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Wilson S, Clarke CD, Carbajal MA, Buccafusca R, Fleck RA, Daskalakis V, Ruban AV. Hydrophobic Mismatch in the Thylakoid Membrane Regulates Photosynthetic Light Harvesting. J Am Chem Soc 2024; 146:14905-14914. [PMID: 38759103 PMCID: PMC11140739 DOI: 10.1021/jacs.4c05220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 05/10/2024] [Accepted: 05/13/2024] [Indexed: 05/19/2024]
Abstract
The ability to harvest light effectively in a changing environment is necessary to ensure efficient photosynthesis and crop growth. One mechanism, known as qE, protects photosystem II (PSII) and regulates electron transfer through the harmless dissipation of excess absorbed photons as heat. This process involves reversible clustering of the major light-harvesting complexes of PSII (LHCII) in the thylakoid membrane and relies upon the ΔpH gradient and the allosteric modulator protein PsbS. To date, the exact role of PsbS in the qE mechanism has remained elusive. Here, we show that PsbS induces hydrophobic mismatch in the thylakoid membrane through dynamic rearrangement of lipids around LHCII leading to observed membrane thinning. We found that upon illumination, the thylakoid membrane reversibly shrinks from around 4.3 to 3.2 nm, without PsbS, this response is eliminated. Furthermore, we show that the lipid digalactosyldiacylglycerol (DGDG) is repelled from the LHCII-PsbS complex due to an increase in both the pKa of lumenal residues and in the dipole moment of LHCII, which allows for further conformational change and clustering in the membrane. Our results suggest a mechanistic role for PsbS as a facilitator of a hydrophobic mismatch-mediated phase transition between LHCII-PsbS and its environment. This could act as the driving force to sort LHCII into photoprotective nanodomains in the thylakoid membrane. This work shows an example of the key role of the hydrophobic mismatch process in regulating membrane protein function in plants.
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Affiliation(s)
- Sam Wilson
- Department
of Biochemistry, School of Biological and Behavioural Sciences, Queen Mary University of London, London E1 4NS, United Kingdom
| | - Charlea D. Clarke
- Department
of Biochemistry, School of Biological and Behavioural Sciences, Queen Mary University of London, London E1 4NS, United Kingdom
| | - M. Alejandra Carbajal
- Centre
for Ultrastructural Imaging, King’s
College London, London SE1 1UL, United Kingdom
| | - Roberto Buccafusca
- Department
of Chemistry, School of Physical and Chemical Sciences, Queen Mary University of London, London E1 4NS, United Kingdom
| | - Roland A. Fleck
- Centre
for Ultrastructural Imaging, King’s
College London, London SE1 1UL, United Kingdom
| | - Vangelis Daskalakis
- Department
of Chemical Engineering, School of Engineering, University of Patras, Patras 26504, Greece
| | - Alexander V. Ruban
- Department
of Biochemistry, School of Biological and Behavioural Sciences, Queen Mary University of London, London E1 4NS, United Kingdom
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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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Cutolo EA, Caferri R, Guardini Z, Dall'Osto L, Bassi R. Analysis of state 1-state 2 transitions by genome editing and complementation reveals a quenching component independent from the formation of PSI-LHCI-LHCII supercomplex in Arabidopsis thaliana. Biol Direct 2023; 18:49. [PMID: 37612770 PMCID: PMC10463614 DOI: 10.1186/s13062-023-00406-5] [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: 06/12/2023] [Accepted: 08/07/2023] [Indexed: 08/25/2023] Open
Abstract
BACKGROUND The light-harvesting antennae of photosystem (PS) I and PSII are pigment-protein complexes responsible of the initial steps of sunlight conversion into chemical energy. In natural environments plants are constantly confronted with the variability of the photosynthetically active light spectrum. PSII and PSI operate in series but have different optimal excitation wavelengths. The prompt adjustment of light absorption by photosystems is thus crucial to ensure efficient electron flow needed to sustain downstream carbon fixing reactions. Fast structural rearrangements equilibrate the partition of excitation pressure between PSII and PSI following the enrichment in the red (PSII-favoring) or far-red (PSI-favoring) spectra. Redox imbalances trigger state transitions (ST), a photoacclimation mechanism which involves the reversible phosphorylation/dephosphorylation of light harvesting complex II (LHCII) proteins by the antagonistic activities of the State Transition 7 (STN7) kinase/TAP38 phosphatase enzyme pair. During ST, a mobile PSII antenna pool associates with PSI increasing its absorption cross section. LHCII consists of assorted trimeric assemblies of Lhcb1, Lhcb2 and Lhcb3 protein isoforms (LHCII), several being substrates of STN7. However, the precise roles of Lhcb phosphorylation during ST remain largely elusive. RESULTS We inactivated the complete Lhcb1 and Lhcb2 gene clades in Arabidopsis thaliana and reintroduced either wild type Lhcb1.3 and Lhcb2.1 isoforms, respectively, or versions lacking N-terminal phosphorylatable residues proposed to mediate state transitions. While the substitution of Lhcb2.1 Thr-40 prevented the formation of the PSI-LHCI-LHCII complex, replacement of Lhcb1.3 Thr-38 did not affect the formation of this supercomplex, nor did influence the amplitude or kinetics of PSII fluorescence quenching upon state 1-state 2 transition. CONCLUSIONS Phosphorylation of Lhcb2 Thr-40 by STN7 alone accounts for ≈ 60% of PSII fluorescence quenching during state transitions. Instead, the presence of Thr-38 phosphosite in Lhcb1.3 was not required for the formation of the PSI-LHCI-LHCII supercomplex nor for re-equilibration of the plastoquinone redox state. The Lhcb2 phosphomutant was still capable of ≈ 40% residual fluorescence quenching, implying that a yet uncharacterized, STN7-dependent, component of state transitions, which is unrelated to Lhcb2 Thr-40 phosphorylation and to the formation of the PSI-LHCI-LHCII supercomplex, contributes to the equilibration of the PSI/PSII excitation pressure upon plastoquinone over-reduction.
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Affiliation(s)
- Edoardo Andrea Cutolo
- Laboratory of Photosynthesis and Bioenergy, Department of Biotechnology, University of Verona, Strada le Grazie 15, 37134, Verona, Italy
| | - Roberto Caferri
- Laboratory of Photosynthesis and Bioenergy, Department of Biotechnology, University of Verona, Strada le Grazie 15, 37134, Verona, Italy
| | - Zeno Guardini
- Laboratory of Photosynthesis and Bioenergy, Department of Biotechnology, University of Verona, Strada le Grazie 15, 37134, Verona, Italy
| | - Luca Dall'Osto
- Laboratory of Photosynthesis and Bioenergy, Department of Biotechnology, University of Verona, Strada le Grazie 15, 37134, Verona, Italy
| | - Roberto Bassi
- Laboratory of Photosynthesis and Bioenergy, Department of Biotechnology, University of Verona, Strada le Grazie 15, 37134, Verona, Italy.
- Accademia Nazionale dei Lincei, Palazzo Corsini, Via Della Lungara, 10, 00165, Rome, Italy.
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4
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Kozuleva MA, Ivanov BN. Superoxide Anion Radical Generation in Photosynthetic Electron Transport Chain. BIOCHEMISTRY. BIOKHIMIIA 2023; 88:1045-1060. [PMID: 37758306 DOI: 10.1134/s0006297923080011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 06/16/2023] [Accepted: 06/18/2023] [Indexed: 10/03/2023]
Abstract
This review analyzes data available in the literature on the rates, characteristics, and mechanisms of oxygen reduction to a superoxide anion radical at the sites of photosynthetic electron transport chain where this reduction has been established. The existing assumptions about the role of the components of these sites in this process are critically examined using thermodynamic approaches and results of the recent studies. The process of O2 reduction at the acceptor side of PSI, which is considered the main site of this process taking place in the photosynthetic chain, is described in detail. Evolution of photosynthetic apparatus in the context of controlling the leakage of electrons to O2 is explored. The reasons limiting application of the results obtained with the isolated segments of the photosynthetic chain to estimate the rates of O2 reduction at the corresponding sites in the intact thylakoid membrane are discussed.
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Affiliation(s)
- Marina A Kozuleva
- Institute of Basic Biological Problems, Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia.
| | - Boris N Ivanov
- Institute of Basic Biological Problems, Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia
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5
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Beraldo C, Guyon-Debast A, Alboresi A, Nogué F, Morosinotto T. Functional analysis of PsbS transmembrane domains through base editing in Physcomitrium patens. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023; 113:1049-1061. [PMID: 36606401 DOI: 10.1111/tpj.16099] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 12/27/2022] [Accepted: 01/03/2023] [Indexed: 06/17/2023]
Abstract
Plants exposed to light fluctuations are protected from photodamage by non-photochemical quenching (NPQ), a reversible mechanism that enables dissipation of excess absorbed energy as heat, which is essential for plant fitness and crop productivity. In plants NPQ requires the presence of the membrane protein PsbS, which upon activation interacts with antenna proteins, inducing their dissipative conformation. Here, we exploited base editing (BE) in the moss Physcomitrium patens to introduce specific amino acid changes in vivo and assess their impact on PsbS activity, targeting transmembrane regions to investigate their role in essential protein-protein interactions. This approach enabled the recognition of residues essential for protein stability and the identification of a hydrophobic cluster of amino acids impacting PsbS activity. This work provides new information on the molecular mechanism of PsbS while also demonstrating the potential of BE approaches for in planta gene function analysis.
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Affiliation(s)
- Claudia Beraldo
- Department of Biology, University of Padova, Via Ugo Bassi 58B, Padova, 35131, Italy
| | - Anouchka Guyon-Debast
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000, Versailles, France
| | - Alessandro Alboresi
- Department of Biology, University of Padova, Via Ugo Bassi 58B, Padova, 35131, Italy
| | - Fabien Nogué
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000, Versailles, France
| | - Tomas Morosinotto
- Department of Biology, University of Padova, Via Ugo Bassi 58B, Padova, 35131, Italy
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6
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Manoj KM, Bazhin NM, Jacob VD, Parashar A, Gideon DA, Manekkathodi A. Structure-function correlations and system dynamics in oxygenic photosynthesis: classical perspectives and murburn precepts. J Biomol Struct Dyn 2022; 40:10997-11023. [PMID: 34323659 DOI: 10.1080/07391102.2021.1953606] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
HIGHLIGHTS Contemporary beliefs on oxygenic photosynthesis are critiqued.Murburn model is suggested as an alternative explanation.In the new model, diffusible reactive species are the main protagonists.All pigments are deemed photo-redox active in the new stochastic mechanism.NADPH synthesis occurs via simple electron transfers, not via elaborate ETC.Oxygenesis is delocalized and not just centered at Mn-Complex.Energetics of murburn proposal for photophosphorylation is provided.The proposal ushers in a paradigm shift in photosynthesis research.
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Affiliation(s)
| | | | - Vivian David Jacob
- Satyamjayatu: The Science & Ethics Foundation, Kulappully, Kerala, India
| | - Abhinav Parashar
- Satyamjayatu: The Science & Ethics Foundation, Kulappully, Kerala, India
| | | | - Afsal Manekkathodi
- Satyamjayatu: The Science & Ethics Foundation, Kulappully, Kerala, India
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7
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Riznichenko GY, Belyaeva NE, Kovalenko IB, Antal TK, Goryachev SN, Maslakov AS, Plyusnina TY, Fedorov VA, Khruschev SS, Yakovleva OV, Rubin AB. Mathematical Simulation of Electron Transport in the Primary Photosynthetic Processes. BIOCHEMISTRY (MOSCOW) 2022; 87:1065-1083. [DOI: 10.1134/s0006297922100017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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8
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Cramer WA, Zakharov SD. Concerning the enigmatic cytochrome b-559 of oxygenic photosynthesis. PHOTOSYNTHESIS RESEARCH 2022; 153:157-162. [PMID: 35838829 DOI: 10.1007/s11120-022-00936-5] [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: 05/10/2022] [Accepted: 06/19/2022] [Indexed: 06/15/2023]
Abstract
Although there is an extensive literature on the properties and possible electron transfer pathways of cytochrome b-559, which is a prominent subunit of the multi-subunit photosystem II complex which functions in oxygenic photosynthesis, there is presently no consensus on the function of b-559 in the photosynthetic electron transport chain. The inability in earlier times to define a redox-linked function of this cytochrome was, to a large extent, a consequence of an absence of biochemical and structure information to complement an extensive array of spectrophotometric studies of the cytochrome in situ. Based on the location of hetero-dimeric b-559 in the photosystem II reaction center complex, derived from crystal crystallographic structure analysis, and the absence of a necessary redox function for the cytochrome in PSII, it is proposed that the main function of cytochrome b-559 is linked to its role as a structure component in the PSII reaction center complex. This function resides in the association of b-559 through its heme histidine residues in the trans-membrane domains of the PsbE and PsbF subunits of the PSII reaction center. These subunits, along with PsbJ, are inferred, from the analysis of structure, to define the intra-membrane portal in the PSII reaction center for plastoquinol (PQH2) export which, through the PSII complex, provides the redox link to the cytochrome b6f complex in the electron transfer chain.
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Affiliation(s)
- W A Cramer
- Department of Biological Sciences, Purdue University, West Lafayette, IN, 47907, USA.
| | - S D Zakharov
- Department of Biological Sciences, Purdue University, West Lafayette, IN, 47907, 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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Hooper CM, Castleden IR, Tanz SK, Grasso SV, Millar AH. Subcellular Proteomics as a Unified Approach of Experimental Localizations and Computed Prediction Data for Arabidopsis and Crop Plants. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1346:67-89. [PMID: 35113396 DOI: 10.1007/978-3-030-80352-0_4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
In eukaryotic organisms, subcellular protein location is critical in defining protein function and understanding sub-functionalization of gene families. Some proteins have defined locations, whereas others have low specificity targeting and complex accumulation patterns. There is no single approach that can be considered entirely adequate for defining the in vivo location of all proteins. By combining evidence from different approaches, the strengths and weaknesses of different technologies can be estimated, and a location consensus can be built. The Subcellular Location of Proteins in Arabidopsis database ( http://suba.live/ ) combines experimental data sets that have been reported in the literature and is analyzing these data to provide useful tools for biologists to interpret their own data. Foremost among these tools is a consensus classifier (SUBAcon) that computes a proposed location for all proteins based on balancing the experimental evidence and predictions. Further tools analyze sets of proteins to define the abundance of cellular structures. Extending these types of resources to plant crop species has been complex due to polyploidy, gene family expansion and contraction, and the movement of pathways and processes within cells across the plant kingdom. The Crop Proteins of Annotated Location database ( http://crop-pal.org/ ) has developed a range of subcellular location resources including a species-specific voting consensus for 12 plant crop species that offers collated evidence and filters for current crop proteomes akin to SUBA. Comprehensive cross-species comparison of these data shows that the sub-cellular proteomes (subcellulomes) depend only to some degree on phylogenetic relationship and are more conserved in major biosynthesis than in metabolic pathways. Together SUBA and cropPAL created reference subcellulomes for plants as well as species-specific subcellulomes for cross-species data mining. These data collections are increasingly used by the research community to provide a subcellular protein location layer, inform models of compartmented cell function and protein-protein interaction network, guide future molecular crop breeding strategies, or simply answer a specific question-where is my protein of interest inside the cell?
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Affiliation(s)
- Cornelia M Hooper
- The Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, WA, Australia
| | - Ian R Castleden
- The Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, WA, Australia
| | - Sandra K Tanz
- The Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, WA, Australia
| | - Sally V Grasso
- The Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, WA, Australia
| | - A Harvey Millar
- The Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, WA, Australia.
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11
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Ilíková I, Ilík P, Opatíková M, Arshad R, Nosek L, Karlický V, Kučerová Z, Roudnický P, Pospíšil P, Lazár D, Bartoš J, Kouřil R. Towards spruce-type photosystem II: consequences of the loss of light-harvesting proteins LHCB3 and LHCB6 in Arabidopsis. PLANT PHYSIOLOGY 2021; 187:2691-2715. [PMID: 34618099 PMCID: PMC8644234 DOI: 10.1093/plphys/kiab396] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 07/26/2021] [Indexed: 05/28/2023]
Abstract
The largest stable photosystem II (PSII) supercomplex in land plants (C2S2M2) consists of a core complex dimer (C2), two strongly (S2) and two moderately (M2) bound light-harvesting protein (LHCB) trimers attached to C2 via monomeric antenna proteins LHCB4-6. Recently, we have shown that LHCB3 and LHCB6, presumably essential for land plants, are missing in Norway spruce (Picea abies), which results in a unique structure of its C2S2M2 supercomplex. Here, we performed structure-function characterization of PSII supercomplexes in Arabidopsis (Arabidopsis thaliana) mutants lhcb3, lhcb6, and lhcb3 lhcb6 to examine the possibility of the formation of the "spruce-type" PSII supercomplex in angiosperms. Unlike in spruce, in Arabidopsis both LHCB3 and LHCB6 are necessary for stable binding of the M trimer to PSII core. The "spruce-type" PSII supercomplex was observed with low abundance only in the lhcb3 plants and its formation did not require the presence of LHCB4.3, the only LHCB4-type protein in spruce. Electron microscopy analysis of grana membranes revealed that the majority of PSII in lhcb6 and namely in lhcb3 lhcb6 mutants were arranged into C2S2 semi-crystalline arrays, some of which appeared to structurally restrict plastoquinone diffusion. Mutants without LHCB6 were characterized by fast induction of non-photochemical quenching and, on the contrary to the previous lhcb6 study, by only transient slowdown of electron transport between PSII and PSI. We hypothesize that these functional changes, associated with the arrangement of PSII into C2S2 arrays in thylakoids, may be important for the photoprotection of both PSI and PSII upon abrupt high-light exposure.
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Affiliation(s)
- Iva Ilíková
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of
the Region Haná for Biotechnological and Agricultural Research, 783 71
Olomouc, Czech Republic
| | - Petr Ilík
- Department of Biophysics, Centre of the Region Haná for Biotechnological and
Agricultural Research, Palacký University, 783 71 Olomouc, Czech Republic
| | - Monika Opatíková
- Department of Biophysics, Centre of the Region Haná for Biotechnological and
Agricultural Research, Palacký University, 783 71 Olomouc, Czech Republic
| | - Rameez Arshad
- Department of Biophysics, Centre of the Region Haná for Biotechnological and
Agricultural Research, Palacký University, 783 71 Olomouc, Czech Republic
- Electron Microscopy Group, Groningen Biomolecular Sciences and Biotechnology
Institute, University of Groningen, Nijenborgh 7, 9747 AG Groningen,
The Netherlands
| | - Lukáš Nosek
- Department of Biophysics, Centre of the Region Haná for Biotechnological and
Agricultural Research, Palacký University, 783 71 Olomouc, Czech Republic
| | - Václav Karlický
- Department of Physics, Faculty of Science, University of Ostrava,
710 00 Ostrava, Czech Republic
- Global Change Research Institute of the Czech Academy of
Sciences, 603 00 Brno, Czech Republic
| | - Zuzana Kučerová
- Department of Biophysics, Centre of the Region Haná for Biotechnological and
Agricultural Research, Palacký University, 783 71 Olomouc, Czech Republic
| | - Pavel Roudnický
- Central European Institute of Technology, Masaryk University, 625
00 Brno, Czech Republic
| | - Pavel Pospíšil
- Department of Biophysics, Centre of the Region Haná for Biotechnological and
Agricultural Research, Palacký University, 783 71 Olomouc, Czech Republic
| | - Dušan Lazár
- Department of Biophysics, Centre of the Region Haná for Biotechnological and
Agricultural Research, Palacký University, 783 71 Olomouc, Czech Republic
| | - Jan Bartoš
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of
the Region Haná for Biotechnological and Agricultural Research, 783 71
Olomouc, Czech Republic
| | - Roman Kouřil
- Department of Biophysics, Centre of the Region Haná for Biotechnological and
Agricultural Research, Palacký University, 783 71 Olomouc, Czech Republic
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12
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Current Knowledge on Mechanisms Preventing Photosynthesis Redox Imbalance in Plants. Antioxidants (Basel) 2021; 10:antiox10111789. [PMID: 34829660 PMCID: PMC8614926 DOI: 10.3390/antiox10111789] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 10/28/2021] [Accepted: 11/05/2021] [Indexed: 12/03/2022] Open
Abstract
Photosynthesis includes a set of redox reactions that are the source of reducing power and energy for the assimilation of inorganic carbon, nitrogen and sulphur, thus generating organic compounds, and oxygen, which supports life on Earth. As sessile organisms, plants have to face continuous changes in environmental conditions and need to adjust the photosynthetic electron transport to prevent the accumulation of damaging oxygen by-products. The balance between photosynthetic cyclic and linear electron flows allows for the maintenance of a proper NADPH/ATP ratio that is adapted to the plant’s needs. In addition, different mechanisms to dissipate excess energy operate in plants to protect and optimise photosynthesis under adverse conditions. Recent reports show an important role of redox-based dithiol–disulphide interchanges, mediated both by classical and atypical chloroplast thioredoxins (TRXs), in the control of these photoprotective mechanisms. Moreover, membrane-anchored TRX-like proteins, such as HCF164, which transfer electrons from stromal TRXs to the thylakoid lumen, play a key role in the regulation of lumenal targets depending on the stromal redox poise. Interestingly, not all photoprotective players were reported to be under the control of TRXs. In this review, we discuss recent findings regarding the mechanisms that allow an appropriate electron flux to avoid the detrimental consequences of photosynthesis redox imbalances.
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13
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Chow WS. My precarious career in photosynthesis: a roller-coaster journey into the fascinating world of chloroplast ultrastructure, composition, function and dysfunction. PHOTOSYNTHESIS RESEARCH 2021; 149:5-24. [PMID: 33543372 DOI: 10.1007/s11120-021-00818-2] [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: 10/23/2020] [Accepted: 01/04/2021] [Indexed: 06/12/2023]
Abstract
Despite my humble beginnings in rural China, I had the good fortune of advancing my career and joining an international community of photosynthesis researchers to work on the 'light reactions' that are a fundamental process in Nature. Along with supervisors, mentors, colleagues, students and lab assistants, I worked on ionic redistributions across the photosynthetic membrane in response to illumination, photophosphorylation, forces that regulate the stacking of photosynthetic membranes, the composition of components of the photosynthetic apparatus during acclimation to the light environment, and the failure of the photosynthetic machinery to acclimate to too much light or even to cope with moderate light due to inevitable photodamage. These fascinating underlying mechanisms were investigated in vitro and in vivo. My career path, with its ups and downs, was never secure, but the reward of knowing a little more of the secret of Nature offset the job uncertainty.
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Affiliation(s)
- Wah Soon Chow
- Division of Plant Sciences, Research School of Biology, The Australian National University, 46 Sullivans Creek Road, Acton, ACT, 2601, Australia.
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14
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Kell DB. A protet-based, protonic charge transfer model of energy coupling in oxidative and photosynthetic phosphorylation. Adv Microb Physiol 2021; 78:1-177. [PMID: 34147184 DOI: 10.1016/bs.ampbs.2021.01.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Textbooks of biochemistry will explain that the otherwise endergonic reactions of ATP synthesis can be driven by the exergonic reactions of respiratory electron transport, and that these two half-reactions are catalyzed by protein complexes embedded in the same, closed membrane. These views are correct. The textbooks also state that, according to the chemiosmotic coupling hypothesis, a (or the) kinetically and thermodynamically competent intermediate linking the two half-reactions is the electrochemical difference of protons that is in equilibrium with that between the two bulk phases that the coupling membrane serves to separate. This gradient consists of a membrane potential term Δψ and a pH gradient term ΔpH, and is known colloquially as the protonmotive force or pmf. Artificial imposition of a pmf can drive phosphorylation, but only if the pmf exceeds some 150-170mV; to achieve in vivo rates the imposed pmf must reach 200mV. The key question then is 'does the pmf generated by electron transport exceed 200mV, or even 170mV?' The possibly surprising answer, from a great many kinds of experiment and sources of evidence, including direct measurements with microelectrodes, indicates it that it does not. Observable pH changes driven by electron transport are real, and they control various processes; however, compensating ion movements restrict the Δψ component to low values. A protet-based model, that I outline here, can account for all the necessary observations, including all of those inconsistent with chemiosmotic coupling, and provides for a variety of testable hypotheses by which it might be refined.
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Affiliation(s)
- Douglas B Kell
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative, Biology, University of Liverpool, Liverpool, United Kingdom; The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark.
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15
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Nicol L, Croce R. The PsbS protein and low pH are necessary and sufficient to induce quenching in the light-harvesting complex of plants LHCII. Sci Rep 2021; 11:7415. [PMID: 33795805 PMCID: PMC8016914 DOI: 10.1038/s41598-021-86975-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 03/11/2021] [Indexed: 11/10/2022] Open
Abstract
Photosynthesis is tightly regulated in order to withstand dynamic light environments. Under high light intensities, a mechanism known as non-photochemical quenching (NPQ) dissipates excess excitation energy, protecting the photosynthetic machinery from damage. An obstacle that lies in the way of understanding the molecular mechanism of NPQ is the large gap between in vitro and in vivo studies. On the one hand, the complexity of the photosynthetic membrane makes it challenging to obtain molecular information from in vivo experiments. On the other hand, a suitable in vitro system for the study of quenching is not available. Here we have developed a minimal NPQ system using proteoliposomes. With this, we demonstrate that the combination of low pH and PsbS is both necessary and sufficient to induce quenching in LHCII, the main antenna complex of plants. This proteoliposome system can be further exploited to gain more insight into how PsbS and other factors (e.g. zeaxanthin) influence the quenching mechanism observed in LHCII.
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Affiliation(s)
- Lauren Nicol
- Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands
| | - Roberta Croce
- Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands.
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16
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Kayanja GE, Ibrahim IM, Puthiyaveetil S. Regulation of Phaeodactylum plastid gene transcription by redox, light, and circadian signals. PHOTOSYNTHESIS RESEARCH 2021; 147:317-328. [PMID: 33387192 DOI: 10.1007/s11120-020-00811-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 12/03/2020] [Indexed: 06/12/2023]
Abstract
Diatoms are a diverse group of photosynthetic unicellular algae with a plastid of red-algal origin. As prolific primary producers in the ocean, diatoms fix as much carbon as all rainforests combined. The molecular mechanisms that contribute to the high photosynthetic productivity and ecological success of diatoms are however not yet fully understood. Using the model diatom Phaeodactylum tricornutum, here we show rhythmic transcript accumulation of plastid psaA, psbA, petB, and atpB genes as driven by a free running circadian clock. Treatment with the electron transport inhibitor 3-(3,4-dichlorophenyl)-1,1-dimethylurea overrides the circadian signal by markedly downregulating transcription of psaA, petB, and atpB genes but not the psbA gene. Changes in light quantity produce little change in plastid gene transcription while the effect of light quality seems modest with only the psaA gene responding in a pattern that is dependent on the redox state of the plastoquinone pool. The significance of these plastid transcriptional responses and the identity of the underlying genetic control systems are discussed with relevance to diatom photosynthetic acclimation.
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Affiliation(s)
- Gilbert E Kayanja
- Department of Biochemistry and Center for Plant Biology, Purdue University, West Lafayette, IN, 47907, USA
| | - Iskander M Ibrahim
- Department of Biochemistry and Center for Plant Biology, Purdue University, West Lafayette, IN, 47907, USA
| | - Sujith Puthiyaveetil
- Department of Biochemistry and Center for Plant Biology, Purdue University, West Lafayette, IN, 47907, USA.
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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: 61] [Impact Index Per Article: 20.3] [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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Flannery SE, Hepworth C, Wood WHJ, Pastorelli F, Hunter CN, Dickman MJ, Jackson PJ, Johnson MP. Developmental acclimation of the thylakoid proteome to light intensity in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 105:223-244. [PMID: 33118270 PMCID: PMC7898487 DOI: 10.1111/tpj.15053] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 10/13/2020] [Accepted: 10/21/2020] [Indexed: 05/03/2023]
Abstract
Photosynthetic acclimation, the ability to adjust the composition of the thylakoid membrane to optimise the efficiency of electron transfer to the prevailing light conditions, is crucial to plant fitness in the field. While much is known about photosynthetic acclimation in Arabidopsis, to date there has been no study that combines both quantitative label-free proteomics and photosynthetic analysis by gas exchange, chlorophyll fluorescence and P700 absorption spectroscopy. Using these methods we investigated how the levels of 402 thylakoid proteins, including many regulatory proteins not previously quantified, varied upon long-term (weeks) acclimation of Arabidopsis to low (LL), moderate (ML) and high (HL) growth light intensity and correlated these with key photosynthetic parameters. We show that changes in the relative abundance of cytb6 f, ATP synthase, FNR2, TIC62 and PGR6 positively correlate with changes in estimated PSII electron transfer rate and CO2 assimilation. Improved photosynthetic capacity in HL grown plants is paralleled by increased cyclic electron transport, which positively correlated with NDH, PGRL1, FNR1, FNR2 and TIC62, although not PGR5 abundance. The photoprotective acclimation strategy was also contrasting, with LL plants favouring slowly reversible non-photochemical quenching (qI), which positively correlated with LCNP, while HL plants favoured rapidly reversible quenching (qE), which positively correlated with PSBS. The long-term adjustment of thylakoid membrane grana diameter positively correlated with LHCII levels, while grana stacking negatively correlated with CURT1 and RIQ protein abundance. The data provide insights into how Arabidopsis tunes photosynthetic electron transfer and its regulation during developmental acclimation to light intensity.
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Affiliation(s)
- Sarah E. Flannery
- Department of Molecular Biology and BiotechnologyUniversity of SheffieldFirth CourtWestern BankSheffieldUK
| | - Christopher Hepworth
- Department of Molecular Biology and BiotechnologyUniversity of SheffieldFirth CourtWestern BankSheffieldUK
| | - William H. J. Wood
- Department of Molecular Biology and BiotechnologyUniversity of SheffieldFirth CourtWestern BankSheffieldUK
| | - Federica Pastorelli
- Department of Molecular Biology and BiotechnologyUniversity of SheffieldFirth CourtWestern BankSheffieldUK
| | - Christopher N. Hunter
- Department of Molecular Biology and BiotechnologyUniversity of SheffieldFirth CourtWestern BankSheffieldUK
| | - Mark J. Dickman
- Department of Chemical and Biological EngineeringChELSI InstituteUniversity of SheffieldSheffieldUK
| | - Philip J. Jackson
- Department of Molecular Biology and BiotechnologyUniversity of SheffieldFirth CourtWestern BankSheffieldUK
- Department of Chemical and Biological EngineeringChELSI InstituteUniversity of SheffieldSheffieldUK
| | - Matthew P. Johnson
- Department of Molecular Biology and BiotechnologyUniversity of SheffieldFirth CourtWestern BankSheffieldUK
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19
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Hooper CM, Castleden IR, Aryamanesh N, Black K, Grasso SV, Millar AH. CropPAL for discovering divergence in protein subcellular location in crops to support strategies for molecular crop breeding. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 104:812-827. [PMID: 32780488 DOI: 10.1111/tpj.14961] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 06/16/2020] [Accepted: 07/06/2020] [Indexed: 06/11/2023]
Abstract
Agriculture faces increasing demand for yield, higher plant-derived protein content and diversity while facing pressure to achieve sustainability. Although the genomes of many of the important crops have been sequenced, the subcellular locations of most of the encoded proteins remain unknown or are only predicted. Protein subcellular location is crucial in determining protein function and accumulation patterns in plants, and is critical for targeted improvements in yield and resilience. Integrating location data from over 800 studies for 12 major crop species into the cropPAL2020 data collection showed that while >80% of proteins in most species are not localised by experimental data, combining species data or integrating predictions can help bridge gaps at similar accuracy. The collation and integration of over 61 505 experimental localisations and more than 6 million predictions showed that the relative sizes of the protein catalogues located in different subcellular compartments are comparable between crops and Arabidopsis. A comprehensive cross-species comparison showed that between 50% and 80% of the subcellulomes are conserved across species and that conservation only depends to some degree on the phylogenetic relationship of the species. Protein subcellular locations in major biosynthesis pathways are more often conserved than in metabolic pathways. Underlying this conservation is a clear potential for subcellular diversity in protein location between species by means of gene duplication and alternative splicing. Our cropPAL data set and search platform (https://crop-pal.org) provide a comprehensive subcellular proteomics resource to drive compartmentation-based approaches for improving yield, protein composition and resilience in future crop varieties.
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Affiliation(s)
- Cornelia M Hooper
- ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, WA, 6009, Australia
| | - Ian R Castleden
- ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, WA, 6009, Australia
| | - Nader Aryamanesh
- Precision Medicine Theme, South Australian Health and Medical Research Institute, Adelaide, SA, 5000, Australia
- Robinson Research Institute and Adelaide Health and Medical Sciences, University of Adelaide, Adelaide, SA, 5000, Australia
| | - Kylie Black
- University Library, The University of Western Australia, Crawley, WA, 6009, Australia
| | - Sally V Grasso
- ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, WA, 6009, Australia
| | - A Harvey Millar
- ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, WA, 6009, Australia
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