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Natale S, Peralta Ogorek LL, Caracciolo L, Morosinotto T, van Amerongen H, Casolo V, Pedersen O, Nardini A. Net O 2 exchange rates under dark and light conditions across different stem compartments. THE NEW PHYTOLOGIST 2024; 243:72-81. [PMID: 38703003 DOI: 10.1111/nph.19782] [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: 01/09/2024] [Accepted: 04/02/2024] [Indexed: 05/06/2024]
Abstract
Woody plants display some photosynthetic activity in stems, but the biological role of stem photosynthesis and the specific contributions of bark and wood to carbon uptake and oxygen evolution remain poorly understood. We aimed to elucidate the functional characteristics of chloroplasts in stems of different ages in Fraxinus ornus. Our investigation employed diverse experimental approaches, including microsensor technology to assess oxygen production rates in whole stem, bark, and wood separately. Additionally, we utilized fluorescence lifetime imaging microscopy (FLIM) to characterize the relative abundance of photosystems I and II (PSI : PSII chlorophyll ratio) in bark and wood. Our findings revealed light-induced increases in O2 production in whole stem, bark, and wood. We present the radial profile of O2 production in F. ornus stems, demonstrating the capability of stem chloroplasts to perform light-dependent electron transport. Younger stems exhibited higher light-induced O2 production and dark respiration rates than older ones. While bark emerged as the primary contributor to net O2 production under light conditions, our data underscored that wood chloroplasts are also photosynthetically active. The FLIM analysis unveiled a lower PSI abundance in wood than in bark, suggesting stem chloroplasts are not only active but also acclimate to the spectral composition of light reaching inner compartments.
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Affiliation(s)
- Sara Natale
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, Trieste, 34127, Italy
- Dipartimento di Biologia, Università di Padova, Via Ugo Bassi 58B, Padova, 35121, Italy
| | - Lucas Léon Peralta Ogorek
- The Freshwater Biological Laboratory, Department of Biology, University of Copenhagen, Universitetsparken 4, Copenhagen, 2100, Denmark
- School of Biosciences, Sutton Bonington Campus, University of Nottingham, Loughborough, LE12 5RD, UK
| | - Ludovico Caracciolo
- Laboratory of Biophysics, Wageningen University & Research, PO Box 8128, 6700 ET, Wageningen, the Netherlands
| | - Tomas Morosinotto
- Dipartimento di Biologia, Università di Padova, Via Ugo Bassi 58B, Padova, 35121, Italy
| | - Herbert van Amerongen
- Laboratory of Biophysics, Wageningen University & Research, PO Box 8128, 6700 ET, Wageningen, the Netherlands
- MicroSpectroscopy Research Facility at Wageningen University & Research, Stippeneng 4, 6708 WE, Wageningen, the Netherlands
| | - Valentino Casolo
- Dipartimento di Scienze Agroalimentari, Ambientali e Animali, Università di Udine, Sezione di Biologia Vegetale, Via delle Scienze 91, Udine, 33100, Italy
| | - Ole Pedersen
- The Freshwater Biological Laboratory, Department of Biology, University of Copenhagen, Universitetsparken 4, Copenhagen, 2100, Denmark
- School of Biological Sciences, The University of Western Australia, Perth, WA, 6009, Australia
| | - Andrea Nardini
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, Trieste, 34127, Italy
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2
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Elias E, Oliver TJ, Croce R. Oxygenic Photosynthesis in Far-Red Light: Strategies and Mechanisms. Annu Rev Phys Chem 2024; 75:231-256. [PMID: 38382567 DOI: 10.1146/annurev-physchem-090722-125847] [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] [Indexed: 02/23/2024]
Abstract
Oxygenic photosynthesis, the process that converts light energy into chemical energy, is traditionally associated with the absorption of visible light by chlorophyll molecules. However, recent studies have revealed a growing number of organisms capable of using far-red light (700-800 nm) to drive oxygenic photosynthesis. This phenomenon challenges the conventional understanding of the limits of this process. In this review, we briefly introduce the organisms that exhibit far-red photosynthesis and explore the different strategies they employ to harvest far-red light. We discuss the modifications of photosynthetic complexes and their impact on the delivery of excitation energy to photochemical centers and on overall photochemical efficiency. Finally, we examine the solutions employed to drive electron transport and water oxidation using relatively low-energy photons. The findings discussed here not only expand our knowledge of the remarkable adaptation capacities of photosynthetic organisms but also offer insights into the potential for enhancing light capture in crops.
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Affiliation(s)
- Eduard Elias
- Department of Physics and Astronomy, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands;
| | - Thomas J Oliver
- Department of Physics and Astronomy, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands;
| | - Roberta Croce
- Department of Physics and Astronomy, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands;
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3
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Bos PR, Berentsen J, Wientjes E. Expansion microscopy resolves the thylakoid structure of spinach. PLANT PHYSIOLOGY 2023; 194:347-358. [PMID: 37792700 PMCID: PMC10756755 DOI: 10.1093/plphys/kiad526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 09/19/2023] [Accepted: 09/19/2023] [Indexed: 10/06/2023]
Abstract
The light-harvesting reactions of photosynthesis take place on the thylakoid membrane inside chloroplasts. The thylakoid membrane is folded into appressed membranes, the grana, and nonappressed membranes that interconnect the grana, the stroma lamellae. This folding is essential for the correct functioning of photosynthesis. Electron microscopy and atomic force microscopy are commonly used to study the thylakoid membrane, but these techniques have limitations in visualizing a complete chloroplast and its organization. To overcome this limitation, we applied expansion microscopy (ExM) on isolated chloroplasts. ExM is a technique that involves physically expanding a sample in a swellable hydrogel to enhance the spatial resolution of fluorescence microscopy. Using all-protein staining, we visualized the 3D structure of spinach (Spinacia oleracea) thylakoids in detail. We were able to resolve stroma lamellae that were 60 nm apart and observe their helical wrapping around the grana. Furthermore, we accurately measured the dimensions of grana from top views of chloroplasts, which allow for precise determination of the granum diameter. Our results demonstrate that ExM is a fast and reliable technique for studying thylakoid organization in great detail.
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Affiliation(s)
- Peter R Bos
- Laboratory of Biophysics, Wageningen University & Research, Wageningen 6700 ET, The Netherlands
| | - Jarne Berentsen
- Laboratory of Biophysics, Wageningen University & Research, Wageningen 6700 ET, The Netherlands
| | - Emilie Wientjes
- Laboratory of Biophysics, Wageningen University & Research, Wageningen 6700 ET, The Netherlands
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4
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Ranepura GA, Mao J, Vermaas JV, Wang J, Gisriel CJ, Wei RJ, Ortiz-Soto J, Uddin MR, Amin M, Brudvig GW, Gunner MR. Computing the Relative Affinity of Chlorophylls a and b to Light-Harvesting Complex II. J Phys Chem B 2023; 127:10974-10986. [PMID: 38097367 DOI: 10.1021/acs.jpcb.3c06273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2023]
Abstract
In plants and algae, the primary antenna protein bound to photosystem II is light-harvesting complex II (LHCII), a pigment-protein complex that binds eight chlorophyll (Chl) a molecules and six Chl b molecules. Chl a and Chl b differ only in that Chl a has a methyl group (-CH3) on one of its pyrrole rings, while Chl b has a formyl group (-CHO) at that position. This blue-shifts the Chl b absorbance relative to Chl a. It is not known how the protein selectively binds the right Chl type at each site. Knowing the selection criteria would allow the design of light-harvesting complexes that bind different Chl types, modifying an organism to utilize the light of different wavelengths. The difference in the binding affinity of Chl a and Chl b in pea and spinach LHCII was calculated using multiconformation continuum electrostatics and free energy perturbation. Both methods have identified some Chl sites where the bound Chl type (a or b) has a significantly higher affinity, especially when the protein provides a hydrogen bond for the Chl b formyl group. However, the Chl a sites often have little calculated preference for one Chl type, so they are predicted to bind a mixture of Chl a and b. The electron density of the spinach LHCII was reanalyzed, which, however, confirmed that there is negligible Chl b in the Chl a-binding sites. It is suggested that the protein chooses the correct Chl type during folding, segregating the preferred Chl to the correct binding site.
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Affiliation(s)
- Gehan A Ranepura
- Ph.D. Program in Physics, The Graduate Center, City University of New York, New York, New York 10016, United States
- Department of Physics, City College of New York, New York, New York 10031, United States
| | - Junjun Mao
- Benjamin Levich Institute for Physico-Chemical Hydrodynamics, City College of New York, New York, New York 10031, United States
| | - Josh V Vermaas
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824, United States
- Department of Biochemistry and Molecular Biology, Michigan State University, 612 Wilson Road, East Lansing, Michigan 48824, United States
| | - Jimin Wang
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Christopher J Gisriel
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Rongmei Judy Wei
- Department of Physics, City College of New York, New York, New York 10031, United States
- Ph.D. Program in Chemistry, The Graduate Center, City University of New York, New York, New York 10016, United States
| | - Jose Ortiz-Soto
- Department of Physics, City College of New York, New York, New York 10031, United States
- Ph.D. Program in Chemistry, The Graduate Center, City University of New York, New York, New York 10016, United States
| | - Md Raihan Uddin
- Department of Physics, City College of New York, New York, New York 10031, United States
- Ph.D. Program in Biochemistry, The Graduate Center, City University of New York, New York, New York 10016, United States
| | - Muhamed Amin
- Laboratory of Computational Biology, National Heart, Lung and Blood, Institute, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Gary W Brudvig
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520, United States
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - M R Gunner
- PhD Program in Physics, in Chemistry and in Biochemistry at the Graduate Center, City University of New York, New York, New York 10016, United States
- Department of Physics, City College of New York, New York, New York 10031, United States
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5
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Battistuzzi M, Cocola L, Liistro E, Claudi R, Poletto L, La Rocca N. Growth and Photosynthetic Efficiency of Microalgae and Plants with Different Levels of Complexity Exposed to a Simulated M-Dwarf Starlight. Life (Basel) 2023; 13:1641. [PMID: 37629498 PMCID: PMC10455698 DOI: 10.3390/life13081641] [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: 06/13/2023] [Revised: 07/16/2023] [Accepted: 07/26/2023] [Indexed: 08/27/2023] Open
Abstract
Oxygenic photosynthetic organisms (OPOs) are primary producers on Earth and generate surface and atmospheric biosignatures, making them ideal targets to search for life from remote on Earth-like exoplanets orbiting stars different from the Sun, such as M-dwarfs. These stars emit very low light in the visible and most light in the far-red, an issue for OPOs, which mostly utilize visible light to photosynthesize and grow. After successfully testing procaryotic OPOs (cyanobacteria) under a simulated M-dwarf star spectrum (M7, 365-850 nm) generated through a custom-made lamp, we tested several eukaryotic OPOs: microalgae (Dixoniella giordanoi, Microchloropsis gaditana, Chromera velia, Chlorella vulgaris), a non-vascular plant (Physcomitrium patens), and a vascular plant (Arabidopsis thaliana). We assessed their growth and photosynthetic efficiency under three light conditions: M7, solar (SOL) simulated spectra, and far-red light (FR). Microalgae grew similarly in SOL and M7, while the moss P. patens showed slower growth in M7 with respect to SOL. A. thaliana grew similarly in SOL and M7, showing traits typical of shade-avoidance syndrome. Overall, the synergistic effect of visible and far-red light, also known as the Emerson enhancing effect, could explain the growth in M7 for all organisms. These results lead to reconsidering the possibility and capability of the growth of OPOs and are promising for finding biosignatures on exoplanets orbiting the habitable zone of distant stars.
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Affiliation(s)
- Mariano Battistuzzi
- National Council of Research of Italy, Institute for Photonics and Nanotechnologies (CNR-IFN), 35131 Padua, Italy; (L.C.)
- Department of Biology, University of Padua, 35121 Padua, Italy (N.L.R.)
- Center for Space Studies and Activities (CISAS), University of Padua, 35131 Padua, Italy
| | - Lorenzo Cocola
- National Council of Research of Italy, Institute for Photonics and Nanotechnologies (CNR-IFN), 35131 Padua, Italy; (L.C.)
| | | | - Riccardo Claudi
- National Institute for Astrophysics (INAF), Astronomical Observatory of Padua, 35122 Padua, Italy
- Department of Mathematics and Physics, University Roma Tre, 00146 Rome, Italy
| | - Luca Poletto
- National Council of Research of Italy, Institute for Photonics and Nanotechnologies (CNR-IFN), 35131 Padua, Italy; (L.C.)
| | - Nicoletta La Rocca
- Department of Biology, University of Padua, 35121 Padua, Italy (N.L.R.)
- Center for Space Studies and Activities (CISAS), University of Padua, 35131 Padua, Italy
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6
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Natale S, La Rocca N, Battistuzzi M, Morosinotto T, Nardini A, Alboresi A. Structure and function of bark and wood chloroplasts in a drought-tolerant tree (Fraxinus ornus L.). TREE PHYSIOLOGY 2023; 43:893-908. [PMID: 36738252 DOI: 10.1093/treephys/tpad013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 01/31/2023] [Indexed: 06/11/2023]
Abstract
Leaves are the most important photosynthetic organs in most woody plants, but chloroplasts are also found in organs optimized for other functions. However, the actual photosynthetic efficiency of these chloroplasts is still unclear. We analyzed bark and wood chloroplasts of Fraxinus ornus L. saplings. Optical and spectroscopic methods were applied to stem samples and compared with leaves. A sharp light gradient was detected along the stem radial direction, with blue light mainly absorbed by the outer bark, and far-red-enriched light reaching the underlying xylem and pith. Chlorophylls were evident in the xylem rays and the pith and showed an increasing concentration gradient toward the bark. The stem photosynthetic apparatus showed features typical of acclimation to a low-light environment, such as larger grana stacks, lower chlorophyll a/b and photosystem I/II ratios compared with leaves. Despite likely receiving very few photons, wood chloroplasts were photosynthetically active and fully capable of generating a light-dependent electron transport. Our data provide a comprehensive scenario of the functional features of bark and wood chloroplasts in a woody species and suggest that stem photosynthesis is coherently optimized to the prevailing micro-environmental conditions at the bark and wood level.
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Affiliation(s)
- Sara Natale
- Department of Life Sciences, University of Trieste, Via L. Giorgieri 10, Trieste 34127, Italy
| | - Nicoletta La Rocca
- Department of Biology, University of Padova, Via Ugo Bassi 58B, Padova 35121, Italy
| | - Mariano Battistuzzi
- Department of Biology, University of Padova, Via Ugo Bassi 58B, Padova 35121, Italy
| | - Tomas Morosinotto
- Department of Biology, University of Padova, Via Ugo Bassi 58B, Padova 35121, Italy
| | - Andrea Nardini
- Department of Life Sciences, University of Trieste, Via L. Giorgieri 10, Trieste 34127, Italy
| | - Alessandro Alboresi
- Department of Biology, University of Padova, Via Ugo Bassi 58B, Padova 35121, Italy
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7
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Hu C, Mascoli V, Elias E, Croce R. The photosynthetic apparatus of the CAM plant Tillandsia flabellate and its response to water deficit. JOURNAL OF PLANT PHYSIOLOGY 2023; 282:153945. [PMID: 36805519 DOI: 10.1016/j.jplph.2023.153945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Revised: 01/30/2023] [Accepted: 02/12/2023] [Indexed: 06/18/2023]
Abstract
CAM plants are superior to C3 plants in drought resistance because of their peculiar photosynthesis pathway and morphological features. While those aspects have been studied for decades, little is known about the photosynthetic machinery of CAM plants. Here, we used a combination of biochemical and biophysical methods to study the photosynthetic apparatus of Tillandsia flabellate, an obligatory CAM plant. Most of the Photosystems super- and sub-complexes have properties very similar to those of Arabidopsis, with the main difference that in Tillandsia PSI-LHCI complexes bind extra LHCI. Functional measurements show that the PSI/PSII ratio is rather low compared to other plants and that the antenna size of both PSI and PSII is small. Upon 30-day water deficiency, the composition of the photosystems does not change significantly, PSII efficiency remains high and no Photosystem II photoinhibition was detected despite a reduction of non-photochemical quenching (NPQ).
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Affiliation(s)
- Chen Hu
- Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Science, Vrije Universiteit Amsterdam, the Netherlands.
| | - Vincenzo Mascoli
- Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Science, Vrije Universiteit Amsterdam, the Netherlands.
| | - Eduard Elias
- Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Science, Vrije Universiteit Amsterdam, the Netherlands.
| | - Roberta Croce
- Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Science, Vrije Universiteit Amsterdam, the Netherlands.
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8
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Zhen S, van Iersel MW, Bugbee B. Photosynthesis in sun and shade: the surprising importance of far-red photons. THE NEW PHYTOLOGIST 2022; 236:538-546. [PMID: 35832002 DOI: 10.1111/nph.18375] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2022] [Accepted: 07/07/2022] [Indexed: 06/15/2023]
Abstract
The current definition of photosynthetically active radiation includes only photons from 400 up to 700 nm, despite evidence of the synergistic interaction between far-red photons and shorter-wavelength photons. The synergy between far-red and shorter-wavelength photons has not been studied in sunlight under natural conditions. We used a filter to remove photons above 700 nm to quantify the effects on photosynthesis in diverse species under full sun, medium light intensity and vegetation shade. Far-red photons (701 to 750 nm) in sunlight are used efficiently for photosynthesis. This is especially important for leaves in vegetation shade, where far-red photons can be > 50% of the total incident photons between 400 and 750 nm. Far-red photons accounted for 24-25% of leaf gross photosynthesis (Pgross ) in a C3 and a C4 species when sunlight was filtered through a leaf, and 10-14% of leaf Pgross in a tree and an understory species in deep shade. Accounting for the photosynthetic activity of far-red photons is critical for accurate measurement and modeling of photosynthesis at single leaf, canopy and ecosystem scales. This, in turn, is crucial in understanding crop productivity, the global carbon cycle and climate change impacts on agriculture and ecosystems.
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Affiliation(s)
- Shuyang Zhen
- Department of Horticultural Sciences, Texas A&M University, College Station, TX, 77843, USA
| | - Marc W van Iersel
- Department of Horticulture, University of Georgia, Athens, GA, 30602, USA
| | - Bruce Bugbee
- Department of Plants, Soils and Climate, Utah State University, Logan, UT, 84341, USA
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9
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Photosystem stoichiometry adjustment is a photoreceptor-mediated process in Arabidopsis. Sci Rep 2022; 12:10982. [PMID: 35768472 PMCID: PMC9243065 DOI: 10.1038/s41598-022-14967-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 06/15/2022] [Indexed: 11/20/2022] Open
Abstract
Plant growth under spectrally-enriched low light conditions leads to adjustment in the relative abundance of the two photosystems in an acclimatory response known as photosystem stoichiometry adjustment. Adjustment of photosystem stoichiometry improves the quantum efficiency of photosynthesis but how this process perceives light quality changes and how photosystem amount is regulated remain largely unknown. By using a label-free quantitative mass spectrometry approach in Arabidopsis here we show that photosystem stoichiometry adjustment is primarily driven by the regulation of photosystem I content and that this forms the major thylakoid proteomic response under light quality. Using light and redox signaling mutants, we further show that the light quality-responsive accumulation of photosystem I gene transcripts and proteins requires phytochrome B photoreceptor but not plastoquinone redox signaling as previously suggested. In far-red light, the increased acceptor side limitation might deplete active photosystem I pool, further contributing to the adjustment of photosystem stoichiometry.
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10
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Molecular Evolution of Far-Red Light-Acclimated Photosystem II. Microorganisms 2022; 10:microorganisms10071270. [PMID: 35888987 PMCID: PMC9325196 DOI: 10.3390/microorganisms10071270] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 06/17/2022] [Accepted: 06/18/2022] [Indexed: 12/10/2022] Open
Abstract
Cyanobacteria are major contributors to global carbon fixation and primarily use visible light (400-700 nm) to drive oxygenic photosynthesis. When shifted into environments where visible light is attenuated, a small, but highly diverse and widespread number of cyanobacteria can express modified pigments and paralogous versions of photosystem subunits and phycobiliproteins that confer far-red light (FRL) absorbance (700-800 nm), a process termed far-red light photoacclimation, or FaRLiP. During FaRLiP, alternate photosystem II (PSII) subunits enable the complex to bind chlorophylls d and f, which absorb at lower energy than chlorophyll a but still support water oxidation. How the FaRLiP response arose remains poorly studied. Here, we report ancestral sequence reconstruction and structure-based molecular evolutionary studies of the FRL-specific subunits of FRL-PSII. We show that the duplications leading to the origin of two PsbA (D1) paralogs required to make chlorophyll f and to bind chlorophyll d in water-splitting FRL-PSII are likely the first to have occurred prior to the diversification of extant cyanobacteria. These duplications were followed by those leading to alternative PsbC (CP43) and PsbD (D2) subunits, occurring early during the diversification of cyanobacteria, and culminating with those leading to PsbB (CP47) and PsbH paralogs coincident with the radiation of the major groups. We show that the origin of FRL-PSII required the accumulation of a relatively small number of amino acid changes and that the ancestral FRL-PSII likely contained a chlorophyll d molecule in the electron transfer chain, two chlorophyll f molecules in the antenna subunits at equivalent positions, and three chlorophyll a molecules whose site energies were altered. The results suggest a minimal model for engineering far-red light absorbance into plant PSII for biotechnological applications.
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11
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Sattari Vayghan H, Nawrocki WJ, Schiphorst C, Tolleter D, Hu C, Douet V, Glauser G, Finazzi G, Croce R, Wientjes E, Longoni F. Photosynthetic Light Harvesting and Thylakoid Organization in a CRISPR/Cas9 Arabidopsis Thaliana LHCB1 Knockout Mutant. FRONTIERS IN PLANT SCIENCE 2022; 13:833032. [PMID: 35330875 PMCID: PMC8940271 DOI: 10.3389/fpls.2022.833032] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 01/28/2022] [Indexed: 06/14/2023]
Abstract
Light absorbed by chlorophylls of Photosystems II and I drives oxygenic photosynthesis. Light-harvesting complexes increase the absorption cross-section of these photosystems. Furthermore, these complexes play a central role in photoprotection by dissipating the excess of absorbed light energy in an inducible and regulated fashion. In higher plants, the main light-harvesting complex is trimeric LHCII. In this work, we used CRISPR/Cas9 to knockout the five genes encoding LHCB1, which is the major component of LHCII. In absence of LHCB1, the accumulation of the other LHCII isoforms was only slightly increased, thereby resulting in chlorophyll loss, leading to a pale green phenotype and growth delay. The Photosystem II absorption cross-section was smaller, while the Photosystem I absorption cross-section was unaffected. This altered the chlorophyll repartition between the two photosystems, favoring Photosystem I excitation. The equilibrium of the photosynthetic electron transport was partially maintained by lower Photosystem I over Photosystem II reaction center ratio and by the dephosphorylation of LHCII and Photosystem II. Loss of LHCB1 altered the thylakoid structure, with less membrane layers per grana stack and reduced grana width. Stable LHCB1 knockout lines allow characterizing the role of this protein in light harvesting and acclimation and pave the way for future in vivo mutational analyses of LHCII.
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Affiliation(s)
- Hamed Sattari Vayghan
- Laboratory of Plant Physiology, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Wojciech J. Nawrocki
- Department of Physics and Astronomy, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Christo Schiphorst
- Laboratory of Biophysics, Wageningen University, Wageningen, Netherlands
| | - Dimitri Tolleter
- Univ. Grenoble Alpes, CNRS, CEA, INRAE, IRIG, LPCV, Grenoble, France
| | - Chen Hu
- Department of Physics and Astronomy, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Véronique Douet
- Laboratory of Plant Physiology, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Gaëtan Glauser
- Neuchâtel Platform of Analytical Chemistry, University of Neuchâtel, Neuchâtel, Switzerland
| | - Giovanni Finazzi
- Univ. Grenoble Alpes, CNRS, CEA, INRAE, IRIG, LPCV, Grenoble, France
| | - Roberta Croce
- Department of Physics and Astronomy, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Emilie Wientjes
- Laboratory of Biophysics, Wageningen University, Wageningen, Netherlands
| | - Fiamma Longoni
- Laboratory of Plant Physiology, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
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12
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Gisriel CJ, Flesher DA, Shen G, Wang J, Ho MY, Brudvig GW, Bryant DA. Structure of a photosystem I-ferredoxin complex from a marine cyanobacterium provides insights into far-red light photoacclimation. J Biol Chem 2022; 298:101408. [PMID: 34793839 PMCID: PMC8689207 DOI: 10.1016/j.jbc.2021.101408] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 11/08/2021] [Accepted: 11/09/2021] [Indexed: 01/08/2023] Open
Abstract
Far-red light photoacclimation exhibited by some cyanobacteria allows these organisms to use the far-red region of the solar spectrum (700-800 nm) for photosynthesis. Part of this process includes the replacement of six photosystem I (PSI) subunits with isoforms that confer the binding of chlorophyll (Chl) f molecules that absorb far-red light (FRL). However, the exact sites at which Chl f molecules are bound are still challenging to determine. To aid in the identification of Chl f-binding sites, we solved the cryo-EM structure of PSI from far-red light-acclimated cells of the cyanobacterium Synechococcus sp. PCC 7335. We identified six sites that bind Chl f with high specificity and three additional sites that are likely to bind Chl f at lower specificity. All of these binding sites are in the core-antenna regions of PSI, and Chl f was not observed among the electron transfer cofactors. This structural analysis also reveals both conserved and nonconserved Chl f-binding sites, the latter of which exemplify the diversity in FRL-PSI among species. We found that the FRL-PSI structure also contains a bound soluble ferredoxin, PetF1, at low occupancy, which suggests that ferredoxin binds less transiently than expected according to the canonical view of ferredoxin-binding to facilitate electron transfer. We suggest that this may result from structural changes in FRL-PSI that occur specifically during FRL photoacclimation.
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Affiliation(s)
| | - David A Flesher
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
| | - Gaozhong Shen
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Jimin Wang
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
| | - Ming-Yang Ho
- Department of Life Science, National Taiwan University, Taipei, Taiwan
| | - Gary W Brudvig
- Department of Chemistry, Yale University, New Haven, Connecticut, USA; Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA.
| | - Donald A Bryant
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA.
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Gisriel CJ, Shen G, Ho MY, Kurashov V, Flesher DA, Wang J, Armstrong WH, Golbeck JH, Gunner MR, Vinyard DJ, Debus RJ, Brudvig GW, Bryant DA. Structure of a monomeric photosystem II core complex from a cyanobacterium acclimated to far-red light reveals the functions of chlorophylls d and f. J Biol Chem 2022; 298:101424. [PMID: 34801554 PMCID: PMC8689208 DOI: 10.1016/j.jbc.2021.101424] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Revised: 11/12/2021] [Accepted: 11/13/2021] [Indexed: 11/26/2022] Open
Abstract
Far-red light (FRL) photoacclimation in cyanobacteria provides a selective growth advantage for some terrestrial cyanobacteria by expanding the range of photosynthetically active radiation to include far-red/near-infrared light (700-800 nm). During this photoacclimation process, photosystem II (PSII), the water:plastoquinone photooxidoreductase involved in oxygenic photosynthesis, is modified. The resulting FRL-PSII is comprised of FRL-specific core subunits and binds chlorophyll (Chl) d and Chl f molecules in place of several of the Chl a molecules found when cells are grown in visible light. These new Chls effectively lower the energy canonically thought to define the "red limit" for light required to drive photochemical catalysis of water oxidation. Changes to the architecture of FRL-PSII were previously unknown, and the positions of Chl d and Chl f molecules had only been proposed from indirect evidence. Here, we describe the 2.25 Å resolution cryo-EM structure of a monomeric FRL-PSII core complex from Synechococcus sp. PCC 7335 cells that were acclimated to FRL. We identify one Chl d molecule in the ChlD1 position of the electron transfer chain and four Chl f molecules in the core antenna. We also make observations that enhance our understanding of PSII biogenesis, especially on the acceptor side of the complex where a bicarbonate molecule is replaced by a glutamate side chain in the absence of the assembly factor Psb28. In conclusion, these results provide a structural basis for the lower energy limit required to drive water oxidation, which is the gateway for most solar energy utilization on earth.
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Affiliation(s)
| | - Gaozhong Shen
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Ming-Yang Ho
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA; Intercollege Graduate Program in Plant Biology, The Pennsylvania State University, University Park, Pennsylvania, USA; Department of Life Science, National Taiwan University, Taipei, Taiwan
| | - Vasily Kurashov
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - David A Flesher
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
| | - Jimin Wang
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
| | | | - John H Golbeck
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA; Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Marilyn R Gunner
- Department of Physics, City College of New York, New York, New York, USA
| | - David J Vinyard
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, USA
| | - Richard J Debus
- Department of Biochemistry, University of California, Riverside, California, USA
| | - Gary W Brudvig
- Department of Chemistry, Yale University, New Haven, Connecticut, USA; Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA.
| | - Donald A Bryant
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA; Intercollege Graduate Program in Plant Biology, The Pennsylvania State University, University Park, Pennsylvania, USA.
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14
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Gisriel CJ, Huang HL, Reiss KM, Flesher DA, Batista VS, Bryant DA, Brudvig GW, Wang J. Quantitative assessment of chlorophyll types in cryo-EM maps of photosystem I acclimated to far-red light. BBA ADVANCES 2021; 1:100019. [PMID: 37082022 PMCID: PMC10074859 DOI: 10.1016/j.bbadva.2021.100019] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Chlorophyll cofactors are vital for the metabolism of photosynthetic organisms. Cryo-electron microscopy (cryo-EM) has been used to elucidate molecular structures of pigment-protein complexes, but the minor structural differences between multiple types of chlorophylls make them difficult to distinguish in cryo-EM maps. This is exemplified by inconsistencies in the assignments of chlorophyll f molecules in structures of photosystem I acclimated to far-red light (FRL-PSI). A quantitative assessment of chlorophyll substituents in cryo-EM maps was used to identify chlorophyll f-binding sites in structures of FRL-PSI from two cyanobacteria. The two cryo-EM maps provide direct evidence for chlorophyll f-binding at two and three binding sites, respectively, and three more sites in each structure exhibit strong indirect evidence for chlorophyll f-binding. Common themes in chlorophyll f-binding are described that clarify the current understanding of the molecular basis for FRL photoacclimation in photosystems.
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