limiting photosynthetic efficiency. De Souza et al. demonstrated that by overexpressing NPQ-related genes, faster NPQ relaxation and enhanced photosynthesis can be achieved under fluctuating light conditions.
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Affiliation(s)
- Dipanshu Ghosh
- Biotechnology Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur 176061, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Sumanta Mohapatra
- Biotechnology Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur 176061, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Vivek Dogra
- Biotechnology Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur 176061, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India.
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6
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Moustakas M, Sperdouli I, Moustaka J, Şaş B, İşgören S, Morales F. Mechanistic Insights on Salicylic Acid Mediated Enhancement of Photosystem II Function in Oregano Seedlings Subjected to Moderate Drought Stress. Plants (Basel) 2023; 12:plants12030518. [PMID: 36771603 PMCID: PMC9919124 DOI: 10.3390/plants12030518] [Citation(s) in RCA: 1] [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: 12/30/2022] [Revised: 01/15/2023] [Accepted: 01/19/2023] [Indexed: 06/12/2023]
Abstract
Dramatic climate change has led to an increase in the intensity and frequency of drought episodes and, together with the high light conditions of the Mediterranean area, detrimentally influences crop production. Salicylic acid (SA) has been shown to supress phototoxicity, offering photosystem II (PSII) photoprotection. In the current study, we attempted to reveal the mechanism by which SA is improving PSII efficiency in oregano seedlings under moderate drought stress (MoDS). Foliar application of SA decreased chlorophyll content under normal growth conditions, but under MoDS increased chlorophyll content, compared to H2O-sprayed oregano seedlings. SA improved the PSII efficiency of oregano seedlings under normal growth conditions at high light (HL), and under MoDS, at both low light (LL) and HL. The mechanism by which, under normal growth conditions and HL, SA sprayed oregano seedlings compared to H2O-sprayed exhibited a more efficient PSII photochemistry, was the increased (17%) fraction of open PSII reaction centers (qp), and the increased (7%) efficiency of these open reaction centers (Fv'/Fm'), which resulted in an enhanced (24%) electron transport rate (ETR). SA application under MoDS, by modulating chlorophyll content, resulted in optimized antenna size and enhanced effective quantum yield of PSII photochemistry (ΦPSII) under both LL (7%) and HL (25%), compared to non-SA-sprayed oregano seedlings. This increased effective quantum yield of PSII photochemistry (ΦPSII) was due to the enhanced efficiency of the oxygen evolving complex (OEC), and the increased fraction of open PSII reaction centers (qp), which resulted in an increased electron transport rate (ETR) and a lower amount of singlet oxygen (1O2) production with less excess excitation energy (EXC).
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Affiliation(s)
- Michael Moustakas
- Department of Botany, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
| | - Ilektra Sperdouli
- Institute of Plant Breeding and Genetic Resources, Hellenic Agricultural Organisation–Demeter (ELGO-Demeter), 57001 Thessaloniki, Greece
| | - Julietta Moustaka
- Department of Botany, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
| | - Begüm Şaş
- Department of Botany, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
| | - Sumrunaz İşgören
- Department of Botany, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
| | - Fermín Morales
- Instituto de Agrobiotecnología (IdAB), CSIC-Gobierno de Navarra, Avda. de Pamplona 123, 31192 Navarra, Spain
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7
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Bellasio C, Ermakova M. Reduction of bundle sheath size boosts cyclic electron flow in C 4 Setaria viridis acclimated to low light. Plant J 2022; 111:1223-1237. [PMID: 35866447 PMCID: PMC9545969 DOI: 10.1111/tpj.15915] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [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: 05/13/2021] [Revised: 06/29/2022] [Accepted: 07/07/2022] [Indexed: 05/22/2023]
Abstract
When C4 leaves are exposed to low light, the CO2 concentration in the bundle sheath (BS) cells decreases, causing an increase in photorespiration relative to assimilation, and a consequent reduction in biochemical efficiency. These effects can be mitigated by complex acclimation syndromes, which are of primary importance for crop productivity but are not well studied. We unveil an acclimation strategy involving the coordination of electron transport processes. First, we characterize the anatomy, gas exchange and electron transport of C4 Setaria viridis grown under low light. Through a purposely developed biochemical model, we resolve the photon fluxes and reaction rates to explain how the concerted acclimation strategies sustain photosynthetic efficiency. Our results show that a smaller BS in low-light-grown plants limited leakiness (the ratio of CO2 leak rate out of the BS over the rate of supply via C4 acid decarboxylation) but sacrificed light harvesting and ATP production. To counter ATP shortage and maintain high assimilation rates, plants facilitated light penetration through the mesophyll and upregulated cyclic electron flow in the BS. This shade tolerance mechanism, based on the optimization of light reactions, is possibly more efficient than the known mechanisms involving the rearrangement of carbon metabolism, and could potentially lead to innovative strategies for crop improvement.
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Affiliation(s)
- Chandra Bellasio
- Department of BiologyUniversity of the Balearic Islands07122PalmaIlles BalearsSpain
- Centre of Excellence for Translational Photosynthesis, Research School of BiologyThe Australian National UniversityActonACT2601Australia
| | - Maria Ermakova
- Centre of Excellence for Translational Photosynthesis, Research School of BiologyThe Australian National UniversityActonACT2601Australia
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8
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Walter J, Kromdijk J. Here comes the sun: How optimization of photosynthetic light reactions can boost crop yields. J Integr Plant Biol 2022; 64:564-591. [PMID: 34962073 PMCID: PMC9302994 DOI: 10.1111/jipb.13206] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [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: 10/29/2021] [Accepted: 12/22/2021] [Indexed: 05/22/2023]
Abstract
Photosynthesis started to evolve some 3.5 billion years ago CO2 is the substrate for photosynthesis and in the past 200-250 years, atmospheric levels have approximately doubled due to human industrial activities. However, this time span is not sufficient for adaptation mechanisms of photosynthesis to be evolutionarily manifested. Steep increases in human population, shortage of arable land and food, and climate change call for actions, now. Thanks to substantial research efforts and advances in the last century, basic knowledge of photosynthetic and primary metabolic processes can now be translated into strategies to optimize photosynthesis to its full potential in order to improve crop yields and food supply for the future. Many different approaches have been proposed in recent years, some of which have already proven successful in different crop species. Here, we summarize recent advances on modifications of the complex network of photosynthetic light reactions. These are the starting point of all biomass production and supply the energy equivalents necessary for downstream processes as well as the oxygen we breathe.
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Affiliation(s)
- Julia Walter
- Department of Plant SciencesUniversity of CambridgeCambridgeCB2 3EAUK
| | - Johannes Kromdijk
- Department of Plant SciencesUniversity of CambridgeCambridgeCB2 3EAUK
- Carl R Woese Institute for Genomic BiologyUniversity of Illinois Urbana‐ChampaignUrbanaIllinois61801USA
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9
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Tadmor Y, Raz A, Reikin-Barak S, Ambastha V, Shemesh E, Leshem Y, Crane O, Stern RA, Goldway M, Tchernov D, Liran O. Metamitron, a Photosynthetic Electron Transport Chain Inhibitor, Modulates the Photoprotective Mechanism of Apple Trees. Plants (Basel) 2021; 10:plants10122803. [PMID: 34961274 PMCID: PMC8707989 DOI: 10.3390/plants10122803] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 12/14/2021] [Accepted: 12/15/2021] [Indexed: 05/17/2023]
Abstract
Chemical thinning of apple fruitlets is an important practice as it reduces the natural fruit load and, therefore, increases the size of the final fruit for commercial markets. In apples, one chemical thinner used is Metamitron, which is sold as the commercial product Brevis® (Adama, Ashdod, Israel). This thinner inhibits the electron transfer between Photosystem II and Quinone-b within light reactions of photosynthesis. In this study, we investigated the responses of two apple cultivars-Golden Delicious and Top Red-and photosynthetic light reactions after administration of Brevis®. The analysis revealed that the presence of the inhibitor affects both cultivars' energetic status. The kinetics of the photoprotective mechanism's sub-processes are attenuated in both cultivars, but this seems more severe in the Top Red cultivar. State transitions of the antenna and Photosystem II repair cycle are decreased substantially when the Metamitron concentration is above 0.6% in the Top Red cultivar but not in the Golden Delicious cultivar. These attenuations result from a biased absorbed energy distribution between photochemistry and photoprotection pathways in the two cultivars. We suggest that Metamitron inadvertently interacts with photoprotective mechanism-related enzymes in chloroplasts of apple tree leaves. Specifically, we hypothesize that it may interact with the kinases responsible for the induction of state transitions and the Photosystem II repair cycle.
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Affiliation(s)
- Yuval Tadmor
- Group of Agrophysics Studies, MIGAL—Galilee Research Institute, Kiryat Shemona, Upper Galilee 11016, Israel;
| | - Amir Raz
- Group of Molecular Genetics in Agriculture, MIGAL—Galilee Research Institute, Kiryat Shemona, Upper Galilee 11016, Israel; (A.R.); (M.G.)
- Faculty of Sciences and Technology, Tel-Hai Academic College, Kiryat-Shemona, Upper Galilee 12208, Israel; (Y.L.); (R.A.S.)
| | - Shira Reikin-Barak
- Northern R&D, Kiryat Shemona, Upper Galilee 11016, Israel; (S.R.-B.); (O.C.)
| | - Vivek Ambastha
- Group of Plant Development and Adaptation, MIGAL—Galilee Research Institute, Kiryat Shemona, Upper Galilee 11016, Israel;
| | - Eli Shemesh
- Morris Kahn Marine Research Station, Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, Mt. Carmel, Haifa 3498838, Israel; (E.S.); (D.T.)
| | - Yehoram Leshem
- Faculty of Sciences and Technology, Tel-Hai Academic College, Kiryat-Shemona, Upper Galilee 12208, Israel; (Y.L.); (R.A.S.)
- Group of Plant Development and Adaptation, MIGAL—Galilee Research Institute, Kiryat Shemona, Upper Galilee 11016, Israel;
| | - Omer Crane
- Northern R&D, Kiryat Shemona, Upper Galilee 11016, Israel; (S.R.-B.); (O.C.)
| | - Raphael A. Stern
- Faculty of Sciences and Technology, Tel-Hai Academic College, Kiryat-Shemona, Upper Galilee 12208, Israel; (Y.L.); (R.A.S.)
- Northern R&D, Kiryat Shemona, Upper Galilee 11016, Israel; (S.R.-B.); (O.C.)
| | - Martin Goldway
- Group of Molecular Genetics in Agriculture, MIGAL—Galilee Research Institute, Kiryat Shemona, Upper Galilee 11016, Israel; (A.R.); (M.G.)
- Faculty of Sciences and Technology, Tel-Hai Academic College, Kiryat-Shemona, Upper Galilee 12208, Israel; (Y.L.); (R.A.S.)
| | - Dan Tchernov
- Morris Kahn Marine Research Station, Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, Mt. Carmel, Haifa 3498838, Israel; (E.S.); (D.T.)
| | - Oded Liran
- Group of Agrophysics Studies, MIGAL—Galilee Research Institute, Kiryat Shemona, Upper Galilee 11016, Israel;
- Morris Kahn Marine Research Station, Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, Mt. Carmel, Haifa 3498838, Israel; (E.S.); (D.T.)
- Correspondence:
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10
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Dobson Z, Ahad S, Vanlandingham J, Toporik H, Vaughn N, Vaughn M, Williams D, Reppert M, Fromme P, Mazor Y. The structure of photosystem I from a high-light-tolerant cyanobacteria. eLife 2021; 10:e67518. [PMID: 34435952 PMCID: PMC8428864 DOI: 10.7554/elife.67518] [Citation(s) in RCA: 9] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Accepted: 08/25/2021] [Indexed: 12/22/2022] Open
Abstract
Photosynthetic organisms have adapted to survive a myriad of extreme environments from the earth's deserts to its poles, yet the proteins that carry out the light reactions of photosynthesis are highly conserved from the cyanobacteria to modern day crops. To investigate adaptations of the photosynthetic machinery in cyanobacteria to excessive light stress, we isolated a new strain of cyanobacteria, Cyanobacterium aponinum 0216, from the extreme light environment of the Sonoran Desert. Here we report the biochemical characterization and the 2.7 Å resolution structure of trimeric photosystem I from this high-light-tolerant cyanobacterium. The structure shows a new conformation of the PsaL C-terminus that supports trimer formation of cyanobacterial photosystem I. The spectroscopic analysis of this photosystem I revealed a decrease in far-red absorption, which is attributed to a decrease in the number of long- wavelength chlorophylls. Using these findings, we constructed two chimeric PSIs in Synechocystis sp. PCC 6803 demonstrating how unique structural features in photosynthetic complexes can change spectroscopic properties, allowing organisms to thrive under different environmental stresses.
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Affiliation(s)
- Zachary Dobson
- School of Molecular Sciences, Arizona State UniversityTempeUnited States
- BiodesignCenter for Applied Structural Discovery, Arizona State UniversityTempeUnited States
| | - Safa Ahad
- Department of Chemistry, Purdue UniversityWest LafayetteUnited States
| | - Jackson Vanlandingham
- School of Molecular Sciences, Arizona State UniversityTempeUnited States
- BiodesignCenter for Applied Structural Discovery, Arizona State UniversityTempeUnited States
| | - Hila Toporik
- School of Molecular Sciences, Arizona State UniversityTempeUnited States
- BiodesignCenter for Applied Structural Discovery, Arizona State UniversityTempeUnited States
| | - Natalie Vaughn
- School of Molecular Sciences, Arizona State UniversityTempeUnited States
- BiodesignCenter for Applied Structural Discovery, Arizona State UniversityTempeUnited States
| | - Michael Vaughn
- School of Molecular Sciences, Arizona State UniversityTempeUnited States
- BiodesignCenter for Applied Structural Discovery, Arizona State UniversityTempeUnited States
| | - Dewight Williams
- John M. Cowley Center for High Resolution Electron Microscopy, Arizona State UniversityTempeUnited States
| | - Michael Reppert
- Department of Chemistry, Purdue UniversityWest LafayetteUnited States
| | - Petra Fromme
- School of Molecular Sciences, Arizona State UniversityTempeUnited States
- BiodesignCenter for Applied Structural Discovery, Arizona State UniversityTempeUnited States
| | - Yuval Mazor
- School of Molecular Sciences, Arizona State UniversityTempeUnited States
- BiodesignCenter for Applied Structural Discovery, Arizona State UniversityTempeUnited States
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11
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Akter T, Nakamoto H. pH-mediated control of anti-aggregation activities of cyanobacterial and E. coli chaperonin GroELs. J Biochem 2021; 169:351-361. [PMID: 32997746 DOI: 10.1093/jb/mvaa108] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 09/10/2020] [Indexed: 11/12/2022] Open
Abstract
In contrast to Escherichia coli, cyanobacteria have multiple GroELs, the bacterial homologues of chaperonin/Hsp60. We have shown that cyanobacterial GroELs are mutually distinct and different from E. coli GroEL with which the paradigm for chaperonin structure/function has been established. However, little is known about regulation of cyanobacterial GroELs. This study investigated effect of pH (varied from 7.0 to 8.5) on chaperone activity of GroEL1 and GroEL2 from the cyanobacterium Synechococcus elongatus PCC7942 and E. coli GroEL. GroEL1 and GroEL2 showed pH dependency in suppression of aggregation of heat-denatured malate dehydrogenase, lactate dehydrogenase and citrate synthase. They exhibited higher anti-aggregation activity at more alkaline pHs. Escherichia coli GroEL showed a similar pH-dependence in suppressing aggregation of heat-denatured lactate dehydrogenase. No pH dependence was observed in all the GroELs when urea-denatured lactate dehydrogenase was used for anti-aggregation assay, suggesting that the pH-dependence is related to some denatured structures. There was no significant influence of pH on the chaperone activity of all the GroELs to promote refolding of heat-denatured malate dehydrogenase. It is known that pH in cyanobacterial cytoplasm increases by one pH unit following a shift from darkness to light, suggesting that the pH-change modulates chaperone activity of cyanobacterial GroEL1 and GroEL2.
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Affiliation(s)
| | - Hitoshi Nakamoto
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University, Saitama 338-8570, Japan
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12
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Gu L, Han J, Wood JD, Chang CYY, Sun Y. Sun-induced Chl fluorescence and its importance for biophysical modeling of photosynthesis based on light reactions. New Phytol 2019; 223:1179-1191. [PMID: 30883811 DOI: 10.1111/nph.15796] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [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: 12/29/2018] [Accepted: 03/11/2019] [Indexed: 05/22/2023]
Abstract
Recent progress in observing sun-induced Chl fluorescence (SIF) provides an unprecedented opportunity to advance photosynthesis research in natural environments. However, we still lack an analytical framework to guide SIF studies and integration with the well-developed active fluorescence approaches. Here, we derive a set of coupled fundamental equations to describe the dynamics of SIF and its relationship with C3 and C4 photosynthesis. These equations show that, although SIF is dynamically as complex as photosynthesis, the measured SIF simplifies photosynthetic modeling from the perspective of light reactions by integrating over the dynamic complexities of photosynthesis. Specifically, the measured SIF contains direct information about the actual electron transport from photosystem II to photosystem I, giving a quantifiable link between light and dark reactions. With much-reduced requirements on inputs and parameters, the light-reactions-centric, SIF-based biophysical model complements the traditional, dark-reactions-centric biochemical model of photosynthesis. The SIF-photosynthesis relationship, however, is nonlinear. This is because photosynthesis saturates at high light whereas SIF has a stronger tendency to keep increasing, as fluorescence quantum yield has a relatively muted sensitivity to light levels. Successful applications of the SIF-based model of photosynthesis will depend on a predictive understanding of several previously underexplored physiological and biophysical processes. Advances can be facilitated by coordinated efforts in plant physiology, remote sensing, and eddy covariance flux observations.
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Affiliation(s)
- Lianhong Gu
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Jimei Han
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
- The Key Laboratory of Oasis Eco-agriculture, Xinjiang Production and Construction Group, Shihezi University, Shihezi, 832003, China
| | - Jeffrey D Wood
- School of Natural Resources, University of Missouri, Columbia, MO, 65211, USA
| | - Christine Y-Y Chang
- School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA
| | - Ying Sun
- School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA
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13
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Nikkanen L, Toivola J, Diaz MG, Rintamäki E. Chloroplast thioredoxin systems: prospects for improving photosynthesis. Philos Trans R Soc Lond B Biol Sci 2018; 372:rstb.2016.0474. [PMID: 28808108 PMCID: PMC5566889 DOI: 10.1098/rstb.2016.0474] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [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: 01/23/2017] [Indexed: 01/07/2023] Open
Abstract
Thioredoxins (TRXs) are protein oxidoreductases that control the structure and function of cellular proteins by cleavage of a disulphide bond between the side chains of two cysteine residues. Oxidized thioredoxins are reactivated by thioredoxin reductases (TR) and a TR-dependent reduction of TRXs is called a thioredoxin system. Thiol-based redox regulation is an especially important mechanism to control chloroplast proteins involved in biogenesis, in regulation of light harvesting and distribution of light energy between photosystems, in photosynthetic carbon fixation and other biosynthetic pathways, and in stress responses of plants. Of the two plant plastid thioredoxin systems, the ferredoxin-dependent system relays reducing equivalents from photosystem I via ferredoxin and ferredoxin-thioredoxin reductase (FTR) to chloroplast proteins, while NADPH-dependent thioredoxin reductase (NTRC) forms a complete thioredoxin system including both reductase and thioredoxin domains in a single polypeptide. Chloroplast thioredoxins transmit environmental light signals to biochemical reactions, which allows fine tuning of photosynthetic processes in response to changing environmental conditions. In this paper we focus on the recent reports on specificity and networking of chloroplast thioredoxin systems and evaluate the prospect of improving photosynthetic performance by modifying the activity of thiol regulators in plants. This article is part of the themed issue ‘Enhancing photosynthesis in crop plants: targets for improvement'.
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Affiliation(s)
- Lauri Nikkanen
- Molecular Plant Biology, Department of Biochemistry, University of Turku, 20014 Turku, Finland
| | - Jouni Toivola
- Molecular Plant Biology, Department of Biochemistry, University of Turku, 20014 Turku, Finland
| | - Manuel Guinea Diaz
- Molecular Plant Biology, Department of Biochemistry, University of Turku, 20014 Turku, Finland
| | - Eevi Rintamäki
- Molecular Plant Biology, Department of Biochemistry, University of Turku, 20014 Turku, Finland
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14
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Dann M, Leister D. Enhancing (crop) plant photosynthesis by introducing novel genetic diversity. Philos Trans R Soc Lond B Biol Sci 2018; 372:rstb.2016.0380. [PMID: 28808099 DOI: 10.1098/rstb.2016.0380] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/04/2017] [Indexed: 12/22/2022] Open
Abstract
Although some elements of the photosynthetic light reactions might appear to be ideal, the overall efficiency of light conversion to biomass has not been optimized during evolution. Because crop plants are depleted of genetic diversity for photosynthesis, efforts to enhance its efficiency with respect to light conversion to yield must generate new variation. In principle, three sources of natural variation are available: (i) rare diversity within extant higher plant species, (ii) photosynthetic variants from algae, and (iii) reconstruction of no longer extant types of plant photosynthesis. Here, we argue for a novel approach that outsources crop photosynthesis to a cyanobacterium that is amenable to adaptive evolution. This system offers numerous advantages, including a short generation time, virtually unlimited population sizes and high mutation rates, together with a versatile toolbox for genetic manipulation. On such a synthetic bacterial platform, 10 000 years of (crop) plant evolution can be recapitulated within weeks. Limitations of this system arise from its unicellular nature, which cannot reproduce all aspects of crop photosynthesis. But successful establishment of such a bacterial host for crop photosynthesis promises not only to enhance the performance of eukaryotic photosynthesis but will also reveal novel facets of the molecular basis of photosynthetic flexibility.This article is part of the themed issue 'Enhancing photosynthesis in crop plants: targets for improvement'.
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Affiliation(s)
- Marcel Dann
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians University of Munich, Großhaderner Str. 2, 82152 Planegg-Martinsried, Germany
| | - Dario Leister
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians University of Munich, Großhaderner Str. 2, 82152 Planegg-Martinsried, Germany
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Hammel A, Zimmer D, Sommer F, Mühlhaus T, Schroda M. Absolute Quantification of Major Photosynthetic Protein Complexes in Chlamydomonas reinhardtii Using Quantification Concatamers (QconCATs). Front Plant Sci 2018; 9:1265. [PMID: 30214453 PMCID: PMC6125352 DOI: 10.3389/fpls.2018.01265] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 08/10/2018] [Indexed: 05/03/2023]
Abstract
For modeling approaches in systems biology, knowledge of the absolute abundances of cellular proteins is essential. One way to gain this knowledge is the use of quantification concatamers (QconCATs), which are synthetic proteins consisting of proteotypic peptides derived from the target proteins to be quantified. The QconCAT protein is labeled with a heavy isotope upon expression in E. coli and known amounts of the purified protein are spiked into a whole cell protein extract. Upon tryptic digestion, labeled and unlabeled peptides are released from the QconCAT protein and the native proteins, respectively, and both are quantified by LC-MS/MS. The labeled Q-peptides then serve as standards for determining the absolute quantity of the native peptides/proteins. Here, we have applied the QconCAT approach to Chlamydomonas reinhardtii for the absolute quantification of the major proteins and protein complexes driving photosynthetic light reactions in the thylakoid membranes and carbon fixation in the pyrenoid. We found that with 25.2 attomol/cell the Rubisco large subunit makes up 6.6% of all proteins in a Chlamydomonas cell and with this exceeds the amount of the small subunit by a factor of 1.56. EPYC1, which links Rubisco to form the pyrenoid, is eight times less abundant than RBCS, and Rubisco activase is 32-times less abundant than RBCS. With 5.2 attomol/cell, photosystem II is the most abundant complex involved in the photosynthetic light reactions, followed by plastocyanin, photosystem I and the cytochrome b6/f complex, which range between 2.9 and 3.5 attomol/cell. The least abundant complex is the ATP synthase with 2 attomol/cell. While applying the QconCAT approach, we have been able to identify many potential pitfalls associated with this technique. We analyze and discuss these pitfalls in detail and provide an optimized workflow for future applications of this technique.
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