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Krämer C, Boehm CR, Liu J, Ting MKY, Hertle AP, Forner J, Ruf S, Schöttler MA, Zoschke R, Bock R. Removal of the large inverted repeat from the plastid genome reveals gene dosage effects and leads to increased genome copy number. NATURE PLANTS 2024; 10:923-935. [PMID: 38802561 PMCID: PMC11208156 DOI: 10.1038/s41477-024-01709-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 04/24/2024] [Indexed: 05/29/2024]
Abstract
The chloroplast genomes of most plants and algae contain a large inverted repeat (IR) region that separates two single-copy regions and harbours the ribosomal RNA operon. We have addressed the functional importance of the IR region by removing an entire copy of the 25.3-kb IR from the tobacco plastid genome. Using plastid transformation and subsequent selectable marker gene elimination, we precisely excised the IR, thus generating plants with a substantially reduced plastid genome size. We show that the lack of the IR results in a mildly reduced plastid ribosome number, suggesting a gene dosage benefit from the duplicated presence of the ribosomal RNA operon. Moreover, the IR deletion plants contain an increased number of plastid genomes, suggesting that genome copy number is regulated by measuring total plastid DNA content rather than by counting genomes. Together, our findings (1) demonstrate that the IR can enhance the translation capacity of the plastid, (2) reveal the relationship between genome size and genome copy number, and (3) provide a simplified plastid genome structure that will facilitate future synthetic biology applications.
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Affiliation(s)
- Carolin Krämer
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | - Christian R Boehm
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | - Jinghan Liu
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | | | - Alexander P Hertle
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | - Joachim Forner
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | - Stephanie Ruf
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | - Mark A Schöttler
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | - Reimo Zoschke
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | - Ralph Bock
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany.
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2
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Moore V, Vermaas W. Functional consequences of modification of the photosystem I/photosystem II ratio in the cyanobacterium Synechocystis sp. PCC 6803. J Bacteriol 2024; 206:e0045423. [PMID: 38695523 PMCID: PMC11112997 DOI: 10.1128/jb.00454-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Accepted: 03/16/2024] [Indexed: 05/24/2024] Open
Abstract
The stoichiometry of photosystem II (PSII) and photosystem I (PSI) varies between photoautotrophic organisms. The cyanobacterium Synechocystis sp. PCC 6803 maintains two- to fivefold more PSI than PSII reaction center complexes, and we sought to modify this stoichiometry by changing the promoter region of the psaAB operon. We thus generated mutants with varied psaAB expression, ranging from ~3% to almost 200% of the wild-type transcript level, but all showing a reduction in PSI levels, relative to wild type, suggesting a role of the psaAB promoter region in translational regulation. Mutants with 25%-70% of wild-type PSI levels were photoautotrophic, with whole-chain oxygen evolution rates on a per-cell basis comparable to that of wild type. In contrast, mutant strains with <10% of the wild-type level of PSI were obligate photoheterotrophs. Variable fluorescence yields of all mutants were much higher than those of wild type, indicating that the PSI content is localized differently than in wild type, with less transfer of PSII-absorbed energy to PSI. Strains with less PSI saturate at a higher light intensity, enhancing productivity at higher light intensities. This is similar to what is found in mutants with reduced antennae. With 3-(3,4-dichlorophenyl)-1,1-dimethylurea present, P700+ re-reduction kinetics in the mutants were slower than in wild type, consistent with the notion that there is less cyclic electron transport if less PSI is present. Overall, strains with a reduction in PSI content displayed surprisingly vigorous growth and linear electron transport. IMPORTANCE Consequences of reduction in photosystem I content were investigated in the cyanobacterium Synechocystis sp. PCC 6803 where photosystem I far exceeds the number of photosystem II complexes. Strains with less photosystem I displayed less cyclic electron transport, grew more slowly at lower light intensity and needed more light for saturation but were surprisingly normal in their whole-chain electron transport rates, implying that a significant fraction of photosystem I is dispensable for linear electron transport in cyanobacteria. These strains with reduced photosystem I levels may have biotechnological relevance as they grow well at higher light intensities.
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Affiliation(s)
- Vicki Moore
- School of Life Sciences and Center for Bioenergy and Photosynthesis, Arizona State University, Tempe, Arizona, USA
| | - Wim Vermaas
- School of Life Sciences and Center for Bioenergy and Photosynthesis, Arizona State University, Tempe, Arizona, USA
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3
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Shikanai T. Molecular Genetic Dissection of the Regulatory Network of Proton Motive Force in Chloroplasts. PLANT & CELL PHYSIOLOGY 2024; 65:537-550. [PMID: 38150384 DOI: 10.1093/pcp/pcad157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 11/27/2023] [Accepted: 12/08/2023] [Indexed: 12/29/2023]
Abstract
The proton motive force (pmf) generated across the thylakoid membrane rotates the Fo-ring of ATP synthase in chloroplasts. The pmf comprises two components: membrane potential (∆Ψ) and proton concentration gradient (∆pH). Acidification of the thylakoid lumen resulting from ∆pH downregulates electron transport in the cytochrome b6f complex. This process, known as photosynthetic control, is crucial for protecting photosystem I (PSI) from photodamage in response to fluctuating light. To optimize the balance between efficient photosynthesis and photoprotection, it is necessary to regulate pmf. Cyclic electron transport around PSI and pseudo-cyclic electron transport involving flavodiiron proteins contribute to the modulation of pmf magnitude. By manipulating the ratio between the two components of pmf, it is possible to modify the extent of photosynthetic control without affecting the pmf size. This adjustment can be achieved by regulating the movement of ions (such as K+ and Cl-) across the thylakoid membrane. Since ATP synthase is the primary consumer of pmf in chloroplasts, its activity must be precisely regulated to accommodate other mechanisms involved in pmf optimization. Although fragments of information about each regulatory process have been accumulated, a comprehensive understanding of their interactions is lacking. Here, I summarize current knowledge of the network for pmf regulation, mainly based on genetic studies.
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Affiliation(s)
- Toshiharu Shikanai
- Department of Botany, Graduate School of Science, Kyoto University, Kyoto, 606-8502 Japan
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Yi S, Guo X, Lou W, Mao S, Luan G, Lu X. Structure, Regulation, and Significance of Cyanobacterial and Chloroplast Adenosine Triphosphate Synthase in the Adaptability of Oxygenic Photosynthetic Organisms. Microorganisms 2024; 12:940. [PMID: 38792770 PMCID: PMC11124002 DOI: 10.3390/microorganisms12050940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Revised: 04/29/2024] [Accepted: 04/30/2024] [Indexed: 05/26/2024] Open
Abstract
In cyanobacteria and chloroplasts (in algae and plants), ATP synthase plays a pivotal role as a photosynthetic membrane complex responsible for producing ATP from adenosine diphosphate and inorganic phosphate, utilizing a proton motive force gradient induced by photosynthesis. These two ATP synthases exhibit similarities in gene organization, amino acid sequences of subunits, structure, and functional mechanisms, suggesting that cyanobacterial ATP synthase is probably the evolutionary precursor to chloroplast ATP synthase. In this review, we explore the precise synthesis and assembly of ATP synthase subunits to address the uneven stoichiometry within the complex during transcription, translation, and assembly processes. We also compare the regulatory strategies governing ATP synthase activity to meet varying energy demands in cyanobacteria and chloroplasts amid fluctuating natural environments. Furthermore, we delve into the role of ATP synthase in stress tolerance and photosynthetic carbon fixation efficiency in oxygenic photosynthetic organisms (OPsOs), along with the current researches on modifying ATP synthase to enhance carbon fixation efficiency under stress conditions. This review aims to offer theoretical insights and serve as a reference for understanding the functional mechanisms of ATP synthase, sparking innovative ideas for enhancing photosynthetic carbon fixation efficiency by utilizing ATP synthase as an effective module in OPsOs.
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Affiliation(s)
- Siyan Yi
- College of Life Science and Technology, Central South University of Forestry and Technology, Changsha 410004, China;
- Hunan Provincial Key Laboratory of Forestry Biotechnology, Central South University of Forestry & Technology, Changsha 410004, China
- Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China; (X.G.); (G.L.); (X.L.)
| | - Xin Guo
- Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China; (X.G.); (G.L.); (X.L.)
- College of Live Science, Henan University, Kaifeng 450001, China
| | - Wenjing Lou
- Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China; (X.G.); (G.L.); (X.L.)
- Shandong Energy Institute, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao 266101, China
| | - Shaoming Mao
- College of Life Science and Technology, Central South University of Forestry and Technology, Changsha 410004, China;
- Hunan Provincial Key Laboratory of Forestry Biotechnology, Central South University of Forestry & Technology, Changsha 410004, China
| | - Guodong Luan
- Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China; (X.G.); (G.L.); (X.L.)
- Shandong Energy Institute, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao 266101, China
| | - Xuefeng Lu
- Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China; (X.G.); (G.L.); (X.L.)
- Shandong Energy Institute, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao 266101, China
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5
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Tikhonov AN. The cytochrome b 6f complex: plastoquinol oxidation and regulation of electron transport in chloroplasts. PHOTOSYNTHESIS RESEARCH 2024; 159:203-227. [PMID: 37369875 DOI: 10.1007/s11120-023-01034-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 06/12/2023] [Indexed: 06/29/2023]
Abstract
In oxygenic photosynthetic systems, the cytochrome b6f (Cytb6f) complex (plastoquinol:plastocyanin oxidoreductase) is a heart of the hub that provides connectivity between photosystems (PS) II and I. In this review, the structure and function of the Cytb6f complex are briefly outlined, being focused on the mechanisms of a bifurcated (two-electron) oxidation of plastoquinol (PQH2). In plant chloroplasts, under a wide range of experimental conditions (pH and temperature), a diffusion of PQH2 from PSII to the Cytb6f does not limit the intersystem electron transport. The overall rate of PQH2 turnover is determined mainly by the first step of the bifurcated oxidation of PQH2 at the catalytic site Qo, i.e., the reaction of electron transfer from PQH2 to the Fe2S2 cluster of the high-potential Rieske iron-sulfur protein (ISP). This point has been supported by the quantum chemical analysis of PQH2 oxidation within the framework of a model system including the Fe2S2 cluster of the ISP and surrounding amino acids, the low-potential heme b6L, Glu78 and 2,3,5-trimethylbenzoquinol (the tail-less analog of PQH2). Other structure-function relationships and mechanisms of electron transport regulation of oxygenic photosynthesis associated with the Cytb6f complex are briefly outlined: pH-dependent control of the intersystem electron transport and the regulatory balance between the operation of linear and cyclic electron transfer chains.
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Affiliation(s)
- Alexander N Tikhonov
- Department of Biophysics, Faculty of Physics, M.V. Lomonosov Moscow State University, Moscow, Russian Federation, 119991.
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6
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Gu L. Optimizing the electron transport chain to sustainably improve photosynthesis. PLANT PHYSIOLOGY 2023; 193:2398-2412. [PMID: 37671674 PMCID: PMC10663115 DOI: 10.1093/plphys/kiad490] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 07/28/2023] [Accepted: 08/11/2023] [Indexed: 09/07/2023]
Abstract
Genetically improving photosynthesis is a key strategy to boosting crop production to meet the rising demand for food and fuel by a rapidly growing global population in a warming climate. Many components of the photosynthetic apparatus have been targeted for genetic modification for improving photosynthesis. Successful translation of these modifications into increased plant productivity in fluctuating environments will depend on whether the electron transport chain (ETC) can support the increased electron transport rate without risking overreduction and photodamage. At present atmospheric conditions, the ETC appears suboptimal and will likely need to be modified to support proposed photosynthetic improvements and to maintain energy balance. Here, I derive photochemical equations to quantify the transport capacity and the corresponding reduction level based on the kinetics of redox reactions along the ETC. Using these theoretical equations and measurements from diverse C3/C4 species across environments, I identify several strategies that can simultaneously increase the transport capacity and decrease the reduction level of the ETC. These strategies include increasing the abundances of reaction centers, cytochrome b6f complexes, and mobile electron carriers, improving their redox kinetics, and decreasing the fraction of secondary quinone-nonreducing photosystem II reaction centers. I also shed light on several previously unexplained experimental findings regarding the physiological impacts of the abundances of the cytochrome b6f complex and plastoquinone. The model developed, and the insights generated from it facilitate the development of sustainable photosynthetic systems for greater crop yields.
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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
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7
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Soufi HR, Roosta HR, Stępień P, Malekzadeh K, Hamidpour M. Manipulation of light spectrum is an effective tool to regulate biochemical traits and gene expression in lettuce under different replacement methods of nutrient solution. Sci Rep 2023; 13:8600. [PMID: 37237093 PMCID: PMC10219983 DOI: 10.1038/s41598-023-35326-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 05/16/2023] [Indexed: 05/28/2023] Open
Abstract
The use of light-emitting diode (LED) technology represents a promising approach to improve plant growth and metabolic activities. The aim of this study was to investigate the effect of different light spectra: red (656 nm), blue (450 nm), red/blue (3:1), and white (peak at 449 nm) on biochemical properties, photosynthesis and gene expression in two lettuce cultivars (Lollo Rossa and Lollo Bionda) grown under different methods of nutrient solution replacement in hydroponics. Complete replacement and EC-based replacement of nutrient solution increased content of proline and soluble sugars and activity of antioxidant enzymes (CAT, GPX and SOD) under the red/blue LED and red LED light treatments in both cultivars. In addition, the red/blue and the monochromatic red light increased the soluble protein content and the antioxidant activity in the Lollo Rosa cultivar under the replacement method according to the needs of the plant. An increase in flavonoid content in the EC-based method in the Lollo Rosa variety treated with a combination of red and blue light was also observed. The red/blue light had the greatest induction effect on anthocyanin content, expression of the UFGT, CHS, and Rubisco small subunit genes, and the net photosynthetic rate. Data presented here will directly contribute to the development of nutrient solution and LED spectrum management strategies to significantly improve plant growth and metabolism, while avoiding water and nutrient waste, and environmental pollution.
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Affiliation(s)
- Hamid Reza Soufi
- Department of Horticultural Sciences, Faculty of Agriculture, Vali-e-Asr University of Rafsanjan, Rafsanjan, Iran
| | - Hamid Reza Roosta
- Department of Horticultural Sciences, Faculty of Agriculture and Natural Resources, Arak University, Arāk, Iran.
| | - Piotr Stępień
- Department of Plant Nutrition, Institute of Soil Science, Plant Nutrition and Environmental Protection, Wroclaw University of Environmental and Life Sciences, ul. Grunwaldzka 53, 50-357, Wrocław, Poland.
| | - Khalil Malekzadeh
- Department of Genetics and Plant Production, Faculty of Agriculture, Vali-e-Asr University of Rafsanjan, Rafsanjan, Iran
| | - Mohsen Hamidpour
- Department of Soil Science and Engineering, Faculty of Agriculture, Vali-e-Asr University of Rafsanjan, Rafsanjan, Iran
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8
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Milrad Y, Nagy V, Elman T, Fadeeva M, Tóth SZ, Yacoby I. A PSII photosynthetic control is activated in anoxic cultures of green algae following illumination. Commun Biol 2023; 6:514. [PMID: 37173420 PMCID: PMC10182038 DOI: 10.1038/s42003-023-04890-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 05/01/2023] [Indexed: 05/15/2023] Open
Abstract
Photosynthetic hydrogen production from microalgae is considered to have potential as a renewable energy source. Yet, the process has two main limitations holding it back from scaling up; (i) electron loss to competing processes, mainly carbon fixation and (ii) sensitivity to O2 which diminishes the expression and the activity of the hydrogenase enzyme catalyzing H2 production. Here we report a third, hitherto unknown challenge: We found that under anoxia, a slow-down switch is activated in photosystem II (PSII), diminishing the maximal photosynthetic productivity by three-fold. Using purified PSII and applying in vivo spectroscopic and mass spectrometric techniques on Chlamydomonas reinhardtii cultures, we show that this switch is activated under anoxia, within 10 s of illumination. Furthermore, we show that the recovery to the initial rate takes place following 15 min of dark anoxia, and propose a mechanism in which, modulation in electron transfer at the acceptor site of PSII diminishes its output. Such insights into the mechanism broaden our understanding of anoxic photosynthesis and its regulation in green algae and inspire new strategies to improve bio-energy yields.
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Affiliation(s)
- Yuval Milrad
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, 69978, Israel
| | - Valéria Nagy
- Institute of Plant Biology, Biological Research Centre, Szeged, Temesvári krt. 62, H-6726 Szeged, Hungary
| | - Tamar Elman
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, 69978, Israel
| | - Maria Fadeeva
- Department of Biochemistry, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, 69978, Israel
| | - Szilvia Z Tóth
- Institute of Plant Biology, Biological Research Centre, Szeged, Temesvári krt. 62, H-6726 Szeged, Hungary
| | - Iftach Yacoby
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, 69978, Israel.
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9
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Shimakawa G. Electron transport in cyanobacterial thylakoid membranes: Are cyanobacteria simple models for photosynthetic organisms? JOURNAL OF EXPERIMENTAL BOTANY 2023:erad118. [PMID: 37025010 DOI: 10.1093/jxb/erad118] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Indexed: 06/19/2023]
Abstract
Cyanobacteria are structurally the simplest oxygenic phototrophs, which makes it difficult to understand the regulation of photosynthesis because the photosynthetic and respiratory processes share the same thylakoid membranes and cytosolic space. This review aimed to summarise the molecular mechanisms and in vivo activities of electron transport in cyanobacterial thylakoid membranes based on the latest progress in photosynthesis research in cyanobacteria. Photosynthetic linear electron transport for CO2 assimilation has the dominant electron flux in the thylakoid membranes. The capacity of O2 photoreduction in cyanobacteria is comparable to the photosynthetic CO2 assimilation, which is mediated by flavodiiron proteins. Additionally, cyanobacterial thylakoid membranes harbour the significant electron flux of respiratory electron transport through a homologue of respiratory complex I, which is also recognized as the part of cyclic electron transport chain if it is coupled with photosystem I in the light. Further, O2-independent alternative electron transports through hydrogenase and nitrate reductase function with reduced ferredoxin as the electron donor. Whereas all these electron transports are recently being understood one by one, the complexity as the whole regulatory system remains to be uncovered in near future.
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Affiliation(s)
- Ginga Shimakawa
- Department of Bioscience, School of Biological and Environmental Sciences, Kwansei Gakuin University, 1 Gakuen Uegahara, Sanda, Hyogo 669-1330, Japan
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10
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Strand DD, Karcher D, Ruf S, Schadach A, Schöttler MA, Sandoval-Ibañez O, Hall D, Kramer DM, Bock R. Characterization of mutants deficient in N-terminal phosphorylation of the chloroplast ATP synthase subunit β. PLANT PHYSIOLOGY 2023; 191:1818-1835. [PMID: 36635853 PMCID: PMC10022623 DOI: 10.1093/plphys/kiad013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 12/05/2022] [Indexed: 06/17/2023]
Abstract
Understanding the regulation of photosynthetic light harvesting and electron transfer is of great importance to efforts to improve the ability of the electron transport chain to supply downstream metabolism. A central regulator of the electron transport chain is ATP synthase, the molecular motor that harnesses the chemiosmotic potential generated from proton-coupled electron transport to synthesize ATP. ATP synthase is regulated both thermodynamically and post-translationally, with proposed phosphorylation sites on multiple subunits. In this study we focused on two N-terminal serines on the catalytic subunit β in tobacco (Nicotiana tabacum), previously proposed to be important for dark inactivation of the complex to avoid ATP hydrolysis at night. Here we show that there is no clear role for phosphorylation in the dark inactivation of ATP synthase. Instead, mutation of one of the two phosphorylated serine residues to aspartate to mimic constitutive phosphorylation strongly decreased ATP synthase abundance. We propose that the loss of N-terminal phosphorylation of ATPβ may be involved in proper ATP synthase accumulation during complex assembly.
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Affiliation(s)
| | - Daniel Karcher
- Max-Planck-Institut für Molecular Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Stephanie Ruf
- Max-Planck-Institut für Molecular Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Anne Schadach
- Max-Planck-Institut für Molecular Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Mark A Schöttler
- Max-Planck-Institut für Molecular Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Omar Sandoval-Ibañez
- Max-Planck-Institut für Molecular Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - David Hall
- DOE Plant Research Laboratory, Michigan State University, 612 Wilson Rd 106, East Lansing, Michigan, 48824, USA
| | - David M Kramer
- DOE Plant Research Laboratory, Michigan State University, 612 Wilson Rd 106, East Lansing, Michigan, 48824, USA
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11
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Yue X, Ke X, Shi Y, Li Y, Zhang C, Wang Y, Hou X. Chloroplast inner envelope protein FtsH11 is involved in the adjustment of assembly of chloroplast ATP synthase under heat stress. PLANT, CELL & ENVIRONMENT 2023; 46:850-864. [PMID: 36573466 DOI: 10.1111/pce.14525] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 12/08/2022] [Accepted: 12/11/2022] [Indexed: 06/17/2023]
Abstract
The maintenance of a proton gradient across the thylakoid membrane is an integral aspect of photosynthesis that is mainly established by the splitting of water molecules in photosystem II and plastoquinol oxidation at the cytochrome complex, and it is necessary for the generation of ATP in the last step of photophosphorylation. Although environmental stresses, such as high temperatures, are known to disrupt this fundamental process, only a few studies have explored the molecular mechanisms underlying proton gradient regulation during stress. The present study identified a heat-sensitive mutant that displays aberrant photosynthesis at high temperatures. This mutation was mapped to AtFtsH11, which encodes an ATP-dependent AAA-family metalloprotease. We showed that AtFtsH11 localizes to the chloroplast inner envelope membrane and is capable of degrading the ATP synthase assembly factor BFA3 under heat stress. We posit that this function limits the amount of ATP synthase integrated into the thylakoid membrane to regulate proton efflux from the lumen to the stroma. Our data also suggest that AtFtsH11 is critical in stabilizing photosystem II and cytochrome complexes at high temperatures, and additional studies can further elucidate the specific molecular functions of this critical regulator of photosynthetic thermotolerance.
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Affiliation(s)
- Xiaohong Yue
- State Key Laboratory of Hybrid Rice, Hubei Hongshan Laboratory, College of Life Sciences, Wuhan University, Wuhan, China
| | - Xiangsheng Ke
- State Key Laboratory of Hybrid Rice, Hubei Hongshan Laboratory, College of Life Sciences, Wuhan University, Wuhan, China
| | - Yafei Shi
- State Key Laboratory of Hybrid Rice, Hubei Hongshan Laboratory, College of Life Sciences, Wuhan University, Wuhan, China
| | - Yangsheng Li
- State Key Laboratory of Hybrid Rice, Hubei Hongshan Laboratory, College of Life Sciences, Wuhan University, Wuhan, China
| | - Chenhao Zhang
- State Key Laboratory of Hybrid Rice, Hubei Hongshan Laboratory, College of Life Sciences, Wuhan University, Wuhan, China
| | - Yetao Wang
- State Key Laboratory of Hybrid Rice, Hubei Hongshan Laboratory, College of Life Sciences, Wuhan University, Wuhan, China
| | - Xin Hou
- State Key Laboratory of Hybrid Rice, Hubei Hongshan Laboratory, College of Life Sciences, Wuhan University, Wuhan, China
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12
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Jackson PJ, Hitchcock A, Brindley AA, Dickman MJ, Hunter CN. Absolute quantification of cellular levels of photosynthesis-related proteins in Synechocystis sp. PCC 6803. PHOTOSYNTHESIS RESEARCH 2023; 155:219-245. [PMID: 36542271 PMCID: PMC9958174 DOI: 10.1007/s11120-022-00990-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 11/24/2022] [Indexed: 06/17/2023]
Abstract
Quantifying cellular components is a basic and important step for understanding how a cell works, how it responds to environmental changes, and for re-engineering cells to produce valuable metabolites and increased biomass. We quantified proteins in the model cyanobacterium Synechocystis sp. PCC 6803 given the general importance of cyanobacteria for global photosynthesis, for synthetic biology and biotechnology research, and their ancestral relationship to the chloroplasts of plants. Four mass spectrometry methods were used to quantify cellular components involved in the biosynthesis of chlorophyll, carotenoid and bilin pigments, membrane assembly, the light reactions of photosynthesis, fixation of carbon dioxide and nitrogen, and hydrogen and sulfur metabolism. Components of biosynthetic pathways, such as those for chlorophyll or for photosystem II assembly, range between 1000 and 10,000 copies per cell, but can be tenfold higher for CO2 fixation enzymes. The most abundant subunits are those for photosystem I, with around 100,000 copies per cell, approximately 2 to fivefold higher than for photosystem II and ATP synthase, and 5-20 fold more than for the cytochrome b6f complex. Disparities between numbers of pathway enzymes, between components of electron transfer chains, and between subunits within complexes indicate possible control points for biosynthetic processes, bioenergetic reactions and for the assembly of multisubunit complexes.
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Affiliation(s)
- Philip J Jackson
- Plants, Photosynthesis and Soil, School of Biosciences, University of Sheffield, Sheffield, S10 2TN, UK.
- Department of Chemical and Biological Engineering, University of Sheffield, Sheffield, S1 3JD, UK.
| | - Andrew Hitchcock
- Plants, Photosynthesis and Soil, School of Biosciences, University of Sheffield, Sheffield, S10 2TN, UK
| | - Amanda A Brindley
- Plants, Photosynthesis and Soil, School of Biosciences, University of Sheffield, Sheffield, S10 2TN, UK
| | - Mark J Dickman
- Department of Chemical and Biological Engineering, University of Sheffield, Sheffield, S1 3JD, UK
| | - C Neil Hunter
- Plants, Photosynthesis and Soil, School of Biosciences, University of Sheffield, Sheffield, S10 2TN, UK
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Reiter B, Rosenhammer L, Marino G, Geimer S, Leister D, Rühle T. CGL160-mediated recruitment of the coupling factor CF1 is required for efficient thylakoid ATP synthase assembly, photosynthesis, and chloroplast development in Arabidopsis. THE PLANT CELL 2023; 35:488-509. [PMID: 36250886 PMCID: PMC9806626 DOI: 10.1093/plcell/koac306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 09/25/2022] [Indexed: 06/16/2023]
Abstract
Chloroplast ATP synthases consist of a membrane-spanning coupling factor (CFO) and a soluble coupling factor (CF1). It was previously demonstrated that CONSERVED ONLY IN THE GREEN LINEAGE160 (CGL160) promotes the formation of plant CFO and performs a similar function in the assembly of its c-ring to that of the distantly related bacterial Atp1/UncI protein. Here, we show that in Arabidopsis (Arabidopsis thaliana) the N-terminal portion of CGL160 (AtCGL160N) is required for late steps in CF1-CFO assembly. In plants that lacked AtCGL160N, CF1-CFO content, photosynthesis, and chloroplast development were impaired. Loss of AtCGL160N did not perturb c-ring formation, but led to a 10-fold increase in the numbers of stromal CF1 subcomplexes relative to that in the wild type. Co-immunoprecipitation and protein crosslinking assays revealed an association of AtCGL160 with CF1 subunits. Yeast two-hybrid assays localized the interaction to a stretch of AtCGL160N that binds to the DELSEED-containing CF1-β subdomain. Since Atp1 of Synechocystis (Synechocystis sp. PCC 6803) could functionally replace the membrane domain of AtCGL160 in Arabidopsis, we propose that CGL160 evolved from a cyanobacterial ancestor and acquired an additional function in the recruitment of a soluble CF1 subcomplex, which is critical for the modulation of CF1-CFO activity and photosynthesis.
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Affiliation(s)
- Bennet Reiter
- Plant Molecular Biology Faculty of Biology I, Ludwig-Maximilians-Universität Munich, D-82152 Planegg-Martinsried, Germany
| | - Lea Rosenhammer
- Plant Molecular Biology Faculty of Biology I, Ludwig-Maximilians-Universität Munich, D-82152 Planegg-Martinsried, Germany
| | - Giada Marino
- Plant Molecular Biology Faculty of Biology I, Ludwig-Maximilians-Universität Munich, D-82152 Planegg-Martinsried, Germany
| | - Stefan Geimer
- Zellbiologie/Elektronenmikroskopie NW I/B1, Universität Bayreuth, 95447 Bayreuth, Germany
| | - Dario Leister
- Plant Molecular Biology Faculty of Biology I, Ludwig-Maximilians-Universität Munich, D-82152 Planegg-Martinsried, Germany
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14
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Fages‐Lartaud M, Hundvin K, Hohmann‐Marriott MF. Mechanisms governing codon usage bias and the implications for protein expression in the chloroplast of Chlamydomonas reinhardtii. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 112:919-945. [PMID: 36071273 PMCID: PMC9828097 DOI: 10.1111/tpj.15970] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 08/29/2022] [Accepted: 09/01/2022] [Indexed: 05/30/2023]
Abstract
Chloroplasts possess a considerably reduced genome that is decoded via an almost minimal set of tRNAs. These features make an excellent platform for gaining insights into fundamental mechanisms that govern protein expression. Here, we present a comprehensive and revised perspective of the mechanisms that drive codon selection in the chloroplast of Chlamydomonas reinhardtii and the functional consequences for protein expression. In order to extract this information, we applied several codon usage descriptors to genes with different expression levels. We show that highly expressed genes strongly favor translationally optimal codons, while genes with lower functional importance are rather affected by directional mutational bias. We demonstrate that codon optimality can be deduced from codon-anticodon pairing affinity and, for a small number of amino acids (leucine, arginine, serine, and isoleucine), tRNA concentrations. Finally, we review, analyze, and expand on the impact of codon usage on protein yield, secondary structures of mRNA, translation initiation and termination, and amino acid composition of proteins, as well as cotranslational protein folding. The comprehensive analysis of codon choice provides crucial insights into heterologous gene expression in the chloroplast of C. reinhardtii, which may also be applicable to other chloroplast-containing organisms and bacteria.
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Affiliation(s)
- Maxime Fages‐Lartaud
- Department of BiotechnologyNorwegian University of Science and TechnologyTrondheimN‐7491Norway
| | - Kristoffer Hundvin
- Department of BiotechnologyNorwegian University of Science and TechnologyTrondheimN‐7491Norway
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15
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Heyno E, Ermakova M, Lopez‐Calcagno PE, Woodford R, Brown KL, Matthews JSA, Osmond B, Raines CA, von Caemmerer S. Rieske FeS overexpression in tobacco provides increased abundance and activity of cytochrome b 6 f. PHYSIOLOGIA PLANTARUM 2022; 174:e13803. [PMID: 36259085 PMCID: PMC9828649 DOI: 10.1111/ppl.13803] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 10/04/2022] [Accepted: 10/14/2022] [Indexed: 05/31/2023]
Abstract
Photosynthesis is fundamental for plant growth and yield. The cytochrome b6 f complex catalyses a rate-limiting step in thylakoid electron transport and therefore represents an important point of regulation of photosynthesis. Here we show that overexpression of a single core subunit of cytochrome b6 f, the Rieske FeS protein, led to up to a 40% increase in the abundance of the complex in Nicotiana tabacum (tobacco) and was accompanied by an enhanced in vitro cytochrome f activity, indicating a full functionality of the complex. Analysis of transgenic plants overexpressing Rieske FeS by the light-induced fluorescence transients technique revealed a more oxidised primary quinone acceptor of photosystem II (QA ) and plastoquinone pool and faster electron transport from the plastoquinone pool to photosystem I upon changes in irradiance, compared to control plants. A faster establishment of qE , the energy-dependent component of nonphotochemical quenching, in transgenic plants suggests a more rapid buildup of the transmembrane proton gradient, also supporting the increased in vivo cytochrome b6 f activity. However, there was no consistent increase in steady-state rates of electron transport or CO2 assimilation in plants overexpressing Rieske FeS grown in either laboratory conditions or field trials, suggesting that the in vivo activity of the complex was only transiently increased upon changes in irradiance. Our results show that overexpression of Rieske FeS in tobacco enhances the abundance of functional cytochrome b6 f and may have the potential to increase plant productivity if combined with other traits.
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Affiliation(s)
- Eiri Heyno
- Centre of Excellence for Translational Photosynthesis, Division of Plant ScienceResearch School of Biology, The Australian National UniversityActonAustralian Capital TerritoryAustralia
| | - Maria Ermakova
- Centre of Excellence for Translational Photosynthesis, Division of Plant ScienceResearch School of Biology, The Australian National UniversityActonAustralian Capital TerritoryAustralia
- School of Biological SciencesMonash UniversityMelbourneVictoriaAustralia
| | - Patricia E. Lopez‐Calcagno
- School of Biological SciencesUniversity of EssexColchesterUK
- School of Natural and Environmental SciencesNewcastle UniversityNewcastleUK
| | - Russell Woodford
- Centre of Excellence for Translational Photosynthesis, Division of Plant ScienceResearch School of Biology, The Australian National UniversityActonAustralian Capital TerritoryAustralia
| | - Kenny L. Brown
- School of Biological SciencesUniversity of EssexColchesterUK
| | | | - Barry Osmond
- Centre of Excellence for Translational Photosynthesis, Division of Plant ScienceResearch School of Biology, The Australian National UniversityActonAustralian Capital TerritoryAustralia
| | | | - Susanne von Caemmerer
- Centre of Excellence for Translational Photosynthesis, Division of Plant ScienceResearch School of Biology, The Australian National UniversityActonAustralian Capital TerritoryAustralia
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16
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Balfagón D, Zandalinas SI, dos Reis de Oliveira T, Santa‐Catarina C, Gómez‐Cadenas A. Reduction of heat stress pressure and activation of photosystem II repairing system are crucial for citrus tolerance to multiple abiotic stress combination. PHYSIOLOGIA PLANTARUM 2022; 174:e13809. [PMID: 36309819 PMCID: PMC9828536 DOI: 10.1111/ppl.13809] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 10/14/2022] [Accepted: 10/21/2022] [Indexed: 05/24/2023]
Abstract
Drought, heat and high irradiance are abiotic stresses that negatively affect plant development and reduce crop productivity. The confluence of these three factors is common in nature, causing extreme situations for plants that compromise their viability. Drought and heat stresses increase the saturation of the photosystem reaction centers, increasing sensitivity to high irradiance. In addition, these stress conditions affect photosystem II (PSII) integrity, alter redox balance of the electron transport chain and decrease the photosynthetic rate. Here, we studied the effect of the stress combinations on the photosynthetic apparatus of two citrus genotypes, Carrizo citrange (Citrus sinensis × Poncirus trifoliata) and Cleopatra mandarin (Citrus reshni). Results obtained showed that physiological responses, such as modulation of stomatal aperture and transpiration rate, aimed to reduce leaf temperature, are key to diminishing heat impact on photosynthetic apparatus and increasing tolerance to double and triple combinations of drought, high irradiance and high temperatures. By using transcriptomic and proteomic analyses, we have demonstrated that under these abiotic stress combinations, Carrizo plants were able to increase expression of genes and proteins related to the photosystem repairing machinery (which better maintained the integrity of PSII) and other components of the photosynthetic apparatus. Our findings reveal crucial physiological and genetic responses in citrus to increase tolerance to the combination of multiple abiotic stresses that could be the basis for breeding programs that ensure a sustainable citrus production.
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Affiliation(s)
- Damián Balfagón
- Departamento de Biología, Bioquímica y Ciencias NaturalesUniversitat Jaume ICastelló de la PlanaSpain
| | - Sara I. Zandalinas
- Departamento de Biología, Bioquímica y Ciencias NaturalesUniversitat Jaume ICastelló de la PlanaSpain
| | - Tadeu dos Reis de Oliveira
- Laboratório de Biologia Celular e Tecidual (LBCT)Centro de Biociências e Biotecnologia (CBB), Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF)Campos Dos GoytacazesBrazil
| | - Claudete Santa‐Catarina
- Laboratório de Biologia Celular e Tecidual (LBCT)Centro de Biociências e Biotecnologia (CBB), Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF)Campos Dos GoytacazesBrazil
| | - Aurelio Gómez‐Cadenas
- Departamento de Biología, Bioquímica y Ciencias NaturalesUniversitat Jaume ICastelló de la PlanaSpain
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17
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Loiacono FV, Walther D, Seeger S, Thiele W, Gerlach I, Karcher D, Schöttler MA, Zoschke R, Bock R. Emergence of Novel RNA-Editing Sites by Changes in the Binding Affinity of a Conserved PPR Protein. Mol Biol Evol 2022; 39:6760358. [PMID: 36227729 PMCID: PMC9750133 DOI: 10.1093/molbev/msac222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 09/23/2022] [Accepted: 10/07/2022] [Indexed: 01/07/2023] Open
Abstract
RNA editing converts cytidines to uridines in plant organellar transcripts. Editing typically restores codons for conserved amino acids. During evolution, specific C-to-U editing sites can be lost from some plant lineages by genomic C-to-T mutations. By contrast, the emergence of novel editing sites is less well documented. Editing sites are recognized by pentatricopeptide repeat (PPR) proteins with high specificity. RNA recognition by PPR proteins is partially predictable, but prediction is often inadequate for PPRs involved in RNA editing. Here we have characterized evolution and recognition of a recently gained editing site. We demonstrate that changes in the RNA recognition motifs that are not explainable with the current PPR code allow an ancient PPR protein, QED1, to uniquely target the ndhB-291 site in Brassicaceae. When expressed in tobacco, the Arabidopsis QED1 edits 33 high-confident off-target sites in chloroplasts and mitochondria causing a spectrum of mutant phenotypes. By manipulating the relative expression levels of QED1 and ndhB-291, we show that the target specificity of the PPR protein depends on the RNA:protein ratio. Finally, our data suggest that the low expression levels of PPR proteins are necessary to ensure the specificity of editing site selection and prevent deleterious off-target editing.
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Affiliation(s)
- F Vanessa Loiacono
- Department of Organelle Biology, Biotechnology and Molecular Ecophysiology, Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Dirk Walther
- Department of Organelle Biology, Biotechnology and Molecular Ecophysiology, Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Stefanie Seeger
- Department of Organelle Biology, Biotechnology and Molecular Ecophysiology, Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Wolfram Thiele
- Department of Organelle Biology, Biotechnology and Molecular Ecophysiology, Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Ines Gerlach
- Department of Organelle Biology, Biotechnology and Molecular Ecophysiology, Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Daniel Karcher
- Department of Organelle Biology, Biotechnology and Molecular Ecophysiology, Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Mark Aurel Schöttler
- Department of Organelle Biology, Biotechnology and Molecular Ecophysiology, Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Reimo Zoschke
- Department of Organelle Biology, Biotechnology and Molecular Ecophysiology, Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
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18
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Lempiäinen T, Rintamäki E, Aro E, Tikkanen M. Plants acclimate to Photosystem I photoinhibition by readjusting the photosynthetic machinery. PLANT, CELL & ENVIRONMENT 2022; 45:2954-2971. [PMID: 35916195 PMCID: PMC9546127 DOI: 10.1111/pce.14400] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 07/14/2022] [Accepted: 07/15/2022] [Indexed: 05/12/2023]
Abstract
Photosynthetic light reactions require strict regulation under dynamic environmental conditions. Still, depending on environmental constraints, photoinhibition of Photosystem (PSII) or PSI occurs frequently. Repair of photodamaged PSI, in sharp contrast to that of PSII, is extremely slow and leads to a functional imbalance between the photosystems. Slow PSI recovery prompted us to take advantage of the PSI-specific photoinhibition treatment and investigate whether the imbalance between functional PSII and PSI leads to acclimation of photosynthesis to PSI-limited conditions, either by short-term or long-term acclimation mechanisms as tested immediately after the photoinhibition treatment or after 24 h recovery in growth conditions, respectively. Short-term acclimation mechanisms were induced directly upon inhibition, including thylakoid protein phosphorylation that redirects excitation energy to PSI as well as changes in the feedback regulation of photosynthesis, which relaxed photosynthetic control and excitation energy quenching. Longer-term acclimation comprised reprogramming of the stromal redox system and an increase in ATP synthase and Cytochrome b6 f abundance. Acclimation to PSI-limited conditions restored the CO2 assimilation capacity of plants without major PSI repair. Response to PSI inhibition demonstrates that plants efficiently acclimate to changes occurring in the photosynthetic apparatus, which is likely a crucial component in plant acclimation to adverse environmental conditions.
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Affiliation(s)
- Tapio Lempiäinen
- Molecular Plant Biology, Department of Life TechnologiesUniversity of TurkuTurkuFinland
| | - Eevi Rintamäki
- Molecular Plant Biology, Department of Life TechnologiesUniversity of TurkuTurkuFinland
| | - Eva‐Mari Aro
- Molecular Plant Biology, Department of Life TechnologiesUniversity of TurkuTurkuFinland
| | - Mikko Tikkanen
- Molecular Plant Biology, Department of Life TechnologiesUniversity of TurkuTurkuFinland
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19
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Takeuchi K, Che Y, Nakano T, Miyake C, Ifuku K. The ability of P700 oxidation in photosystem I reflects chilling stress tolerance in cucumber. JOURNAL OF PLANT RESEARCH 2022; 135:681-692. [PMID: 35767130 DOI: 10.1007/s10265-022-01404-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Accepted: 06/08/2022] [Indexed: 06/15/2023]
Abstract
Low temperature inhibits photosynthesis and negatively affects plant growth. Cucumber (Cucumis sativus L.) is a chilling-sensitive plant, and its greenhouse production requires considerable energy during the winter. Therefore, a useful stress marker for selecting chilling-tolerant cucumber cultivars is desirable. In this study, we evaluated chilling-stress damage in different cucumber cultivars by measuring photosynthetic parameters. The majority of cultivars showed decreases in the quantum yield of photosystem (PS) II [Fv/Fm and Y(II)] and the quantity of active PS I (Pm) after chilling stress. In contrast, Y(ND)-the ratio of the oxidized state of PSI reaction center chlorophyll P700 (P700+)-differed among cultivars and was perfectly inversely correlated with Y(NA)-the ratio of the non-photooxidizable P700. It has been known that P700+ accumulates under stress conditions and protects plants to suppress the generation of reactive oxygen species. In fact, cultivars unable to induce Y(ND) after chilling stress showed growth retardation with reductions in chlorophyll content and leaf area. Therefore, Y(ND) can be a useful marker to evaluate chilling-stress tolerance in cucumber.
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Affiliation(s)
- Ko Takeuchi
- Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Yufen Che
- Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Takeshi Nakano
- Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Chikahiro Miyake
- Graduate School of Agriculture, Kobe University, Kobe, Hyogo, Japan
| | - Kentaro Ifuku
- Graduate School of Agriculture, Kyoto University, Kitashirakawa oiwake-cho, Sakyo-ku, Kyoto, 606-8502, Japan.
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20
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Perera-Castro AV, Waterman MJ, Robinson SA, Flexas J. Limitations to photosynthesis in bryophytes: certainties and uncertainties regarding methodology. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:4592-4604. [PMID: 35524766 DOI: 10.1093/jxb/erac189] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 05/05/2022] [Indexed: 06/14/2023]
Abstract
Bryophytes are the group of land plants with the lowest photosynthetic rates, which was considered to be a consequence of their higher anatomical CO2 diffusional limitation compared with tracheophytes. However, the most recent studies assessing limitations due to biochemistry and mesophyll conductance in bryophytes reveal discrepancies based on the methodology used. In this study, we compared data calculated from two different methodologies for estimating mesophyll conductance: variable J and the curve-fitting method. Although correlated, mesophyll conductance estimated by the curve-fitting method was on average 4-fold higher than the conductance obtained by the variable J method; a large enough difference to account for the scale of differences previously shown between the biochemical and diffusional limitations to photosynthesis. Biochemical limitations were predominant when the curve-fitting method was used. We also demonstrated that variations in bryophyte relative water content during measurements can also introduce errors in the estimation of mesophyll conductance, especially for samples which are overly desiccated. Furthermore, total chlorophyll concentration and soluble proteins were significantly lower in bryophytes than in tracheophytes, and the percentage of proteins quantified as Rubisco was also significantly lower in bryophytes (<6.3% in all studied species) than in angiosperms (>16% in all non-stressed cases). Photosynthetic rates normalized by Rubisco were not significantly different between bryophytes and angiosperms. Our data suggest that the biochemical limitation to photosynthesis in bryophytes is more relevant than so far assumed.
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Affiliation(s)
- Alicia V Perera-Castro
- Universitat de les Illes Balears, Department of Biology, INAGEA, Carretera de Valldemossa Km 7.5, 07122, Palma de Mallorca, Illes Balears, Spain
- Universidad de La Laguna, Department of Botany, Ecology and Plant Physiology, Av. Astrofísico Francisco Sánchez, S/N, 38200 La Laguna, Canary Islands, Spain
| | - Melinda J Waterman
- Centre for Sustainable Ecosystem Solutions, School of Earth, Atmosphere and Life Sciences, University of Wollongong, Wollongong, NSW, Australia
- Securing Antarctica's Environmental Future, University of Wollongong, Wollongong, NSW, Australia
| | - Sharon A Robinson
- Centre for Sustainable Ecosystem Solutions, School of Earth, Atmosphere and Life Sciences, University of Wollongong, Wollongong, NSW, Australia
- Securing Antarctica's Environmental Future, University of Wollongong, Wollongong, NSW, Australia
| | - Jaume Flexas
- Universitat de les Illes Balears, Department of Biology, INAGEA, Carretera de Valldemossa Km 7.5, 07122, Palma de Mallorca, Illes Balears, Spain
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21
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Regulation of the generation of reactive oxygen species during photosynthetic electron transport. Biochem Soc Trans 2022; 50:1025-1034. [PMID: 35437580 DOI: 10.1042/bst20211246] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 03/31/2022] [Accepted: 04/04/2022] [Indexed: 11/17/2022]
Abstract
Light capture by chlorophylls and photosynthetic electron transport bury the risk of the generation of reactive oxygen species (ROS) including singlet oxygen, superoxide anion radicals and hydrogen peroxide. Rapid changes in light intensity, electron fluxes and accumulation of strong oxidants and reductants increase ROS production. Superoxide is mainly generated at the level of photosystem I while photosystem II is the main source of singlet oxygen. ROS can induce oxidative damage of the photosynthetic apparatus, however, ROS are also important to tune processes inside the chloroplast and participate in retrograde signalling regulating the expression of genes involved in acclimation responses. Under most physiological conditions light harvesting and photosynthetic electron transport are regulated to keep the level of ROS at a non-destructive level. Photosystem II is most prone to photoinhibition but can be quickly repaired while photosystem I is protected in most cases. The size of the transmembrane proton gradient is central for the onset of mechanisms that protect against photoinhibition. The proton gradient allows dissipation of excess energy as heat in the antenna systems and it regulates electron transport. pH-dependent slowing down of electron donation to photosystem I protects it against ROS generation and damage. Cyclic electron transfer and photoreduction of oxygen contribute to the size of the proton gradient. The yield of singlet oxygen production in photosystem II is regulated by changes in the midpoint potential of its primary quinone acceptor. In addition, numerous antioxidants inside the photosystems, the antenna and the thylakoid membrane quench or scavenge ROS.
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22
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Oung HMO, Mukhopadhyay R, Svoboda V, Charuvi D, Reich Z, Kirchhoff H. Differential response of the photosynthetic machinery to dehydration in older and younger resurrection plants. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:1566-1580. [PMID: 34747457 DOI: 10.1093/jxb/erab485] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 11/03/2021] [Indexed: 06/13/2023]
Abstract
A group of vascular plants called homoiochlorophyllous resurrection plants evolved unique capabilities to protect their photosynthetic machinery against desiccation-induced damage. This study examined whether the ontogenetic status of the resurrection plant Craterostigma pumilum has an impact on how the plant responds to dehydration at the thylakoid membrane level to prepare cells for the desiccated state. Thus, younger plants (<4 months) were compared with their older (>6 months) counterparts. Ultrastructural analysis provided evidence that younger plants suppressed senescence-like programs that are realized in older plants. During dehydration, older plants degrade specific subunits of the photosynthetic apparatus such as the D1 subunit of PSII and subunits of the cytochrome b6f complex. The latter leads to a controlled down-regulation of linear electron transport. In contrast, younger plants increased photoprotective high-energy quenching mechanisms and maintained a high capability to replace damaged D1 subunits. It follows that depending on the ontogenetic state, either more degradation-based or more photoprotective mechanisms are employed during dehydration of Craterostigma pumilum.
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Affiliation(s)
- Hui Min Olivia Oung
- Institute of Biological Chemistry, Washington State University, Pullman, WA 99164, USA
| | - Roma Mukhopadhyay
- Institute of Biological Chemistry, Washington State University, Pullman, WA 99164, USA
| | - Vaclav Svoboda
- Institute of Biological Chemistry, Washington State University, Pullman, WA 99164, USA
| | - Dana Charuvi
- Institute of Plant Sciences, Agricultural Research Organization - Volcani Institute, Rishon LeZion 7505101, Israel
| | - Ziv Reich
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Helmut Kirchhoff
- Institute of Biological Chemistry, Washington State University, Pullman, WA 99164, USA
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Malinova I, Zupok A, Massouh A, Schöttler MA, Meyer EH, Yaneva-Roder L, Szymanski W, Rößner M, Ruf S, Bock R, Greiner S. Correction of frameshift mutations in the atpB gene by translational recoding in chloroplasts of Oenothera and tobacco. THE PLANT CELL 2021; 33:1682-1705. [PMID: 33561268 PMCID: PMC8254509 DOI: 10.1093/plcell/koab050] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 02/02/2021] [Indexed: 05/10/2023]
Abstract
Translational recoding, also known as ribosomal frameshifting, is a process that causes ribosome slippage along the messenger RNA, thereby changing the amino acid sequence of the synthesized protein. Whether the chloroplast employs recoding is unknown. I-iota, a plastome mutant of Oenothera (evening primrose), carries a single adenine insertion in an oligoA stretch [11A] of the atpB coding region (encoding the β-subunit of the ATP synthase). The mutation is expected to cause synthesis of a truncated, nonfunctional protein. We report that a full-length AtpB protein is detectable in I-iota leaves, suggesting operation of a recoding mechanism. To characterize the phenomenon, we generated transplastomic tobacco lines in which the atpB reading frame was altered by insertions or deletions in the oligoA motif. We observed that insertion of two adenines was more efficiently corrected than insertion of a single adenine, or deletion of one or two adenines. We further show that homopolymeric composition of the oligoA stretch is essential for recoding, as an additional replacement of AAA lysine codon by AAG resulted in an albino phenotype. Our work provides evidence for the operation of translational recoding in chloroplasts. Recoding enables correction of frameshift mutations and can restore photoautotrophic growth in the presence of a mutation that otherwise would be lethal.
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Affiliation(s)
- Irina Malinova
- Department Organelle Biology, Biotechnology and Molecular Ecophysiology, Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Arkadiusz Zupok
- Department Organelle Biology, Biotechnology and Molecular Ecophysiology, Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Amid Massouh
- Department Organelle Biology, Biotechnology and Molecular Ecophysiology, Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Mark Aurel Schöttler
- Department Organelle Biology, Biotechnology and Molecular Ecophysiology, Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Etienne H Meyer
- Department Organelle Biology, Biotechnology and Molecular Ecophysiology, Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Liliya Yaneva-Roder
- Department Organelle Biology, Biotechnology and Molecular Ecophysiology, Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Witold Szymanski
- Department Organelle Biology, Biotechnology and Molecular Ecophysiology, Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Margit Rößner
- Department Organelle Biology, Biotechnology and Molecular Ecophysiology, Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Stephanie Ruf
- Department Organelle Biology, Biotechnology and Molecular Ecophysiology, Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Ralph Bock
- Department Organelle Biology, Biotechnology and Molecular Ecophysiology, Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Stephan Greiner
- Department Organelle Biology, Biotechnology and Molecular Ecophysiology, Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
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Liu XY, Jiang RC, Wang Y, Tang JJ, Sun F, Yang YZ, Tan BC. ZmPPR26, a DYW-type pentatricopeptide repeat protein, is required for C-to-U RNA editing at atpA-1148 in maize chloroplasts. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:4809-4821. [PMID: 33929512 DOI: 10.1093/jxb/erab185] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 04/29/2021] [Indexed: 06/12/2023]
Abstract
Pentatricopeptide repeat (PPR) proteins are involved in the C-to-U RNA editing of organellar transcripts. The maize genome contains over 600 PPR proteins and few have been found to function in the C-to-U RNA editing in chloroplasts. Here, we report the function of ZmPPR26 in the C-to-U RNA editing and chloroplast biogenesis in maize. ZmPPR26 encodes a DYW-type PPR protein targeted to chloroplasts. The zmppr26 mutant exhibits albino seedling-lethal phenotype. Loss of function of ZmPPR26 abolishes the editing at atpA-1148 site, and decreases the editing at ndhF-62, rpl20-308, rpl2-2, rpoC2-2774, petB-668, rps8-182, and ndhA-50 sites. Overexpression of ZmPPR26 in zmppr26 restores the editing efficiency and rescues the albino seedling-lethal phenotype. Abolished editing at atpA-1148 causes a Leu to Ser change at AtpA-383 that leads to a reduction in the abundance of chloroplast ATP synthase in zmppr26. The accumulation of photosynthetic complexes are also markedly reduced in zmppr26, providing an explanation for the albino seedling-lethal phenotype. These results indicate that ZmPPR26 is required for the editing at atpA-1148 and is important for editing at the other seven sites in maize chloroplasts. The editing at atpA-1148 is critical for AtpA function, assembly of ATP synthase complex, and chloroplast biogenesis in maize.
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Affiliation(s)
- Xin-Yuan Liu
- Key Lab of Plant Development and Environment Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, China
| | - Rui-Cheng Jiang
- Key Lab of Plant Development and Environment Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, China
| | - Yong Wang
- Key Lab of Plant Development and Environment Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, China
| | - Jiao-Jiao Tang
- Key Lab of Plant Development and Environment Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, China
| | - Feng Sun
- Key Lab of Plant Development and Environment Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, China
| | - Yan-Zhuo Yang
- Key Lab of Plant Development and Environment Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, China
| | - Bao-Cai Tan
- Key Lab of Plant Development and Environment Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, China
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25
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Höhner R, Day PM, Zimmermann SE, Lopez LS, Krämer M, Giavalisco P, Correa Galvis V, Armbruster U, Schöttler MA, Jahns P, Krueger S, Kunz HH. Stromal NADH supplied by PHOSPHOGLYCERATE DEHYDROGENASE3 is crucial for photosynthetic performance. PLANT PHYSIOLOGY 2021; 186:142-167. [PMID: 33779763 PMCID: PMC8154072 DOI: 10.1093/plphys/kiaa117] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 12/17/2020] [Indexed: 05/22/2023]
Abstract
During photosynthesis, electrons travel from light-excited chlorophyll molecules along the electron transport chain to the final electron acceptor nicotinamide adenine dinucleotide phosphate (NADP) to form NADPH, which fuels the Calvin-Benson-Bassham cycle (CBBC). To allow photosynthetic reactions to occur flawlessly, a constant resupply of the acceptor NADP is mandatory. Several known stromal mechanisms aid in balancing the redox poise, but none of them utilizes the structurally highly similar coenzyme NAD(H). Using Arabidopsis (Arabidopsis thaliana) as a C3-model, we describe a pathway that employs the stromal enzyme PHOSPHOGLYCERATE DEHYDROGENASE 3 (PGDH3). We showed that PGDH3 exerts high NAD(H)-specificity and is active in photosynthesizing chloroplasts. PGDH3 withdrew its substrate 3-PGA directly from the CBBC. As a result, electrons become diverted from NADPH via the CBBC into the separate NADH redox pool. pgdh3 loss-of-function mutants revealed an overreduced NADP(H) redox pool but a more oxidized plastid NAD(H) pool compared to wild-type plants. As a result, photosystem I acceptor side limitation increased in pgdh3. Furthermore, pgdh3 plants displayed delayed CBBC activation, changes in nonphotochemical quenching, and altered proton motive force partitioning. Our fluctuating light-stress phenotyping data showed progressing photosystem II damage in pgdh3 mutants, emphasizing the significance of PGDH3 for plant performance under natural light environments. In summary, this study reveals an NAD(H)-specific mechanism in the stroma that aids in balancing the chloroplast redox poise. Consequently, the stromal NAD(H) pool may provide a promising target to manipulate plant photosynthesis.
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Affiliation(s)
- Ricarda Höhner
- School of Biological Sciences, Washington State University, Pullman, WA 99164-4236, USA
| | - Philip M Day
- School of Biological Sciences, Washington State University, Pullman, WA 99164-4236, USA
| | - Sandra E Zimmermann
- Biocenter University of Cologne, Institute for Plant Science, Cologne 50674, Germany
| | - Laura S Lopez
- School of Biological Sciences, Washington State University, Pullman, WA 99164-4236, USA
| | - Moritz Krämer
- School of Biological Sciences, Washington State University, Pullman, WA 99164-4236, USA
| | | | - Viviana Correa Galvis
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, Potsdam 14476, Germany
| | - Ute Armbruster
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, Potsdam 14476, Germany
| | - Mark Aurel Schöttler
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, Potsdam 14476, Germany
| | - Peter Jahns
- Plant Biochemistry, Heinrich-Heine-University Düsseldorf, Düsseldorf D-40225, Germany
| | - Stephan Krueger
- Biocenter University of Cologne, Institute for Plant Science, Cologne 50674, Germany
| | - Hans-Henning Kunz
- School of Biological Sciences, Washington State University, Pullman, WA 99164-4236, USA
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Claypool NB, Lieth JH. Green Light Improves Photosystem Stoichiometry in Cucumber Seedlings ( Cucumis sativus) Compared to Monochromatic Red Light. PLANTS (BASEL, SWITZERLAND) 2021; 10:plants10050824. [PMID: 33919086 PMCID: PMC8143185 DOI: 10.3390/plants10050824] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 04/14/2021] [Accepted: 04/18/2021] [Indexed: 06/12/2023]
Abstract
It has been shown that monochromatic red and blue light influence photosynthesis and morphology in cucumber. It is less clear how green light impacts photosynthetic performance or morphology, either alone or in concert with other wavelengths. In this study, cucumber (Cucumis sativus) was grown under monochromatic blue, green, and red light, dichromatic blue-green, red-blue, and red-green light, as well as light containing red, green, and blue wavelengths, with or without supplemental far-red light. Photosynthetic data collected under treatment spectra at light-limiting conditions showed that both red and green light enhance photosynthesis. However, photosynthetic data collected with a 90% red, 10% blue, 1000 µmol photons m-2 s-1, saturating light show significantly lower photosynthesis in the green, red, and red-green treatments, indicating a blue light enhancement due to photosystem stoichiometric differences. The red-green and green light treatments show improved photosynthetic capacity relative to red light, indicating partial remediation by green light. Despite a lower quantum efficiency and the lowest ambient photosynthesis levels, the monochromatic blue treatment produced among the tallest, most massive plants with the greatest leaf area and thickest stems.
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27
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Yavari N, Tripathi R, Wu BS, MacPherson S, Singh J, Lefsrud M. The effect of light quality on plant physiology, photosynthetic, and stress response in Arabidopsis thaliana leaves. PLoS One 2021; 16:e0247380. [PMID: 33661984 PMCID: PMC7932170 DOI: 10.1371/journal.pone.0247380] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 12/13/2020] [Indexed: 12/15/2022] Open
Abstract
The impacts of wavelengths in 500-600 nm on plant response and their underlying mechanisms remain elusive and required further investigation. Here, we investigated the effect of light quality on leaf area growth, biomass, pigments content, and net photosynthetic rate (Pn) across three Arabidopsis thaliana accessions, along with changes in transcription, photosynthates content, and antioxidative enzyme activity. Eleven-leaves plants were treated with BL; 450 nm, AL; 595 nm, RL; 650 nm, and FL; 400-700 nm as control. RL significantly increased leaf area growth, biomass, and promoted Pn. BL increased leaf area growth, carotenoid and anthocyanin content. AL significantly reduced leaf area growth and biomass, while Pn remained unaffected. Petiole elongation was further observed across accessions under AL. To explore the underlying mechanisms under AL, expression of key marker genes involved in light-responsive photosynthetic reaction, enzymatic activity of antioxidants, and content of photosynthates were monitored in Col-0 under AL, RL (as contrast), and FL (as control). AL induced transcription of GSH2 and PSBA, while downregulated NPQ1 and FNR2. Photosynthates, including proteins and starches, showed lower content under AL. SOD and APX showed enhanced enzymatic activity under AL. These results provide insight into physiological and photosynthetic responses to light quality, in addition to identifying putative protective-mechanisms that may be induced to cope with lighting-stress in order to enhance plant stress tolerance.
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Affiliation(s)
- Nafiseh Yavari
- Department of Bioresource Engineering, McGill University–Macdonald Campus, Sainte-Anne-de-Bellevue, Quebec, Canada
- * E-mail: (ML); (NY)
| | - Rajiv Tripathi
- Department of Plant Science, McGill University–Macdonald Campus, Sainte-Anne-de-Bellevue, Quebec, Canada
| | - Bo-Sen Wu
- Department of Bioresource Engineering, McGill University–Macdonald Campus, Sainte-Anne-de-Bellevue, Quebec, Canada
| | - Sarah MacPherson
- Department of Bioresource Engineering, McGill University–Macdonald Campus, Sainte-Anne-de-Bellevue, Quebec, Canada
| | - Jaswinder Singh
- Department of Plant Science, McGill University–Macdonald Campus, Sainte-Anne-de-Bellevue, Quebec, Canada
| | - Mark Lefsrud
- Department of Bioresource Engineering, McGill University–Macdonald Campus, Sainte-Anne-de-Bellevue, Quebec, Canada
- * E-mail: (ML); (NY)
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28
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New insights into the response of maize to fluctuations in the light environment. Mol Genet Genomics 2021; 296:615-629. [PMID: 33630129 DOI: 10.1007/s00438-021-01761-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 01/11/2021] [Indexed: 10/22/2022]
Abstract
Light is the most important environmental cue signaling the transition from skotomorphogenesis to photomorphogenesis, thus affecting plant development and metabolic activity. How the light response mechanisms of maize seedlings respond to fluctuations in the light environment has not been well characterized to date. In this study, we built a gene coexpression network from a dynamic transcriptomic map of maize seedlings exposed to different light environments. Coexpression analysis identified ten modules and multiple genes that closely correlate with photosynthesis and characterized hub genes associated with regulatory networks, duplication events, domestication and improvement. In addition, we identified that 38% of hub genes underwent duplication events, 74% of which are related to photosynthesis. Moreover, we captured the dynamic expression atlas of gene sets involved in the chloroplast photosynthetic apparatus and photosynthetic carbon assimilation in different light environments, which should help to elucidate the key mechanisms and regulatory networks that underlie photosynthesis in maize. Insights from this study provide a valuable resource to better understand the genetic mechanisms of the response to fluctuations in the light environment in maize.
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29
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Pipitone R, Eicke S, Pfister B, Glauser G, Falconet D, Uwizeye C, Pralon T, Zeeman SC, Kessler F, Demarsy E. A multifaceted analysis reveals two distinct phases of chloroplast biogenesis during de-etiolation in Arabidopsis. eLife 2021; 10:e62709. [PMID: 33629953 PMCID: PMC7906606 DOI: 10.7554/elife.62709] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 02/04/2021] [Indexed: 11/18/2022] Open
Abstract
Light triggers chloroplast differentiation whereby the etioplast transforms into a photosynthesizing chloroplast and the thylakoid rapidly emerges. However, the sequence of events during chloroplast differentiation remains poorly understood. Using Serial Block Face Scanning Electron Microscopy (SBF-SEM), we generated a series of chloroplast 3D reconstructions during differentiation, revealing chloroplast number and volume and the extent of envelope and thylakoid membrane surfaces. Furthermore, we used quantitative lipid and whole proteome data to complement the (ultra)structural data, providing a time-resolved, multi-dimensional description of chloroplast differentiation. This showed two distinct phases of chloroplast biogenesis: an initial photosynthesis-enabling 'Structure Establishment Phase' followed by a 'Chloroplast Proliferation Phase' during cell expansion. Moreover, these data detail thylakoid membrane expansion during de-etiolation at the seedling level and the relative contribution and differential regulation of proteins and lipids at each developmental stage. Altogether, we establish a roadmap for chloroplast differentiation, a critical process for plant photoautotrophic growth and survival.
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Affiliation(s)
- Rosa Pipitone
- Plant Physiology Laboratory, University of NeuchâtelNeuchâtelSwitzerland
| | - Simona Eicke
- Institute of Molecular Plant Biology, Department of Biology, ETH ZurichZurichSwitzerland
| | - Barbara Pfister
- Institute of Molecular Plant Biology, Department of Biology, ETH ZurichZurichSwitzerland
| | - Gaetan Glauser
- Neuchâtel Platform of Analytical Chemistry, University of NeuchâtelNeuchâtelSwitzerland
| | - Denis Falconet
- Université Grenoble Alpes, CNRS, CEA, INRAE, IRIG-DBSCI-LPCVGrenobleFrance
| | - Clarisse Uwizeye
- Université Grenoble Alpes, CNRS, CEA, INRAE, IRIG-DBSCI-LPCVGrenobleFrance
| | - Thibaut Pralon
- Plant Physiology Laboratory, University of NeuchâtelNeuchâtelSwitzerland
| | - Samuel C Zeeman
- Institute of Molecular Plant Biology, Department of Biology, ETH ZurichZurichSwitzerland
| | - Felix Kessler
- Plant Physiology Laboratory, University of NeuchâtelNeuchâtelSwitzerland
| | - Emilie Demarsy
- Plant Physiology Laboratory, University of NeuchâtelNeuchâtelSwitzerland
- Department of Botany and Plant Biology, University of GenevaGenevaSwitzerland
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30
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Sarewicz M, Pintscher S, Pietras R, Borek A, Bujnowicz Ł, Hanke G, Cramer WA, Finazzi G, Osyczka A. Catalytic Reactions and Energy Conservation in the Cytochrome bc1 and b6f Complexes of Energy-Transducing Membranes. Chem Rev 2021; 121:2020-2108. [PMID: 33464892 PMCID: PMC7908018 DOI: 10.1021/acs.chemrev.0c00712] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Indexed: 12/16/2022]
Abstract
This review focuses on key components of respiratory and photosynthetic energy-transduction systems: the cytochrome bc1 and b6f (Cytbc1/b6f) membranous multisubunit homodimeric complexes. These remarkable molecular machines catalyze electron transfer from membranous quinones to water-soluble electron carriers (such as cytochromes c or plastocyanin), coupling electron flow to proton translocation across the energy-transducing membrane and contributing to the generation of a transmembrane electrochemical potential gradient, which powers cellular metabolism in the majority of living organisms. Cytsbc1/b6f share many similarities but also have significant differences. While decades of research have provided extensive knowledge on these enzymes, several important aspects of their molecular mechanisms remain to be elucidated. We summarize a broad range of structural, mechanistic, and physiological aspects required for function of Cytbc1/b6f, combining textbook fundamentals with new intriguing concepts that have emerged from more recent studies. The discussion covers but is not limited to (i) mechanisms of energy-conserving bifurcation of electron pathway and energy-wasting superoxide generation at the quinol oxidation site, (ii) the mechanism by which semiquinone is stabilized at the quinone reduction site, (iii) interactions with substrates and specific inhibitors, (iv) intermonomer electron transfer and the role of a dimeric complex, and (v) higher levels of organization and regulation that involve Cytsbc1/b6f. In addressing these topics, we point out existing uncertainties and controversies, which, as suggested, will drive further research in this field.
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Affiliation(s)
- Marcin Sarewicz
- Department
of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Sebastian Pintscher
- Department
of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Rafał Pietras
- Department
of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Arkadiusz Borek
- Department
of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Łukasz Bujnowicz
- Department
of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Guy Hanke
- School
of Biological and Chemical Sciences, Queen
Mary University of London, London E1 4NS, U.K.
| | - William A. Cramer
- Department
of Biological Sciences, Purdue University, West Lafayette, Indiana 47907 United States
| | - Giovanni Finazzi
- Laboratoire
de Physiologie Cellulaire et Végétale, Université Grenoble Alpes, Centre National Recherche Scientifique,
Commissariat Energie Atomique et Energies Alternatives, Institut National
Recherche l’agriculture, l’alimentation et l’environnement, 38054 Grenoble Cedex 9, France
| | - Artur Osyczka
- Department
of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
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Mu X, Chen Y. The physiological response of photosynthesis to nitrogen deficiency. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2021; 158:76-82. [PMID: 33296848 DOI: 10.1016/j.plaphy.2020.11.019] [Citation(s) in RCA: 95] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 11/15/2020] [Indexed: 05/19/2023]
Abstract
Nitrogen (N), as a macro-element, plays a vital role in plant growth and development. N deficiency affects plant productivity by decreasing photosynthesis, leaf area and longevity of green leaf. To date, many studies have reported that the relationship between photosynthesis and N supply. Here, we summarized the physiological response of photosynthesis to N deficiency in leaf structure and N allocation within the leaf. In serious N stress, photosynthetic rate decreases for almost all plants. The reasons as follows:(1) reducing stomatal conductance of mesophyll cell (gs) and bundle sheath cells (gbs) which influences intercellular CO2 concentration; (2) reducing the content of bioenergetics and light-harvesting protein which inhibits electron transport rate and increase the light energy dissipated as heat; (3) reducing the content and/or activity of photosynthetic enzymes which reduces carboxylation rate. During reproductive stage, N stress induces plant senescence and N components degradation, especially photosynthetic enzymes and thylakoid N, and thus reduces photosynthesis. To keep high grain yield in low N deficiency, we should choose the genotype with higher N allocation within bioenergetics and lower degradation of photosynthetic enzymes. This review provides a generalized N allocation in response to N stress and gives a new prospect for breeding N-efficient genotypes.
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Affiliation(s)
- Xiaohuan Mu
- College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, PR China.
| | - Yanling Chen
- College of Resources and Environment, Qingdao Agricultural University, Qingdao, Shandong, 266109, PR China.
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32
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Shimakawa G, Roach T, Krieger-Liszkay A. Changes in Photosynthetic Electron Transport during Leaf Senescence in Two Barley Varieties Grown in Contrasting Growth Regimes. PLANT & CELL PHYSIOLOGY 2020; 61:1986-1994. [PMID: 32886785 DOI: 10.1093/pcp/pcaa114] [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: 02/24/2020] [Accepted: 08/26/2020] [Indexed: 06/11/2023]
Abstract
Leaf senescence is an important process for plants to remobilize a variety of metabolites and nutrients to sink tissues, such as developing leaves, fruits and seeds. It has been suggested that reactive oxygen species (ROS) play an important role in the initiation of leaf senescence. Flag leaves of two different barley varieties, cv. Lomerit and cv. Carina, showed differences in the loss of photosystems and in the production of ROS at a late stage of senescence after significant loss of chlorophyll (Krieger-Liszkay et al. 2015). Here, we investigated photosynthetic electron transport and ROS production in primary leaves of these two varieties at earlier stages of senescence. Comparisons were made between plants grown outside in natural light and temperatures and plants grown in temperature-controlled growth chambers under low light intensity. Alterations in the content of photoactive P700, ferredoxin and plastocyanin (PC) photosynthetic electron transport were analyzed using in vivo near-infrared absorbance changes and chlorophyll fluorescence, while ROS were measured with spin-trapping electron paramagnetic resonance spectroscopy. Differences in ROS production between the two varieties were only observed in outdoor plants, whereas a loss of PC was common in both barley varieties regardless of growth conditions. We conclude that the loss of PC is the earliest detectable photosynthetic parameter of leaf senescence while differences in the production of individual ROS species occur later and depend on environmental factors.
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Affiliation(s)
- Ginga Shimakawa
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
| | - Thomas Roach
- Institut für Botanik, Leopold-Franzens-Universität-Innsbruck, Innsbruck, Austria
| | - Anja Krieger-Liszkay
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
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33
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Comparative Transcriptome Analysis of Iron and Zinc Deficiency in Maize ( Zea mays L.). PLANTS 2020; 9:plants9121812. [PMID: 33371388 PMCID: PMC7767415 DOI: 10.3390/plants9121812] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 11/30/2020] [Accepted: 11/30/2020] [Indexed: 11/17/2022]
Abstract
Globally, one-third of the population is affected by iron (Fe) and zinc (Zn) deficiency, which is severe in developing and underdeveloped countries where cereal-based diets predominate. The genetic biofortification approach is the most sustainable and one of the cost-effective ways to address Fe and Zn malnutrition. Maize is a major source of nutrition in sub-Saharan Africa, South Asia and Latin America. Understanding systems’ biology and the identification of genes involved in Fe and Zn homeostasis facilitate the development of Fe- and Zn-enriched maize. We conducted a genome-wide transcriptome assay in maize inbred SKV616, under –Zn, –Fe and –Fe–Zn stresses. The results revealed the differential expression of several genes related to the mugineic acid pathway, metal transporters, photosynthesis, phytohormone and carbohydrate metabolism. We report here Fe and Zn deficiency-mediated changes in the transcriptome, root length, stomatal conductance, transpiration rate and reduced rate of photosynthesis. Furthermore, the presence of multiple regulatory elements and/or the co-factor nature of Fe and Zn in enzymes indicate their association with the differential expression and opposite regulation of several key gene(s). The differentially expressed candidate genes in the present investigation would help in breeding for Fe and Zn efficient and kernel Fe- and Zn-rich maize cultivars through gene editing, transgenics and molecular breeding.
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34
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Moreno JC, Mi J, Agrawal S, Kössler S, Turečková V, Tarkowská D, Thiele W, Al-Babili S, Bock R, Schöttler MA. Expression of a carotenogenic gene allows faster biomass production by redesigning plant architecture and improving photosynthetic efficiency in tobacco. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 103:1967-1984. [PMID: 32623777 DOI: 10.1111/tpj.14909] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 06/23/2020] [Indexed: 05/11/2023]
Abstract
Because carotenoids act as accessory pigments in photosynthesis, play a key photoprotective role and are of major nutritional importance, carotenogenesis has been a target for crop improvement. Although carotenoids are important precursors of phytohormones, previous genetic manipulations reported little if any effects on biomass production and plant development, but resulted in specific modifications in carotenoid content. Unexpectedly, the expression of the carrot lycopene β-cyclase (DcLCYB1) in Nicotiana tabacum cv. Xanthi not only resulted in increased carotenoid accumulation, but also in altered plant architecture characterized by longer internodes, faster plant growth, early flowering and increased biomass. Here, we have challenged these transformants with a range of growth conditions to determine the robustness of their phenotype and analyze the underlying mechanisms. Transgenic DcLCYB1 lines showed increased transcript levels of key genes involved in carotenoid, chlorophyll, gibberellin (GA) and abscisic acid (ABA) biosynthesis, but also in photosynthesis-related genes. Accordingly, their carotenoid, chlorophyll, ABA and GA contents were increased. Hormone application and inhibitor experiments confirmed the key role of altered GA/ABA contents in the growth phenotype. Because the longer internodes reduce shading of mature leaves, induction of leaf senescence was delayed, and mature leaves maintained a high photosynthetic capacity. This increased total plant assimilation, as reflected in higher plant yields under both fully controlled constant and fluctuating light, and in non-controlled conditions. Furthermore, our data are a warning that engineering of isoprenoid metabolism can cause complex changes in phytohormone homeostasis and therefore plant development, which have not been sufficiently considered in previous studies.
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Affiliation(s)
- Juan C Moreno
- Max Planck Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, Potsdam-Golm, 14476, Germany
| | - Jianing Mi
- King Abdullah University of Science and Technology, Thuwal, 23955-6900, Kingdom of Saudi Arabia
| | - Shreya Agrawal
- Max Planck Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, Potsdam-Golm, 14476, Germany
| | - Stella Kössler
- Max Planck Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, Potsdam-Golm, 14476, Germany
| | - Veronika Turečková
- Laboratory of Growth Regulators, The Czech Academy of Sciences, Institute of Experimental Botany & Palacký University, Šlechtitelů 27, Olomouc, CZ-78371, Czech Republic
| | - Danuše Tarkowská
- Laboratory of Growth Regulators, The Czech Academy of Sciences, Institute of Experimental Botany & Palacký University, Šlechtitelů 27, Olomouc, CZ-78371, Czech Republic
| | - Wolfram Thiele
- Max Planck Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, Potsdam-Golm, 14476, Germany
| | - Salim Al-Babili
- King Abdullah University of Science and Technology, Thuwal, 23955-6900, Kingdom of Saudi Arabia
| | - Ralph Bock
- Max Planck Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, Potsdam-Golm, 14476, Germany
| | - Mark Aurel Schöttler
- Max Planck Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, Potsdam-Golm, 14476, Germany
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Li LF, Cushman SA, He YX, Li Y. Genome sequencing and population genomics modeling provide insights into the local adaptation of weeping forsythia. HORTICULTURE RESEARCH 2020; 7:130. [PMID: 32821413 PMCID: PMC7395120 DOI: 10.1038/s41438-020-00352-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 05/24/2020] [Accepted: 05/24/2020] [Indexed: 05/06/2023]
Abstract
Understanding the genetic basis underlying the local adaptation of nonmodel species is a fundamental goal in evolutionary biology. In this study, we explored the genetic mechanisms of the local adaptation of Forsythia suspensa using genome sequence and population genomics data obtained from specific-locus amplified fragment sequencing. We assembled a high-quality reference genome of weeping forsythia (Scaffold N50 = 7.3 Mb) using ultralong Nanopore reads. Then, genome-wide comparative analysis was performed for 15 natural populations of weeping forsythia across its current distribution range. Our results revealed that candidate genes associated with local adaptation are functionally correlated with solar radiation, temperature and water variables across heterogeneous environmental scenarios. In particular, solar radiation during the period of fruit development and seed drying after ripening, cold, and drought significantly contributed to the adaptive differentiation of F. suspensa. Natural selection exerted by environmental factors contributed substantially to the population genetic structure of F. suspensa. Our results supported the hypothesis that adaptive differentiation should be highly pronounced in the genes involved in signal crosstalk between different environmental variables. Our population genomics study of F. suspensa provides insights into the fundamental genetic mechanisms of the local adaptation of plant species to climatic gradients.
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Affiliation(s)
- Lin-Feng Li
- Innovation Platform of Molecular Biology, College of Forestry, Henan Agricultural University, Zhengzhou, China
- Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, School of Life Sciences, Fudan University, Shanghai, 200438 China
| | - Samuel A. Cushman
- U.S. Forest Service, Rocky Mountain Research Station, 2500 S. Pine Knoll Dr., Flagstaff, Arizona USA
| | - Yan-Xia He
- School of Life Sciences, Henan University, Kaifeng, China
| | - Yong Li
- Innovation Platform of Molecular Biology, College of Forestry, Henan Agricultural University, Zhengzhou, China
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36
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Bielczynski LW, Schansker G, Croce R. Consequences of the reduction of the Photosystem II antenna size on the light acclimation capacity of Arabidopsis thaliana. PLANT, CELL & ENVIRONMENT 2020; 43:866-879. [PMID: 31834625 PMCID: PMC7154682 DOI: 10.1111/pce.13701] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Revised: 11/04/2019] [Accepted: 12/09/2019] [Indexed: 05/24/2023]
Abstract
In several systems, from plant's canopy to algal bioreactors, the decrease of the antenna size has been proposed as a strategy to increase the photosynthetic efficiency. However, still little is known about possible secondary effects of such modifications. This is particularly relevant because the modulation of the antenna size is one of the most important light acclimation responses in photosynthetic organisms. In our study, we used an Arabidopsis thaliana mutant (dLhcb2), which has a 60% decrease of Lhcb1 and Lhcb2, the two main components of the major Photosystem II antenna complex. We show that the mutant maintains the photosynthetic and photoprotective capacity of the Wild Type (WT) and adapts to different light conditions by remodelling its photosynthetic apparatus, but the regulatory mechanism differs from that of the WT. Surprisingly, it does not compensate for the decreased light-harvesting capacity by increasing other pigment-protein complexes. Instead, it lowers the ratio of the cytochrome b6 f and ATP synthase to the photosystems, regulating linear electron flow and maintaining the photosynthetic control at the level of these complexes as in the WT. We show that targeting the reduction of two specific antenna proteins, Lhcb1 and Lhcb2, represents a viable solution to obtain plants with a truncated antenna size, which still maintain the capacity to acclimate to different light conditions.
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Affiliation(s)
- Ludwik W. Bielczynski
- Biophysics of Photosynthesis/Energy, Faculty of Sciences, Department of Physics and AstronomyVU University AmsterdamAmsterdamThe Netherlands
| | - Gert Schansker
- Biophysics of Photosynthesis/Energy, Faculty of Sciences, Department of Physics and AstronomyVU University AmsterdamAmsterdamThe Netherlands
| | - Roberta Croce
- Biophysics of Photosynthesis/Energy, Faculty of Sciences, Department of Physics and AstronomyVU University AmsterdamAmsterdamThe Netherlands
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37
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Vanlerberghe GC, Dahal K, Chadee A. Does the stromal concentration of P i control chloroplast ATP synthase protein amount in contrasting growth environments? PLANT SIGNALING & BEHAVIOR 2019; 14:1675473. [PMID: 31583956 PMCID: PMC6866698 DOI: 10.1080/15592324.2019.1675473] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 09/25/2019] [Accepted: 09/27/2019] [Indexed: 05/16/2023]
Abstract
Changes in the growth environment can generate imbalances in chloroplast photosynthetic metabolism. Under water deficit, stomatal closure limits CO2 availability such that the production of ATP and NADPH by the thylakoid membrane-localized electron transport chain may not match the consumption of these energy intermediates by the stroma-localized Calvin-Benson cycle, thus challenging energy balance. Alternatively, in an elevated CO2 atmosphere, carbon fixation by the Calvin-Benson cycle may outpace the activity of downstream carbohydrate-utilizing processes, thus challenging carbon balance. Our previous studies have shown that, in both of the above scenarios, a mitochondrial alternative oxidase contributes to maintaining energy or carbon balance, highlighting the importance of photosynthesis-respiration interactions in optimizing photosynthesis in different growth environments. In these previous studies, we observed aberrant amounts of chloroplast ATP synthase protein across the different transgenic plant lines and growth conditions, compared to wild-type. Based on these observations, we develop here the hypothesis that an important determinant of chloroplast ATP synthase protein amount is the stromal concentration of inorganic phosphate. ATP synthase is a master regulator of photosynthesis. Coarse control of ATP synthase protein amount by the stromal inorganic phosphate status could provide a means to coordinate the electron transport and carbon fixation reactions of photosynthesis.
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Affiliation(s)
- Greg C. Vanlerberghe
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, Toronto, ON, Canada
| | - Keshav Dahal
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, Toronto, ON, Canada
| | - Avesh Chadee
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, Toronto, ON, Canada
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38
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Ermakova M, Lopez-Calcagno PE, Raines CA, Furbank RT, von Caemmerer S. Overexpression of the Rieske FeS protein of the Cytochrome b6f complex increases C 4 photosynthesis in Setaria viridis. Commun Biol 2019; 2:314. [PMID: 31453378 PMCID: PMC6697696 DOI: 10.1038/s42003-019-0561-9] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 07/29/2019] [Indexed: 11/25/2022] Open
Abstract
C4 photosynthesis is characterised by a CO2 concentrating mechanism that operates between mesophyll and bundle sheath cells increasing CO2 partial pressure at the site of Rubisco and photosynthetic efficiency. Electron transport chains in both cell types supply ATP and NADPH for C4 photosynthesis. Cytochrome b6f is a key control point of electron transport in C3 plants. To study whether C4 photosynthesis is limited by electron transport we constitutively overexpressed the Rieske FeS subunit in Setaria viridis. This resulted in a higher Cytochrome b6f content in mesophyll and bundle sheath cells without marked changes in the abundances of other photosynthetic proteins. Rieske overexpression plants showed better light conversion efficiency in both Photosystems and could generate higher proton-motive force across the thylakoid membrane underpinning an increase in CO2 assimilation rate at ambient and saturating CO2 and high light. Our results demonstrate that removing electron transport limitations can increase C4 photosynthesis.
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Affiliation(s)
- Maria Ermakova
- Australian Research Council Centre of Excellence for Translational Photosynthesis, Division of Plant Science, Research School of Biology, The Australian National University, Acton, Australian Capital Territory 2601 Australia
| | | | - Christine A. Raines
- School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ UK
| | - Robert T. Furbank
- Australian Research Council Centre of Excellence for Translational Photosynthesis, Division of Plant Science, Research School of Biology, The Australian National University, Acton, Australian Capital Territory 2601 Australia
| | - Susanne von Caemmerer
- Australian Research Council Centre of Excellence for Translational Photosynthesis, Division of Plant Science, Research School of Biology, The Australian National University, Acton, Australian Capital Territory 2601 Australia
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39
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Majeran W, Wostrikoff K, Wollman FA, Vallon O. Role of ClpP in the Biogenesis and Degradation of RuBisCO and ATP Synthase in Chlamydomonas reinhardtii. PLANTS (BASEL, SWITZERLAND) 2019; 8:E191. [PMID: 31248038 PMCID: PMC6681370 DOI: 10.3390/plants8070191] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 06/17/2019] [Accepted: 06/19/2019] [Indexed: 01/17/2023]
Abstract
Ribulose 1,5-bisphosphate carboxylase/oxygenase (RuBisCO) associates a chloroplast- and a nucleus-encoded subunit (LSU and SSU). It constitutes the major entry point of inorganic carbon into the biosphere as it catalyzes photosynthetic CO2 fixation. Its abundance and richness in sulfur-containing amino acids make it a prime source of N and S during nutrient starvation, when photosynthesis is downregulated and a high RuBisCO level is no longer needed. Here we show that translational attenuation of ClpP1 in the green alga Chlamydomonas reinhardtii results in retarded degradation of RuBisCO during S- and N-starvation, suggesting that the Clp protease is a major effector of RubisCO degradation in these conditions. Furthermore, we show that ClpP cannot be attenuated in the context of rbcL point mutations that prevent LSU folding. The mutant LSU remains in interaction with the chloroplast chaperonin complex. We propose that degradation of the mutant LSU by the Clp protease is necessary to prevent poisoning of the chaperonin. In the total absence of LSU, attenuation of ClpP leads to a dramatic stabilization of unassembled SSU, indicating that Clp is responsible for its degradation. In contrast, attenuation of ClpP in the absence of SSU does not lead to overaccumulation of LSU, whose translation is controlled by assembly. Altogether, these results point to RuBisCO degradation as one of the major house-keeping functions of the essential Clp protease. In addition, we show that non-assembled subunits of the ATP synthase are also stabilized when ClpP is attenuated. In the case of the atpA-FUD16 mutation, this can even allow the assembly of a small amount of CF1, which partially restores phototrophy.
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Affiliation(s)
- Wojciech Majeran
- Institute of Plant Sciences Paris-Saclay (IPS2), CNRS, Université Paris-Diderot, Université Paris-Sud, INRA, Université Evry, Université Paris-Saclay, Rue de Noetzlin, 91190 Gif-sur-Yvette, France.
| | - Katia Wostrikoff
- UMR7141 CNRS/Sorbonne Université, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France.
| | - Francis-André Wollman
- UMR7141 CNRS/Sorbonne Université, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France.
| | - Olivier Vallon
- UMR7141 CNRS/Sorbonne Université, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France.
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40
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Cui J, Xia W, Wei S, Zhang M, Wang W, Zeng D, Liu M, Sun Y, Lu W. Photosynthetic Performance of Rice Seedlings Originated from Seeds Exposed to Spaceflight Conditions. Photochem Photobiol 2019; 95:1205-1212. [PMID: 30864196 DOI: 10.1111/php.13097] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 03/05/2019] [Indexed: 12/17/2022]
Abstract
The mechanism of the regulation on photosynthesis after spaceflight has not been fully understood. To learn more information about this, we conducted a series of experiments of photosystem, including photosynthetic physiological characteristics (fluorescence parameters, pigment contents), gene expression and proteomic change. We want to examine the response of rice (Oryza sativaDN416), whose seeds were placed in Bio-Radiation Box on the ShiJian-10(SJ-10) recoverable satellite. Our results demonstrated that the photosynthesis capacity of plants after spaceflight declined, compared to ground control plants. Specifically, Fv/Fm is significantly reduced for 7.5%. Chlorophyll content decreased in the three growth stages of rice, trefoil, tillering and mature stages. To further analyze changes under spaceflight environment, quantitative real-time PCR technology and isobaric tags for relative and absolute quantization (iTRAQ) labeling technology were deployed. We found that the gene expression of important subunits of key enzymes and important structures had been decreased after spaceflight. As for the results of changes in proteins, we discovered that the content of proteins related to electron transport and photosynthesis key enzyme declined. Our experiments can provide reference for further research to learn more about the effects of spaceflight on photosynthesis.
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Affiliation(s)
- Jie Cui
- Department of Food Science and Engineering, Harbin Institute of Technology, Harbin, China
| | - Wenyan Xia
- Department of Food Science and Engineering, Harbin Institute of Technology, Harbin, China.,Institute of Extreme Environment Nutrition and Protection, Harbin Institute of Technology, Harbin, China.,National and Local Joint Engineering Laboratory for Synthesis, Transformation and Separation of Extreme Environmental Nutrients, Harbin Institute of Technology, Harbin, China
| | - Shiyun Wei
- Department of Food Science and Engineering, Harbin Institute of Technology, Harbin, China.,Institute of Extreme Environment Nutrition and Protection, Harbin Institute of Technology, Harbin, China.,National and Local Joint Engineering Laboratory for Synthesis, Transformation and Separation of Extreme Environmental Nutrients, Harbin Institute of Technology, Harbin, China
| | - Meng Zhang
- Institute of Environmental Systems Biology, College of Environmental Science and Engineering, Dalian Maritime University, Dalian, China
| | - Wei Wang
- Institute of Environmental Systems Biology, College of Environmental Science and Engineering, Dalian Maritime University, Dalian, China
| | - Deyong Zeng
- Department of Food Science and Engineering, Harbin Institute of Technology, Harbin, China.,Institute of Extreme Environment Nutrition and Protection, Harbin Institute of Technology, Harbin, China.,National and Local Joint Engineering Laboratory for Synthesis, Transformation and Separation of Extreme Environmental Nutrients, Harbin Institute of Technology, Harbin, China
| | - Mengyao Liu
- Department of Food Science and Engineering, Harbin Institute of Technology, Harbin, China.,Institute of Extreme Environment Nutrition and Protection, Harbin Institute of Technology, Harbin, China.,National and Local Joint Engineering Laboratory for Synthesis, Transformation and Separation of Extreme Environmental Nutrients, Harbin Institute of Technology, Harbin, China
| | - Yeqing Sun
- Institute of Environmental Systems Biology, College of Environmental Science and Engineering, Dalian Maritime University, Dalian, China
| | - Weihong Lu
- Department of Food Science and Engineering, Harbin Institute of Technology, Harbin, China.,Institute of Extreme Environment Nutrition and Protection, Harbin Institute of Technology, Harbin, China.,National and Local Joint Engineering Laboratory for Synthesis, Transformation and Separation of Extreme Environmental Nutrients, Harbin Institute of Technology, Harbin, China
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41
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Shimakawa G, Murakami A, Niwa K, Matsuda Y, Wada A, Miyake C. Comparative analysis of strategies to prepare electron sinks in aquatic photoautotrophs. PHOTOSYNTHESIS RESEARCH 2019; 139:401-411. [PMID: 29845382 DOI: 10.1007/s11120-018-0522-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Accepted: 05/18/2018] [Indexed: 05/24/2023]
Abstract
While subject to illumination, photosystem I (PSI) has the potential to produce reactive oxygen species (ROS) that can cause photo-oxidative damage in oxygenic photoautotrophs. The reaction center chlorophyll in PSI (P700) is kept oxidized in excess light conditions to limit over-excitation of PSI and alleviate the production of ROS. Oxidation of P700 requires a sufficient electron sink for PSI, which is responsible for flavodiiron proteins (FLV) safely dissipating electrons to O2 in cyanobacteria, green algae, and land plants except for angiosperms during short-pulse light (SP) illumination under which photosynthesis and photorespiration do not occur. This fact implies that O2 usage is essential for P700 oxidation but also raises the question why angiosperms lost FLV. Here, we first found that aquatic photoautotrophs in red plastid lineage, in which no gene for FLV has been found, could keep P700 oxidized during SP illumination alleviating the photo-oxidative damage in PSI even without O2 usage. We comprehensively assessed P700 oxidation during SP illumination in the presence and absence of O2 in cyanobacteria (Cyanophyta), green algae (Chlorophyta), angiosperms (Streptophyta), red algae (Rhodophyta), and secondary algae (Cryptophyta, Haptophyta, and Heterokontophyta). A variety of dependencies of P700 oxidation on O2 among these photoautotrophs clearly suggest that O2 usage and FLV are not universally required to oxidize P700 for protecting PSI against ROS damage. Our results expand the understanding of the diverse strategies taken by oxygenic photoautotrophs to oxidize P700 and mitigate the risks of ROS.
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Affiliation(s)
- Ginga Shimakawa
- Department of Biological and Environmental Science, Faculty of Agriculture, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe, Hyogo, 657-8501, Japan
| | - Akio Murakami
- Kobe University Research Center for Inland Seas, 2746 Iwaya, Awaji, Hyogo, 656-2401, Japan
| | - Kyosuke Niwa
- Fisheries Technology Institute, Hyogo Prefectural Technology Center for Agriculture, Forestry and Fisheries, Akashi, Hyogo, 674-0093, Japan
- Department of Marine Biosciences, Faculty of Marine Life Science, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato, Tokyo, 108-8477, Japan
| | - Yusuke Matsuda
- Research Center for the Development of Intelligent Self-Organized Biomaterials, Research Center for Environmental Bioscience, Department of Bioscience, Kwansei-Gakuin University, 2-1 Gakuen, Sanda, Hyogo, 669-1337, Japan
| | - Ayumi Wada
- Department of Biological and Environmental Science, Faculty of Agriculture, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe, Hyogo, 657-8501, Japan
| | - Chikahiro Miyake
- Department of Biological and Environmental Science, Faculty of Agriculture, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe, Hyogo, 657-8501, Japan.
- Core Research for Environmental Science and Technology, Japan Science and Technology Agency, 7 Goban, Chiyoda, Tokyo, 102-0076, Japan.
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42
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Simkin AJ, López-Calcagno PE, Raines CA. Feeding the world: improving photosynthetic efficiency for sustainable crop production. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:1119-1140. [PMID: 30772919 PMCID: PMC6395887 DOI: 10.1093/jxb/ery445] [Citation(s) in RCA: 207] [Impact Index Per Article: 41.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 11/27/2018] [Indexed: 05/18/2023]
Abstract
A number of recent studies have provided strong support demonstrating that improving the photosynthetic processes through genetic engineering can provide an avenue to improve yield potential. The major focus of this review is on improvement of the Calvin-Benson cycle and electron transport. Consideration is also given to how altering regulatory process may provide an additional route to increase photosynthetic efficiency. Here we summarize some of the recent successes that have been observed through genetic manipulation of photosynthesis, showing that, in both the glasshouse and the field, yield can be increased by >40%. These results provide a clear demonstration of the potential for increasing yield through improvements in photosynthesis. In the final section, we consider the need to stack improvement in photosynthetic traits with traits that target the yield gap in order to provide robust germplasm for different crops across the globe.
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Affiliation(s)
- Andrew J Simkin
- NIAB EMR, New Road, East Malling, Kent, UK
- School of Biological Sciences, Wivenhoe Park, University of Essex, Colchester, UK
| | | | - Christine A Raines
- School of Biological Sciences, Wivenhoe Park, University of Essex, Colchester, UK
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43
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Ermakova M, Lopez-Calcagno PE, Raines CA, Furbank RT, von Caemmerer S. Overexpression of the Rieske FeS protein of the Cytochrome b6f complex increases C 4 photosynthesis in Setaria viridis. Commun Biol 2019. [PMID: 31453378 DOI: 10.1038/s42003-019-0561-569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2023] Open
Abstract
C4 photosynthesis is characterised by a CO2 concentrating mechanism that operates between mesophyll and bundle sheath cells increasing CO2 partial pressure at the site of Rubisco and photosynthetic efficiency. Electron transport chains in both cell types supply ATP and NADPH for C4 photosynthesis. Cytochrome b6f is a key control point of electron transport in C3 plants. To study whether C4 photosynthesis is limited by electron transport we constitutively overexpressed the Rieske FeS subunit in Setaria viridis. This resulted in a higher Cytochrome b6f content in mesophyll and bundle sheath cells without marked changes in the abundances of other photosynthetic proteins. Rieske overexpression plants showed better light conversion efficiency in both Photosystems and could generate higher proton-motive force across the thylakoid membrane underpinning an increase in CO2 assimilation rate at ambient and saturating CO2 and high light. Our results demonstrate that removing electron transport limitations can increase C4 photosynthesis.
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Affiliation(s)
- Maria Ermakova
- 1Australian Research Council Centre of Excellence for Translational Photosynthesis, Division of Plant Science, Research School of Biology, The Australian National University, Acton, Australian Capital Territory 2601 Australia
| | | | - Christine A Raines
- 2School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ UK
| | - Robert T Furbank
- 1Australian Research Council Centre of Excellence for Translational Photosynthesis, Division of Plant Science, Research School of Biology, The Australian National University, Acton, Australian Capital Territory 2601 Australia
| | - Susanne von Caemmerer
- 1Australian Research Council Centre of Excellence for Translational Photosynthesis, Division of Plant Science, Research School of Biology, The Australian National University, Acton, Australian Capital Territory 2601 Australia
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Hilgers EJA, Schöttler MA, Mettler-Altmann T, Krueger S, Dörmann P, Eicks M, Flügge UI, Häusler RE. The Combined Loss of Triose Phosphate and Xylulose 5-Phosphate/Phosphate Translocators Leads to Severe Growth Retardation and Impaired Photosynthesis in Arabidopsis thaliana tpt/xpt Double Mutants. FRONTIERS IN PLANT SCIENCE 2018; 9:1331. [PMID: 30333839 PMCID: PMC6175978 DOI: 10.3389/fpls.2018.01331] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2018] [Accepted: 08/24/2018] [Indexed: 05/18/2023]
Abstract
The xylulose 5-phosphate/phosphate translocator (XPT) represents the fourth functional member of the phosphate translocator (PT) family residing in the plastid inner envelope membrane. In contrast to the other three members, little is known on the physiological role of the XPT. Based on its major transport substrates (i.e., pentose phosphates) the XPT has been proposed to act as a link between the plastidial and extraplastidial branches of the oxidative pentose phosphate pathway (OPPP). As the XPT is also capable of transporting triose phosphates, it might as well support the triose phosphate PT (TPT) in exporting photoassimilates from the chloroplast in the light ('day path of carbon') and hence in supplying the whole plant with carbohydrates. Two independent knockout mutant alleles of the XPT (xpt-1 and xpt-2) lacked any specific phenotype, suggesting that the XPT function is redundant. However, double mutants generated from crossings of xpt-1 to different mutant alleles of the TPT (tpt-1 and tpt-2) were severely retarded in size, exhibited a high chlorophyll fluorescence phenotype, and impaired photosynthetic electron transport rates. In the double mutant the export of triose phosphates from the chloroplasts is completely blocked. Hence, precursors for sucrose biosynthesis derive entirely from starch turnover ('night path of carbon'), which was accompanied by a marked accumulation of maltose as a starch breakdown product. Moreover, pentose phosphates produced by the extraplastidial branch of the OPPP also accumulated in the double mutants. Thus, an active XPT indeed retrieves excessive pentose phosphates from the extra-plastidial space and makes them available to the plastids. Further metabolic profiling revealed that phosphorylated intermediates remained largely unaffected, whereas fumarate and glycine contents were diminished in the double mutants. The assessment of C/N-ratios suggested co-limitations of C- and N-metabolism as possible cause for growth retardation of the double mutants. Feeding of sucrose partially rescued the growth and photosynthesis phenotypes of the double mutants. Immunoblots of thylakoid proteins, spectroscopic determinations of photosynthesis complexes, and chlorophyll a fluorescence emission spectra at 77 Kelvin could only partially explain constrains in photosynthesis observed in the double mutants. The data are discussed together with aspects of the OPPP and central carbon metabolism.
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Affiliation(s)
- Elke J. A. Hilgers
- Department of Biology, Cologne Biocenter, Botanical Institute II and Cluster of Excellence on Plant Sciences, University of Cologne, Cologne, Germany
| | | | | | - Stephan Krueger
- Department of Biology, Cologne Biocenter, Botanical Institute II and Cluster of Excellence on Plant Sciences, University of Cologne, Cologne, Germany
| | - Peter Dörmann
- Molecular Biotechnology and Biochemistry, Universität Bonn, Bonn, Germany
| | | | - Ulf-Ingo Flügge
- Department of Biology, Cologne Biocenter, Botanical Institute II and Cluster of Excellence on Plant Sciences, University of Cologne, Cologne, Germany
| | - Rainer E. Häusler
- Department of Biology, Cologne Biocenter, Botanical Institute II and Cluster of Excellence on Plant Sciences, University of Cologne, Cologne, Germany
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A Specific Single Nucleotide Polymorphism in the ATP Synthase Gene Significantly Improves Environmental Stress Tolerance of Synechococcus elongatus PCC 7942. Appl Environ Microbiol 2018; 84:AEM.01222-18. [PMID: 30006407 DOI: 10.1128/aem.01222-18] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 07/11/2018] [Indexed: 01/08/2023] Open
Abstract
In response to a broad range of habitats and environmental stresses, cyanobacteria have evolved various effective acclimation strategies, which will be helpful for improving the stress tolerances of photosynthetic organisms, including higher plants. Synechococcus elongatus UTEX 2973 and PCC 7942 possess genomes that are 99.8% identical but exhibit significant differences in cell growth and stress tolerance. In this study, we found that a single amino acid substitution at FoF1 ATP synthase subunit α (AtpA), C252Y, is the primary contributor to the improved stress tolerance of S. elongatus UTEX 2973. Site-saturation mutagenesis experiments showed that point mutations of cysteine 252 to any of the four conjugated amino acids could significantly improve the stress tolerance of S. elongatus PCC 7942. We further confirmed that the C252Y mutation increases AtpA protein levels, intracellular ATP synthase activity, intracellular ATP abundance, transcription of psbA genes (especially psbA2), photosystem II activity, and glycogen accumulation in S. elongatus PCC 7942. This work highlights the importance of AtpA in improving the stress tolerance of cyanobacteria and provides insight into how cyanobacteria evolve via point mutations in the face of environmental selection pressures.IMPORTANCE Two closely related Synechococcus strains showed significantly different tolerances to high light and high temperature but limited genomic differences, providing us opportunities to identify key genes responsible for stress acclimation by a gene complementation approach. In this study, we confirmed that a single point mutation in the α subunit of FoF1 ATP synthase (AtpA) contributes mainly to the improved stress tolerance of Synechococcus elongatus UTEX 2973. The point mutation of AtpA, the important ATP-generating complex of photosynthesis, increases AtpA protein levels, intracellular ATP synthase activity, and ATP concentrations under heat stress, as well as photosystem II activity. This work proves the importance of ATP synthase in cyanobacterial stress acclimation and provides a good target for future improvement of cyanobacterial stress tolerance by metabolic engineering.
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Li L, Aro EM, Millar AH. Mechanisms of Photodamage and Protein Turnover in Photoinhibition. TRENDS IN PLANT SCIENCE 2018; 23:667-676. [PMID: 29887276 DOI: 10.1016/j.tplants.2018.05.004] [Citation(s) in RCA: 115] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 05/05/2018] [Accepted: 05/08/2018] [Indexed: 05/05/2023]
Abstract
Rapid protein degradation and replacement is an important response to photodamage and a means of photoprotection by recovering proteostasis. Protein turnover and translation efficiency studies have discovered fast turnover subunits in cytochrome b6f and the NAD(P)H dehydrogenase (NDH) complex, in addition to PSII subunit D1. Mutations of these complexes have been linked to enhanced photodamage at least partially via cyclic electron flow. Photodamage and photoprotection involving cytochrome b6f, NDH complex, cyclic electron flow, PSI, and nonphotochemical quenching proteins have been reported. Here, we propose that the rapid turnover of specific proteins in cytochrome b6f and the NDH complex need to be characterised and compared with the inhibition of PSII by excess excitation energy and PSI by excess electron flux to expand our understanding of photoinhibition mechanisms.
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Affiliation(s)
- Lei Li
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, 35 Stirling Hwy, 6009, Perth, WA, Australia
| | - Eva-Mari Aro
- Finnish Centre of Excellence in Molecular Biology of Primary Producers, Department of Biochemistry, Molecular Plant Biology, University of Turku, FI-20014, Turku, Finland
| | - A Harvey Millar
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, 35 Stirling Hwy, 6009, Perth, WA, Australia.
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Patil M, Seifert S, Seiler F, Soll J, Schwenkert S. FZL is primarily localized to the inner chloroplast membrane however influences thylakoid maintenance. PLANT MOLECULAR BIOLOGY 2018; 97:421-433. [PMID: 29951988 DOI: 10.1007/s11103-018-0748-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 06/05/2018] [Indexed: 06/08/2023]
Abstract
FZL is primarily localized to the chloroplast inner envelope and not to the thylakoids, but nevertheless affects the maintenance of thylakoid membranes and photosynthetic protein complexes. The fuzzy-onion-like protein (FZL) is a membrane-bound dynamin-like GTPase located in the chloroplast. We have investigated the chloroplast sub-localization of the endogenous FZL protein and found it to be primarily localized to the inner envelope. Moreover, we observed that mature leaves of fzl mutants start to turn pale, especially in the midvein area of the leaves, 11 days after germination. We therefore assessed their photosynthetic performance as well as the accumulation of thylakoid membrane proteins and complexes after the initial appearance of the phenotype. Interestingly, we could observe a significant decrease in amounts of the cytochrome b6f complex in 20-day-old mutants, which was also reflected in an impaired electron transport rate as well as a more oxidized P700 redox state. Analysis of differences in transcriptome datasets obtained before and after onset of the phenotype, revealed large-scale changes in gene expression after the phenotype became visible. In summary, we propose that FZL, despite its localization in the inner chloroplast envelope has an important role in thylakoid maintenance in mature and aging leaves.
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Affiliation(s)
- Manali Patil
- Department Biologie I, Botanik, Ludwig-Maximilians-Universität, Großhaderner Strasse. 2-4, 82152, Planegg-Martinsried, Germany
- Munich Center for Integrated Protein Science CiPSM, Ludwig-Maximilians-Universität, Feodor-Lynen-Strasse 25, 81377, Munich, Germany
| | - Stephanie Seifert
- Department Biologie I, Botanik, Ludwig-Maximilians-Universität, Großhaderner Strasse. 2-4, 82152, Planegg-Martinsried, Germany
| | - Franka Seiler
- Department Biologie I, Botanik, Ludwig-Maximilians-Universität, Großhaderner Strasse. 2-4, 82152, Planegg-Martinsried, Germany
| | - Jürgen Soll
- Department Biologie I, Botanik, Ludwig-Maximilians-Universität, Großhaderner Strasse. 2-4, 82152, Planegg-Martinsried, Germany
- Munich Center for Integrated Protein Science CiPSM, Ludwig-Maximilians-Universität, Feodor-Lynen-Strasse 25, 81377, Munich, Germany
| | - Serena Schwenkert
- Department Biologie I, Botanik, Ludwig-Maximilians-Universität, Großhaderner Strasse. 2-4, 82152, Planegg-Martinsried, Germany.
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Shimakawa G, Miyake C. Changing frequency of fluctuating light reveals the molecular mechanism for P700 oxidation in plant leaves. PLANT DIRECT 2018; 2:e00073. [PMID: 31245737 PMCID: PMC6508772 DOI: 10.1002/pld3.73] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 04/05/2018] [Accepted: 06/15/2018] [Indexed: 05/19/2023]
Abstract
Natural sunlight exceeds the demand of photosynthesis such that it can cause plants to produce reactive oxygen species (ROS), which subsequently cause photo-oxidative damage. Because photosystem I (PSI) is a major source of ROS, plants actively maintain the reaction center chlorophyll of PSI(P700) oxidized under excessive light conditions to alleviate the ROS production. P700 oxidation is universally recognized in photosynthetic organisms as a physiological response to excessive light. However, it is still poorly understood how P700 oxidation is induced in response to fluctuating light with a variety of frequencies. Here, we investigated the relationships of photosynthetic parameters with P700 oxidation in Arabidopsis thaliana under a sine fluctuating light with different frequencies. As the photon flux density of the light increased, P700 was oxidized concurrently with the chlorophyll fluorescence parameter qL unless the electron acceptor side of PSI was limited. Conversely, we did not observe a proportional relationship of non-photochemical quenching with P700 oxidation. The mutant crr-2, which lacks chloroplast NADPH dehydrogenase, was impaired in P700 oxidation during light fluctuation at high, but not low frequency, unlike the pgrl1 mutant deficient in PGR5 and PGRL1 proteins, which could not oxidize P700 during light fluctuation at both high and low frequencies. Taken together, our findings suggested that the changing frequency of fluctuating light reveals the tracking performance of molecular mechanisms underlying P700 oxidation.
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Affiliation(s)
- Ginga Shimakawa
- Department of Biological and Environmental ScienceFaculty of AgricultureGraduate School of Agricultural ScienceKobe UniversityKobeJapan
| | - Chikahiro Miyake
- Department of Biological and Environmental ScienceFaculty of AgricultureGraduate School of Agricultural ScienceKobe UniversityKobeJapan
- Core Research for Environmental Science and TechnologyJapan Science and Technology AgencyTokyoJapan
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Dahal K, Vanlerberghe GC. Improved chloroplast energy balance during water deficit enhances plant growth: more crop per drop. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:1183-1197. [PMID: 29281082 PMCID: PMC6018952 DOI: 10.1093/jxb/erx474] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Accepted: 12/07/2017] [Indexed: 05/02/2023]
Abstract
The non-energy-conserving alternative oxidase (AOX) respiration of plant mitochondria is known to interact with chloroplast photosynthesis. This may have consequences for growth, particularly under sub-optimal conditions when energy imbalances can impede photosynthesis. This hypothesis was tested by comparing the metabolism and growth of wild-type Nicotiana tabacum with that of AOX knockdown and overexpression lines during a prolonged steady-state mild to moderate water deficit. Under moderate water deficit, the AOX amount was an important determinant of the rate of both mitochondrial respiration in the light and net photosynthetic CO2 assimilation (A) at the growth irradiance. In particular, AOX respiration was necessary to maintain optimal proton and electron fluxes at the chloroplast thylakoid membrane, which in turn prevented a water-deficit-induced biochemical limitation of photosynthesis. As a result of differences in A, AOX overexpressors gained more biomass and knockdowns gained less biomass than wild-type during moderate water deficit. Biomass partitioning also differed, with the overexpressors having a higher percentage, and the knockdowns having a lower percentage, of total above-ground biomass in reproductive tissue than wild-type. The results establish that improving chloroplast energy balance by using a non-energy-conserving respiratory electron sink can increase photosynthesis and growth during prolonged water deficit.
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Affiliation(s)
- Keshav Dahal
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, Toronto, Ontario, Canada
| | - Greg C Vanlerberghe
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, Toronto, Ontario, Canada
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Abstract
This chapter presents an overview of structural properties of the cytochrome (Cyt) b 6 f complex and its functioning in chloroplasts. The Cyt b 6 f complex stands at the crossroad of photosynthetic electron transport pathways, providing connectivity between Photosystem (PSI) and Photosysten II (PSII) and pumping protons across the membrane into the thylakoid lumen. After a brief review of the chloroplast electron transport chain, the consideration is focused on the structural organization of the Cyt b 6 f complex and its interaction with plastoquinol (PQH2, reduced form of plastoquinone), a mediator of electron transfer from PSII to the Cyt b 6 f complex. The processes of PQH2 oxidation by the Cyt b 6 f complex have been considered within the framework of the Mitchell's Q-cycle. The overall rate of the intersystem electron transport is determined by PQH2 turnover at the quinone-binding site Qo of the Cyt b 6 f complex. The rate of PQH2 oxidation is controlled by the intrathylakoid pHin, which value determines the protonation/deprotonation events in the Qo-center. Two other regulatory mechanisms associated with the Cyt b 6 f complex are briefly overviewed: (i) redistribution of electron fluxes between alternative (linear and cyclic) pathways, and (ii) "state transitions" related to redistribution of solar energy between PSI and PSII.
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