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Vinyard DJ, Govindjee G. Bicarbonate is a key regulator but not a substrate for O 2 evolution in Photosystem II. PHOTOSYNTHESIS RESEARCH 2024; 162:93-99. [PMID: 39037690 DOI: 10.1007/s11120-024-01111-8] [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: 06/20/2024] [Accepted: 07/11/2024] [Indexed: 07/23/2024]
Abstract
Photosystem II (PSII) uses light energy to oxidize water and to reduce plastoquinone in the photosynthetic electron transport chain. O2 is produced as a byproduct. While most members of the PSII research community agree that O2 originates from water molecules, alternative hypotheses involving bicarbonate persist in the literature. In this perspective, we provide an overview of the important roles of bicarbonate in regulating PSII activity and assembly. Further, we emphasize that biochemistry, spectroscopy, and structural biology experiments have all failed to detect bicarbonate near the active site of O2 evolution. While thermodynamic arguments for oxygen-centered bicarbonate oxidation are valid, the claim that bicarbonate is a substrate for photosynthetic O2 evolution is challenged.
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Affiliation(s)
- David J Vinyard
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, 70803, USA.
| | - Govindjee Govindjee
- Department of Biochemistry, Department of Plant Biology, Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
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2
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Krysiak S, Burda K. The Effect of Removal of External Proteins PsbO, PsbP and PsbQ on Flash-Induced Molecular Oxygen Evolution and Its Biphasicity in Tobacco PSII. Curr Issues Mol Biol 2024; 46:7187-7218. [PMID: 39057069 PMCID: PMC11276211 DOI: 10.3390/cimb46070428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2024] [Revised: 06/30/2024] [Accepted: 07/02/2024] [Indexed: 07/28/2024] Open
Abstract
The oxygen evolution within photosystem II (PSII) is one of the most enigmatic processes occurring in nature. It is suggested that external proteins surrounding the oxygen-evolving complex (OEC) not only stabilize it and provide an appropriate ionic environment but also create water channels, which could be involved in triggering the ingress of water and the removal of O2 and protons outside the system. To investigate the influence of these proteins on the rate of oxygen release and the efficiency of OEC function, we developed a measurement protocol for the direct measurement of the kinetics of oxygen release from PSII using a Joliot-type electrode. PSII-enriched tobacco thylakoids were used in the experiments. The results revealed the existence of slow and fast modes of oxygen evolution. This observation is model-independent and requires no specific assumptions about the initial distribution of the OEC states. The gradual removal of exogenous proteins resulted in a slowdown of the rapid phase (~ms) of O2 release and its gradual disappearance while the slow phase (~tens of ms) accelerated. The role of external proteins in regulating the biphasicity and efficiency of oxygen release is discussed based on observed phenomena and current knowledge.
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Affiliation(s)
| | - Kvetoslava Burda
- Faculty of Physics and Applied Computer Science, AGH University of Krakow, al. Mickiewicza 30, 30-059 Krakow, Poland;
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3
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Arshad F, Eaton-Rye JJ. Indirect interactions involving the PsbM or PsbT subunits and the PsbO, PsbU and PsbV proteins stabilize assembly and activity of Photosystem II in Synechocystis sp. PCC 6803. PHOTOSYNTHESIS RESEARCH 2024; 160:61-75. [PMID: 38488942 PMCID: PMC11108944 DOI: 10.1007/s11120-024-01091-9] [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: 01/30/2024] [Accepted: 03/05/2024] [Indexed: 03/17/2024]
Abstract
The low-molecular-weight PsbM and PsbT proteins of Photosystem II (PS II) are both located at the monomer-monomer interface of the mature PS II dimer. Since the extrinsic proteins are associated with the final step of assembly of an active PS II monomer and, in the case of PsbO, are known to impact the stability of the PS II dimer, we have investigated the potential cooperativity between the PsbM and PsbT subunits and the PsbO, PsbU and PsbV extrinsic proteins. Blue-native polyacrylamide electrophoresis and western blotting detected stable PS II monomers in the ∆PsbM:∆PsbO and ∆PsbT:∆PsbO mutants that retained sufficient oxygen-evolving activity to support reduced photoautotrophic growth. In contrast, the ∆PsbM:∆PsbU and ∆PsbT:∆PsbU mutants assembled dimeric PS II at levels comparable to wild type and supported photoautotrophic growth at rates similar to those obtained with the corresponding ∆PsbM and ∆PsbT cells. Removal of PsbV was more detrimental than removal of PsbO. Only limited levels of dimeric PS II were observed in the ∆PsbM:∆PsbV mutant and the overall reduced level of assembled PS II in this mutant resulted in diminished rates of photoautotrophic growth and PS II activity below those obtained in the ∆PsbM:∆PsbO and ∆PsbT:∆PsbO strains. In addition, the ∆PsbT:∆PsbV mutant did not assemble active PS II centers although inactive monomers could be detected. The inability of the ∆PsbT:∆PsbV mutant to grow photoautotrophically, or to evolve oxygen, suggested a stable oxygen-evolving complex could not assemble in this mutant.
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Affiliation(s)
- Faiza Arshad
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
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4
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Bhattacharjee S, Arra S, Daidone I, Pantazis DA. Excitation landscape of the CP43 photosynthetic antenna complex from multiscale simulations. Chem Sci 2024; 15:7269-7284. [PMID: 38756808 PMCID: PMC11095388 DOI: 10.1039/d3sc06714a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Accepted: 04/07/2024] [Indexed: 05/18/2024] Open
Abstract
Photosystem II (PSII), the principal enzyme of oxygenic photosynthesis, contains two integral light harvesting proteins (CP43 and CP47) that bind chlorophylls and carotenoids. The two intrinsic antennae play crucial roles in excitation energy transfer and photoprotection. CP43 interacts most closely with the reaction center of PSII, specifically with the branch of the reaction center (D1) that is responsible for primary charge separation and electron transfer. Deciphering the function of CP43 requires detailed atomic-level insights into the properties of the embedded pigments. To advance this goal, we employ a range of multiscale computational approaches to determine the site energies and excitonic profile of CP43 chlorophylls, using large all-atom models of a membrane-bound PSII monomer. In addition to time-dependent density functional theory (TD-DFT) used in the context of a quantum-mechanics/molecular-mechanics setup (QM/MM), we present a thorough analysis using the perturbed matrix method (PMM), which enables us to utilize information from long-timescale molecular dynamics simulations of native PSII-complexed CP43. The excited state energetics and excitonic couplings have both similarities and differences compared with previous experimental fits and theoretical calculations. Both static TD-DFT and dynamic PMM results indicate a layered distribution of site energies and reveal specific groups of chlorophylls that have shared contributions to low-energy excitations. Importantly, the contribution to the lowest energy exciton does not arise from the same chlorophylls at each system configuration, but rather changes as a function of conformational dynamics. An unexpected finding is the identification of a low-energy charge-transfer excited state within CP43 that involves a lumenal (C2) and the central (C10) chlorophyll of the complex. The results provide a refined basis for structure-based interpretation of spectroscopic observations and for further deciphering excitation energy transfer in oxygenic photosynthesis.
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Affiliation(s)
- Sinjini Bhattacharjee
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany
| | - Srilatha Arra
- Department of Physical and Chemical Sciences, University of L'Aquila Via Vetoio (Coppito 1) 67010 L'Aquila Italy
| | - Isabella Daidone
- Department of Physical and Chemical Sciences, University of L'Aquila Via Vetoio (Coppito 1) 67010 L'Aquila Italy
| | - Dimitrios A Pantazis
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany
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5
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Ji N, Wang J, Huang W, Huang J, Cai Y, Sun S, Shen X, Liang Y. Transcriptome analysis of the harmful alga Heterosigma akashiwo under a 24-hour light-dark cycle. HARMFUL ALGAE 2024; 133:102601. [PMID: 38485440 DOI: 10.1016/j.hal.2024.102601] [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: 09/12/2023] [Revised: 01/29/2024] [Accepted: 02/05/2024] [Indexed: 03/19/2024]
Abstract
The photoperiod, which is defined as the period of time within a 24-hour time frame that light is available, is an important environmental regulator of several physiological processes in phytoplankton, including harmful bloom-forming phytoplankton. The ichthyotoxic raphidophyte Heterosigma akashiwo is a globally distributed bloom-forming phytoplankton. Despite extensive studies on the ecological impact of H. akashiwo, the influence of the photoperiod on crucial biological processes of this species remains unclear. In this study, gene expression in H. akashiwo was analyzed over a 24-hour light-dark (14:10) treatment period. Approximately 36 % of unigenes in H. akashiwo were differentially expressed during this 24-hour treatment period, which is indicative of their involvement in the response to light-dark variation. Notably, the number of differentially expressed genes exhibited an initial increase followed by a subsequent decrease as the sampling time progressed (T0 vs. other time points). Unigenes associated with photosynthesis and photoprotection reached their peak expression levels after 2-4 h of illumination (T12-T14). In contrast, the expression of unigenes associated with DNA replication peaked at the starting point of the dark period (T0). Furthermore, although several unigenes annotated to photoreceptors displayed potential diel periodicity, genes from various photoreceptor families (such as phytochrome and cryptochrome) showed unique expression patterns. Collectively, our findings offer novel perspectives on the response of H. akashiwo to the light-dark cycle, serving as a valuable resource for investigating the physiology and ecology of this species.
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Affiliation(s)
- Nanjing Ji
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang 222005, China; Jiangsu Marine Resources Development Research Institute, Lianyungang 222005, China; CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
| | - Junyue Wang
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang 222005, China
| | - Wencong Huang
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang 222005, China
| | - Jinwang Huang
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang 222005, China
| | - Yuefeng Cai
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang 222005, China
| | - Song Sun
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
| | - Xin Shen
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang 222005, China
| | - Yue Liang
- Center of Deep Sea Research, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
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Fadeeva M, Klaiman D, Kandiah E, Nelson N. Structure of native photosystem II assembly intermediate from Chlamydomonas reinhardtii. FRONTIERS IN PLANT SCIENCE 2024; 14:1334608. [PMID: 38322422 PMCID: PMC10844431 DOI: 10.3389/fpls.2023.1334608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 12/04/2023] [Indexed: 02/08/2024]
Abstract
Chlamydomonas reinhardtii Photosystem II (PSII) is a dimer consisting of at least 13 nuclear-encoded and four chloroplast-encoded protein subunits that collectively function as a sunlight-driven oxidoreductase. In this study, we present the inaugural structure of a green alga PSII assembly intermediate (pre-PSII-int). This intermediate was isolated from chloroplast membranes of the temperature-sensitive mutant TSP4, cultivated for 14 hours at a non-permissive temperature. The assembly state comprises a monomer containing subunits A, B, C, D, E, F, H, I, K, and two novel assembly factors, Psb1 and Psb2. Psb1 is identified as a novel transmembrane helix located adjacent to PsbE and PsbF (cytochrome b559). The absence of PsbJ, typically found in mature PSII close to this position, indicates that Psb1 functions as an assembly factor. Psb2 is an eukaryotic homolog of the cyanobacterial assembly factor Psb27. The presence of iron, coupled with the absence of QA, QB, and the manganese cluster, implies a protective mechanism against photodamage and provides insights into the intricate assembly process.
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Affiliation(s)
- Mariia Fadeeva
- The George S. Wise Faculty of Life Sciences, Department of Biochemistry and Molecular Biology, Tel Aviv University, Tel Aviv, Israel
| | - Daniel Klaiman
- The George S. Wise Faculty of Life Sciences, Department of Biochemistry and Molecular Biology, Tel Aviv University, Tel Aviv, Israel
| | - Eaazhisai Kandiah
- CM01 Beamline, European Synchrotron Radiation Facility (ESRF), Grenoble, France
| | - Nathan Nelson
- The George S. Wise Faculty of Life Sciences, Department of Biochemistry and Molecular Biology, Tel Aviv University, Tel Aviv, Israel
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Kappachery S, AlHosani M, Khan TA, AlKharoossi SN, AlMansoori N, AlShehhi SAS, AlMansoori H, AlKarbi M, Sasi S, Karumannil S, Elangovan SK, Shah I, Gururani MA. Modulation of antioxidant defense and PSII components by exogenously applied acetate mitigates salinity stress in Avena sativa. Sci Rep 2024; 14:620. [PMID: 38182773 PMCID: PMC10770181 DOI: 10.1038/s41598-024-51302-5] [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: 09/26/2023] [Accepted: 01/03/2024] [Indexed: 01/07/2024] Open
Abstract
Salinity stress has detrimental effects on various aspects of plant development. However, our understanding of strategies to mitigate these effects in crop plants remains limited. Recent research has shed light on the potential of sodium acetate as a mitigating component against salinity stress in several plant species. Here, we show the role of acetate sodium in counteracting the adverse effects on oat (Avena sativa) plants subjected to NaCl-induced salinity stress, including its impact on plant morphology, photosynthetic parameters, and gene expression related to photosynthesis and antioxidant capacity, ultimately leading to osmoprotection. The five-week experiment involved subjecting oat plants to four different conditions: water, salt (NaCl), sodium acetate, and a combination of salt and sodium acetate. The presence of NaCl significantly inhibited plant growth and root elongation, disrupted chlorophylls and carotenoids content, impaired chlorophyll fluorescence, and down-regulated genes associated with the plant antioxidant defense system. Furthermore, our findings reveal that when stressed plants were treated with sodium acetate, it partially reversed these adverse effects across all analyzed parameters. This reversal was particularly evident in the increased content of proline, thereby ensuring osmoprotection for oat plants, even under stressful conditions. These results provide compelling evidence regarding the positive impact of sodium acetate on various plant development parameters, with a particular focus on the enhancement of photosynthetic activity.
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Affiliation(s)
- Sajeesh Kappachery
- Department of Biology, College of Science, United Arab Emirates University, P.O.Box 15551, Al Ain, UAE
| | - Mohamed AlHosani
- Department of Biology, College of Science, United Arab Emirates University, P.O.Box 15551, Al Ain, UAE
| | - Tanveer Alam Khan
- Department of Biology, College of Science, United Arab Emirates University, P.O.Box 15551, Al Ain, UAE
| | - Sara Nouh AlKharoossi
- Department of Chemistry, College of Science, United Arab Emirates University, P.O.Box 15551, Al Ain, UAE
| | - Nemah AlMansoori
- Department of Biology, College of Science, United Arab Emirates University, P.O.Box 15551, Al Ain, UAE
| | - Sara Ali Saeed AlShehhi
- Department of Biology, College of Science, United Arab Emirates University, P.O.Box 15551, Al Ain, UAE
| | - Hamda AlMansoori
- Department of Chemistry, College of Science, United Arab Emirates University, P.O.Box 15551, Al Ain, UAE
| | - Maha AlKarbi
- Department of Chemistry, College of Science, United Arab Emirates University, P.O.Box 15551, Al Ain, UAE
| | - Shina Sasi
- Khalifa Center for Genetic Engineering and Biotechnology, College of Science, United Arab Emirates University, P.O.Box 15551, Al Ain, UAE
| | - Sameera Karumannil
- Department of Biology, College of Science, United Arab Emirates University, P.O.Box 15551, Al Ain, UAE
| | - Sampath Kumar Elangovan
- Department of Chemistry, College of Science, United Arab Emirates University, P.O.Box 15551, Al Ain, UAE
| | - Iltaf Shah
- Department of Chemistry, College of Science, United Arab Emirates University, P.O.Box 15551, Al Ain, UAE
| | - Mayank Anand Gururani
- Department of Biology, College of Science, United Arab Emirates University, P.O.Box 15551, Al Ain, UAE.
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8
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Russell BP, Vinyard DJ. Conformational changes in a Photosystem II hydrogen bond network stabilize the oxygen-evolving complex. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2024; 1865:149020. [PMID: 37956939 DOI: 10.1016/j.bbabio.2023.149020] [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: 08/02/2023] [Revised: 10/26/2023] [Accepted: 11/06/2023] [Indexed: 11/19/2023]
Abstract
The Mn4CaO5 oxygen-evolving complex (OEC) in Photosystem II (PSII) is assembled in situ and catalyzes water oxidation. After OEC assembly, the PsbO extrinsic subunit docks to the lumenal face of PSII and both stabilizes the OEC and facilitates efficient proton transfer to the lumen. D1 residue R334 is part of a hydrogen bond network involved in proton release during catalysis and interacts directly with PsbO. D1-R334 has recently been observed in different conformations in apo- and holo-OEC PSII structures. We generated a D1-R334G point mutant in Synechocystis sp. PCC 6803 to better understand this residue's function. D1-R334G PSII is active under continuous light, but the OEC is unstable in darkness. Isolated D1-R334G core complexes have little bound PsbO and less manganese as the wild type control. The S2 intermediate is stabilized in D1-R334G indicating that the local environment around the OEC has been altered. These results suggest that the hydrogen bond network that includes D1-R334 exists in a different functional conformation during PSII biogenesis in the absence of PsbO.
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Affiliation(s)
- Brandon P Russell
- Department of Biological Sciences, Louisiana State University, 202 Life Sciences Building, Baton Rouge, LA 70803, United States of America
| | - David J Vinyard
- Department of Biological Sciences, Louisiana State University, 202 Life Sciences Building, Baton Rouge, LA 70803, United States of America.
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Clarke VC, Marcelo-Silva J, Claassens S, Siebert SJ. Crinum bulbispermum, a Medicinal Geophyte with Phytostabilization Properties in Metal-Enriched Mine Tailings. PLANTS (BASEL, SWITZERLAND) 2023; 13:79. [PMID: 38202387 PMCID: PMC10780652 DOI: 10.3390/plants13010079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 12/18/2023] [Accepted: 12/20/2023] [Indexed: 01/12/2024]
Abstract
Ancient grasslands are lost through transformation to agriculture, mining, and urban expansion. Land-use change leads to ecosystem degradation and a subsequent loss of biodiversity. Globally, degraded grasslands have become a priority for restoration efforts to recover lost ecosystem services. Although the ecological and social benefits of woody species and grasses are well documented, limited research has considered the use of forbs for restoration purposes despite their benefits (e.g., C sequestration and medicinal uses). The aim of this study was to determine if Crinum bulbispermum (Burm.f.) Milne-Redh. & Schweick., a medicinal geophyte, could form part of restoration initiatives to restore mine soils in grasslands of the South African Highveld. A pot experiment was conducted to assess the performance of C. bulbispermum in a random design, with three soil treatments varying in level of degradation and metal contamination. The plants were monitored for 12 months, and the morphological characters were measured monthly to assess performance and survival. Inductively coupled plasma mass spectrometry (ICP-MS) was used to determine the soil and plant tissue concentration of potentially toxic metals. The results indicated that mine tailings negatively affected the growth and development of C. bulbispermum. Although the survival rates indicated that it could survive on tailings, its below-par productivity indicated that the species is not ideal for restoration purposes unless the tailings are ameliorated with topsoil. Although there was root accumulation of metals (Co, Cd, Cu, Mo, and Zn), there was no translocation to the bulbs and leaves, which makes C. bulbispermum suitable for medicinal use even when grown on metal-enriched soil. This species may not be viable for phytoremediation but is a contender to be used in phytostabilization due to its ecological advantages and the fact that it does not accumulate or store metals. These findings underscore the importance of considering geophytes in grassland restoration strategies, expanding their ecological and societal benefits beyond conventional approaches.
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Affiliation(s)
- Vincent C. Clarke
- Unit for Environmental Sciences and Management, North-West University, Potchefstroom 2531, South Africa; (V.C.C.); (S.C.)
| | - João Marcelo-Silva
- Unit for Environmental Sciences and Management, North-West University, Potchefstroom 2531, South Africa; (V.C.C.); (S.C.)
| | - Sarina Claassens
- Unit for Environmental Sciences and Management, North-West University, Potchefstroom 2531, South Africa; (V.C.C.); (S.C.)
- School of Molecular and Life Sciences, Curtin University, Bentley, WA 6102, Australia
| | - Stefan J. Siebert
- Unit for Environmental Sciences and Management, North-West University, Potchefstroom 2531, South Africa; (V.C.C.); (S.C.)
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10
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Su J, Jiao Q, Jia T, Hu X. The photosystem-II repair cycle: updates and open questions. PLANTA 2023; 259:20. [PMID: 38091081 DOI: 10.1007/s00425-023-04295-w] [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: 03/01/2023] [Accepted: 11/15/2023] [Indexed: 12/18/2023]
Abstract
MAIN CONCLUSION The photosystem-II (PSII) repair cycle is essential for the maintenance of photosynthesis in plants. A number of novel findings have illuminated the regulatory mechanisms of the PSII repair cycle. Photosystem II (PSII) is a large pigment-protein complex embedded in the thylakoid membrane. It plays a vital role in photosynthesis by absorbing light energy, splitting water, releasing molecular oxygen, and transferring electrons for plastoquinone reduction. However, PSII, especially the PsbA (D1) core subunit, is highly susceptible to oxidative damage. To prevent irreversible damage, plants have developed a repair cycle. The main objective of the PSII repair cycle is the degradation of photodamaged D1 and insertion of newly synthesized D1 into the PSII complex. While many factors are known to be involved in PSII repair, the exact mechanism is still under investigation. In this review, we discuss the primary steps of PSII repair, focusing on the proteolytic degradation of photodamaged D1 and the factors involved.
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Affiliation(s)
- Jinling Su
- International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education of China, Yangzhou University, Yangzhou, 225009, China
- Laboratory of Plant Functional Genomics of the Ministry of Education, Yangzhou University, Yangzhou, 225009, China
- College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, 225009, China
| | - Qingsong Jiao
- International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education of China, Yangzhou University, Yangzhou, 225009, China
- Laboratory of Plant Functional Genomics of the Ministry of Education, Yangzhou University, Yangzhou, 225009, China
- College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, 225009, China
| | - Ting Jia
- International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education of China, Yangzhou University, Yangzhou, 225009, China.
- Laboratory of Plant Functional Genomics of the Ministry of Education, Yangzhou University, Yangzhou, 225009, China.
| | - Xueyun Hu
- International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education of China, Yangzhou University, Yangzhou, 225009, China.
- Laboratory of Plant Functional Genomics of the Ministry of Education, Yangzhou University, Yangzhou, 225009, China.
- College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, 225009, China.
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11
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Kumar A, Prasad A, Sedlářová M, Pospíšil P. Malondialdehyde enhances PsbP protein release during heat stress in Arabidopsis. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2023; 202:107984. [PMID: 37669610 DOI: 10.1016/j.plaphy.2023.107984] [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: 04/14/2023] [Revised: 08/18/2023] [Accepted: 08/20/2023] [Indexed: 09/07/2023]
Abstract
Under environmental conditions, plants are exposed to various abiotic and biotic stress factors, which commonly cause the oxidation of lipids and proteins. Lipid peroxidation constantly produces malondialdehyde (MDA), a secondary product of lipid peroxidation, which is covalently bound to proteins forming MDA-protein adducts. The spatial distribution of MDA-protein adducts in Arabidopsis leaves shows that MDA-protein adducts are located in the chloroplasts, uniformly spread out over the thylakoid membrane. At the lumenal side of thylakoid membrane, MDA interacts with PsbP, an extrinsic subunit of the photosystem II (PSII), which is in electrostatic interaction with the PSII core proteins. Under heat stress, when MDA is moderately enhanced, the electrostatic interaction between PsbP and PSII core proteins is weakened, and PsbP with bound MDA is released in the lumen. It is proposed here that the electrophilic MDA is bound to the nucleophilic lysine residues of PsbP, which are involved in electrostatic interactions with the negatively charged glutamate of the PSII core protein. Our data provide crucial information about the MDA binding topology in the higher plant PSII complex, which is necessary to understand better the physiological functions of MDA for plant survival under stress.
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Affiliation(s)
- Aditya Kumar
- Department of Biophysics, Faculty of Science, Palacký University, Šlechtitelů 27, 783 71 Olomouc, Czech Republic
| | - Ankush Prasad
- Department of Biophysics, Faculty of Science, Palacký University, Šlechtitelů 27, 783 71 Olomouc, Czech Republic
| | - Michaela Sedlářová
- Department of Botany, Faculty of Science, Palacký University, Šlechtitelů 27, 783 71, Olomouc, Czech Republic
| | - Pavel Pospíšil
- Department of Biophysics, Faculty of Science, Palacký University, Šlechtitelů 27, 783 71 Olomouc, Czech Republic.
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12
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Xu W, Wuyun T, Chen J, Yu S, Zhang X, Zhang L. Responses of Trollius chinensis to drought stress and rehydration: From photosynthetic physiology to gene expression. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2023; 201:107841. [PMID: 37331075 DOI: 10.1016/j.plaphy.2023.107841] [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: 03/26/2023] [Revised: 05/20/2023] [Accepted: 06/13/2023] [Indexed: 06/20/2023]
Abstract
Drought stress occurs more frequently in recent years due to the global climate change. Widely distributed in northern China, Mongolia, and Russia, Trollius chinensis Bunge has high medicinal and ornamental values and is often exposed to drought stress, while the mechanism underlying its drought response is still unclear. In this study, we applied 74-76% (control, CK), 49-51% (mild drought), 34-36% (moderate drought), and 19-21% (severe drought, SD) of the soil gravimetric water content to T. chinensis, and measured leaf physiological characteristics on the 0, 5th, 10th, 15th day after the soil reaching the set drought severities, and on the 10th day after rehydration. The results showed that many physiological parameters, such as chlorophyll contents, Fv/Fm, ΦPSⅡ, Pn, and gs decreased with the deepening of severity and duration of drought stress and recovered to some extent after rehydration. On the 10th day of drought stress, leaves in SD and CK were selected for RNA-Seq, and 1649 differentially expressed genes (DEGs) were found, including 548 up-regulated and 1101 down-regulated DEGs. Gene Ontology enrichment found that the DEGs were mainly enriched in catalytic activity and thylakoid. Koyto Encyclopedia of Genes and Genomes enrichment found that DEGs were enriched in some metabolic pathways such as carbon fixation and photosynthesis. Among them, the differential expression of genes related to photosynthesis process, ABA biosynthesis and signaling pathway, such as NCED, SnRK2, PsaD, PsbQ, and PetE, might explain why T. chinensis could tolerate and recover from as long as 15 days of severe drought conditions.
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Affiliation(s)
- Wenyi Xu
- College of Landscape Architecture, Zhejiang A&F University, Hangzhou, 311300, China; College of Horticulture and Landscape Architecture, Northeast Agricultural University, Harbin, 150030, China
| | - Tana Wuyun
- Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Tartu, 51006, Estonia.
| | - Jing Chen
- College of Horticulture and Landscape Architecture, Northeast Agricultural University, Harbin, 150030, China
| | - Shuhan Yu
- College of Landscape Architecture, Zhejiang A&F University, Hangzhou, 311300, China
| | - Xinyang Zhang
- College of Landscape Architecture, Zhejiang A&F University, Hangzhou, 311300, China
| | - Lu Zhang
- College of Landscape Architecture, Zhejiang A&F University, Hangzhou, 311300, China.
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13
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Shevela D, Kern JF, Govindjee G, Messinger J. Solar energy conversion by photosystem II: principles and structures. PHOTOSYNTHESIS RESEARCH 2023; 156:279-307. [PMID: 36826741 PMCID: PMC10203033 DOI: 10.1007/s11120-022-00991-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 12/01/2022] [Indexed: 05/23/2023]
Abstract
Photosynthetic water oxidation by Photosystem II (PSII) is a fascinating process because it sustains life on Earth and serves as a blue print for scalable synthetic catalysts required for renewable energy applications. The biophysical, computational, and structural description of this process, which started more than 50 years ago, has made tremendous progress over the past two decades, with its high-resolution crystal structures being available not only of the dark-stable state of PSII, but of all the semi-stable reaction intermediates and even some transient states. Here, we summarize the current knowledge on PSII with emphasis on the basic principles that govern the conversion of light energy to chemical energy in PSII, as well as on the illustration of the molecular structures that enable these reactions. The important remaining questions regarding the mechanism of biological water oxidation are highlighted, and one possible pathway for this fundamental reaction is described at a molecular level.
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Affiliation(s)
- Dmitry Shevela
- Department of Chemistry, Chemical Biological Centre, Umeå University, 90187, Umeå, Sweden.
| | - Jan F Kern
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Govindjee Govindjee
- Department of Plant Biology, Department of Biochemistry and Center of Biophysics & Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Johannes Messinger
- Department of Chemistry, Chemical Biological Centre, Umeå University, 90187, Umeå, Sweden.
- Molecular Biomimetics, Department of Chemistry - Ångström, Uppsala University, 75120, Uppsala, Sweden.
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14
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Dedman CJ, Barton S, Fournier M, Rickaby REM. The cellular response to ocean warming in Emiliania huxleyi. Front Microbiol 2023; 14:1177349. [PMID: 37256052 PMCID: PMC10225680 DOI: 10.3389/fmicb.2023.1177349] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 04/12/2023] [Indexed: 06/01/2023] Open
Abstract
Marine phytoplankton contribute substantially to the global flux of carbon from the atmosphere to the deep ocean. Sea surface temperatures will inevitably increase in line with global climate change, altering the performance of marine phytoplankton. Differing sensitivities of photosynthesis and respiration to temperature, will likely shift the strength of the future oceanic carbon sink. To further clarify the molecular mechanisms driving these alterations in phytoplankton function, shotgun proteomic analysis was carried out on the globally-occurring coccolithophore Emiliania huxleyi exposed to moderate- (23°C) and elevated- (28°C) warming. Compared to the control (17°C), growth of E. huxleyi increased under elevated temperatures, with higher rates recorded under moderate- relative to elevated- warming. Proteomic analysis revealed a significant modification of the E. huxleyi cellular proteome as temperatures increased: at lower temperature, ribosomal proteins and photosynthetic machinery appeared abundant, as rates of protein translation and photosynthetic performance are restricted by low temperatures. As temperatures increased, evidence of heat stress was observed in the photosystem, characterized by a relative down-regulation of the Photosystem II oxygen evolving complex and ATP synthase. Acclimation to elevated warming (28°C) revealed a substantial alteration to carbon metabolism. Here, E. huxleyi made use of the glyoxylate cycle and succinate metabolism to optimize carbon use, maintain growth and maximize ATP production in heat-damaged mitochondria, enabling cultures to maintain growth at levels significantly higher than those recorded in the control (17°C). Based on the metabolic changes observed, we can predict that warming may benefit photosynthetic carbon fixation by E. huxleyi in the sub-optimal to optimal thermal range. Past the thermal optima, increasing rates of respiration and costs of repair will likely constrain growth, causing a possible decline in the contribution of this species to the oceanic carbon sink depending on the evolvability of these temperature thresholds.
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Affiliation(s)
- Craig J. Dedman
- Department of Earth Sciences, University of Oxford, Oxford, United Kingdom
| | - Samuel Barton
- Department of Earth Sciences, University of Oxford, Oxford, United Kingdom
| | - Marjorie Fournier
- Advanced Proteomics Facility, Department of Biochemistry, University of Oxford, Oxford, United Kingdom
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15
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Enez S, Karani Konuksever V, Samuei S, Karadas F, Ülker E. Enhancing Oxygen Evolution Catalytic Performance of Nickel Borate with Cobalt Doping and Carbon Nanotubes. ChemistrySelect 2023. [DOI: 10.1002/slct.202203561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Affiliation(s)
- Semra Enez
- Department of Chemistry Faculty of Arts & Sciences Recep Tayyip Erdogan University 53100 Rize Turkey
| | - Veysel Karani Konuksever
- Department of Chemistry Faculty of Arts & Sciences Recep Tayyip Erdogan University 53100 Rize Turkey
| | - Sara Samuei
- Department of Chemistry Faculty of Sciences Bilkent University 06800 Ankara Turkey
| | - Ferdi Karadas
- Department of Chemistry Faculty of Sciences Bilkent University 06800 Ankara Turkey
- UNAM-Institute of Materials Science and Nanotechnology Bilkent University 06800 Ankara Turkey
| | - Emine Ülker
- Department of Chemistry Faculty of Arts & Sciences Recep Tayyip Erdogan University 53100 Rize Turkey
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16
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Li W, Guo J, Han X, Da X, Wang K, Zhao H, Huang ST, Li B, He H, Jiang R, Zhou S, Yan P, Chen T, He Y, Xu J, Liu Y, Wu Y, Shou H, Wu Z, Mao C, Mo X. A novel protein domain is important for photosystem II complex assembly and photoautotrophic growth in angiosperms. MOLECULAR PLANT 2023; 16:374-392. [PMID: 36566350 DOI: 10.1016/j.molp.2022.12.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 11/24/2022] [Accepted: 12/21/2022] [Indexed: 06/17/2023]
Abstract
Photosystem II (PSII) is a multi-subunit protein complex of the photosynthetic electron transport chain that is vital to photosynthesis. Although the structure, composition, and function of PSII have been extensively studied, its biogenesis mechanism remains less understood. Thylakoid rhodanese-like (TROL) provides an anchor for leaf-type ferredoxin:NADP+ oxidoreductase. Here, we report the chacterizaton of a second type of TROL protein, TROL2, encoded by seed plant genomes whose function has not previously been reported. We show that TROL2 is a PSII assembly cofactor with essential roles in the establishment of photoautotrophy. TROL2 contains a 45-amino-acid domain, termed the chlorotic lethal seedling (CLS) domain, that is both necessary and sufficient for TROL2 function in PSII assembly and photoautotrophic growth. Phylogenetic analyses suggest that TROL2 may have arisen from ancestral TROL1 via gene duplication before the emergence of seed plants and acquired the CLS domain via evolution of the sequence encoding its N-terminal portion. We further reveal that TROL2 (or CLS) forms an assembly cofactor complex with the intrinsic thylakoid membrane protein LOW PSII ACCUMULATION2 and interacts with small PSII subunits to facilitate PSII complex assembly. Collectively, our study not only shows that TROL2 (CLS) is essential for photoautotrophy in angiosperms but also reveals its mechanistic role in PSII complex assembly, shedding light on the molecular and evolutionary mechanisms of photosynthetic complex assemblyin angiosperms.
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Affiliation(s)
- Wei Li
- State Key Laboratory of Plant Environmental Resilience, College of Life Science, Zhejiang University, Hangzhou 310058, PR China
| | - Jiangfan Guo
- College of Life Science, Shaanxi Normal University, Xi'an, Shaanxi Province 710062, PR China
| | - Xue Han
- School of Advanced Agricultural Sciences and School of Life Sciences, State Key Laboratory of Protein and Plant Gene Research, Peking University, Beijing 100871, China; Peking University Institute of Advanced Agricultural Sciences, Shandong Laboratory of Advanced Agricultural Sciences at Weifang, Weifang, Shandong 261000, China
| | - Xiaowen Da
- State Key Laboratory of Plant Environmental Resilience, College of Life Science, Zhejiang University, Hangzhou 310058, PR China
| | - Kai Wang
- State Key Laboratory of Plant Environmental Resilience, College of Life Science, Zhejiang University, Hangzhou 310058, PR China
| | - Hongfei Zhao
- College of Urban Construction, Zhejiang Shuren University, Hangzhou 310015, PR China
| | - Shi-Tang Huang
- School of Life Sciences, Peking University, Beijing 100871, PR China
| | - Bosheng Li
- Peking University Institute of Advanced Agricultural Sciences, Shandong Laboratory of Advanced Agricultural Sciences at Weifang, Weifang, Shandong 261000, China
| | - Hang He
- School of Advanced Agricultural Sciences and School of Life Sciences, State Key Laboratory of Protein and Plant Gene Research, Peking University, Beijing 100871, China; Peking University Institute of Advanced Agricultural Sciences, Shandong Laboratory of Advanced Agricultural Sciences at Weifang, Weifang, Shandong 261000, China
| | - Ruirui Jiang
- State Key Laboratory of Plant Environmental Resilience, College of Life Science, Zhejiang University, Hangzhou 310058, PR China
| | - Shichen Zhou
- State Key Laboratory of Plant Environmental Resilience, College of Life Science, Zhejiang University, Hangzhou 310058, PR China
| | - Peng Yan
- State Key Laboratory of Plant Environmental Resilience, College of Life Science, Zhejiang University, Hangzhou 310058, PR China
| | - Tao Chen
- State Key Laboratory of Plant Environmental Resilience, College of Life Science, Zhejiang University, Hangzhou 310058, PR China
| | - Yi He
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, Hangzhou 311300, PR China
| | - Jiming Xu
- State Key Laboratory of Plant Environmental Resilience, College of Life Science, Zhejiang University, Hangzhou 310058, PR China
| | - Yu Liu
- State Key Laboratory of Plant Environmental Resilience, College of Life Science, Zhejiang University, Hangzhou 310058, PR China
| | - Yunrong Wu
- State Key Laboratory of Plant Environmental Resilience, College of Life Science, Zhejiang University, Hangzhou 310058, PR China
| | - Huixia Shou
- State Key Laboratory of Plant Environmental Resilience, College of Life Science, Zhejiang University, Hangzhou 310058, PR China
| | - Zhongchang Wu
- State Key Laboratory of Plant Environmental Resilience, College of Life Science, Zhejiang University, Hangzhou 310058, PR China
| | - Chuanzao Mao
- State Key Laboratory of Plant Environmental Resilience, College of Life Science, Zhejiang University, Hangzhou 310058, PR China
| | - Xiaorong Mo
- State Key Laboratory of Plant Environmental Resilience, College of Life Science, Zhejiang University, Hangzhou 310058, PR China.
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Vidal‐Meireles A, Kuntam S, Széles E, Tóth D, Neupert J, Bock R, Tóth SZ. The lifetime of the oxygen-evolving complex subunit PSBO depends on light intensity and carbon availability in Chlamydomonas. PLANT, CELL & ENVIRONMENT 2023; 46:422-439. [PMID: 36320098 PMCID: PMC10100022 DOI: 10.1111/pce.14481] [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: 08/22/2022] [Revised: 10/13/2022] [Accepted: 10/14/2022] [Indexed: 06/16/2023]
Abstract
PSBO is essential for the assembly of the oxygen-evolving complex in plants and green algae. Despite its importance, we lack essential information on its lifetime and how it depends on the environmental conditions. We have generated nitrate-inducible PSBO amiRNA lines in the green alga Chlamydomonas reinhardtii. Transgenic strains grew normally under non-inducing conditions, and their photosynthetic performance was comparable to the control strain. Upon induction of the PSBO amiRNA constructs, cell division halted. In acetate-containing medium, cellular PSBO protein levels decreased by 60% within 24 h in the dark, by 75% in moderate light, and in high light, the protein completely degraded. Consequently, the photosynthetic apparatus became strongly damaged, probably due to 'donor-side-induced photoinhibition', and cellular ultrastructure was also severely affected. However, in the absence of acetate during induction, PSBO was remarkably stable at all light intensities and less substantial changes occurred in photosynthesis. Our results demonstrate that the lifetime of PSBO strongly depends on the light intensity and carbon availability, and thus, on the metabolic status of the cells. We also confirm that PSBO is required for photosystem II stability in C. reinhardtii and demonstrate that its specific loss also entails substantial changes in cell morphology and cell cycle.
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Affiliation(s)
- André Vidal‐Meireles
- Laboratory for Molecular Photobioenergetics, Biological Research CentreInstitute of Plant BiologySzegedHungary
- Present address:
Institute of Plant Biology and Biotechnology (IBBP), Westfälische Wilhelms‐Universität Münster (WWU)MünsterGermany
| | - Soujanya Kuntam
- Laboratory for Molecular Photobioenergetics, Biological Research CentreInstitute of Plant BiologySzegedHungary
| | - Eszter Széles
- Laboratory for Molecular Photobioenergetics, Biological Research CentreInstitute of Plant BiologySzegedHungary
- Doctoral School of BiologyUniversity of SzegedSzegedHungary
| | - Dávid Tóth
- Laboratory for Molecular Photobioenergetics, Biological Research CentreInstitute of Plant BiologySzegedHungary
- Doctoral School of BiologyUniversity of SzegedSzegedHungary
| | - Juliane Neupert
- Max Planck Institute of Molecular Plant PhysiologyPotsdam‐GolmGermany
| | - Ralph Bock
- Max Planck Institute of Molecular Plant PhysiologyPotsdam‐GolmGermany
| | - Szilvia Z. Tóth
- Laboratory for Molecular Photobioenergetics, Biological Research CentreInstitute of Plant BiologySzegedHungary
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18
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Gisriel CJ, Shen G, Flesher DA, Kurashov V, Golbeck JH, Brudvig GW, Amin M, Bryant DA. Structure of a dimeric photosystem II complex from a cyanobacterium acclimated to far-red light. J Biol Chem 2023; 299:102815. [PMID: 36549647 PMCID: PMC9843442 DOI: 10.1016/j.jbc.2022.102815] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 12/12/2022] [Accepted: 12/13/2022] [Indexed: 12/24/2022] Open
Abstract
Photosystem II (PSII) is the water-splitting enzyme central to oxygenic photosynthesis. To drive water oxidation, light is harvested by accessory pigments, mostly chlorophyll (Chl) a molecules, which absorb visible light (400-700 nm). Some cyanobacteria facultatively acclimate to shaded environments by altering their photosynthetic machinery to additionally absorb far-red light (FRL, 700-800 nm), a process termed far-red light photoacclimation or FaRLiP. During far-red light photoacclimation, FRL-PSII is assembled with FRL-specific isoforms of the subunits PsbA, PsbB, PsbC, PsbD, and PsbH, and some Chl-binding sites contain Chls d or f instead of the usual Chl a. The structure of an apo-FRL-PSII monomer lacking the FRL-specific PsbH subunit has previously been determined, but visualization of the dimeric complex has remained elusive. Here, we report the cryo-EM structure of a dimeric FRL-PSII complex. The site assignments for Chls d and f are consistent with those assigned in the previous apo-FRL-PSII monomeric structure. All sites that bind Chl d or Chl f at high occupancy exhibit a FRL-specific interaction of the formyl moiety of the Chl d or Chl f with the protein environment, which in some cases involves a phenylalanine sidechain. The structure retains the FRL-specific PsbH2 subunit, which appears to alter the energetic landscape of FRL-PSII, redirecting energy transfer from the phycobiliprotein complex to a Chl f molecule bound by PsbB2 that acts as a bridge for energy transfer to the electron transfer chain. Collectively, these observations extend our previous understanding of the structure-function relationship that allows PSII to function using lower energy FRL.
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Affiliation(s)
| | - Gaozhong Shen
- 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
| | - Vasily Kurashov
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, 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
| | - Gary W Brudvig
- Department of Chemistry, Yale University, New Haven, Connecticut, USA; Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
| | - Muhamed Amin
- Department of Sciences, University College Groningen, University of Groningen, Groningen, the Netherlands; Rijksuniversiteit Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, the Netherlands; Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
| | - Donald A Bryant
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA.
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Li J, Liu X, Xu L, Li W, Yao Q, Yin X, Wang Q, Tan W, Xing W, Liu D. Low nitrogen stress-induced transcriptome changes revealed the molecular response and tolerance characteristics in maintaining the C/N balance of sugar beet ( Beta vulgaris L.). FRONTIERS IN PLANT SCIENCE 2023; 14:1164151. [PMID: 37152145 PMCID: PMC10160481 DOI: 10.3389/fpls.2023.1164151] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2023] [Accepted: 03/31/2023] [Indexed: 05/09/2023]
Abstract
Nitrogen (N) is an essential macronutrient for plants, acting as a common limiting factor for crop yield. The application of nitrogen fertilizer is related to the sustainable development of both crops and the environment. To further explore the molecular response of sugar beet under low nitrogen (LN) supply, transcriptome analysis was performed on the LN-tolerant germplasm '780016B/12 superior'. In total, 580 differentially expressed genes (DEGs) were identified in leaves, and 1,075 DEGs were identified in roots (log2 |FC| ≥ 1; q value < 0.05). Gene Ontology (GO), protein-protein interaction (PPI), and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses clarified the role and relationship of DEGs under LN stress. Most of the downregulated DEGs were closely related to "photosynthesis" and the metabolism of "photosynthesis-antenna proteins", "carbon", "nitrogen", and "glutathione", while the upregulated DEGs were involved in flavonoid and phenylalanine biosynthesis. For example, GLUDB (glutamate dehydrogenase B) was identified as a key downregulated gene, linking carbon, nitrogen, and glutamate metabolism. Thus, low nitrogen-tolerant sugar beet reduced energy expenditure mainly by reducing the synthesis of energy-consuming amino acids, which in turn improved tolerance to low nitrogen stress. The glutathione metabolism biosynthesis pathway was promoted to quench reactive oxygen species (ROS) and protect cells from oxidative damage. The expression levels of nitrogen assimilation and amino acid transport genes, such as NRT2.5 (high-affinity nitrate transporter), NR (nitrate reductase [NADH]), NIR (ferredoxin-nitrite reductase), GS (glutamine synthetase leaf isozyme), GLUDB, GST (glutathione transferase) and GGT3 (glutathione hydrolase 3) at low nitrogen levels play a decisive role in nitrogen utilization and may affect the conversion of the carbon skeleton. DFRA (dihydroflavonol 4-reductase) in roots was negatively correlated with NIR in leaves (coefficient = -0.98, p < 0.05), suggesting that there may be corresponding remote regulation between "flavonoid biosynthesis" and "nitrogen metabolism" in roots and leaves. FBP (fructose 1,6-bisphosphatase) and PGK (phosphoglycerate kinase) were significantly positively correlated (p < 0.001) with Ci (intercellular CO2 concentration). The reliability and reproducibility of the RNA-seq data were further confirmed by real-time fluorescence quantitative PCR (qRT-PCR) validation of 22 genes (R2 = 0.98). This study reveals possible pivotal genes and metabolic pathways for sugar beet adaptation to nitrogen-deficient environments.
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Affiliation(s)
- Jiajia Li
- National Beet Medium-term Gene Bank, Heilongjiang University, Harbin, China
- Key Laboratory of Sugar Beet Genetics and Breeding, Heilongjiang Province Common College/College of Advanced agriculture and ecological environment, Heilongjiang University, Harbin, China
| | - Xinyu Liu
- National Beet Medium-term Gene Bank, Heilongjiang University, Harbin, China
- Key Laboratory of Sugar Beet Genetics and Breeding, Heilongjiang Province Common College/College of Advanced agriculture and ecological environment, Heilongjiang University, Harbin, China
- Key Laboratory of Molecular Biology, School of Life Sciences, Heilongjiang University, Harbin, China
| | - Lingqing Xu
- National Beet Medium-term Gene Bank, Heilongjiang University, Harbin, China
- Key Laboratory of Sugar Beet Genetics and Breeding, Heilongjiang Province Common College/College of Advanced agriculture and ecological environment, Heilongjiang University, Harbin, China
| | - Wangsheng Li
- National Beet Medium-term Gene Bank, Heilongjiang University, Harbin, China
- Key Laboratory of Sugar Beet Genetics and Breeding, Heilongjiang Province Common College/College of Advanced agriculture and ecological environment, Heilongjiang University, Harbin, China
| | - Qi Yao
- National Beet Medium-term Gene Bank, Heilongjiang University, Harbin, China
- Key Laboratory of Sugar Beet Genetics and Breeding, Heilongjiang Province Common College/College of Advanced agriculture and ecological environment, Heilongjiang University, Harbin, China
- Key Laboratory of Molecular Biology, School of Life Sciences, Heilongjiang University, Harbin, China
| | - Xilong Yin
- National Beet Medium-term Gene Bank, Heilongjiang University, Harbin, China
- Key Laboratory of Sugar Beet Genetics and Breeding, Heilongjiang Province Common College/College of Advanced agriculture and ecological environment, Heilongjiang University, Harbin, China
| | - Qiuhong Wang
- National Beet Medium-term Gene Bank, Heilongjiang University, Harbin, China
- Key Laboratory of Sugar Beet Genetics and Breeding, Heilongjiang Province Common College/College of Advanced agriculture and ecological environment, Heilongjiang University, Harbin, China
| | - Wenbo Tan
- National Beet Medium-term Gene Bank, Heilongjiang University, Harbin, China
- Key Laboratory of Sugar Beet Genetics and Breeding, Heilongjiang Province Common College/College of Advanced agriculture and ecological environment, Heilongjiang University, Harbin, China
| | - Wang Xing
- National Beet Medium-term Gene Bank, Heilongjiang University, Harbin, China
- Key Laboratory of Sugar Beet Genetics and Breeding, Heilongjiang Province Common College/College of Advanced agriculture and ecological environment, Heilongjiang University, Harbin, China
- *Correspondence: Dali Liu, ; Wang Xing,
| | - Dali Liu
- National Beet Medium-term Gene Bank, Heilongjiang University, Harbin, China
- Key Laboratory of Sugar Beet Genetics and Breeding, Heilongjiang Province Common College/College of Advanced agriculture and ecological environment, Heilongjiang University, Harbin, China
- *Correspondence: Dali Liu, ; Wang Xing,
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Wu R, Yao F, Li X, Shi C, Zang X, Shu X, Liu H, Zhang W. Manganese Pollution and Its Remediation: A Review of Biological Removal and Promising Combination Strategies. Microorganisms 2022; 10:2411. [PMID: 36557664 PMCID: PMC9781601 DOI: 10.3390/microorganisms10122411] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 11/30/2022] [Accepted: 12/01/2022] [Indexed: 12/12/2022] Open
Abstract
Manganese (Mn), as a cofactor of multiple enzymes, exhibits great significance to the human body, plants and animals. It is also a critical raw material and alloying element. However, extensive employment for industrial purposes leads to its excessive emission into the environment and turns into a significant threat to the ecosystem and public health. This review firstly introduces the essentiality, toxicity and regulation of Mn. Several traditional physicochemical methods and their problems are briefly discussed as well. Biological remediation, especially microorganism-mediated strategies, is a potential alternative for remediating Mn-polluted environments in a cost-efficient and eco-friendly manner. Among them, microbially induced carbonate precipitation (MICP), biosorption, bioaccumulation, bio-oxidation are discussed in detail, including their mechanisms, pivotal influencing factors along with strengths and limitations. In order to promote bioremediation efficiency, the combination of different techniques is preferable, and their research progress is also summarized. Finally, we propose the future directions of Mn bioremediation by microbes. Conclusively, this review provides a scientific basis for the microbial remediation performance for Mn pollution and guides the development of a comprehensive competent strategy towards practical Mn remediation.
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Affiliation(s)
| | | | | | | | | | | | - Hengwei Liu
- School of Chemistry and Life Sciences, Suzhou University of Science and Technology, Suzhou 215009, China
| | - Wenchao Zhang
- School of Chemistry and Life Sciences, Suzhou University of Science and Technology, Suzhou 215009, China
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21
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Khristin MS, Smolova TN, Khorobrykh AA. Dimerization of the Free and Photosystem II-Associated PsbO Protein upon Irradiation with UV Light. Biophysics (Nagoya-shi) 2022. [DOI: 10.1134/s0006350922060100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023] Open
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Castell C, Díaz-Santos E, Heredia-Martínez LG, López-Maury L, Ortega JM, Navarro JA, Roncel M, Hervás M. Iron Deficiency Promotes the Lack of Photosynthetic Cytochrome c550 and Affects the Binding of the Luminal Extrinsic Subunits to Photosystem II in the Diatom Phaeodactylum tricornutum. Int J Mol Sci 2022; 23:ijms232012138. [PMID: 36292994 PMCID: PMC9603157 DOI: 10.3390/ijms232012138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 10/06/2022] [Accepted: 10/08/2022] [Indexed: 12/04/2022] Open
Abstract
In the diatom Phaeodactylum tricornutum, iron limitation promotes a decrease in the content of photosystem II, as determined by measurements of oxygen-evolving activity, thermoluminescence, chlorophyll fluorescence analyses and protein quantification methods. Thermoluminescence experiments also indicate that iron limitation induces subtle changes in the energetics of the recombination reaction between reduced QB and the S2/S3 states of the water-splitting machinery. However, electron transfer from QA to QB, involving non-heme iron, seems not to be significantly inhibited. Moreover, iron deficiency promotes a severe decrease in the content of the extrinsic PsbV/cytochrome c550 subunit of photosystem II, which appears in eukaryotic algae from the red photosynthetic lineage (including diatoms) but is absent in green algae and plants. The decline in the content of cytochrome c550 under iron-limiting conditions is accompanied by a decrease in the binding of this protein to photosystem II, and also of the extrinsic PsbO subunit. We propose that the lack of cytochrome c550, induced by iron deficiency, specifically affects the binding of other extrinsic subunits of photosystem II, as previously described in cyanobacterial PsbV mutants.
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23
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Ślesak I, Mazur Z, Ślesak H. Genes encoding the photosystem II proteins are under purifying selection: an insight into the early evolution of oxygenic photosynthesis. PHOTOSYNTHESIS RESEARCH 2022; 153:163-175. [PMID: 35648248 DOI: 10.1007/s11120-022-00917-8] [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: 01/21/2022] [Accepted: 03/28/2022] [Indexed: 06/15/2023]
Abstract
The molecular evolution concerns coding sequences (CDSs) of genes and may affect the structure and function of proteins. Non-uniform use of synonymous codons during translation, known as codon usage bias (CUB), depends on the balance between mutations bias and natural selection. We estimated different CUB indices, i.e. the effective number of codons (ENC), G + C content in the 3rd codon positions (GC3), and codon adaptation index for CDSs of intrinsic proteins of photosystem II (PSII), such as psbA (D1), psbD (D2), psbB (CP47), psbC (CP43), and CDSs of the extrinsic protein psbO (PsbO). These genes occur in all organisms that perform oxygenic photosynthesis (OP) on Earth: cyanobacteria, algae and plants. Comparatively, a similar analysis of codon bias for CDSs of L and M subunits that constitute the core proteins of the type II reaction centre (RCII) in anoxygenic bacteria was performed. Analysis of CUB indices and determination of the number of synonymous (dS) and nonsynonymous substitutions (dN) in all analysed CDSs indicated that the crucial PSII and RCII proteins were under strong purifying (negative) selection in course of evolution. Purifying selection was also estimated for CDSs of atpA, the α subunit of ATP synthase, an enzyme that was most likely already present in the last universal common ancestor (LUCA). The data obtained point to an ancient origin of OP, even in the earliest stages of the evolution of life on Earth.
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Affiliation(s)
- Ireneusz Ślesak
- The Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Niezapominajek 21, 30-239, Kraków, Poland.
| | - Zofia Mazur
- The Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Niezapominajek 21, 30-239, Kraków, Poland
| | - Halina Ślesak
- Institute of Botany, Faculty of Biology, Jagiellonian University, Gronostajowa 9, 30-387, Kraków, Poland
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24
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Imaizumi K, Ifuku K. Binding and functions of the two chloride ions in the oxygen-evolving center of photosystem II. PHOTOSYNTHESIS RESEARCH 2022; 153:135-156. [PMID: 35698013 DOI: 10.1007/s11120-022-00921-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 05/02/2022] [Indexed: 06/15/2023]
Abstract
Light-driven water oxidation in photosynthesis occurs at the oxygen-evolving center (OEC) of photosystem II (PSII). Chloride ions (Cl-) are essential for oxygen evolution by PSII, and two Cl- ions have been found to specifically bind near the Mn4CaO5 cluster in the OEC. The retention of these Cl- ions within the OEC is critically supported by some of the membrane-extrinsic subunits of PSII. The functions of these two Cl- ions and the mechanisms of their retention both remain to be fully elucidated. However, intensive studies performed recently have advanced our understanding of the functions of these Cl- ions, and PSII structures from various species have been reported, aiding the interpretation of previous findings regarding Cl- retention by extrinsic subunits. In this review, we summarize the findings to date on the roles of the two Cl- ions bound within the OEC. Additionally, together with a short summary of the functions of PSII membrane-extrinsic subunits, we discuss the mechanisms of Cl- retention by these extrinsic subunits.
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Affiliation(s)
- Ko Imaizumi
- Division of Integrated Life Science, Graduate School of Biostudies, Kyoto University, Kyoto, 606-8502, Japan
| | - Kentaro Ifuku
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, 606-8502, Japan.
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25
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Adamczyk-Szabela D, Wolf WM. The Impact of Soil pH on Heavy Metals Uptake and Photosynthesis Efficiency in Melissa officinalis, Taraxacum officinalis, Ocimum basilicum. Molecules 2022; 27:molecules27154671. [PMID: 35897849 PMCID: PMC9331646 DOI: 10.3390/molecules27154671] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 07/18/2022] [Accepted: 07/19/2022] [Indexed: 02/01/2023] Open
Abstract
Herbs used in medicine should be grown under controlled and standardized conditions. Agricultural practices often induce changes to soil pH, which may affect migration of heavy metals in the environment, their accumulation in plant tissues and the concentration of medicinal ingredients. The aim of this work was to assess the influence of various soil pH on the biological parameters and uptake of manganese, copper and zinc by basil, dandelion and lemon balm. The soil analysis covered pH, organic matter content, bioavailable and total forms of investigated metals in soil. In plants cultivated in soil at pH covering the range 4.7–8.5 the concentrations of Mn, Cu and Zn were analyzed. Their mobility and availability were assessed by bioaccumulation factors, translocation factors and transfer coefficients. The seed germination and subsequent herbs growth were strongly dependent on soil pH for all investigated plant species. Photosynthetic efficiency at different pHs was positively correlated with uptake of Cu and Mn while Zn behaved in a more random way.
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26
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Imaizumi K, Nishimura T, Nagao R, Saito K, Nakano T, Ishikita H, Noguchi T, Ifuku K. D139N mutation of PsbP enhances the oxygen-evolving activity of photosystem II through stabilized binding of a chloride ion. PNAS NEXUS 2022; 1:pgac136. [PMID: 36741451 PMCID: PMC9896922 DOI: 10.1093/pnasnexus/pgac136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 07/19/2022] [Indexed: 02/07/2023]
Abstract
Photosystem II (PSII) is a multisubunit membrane protein complex that catalyzes light-driven oxidation of water to molecular oxygen. The chloride ion (Cl-) has long been known as an essential cofactor for oxygen evolution by PSII, and two Cl- ions (Cl-1 and Cl-2) have been found to specifically bind near the Mn4CaO5 cluster within the oxygen-evolving center (OEC). However, despite intensive studies on these Cl- ions, little is known about the function of Cl-2, the Cl- ion that is associated with the backbone nitrogens of D1-Asn338, D1-Phe339, and CP43-Glu354. In green plant PSII, the membrane extrinsic subunits-PsbP and PsbQ-are responsible for Cl- retention within the OEC. The Loop 4 region of PsbP, consisting of highly conserved residues Thr135-Gly142, is inserted close to Cl-2, but its importance has not been examined to date. Here, we investigated the importance of PsbP-Loop 4 using spinach PSII membranes reconstituted with spinach PsbP proteins harboring mutations in this region. Mutations in PsbP-Loop 4 had remarkable effects on the rate of oxygen evolution by PSII. Moreover, we found that a specific mutation, PsbP-D139N, significantly enhances the oxygen-evolving activity in the absence of PsbQ, but not significantly in its presence. The D139N mutation increased the Cl- retention ability of PsbP and induced a unique structural change in the OEC, as indicated by light-induced Fourier transform infrared (FTIR) difference spectroscopy and theoretical calculations. Our findings provide insight into the functional significance of Cl-2 in the water-oxidizing reaction of PSII.
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Affiliation(s)
- Ko Imaizumi
- Division of Integrated Life Science, Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Taishi Nishimura
- Division of Integrated Life Science, Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Ryo Nagao
- Division of Material Science, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan
- Research Institute for Interdisciplinary Science, Okayama University, Okayama 700-8530, Japan
| | - Keisuke Saito
- Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo 153-8904, Japan
- Department of Applied Chemistry, The University of Tokyo, Tokyo 113-8654 , Japan
| | - Takeshi Nakano
- Division of Integrated Life Science, Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Hiroshi Ishikita
- Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo 153-8904, Japan
- Department of Applied Chemistry, The University of Tokyo, Tokyo 113-8654 , Japan
| | - Takumi Noguchi
- Division of Material Science, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan
| | - Kentaro Ifuku
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
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27
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Arsic M, Persson DP, Schjoerring JK, Thygesen LG, Lombi E, Doolette CL, Husted S. Foliar-applied manganese and phosphorus in deficient barley: Linking absorption pathways and leaf nutrient status. PHYSIOLOGIA PLANTARUM 2022; 174:e13761. [PMID: 36004733 PMCID: PMC9543583 DOI: 10.1111/ppl.13761] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 07/08/2022] [Accepted: 08/02/2022] [Indexed: 06/15/2023]
Abstract
Foliar fertilization delivers essential nutrients directly to plant tissues, reducing excessive soil fertilizer applications that can lead to eutrophication following nutrient leaching. Foliar nutrient absorption is a dynamic process affected by leaf surface structure and composition, plant nutrient status, and ion physicochemical properties. We applied multiple methods to study the foliar absorption behaviors of manganese (Mn) and phosphorus (P) in nutrient-deficient spring barley (Hordeum vulgare) at two growth stages. Nutrient-specific chlorophyll a fluorescence assays were used to visualize leaf nutrient status, while laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) was used to visualize foliar absorption pathways for P and Mn ions. Rapid Mn absorption was facilitated by a relatively thin cuticle with a low abundance of waxes and a higher stomatal density in Mn-deficient plants. Following absorption, Mn accumulated in epidermal cells and in the photosynthetically active mesophyll, enabling a fast (6 h) restoration of Mn-dependent photosynthetic processes. Conversely, P-deficient plants developed thicker cuticles and epidermal cell walls, which reduced the penetration of P across the leaf surface. Foliar-applied P accumulated in trichomes and fiber cells above leaf veins without reaching the mesophyll and, as a consequence, no restoration of P-dependent photosynthetic processes was observed. This study reveals new links between leaf surface morphology, foliar-applied ion absorption pathways, and the restoration of affected physiological processes in nutrient-deficient leaves. Understanding that ions may have different absorption pathways across the leaf surface is critical for the future development of efficient fertilization strategies for crops in nutrient-limited soils.
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Affiliation(s)
- Maja Arsic
- Department of Plant and Environmental SciencesUniversity of CopenhagenFrederiksberg CDenmark
- University of South AustraliaFuture Industries InstituteMawson LakesSouth AustraliaAustralia
- Present address:
CSIRO Agriculture and Food, Queensland Biosciences PrecinctSt. LuciaQueenslandAustralia
| | - Daniel P. Persson
- Department of Plant and Environmental SciencesUniversity of CopenhagenFrederiksberg CDenmark
| | - Jan K. Schjoerring
- Department of Plant and Environmental SciencesUniversity of CopenhagenFrederiksberg CDenmark
| | - Lisbeth G. Thygesen
- Department of Geosciences and Natural Resource ManagementUniversity of CopenhagenFrederiksberg CDenmark
| | - Enzo Lombi
- University of South AustraliaFuture Industries InstituteMawson LakesSouth AustraliaAustralia
| | - Casey L. Doolette
- University of South AustraliaFuture Industries InstituteMawson LakesSouth AustraliaAustralia
| | - Søren Husted
- Department of Plant and Environmental SciencesUniversity of CopenhagenFrederiksberg CDenmark
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28
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Khaing EP, Zhong V, Kodru S, Vass I, Eaton-Rye JJ. Tyr244 of the D2 Protein Is Required for Correct Assembly and Operation of the Quinone-Iron-Bicarbonate Acceptor Complex of Photosystem II. Biochemistry 2022; 61:1298-1312. [PMID: 35699437 DOI: 10.1021/acs.biochem.2c00164] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Two plastoquinone electron acceptors, QA and QB, are present in Photosystem II (PS II) with their binding sites formed by the D2 and D1 proteins, respectively. A hexacoordinate non-heme iron is bound between QA and QB by D2 and D1, each providing two histidine ligands, and a bicarbonate that is stabilized via hydrogen bonds with D2-Tyr244 and D1-Tyr246. Both tyrosines and bicarbonate are conserved in oxygenic photosynthetic organisms but absent from the corresponding quinone-iron electron acceptor complex of anoxygenic photosynthetic bacteria. We investigated the role of D2-Tyr244 by introducing mutations in the cyanobacterium Synechocystis sp. PCC 6803. Alanine, histidine, and phenylalanine substitutions were introduced creating the Y244A, Y244H, and Y244F mutants. Electron transfer between QA and QB was impaired, the back-reaction with the S2 state of the oxygen-evolving complex was modified, and PS II assembly was disrupted, with the Y244A strain being more affected than the Y244F and Y244H mutants. The strains were also highly susceptible to photodamage in the presence of PS II-specific electron acceptors. Thermoluminescence and chlorophyll a fluorescence decay measurements indicated that the redox potential of the QA/QA- couple became more positive in the Y244F and Y244H mutants, consistent with bicarbonate binding being impacted. The replacement of Tyr244 by alanine also led to an insertion of two amino acid repeats from Gln239 to Ala249 within the DE loop of D2, resulting in an inactive PS II complex that lacked PS II-specific variable fluorescence. The 66 bp insertion giving rise to the inserted amino acids therefore created an obligate photoheterotrophic mutant.
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Affiliation(s)
- Ei Phyo Khaing
- Department of Biochemistry, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand
| | - Victor Zhong
- Department of Biochemistry, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand
| | - Sandeesha Kodru
- Biological Research Center, Institute of Plant Biology, Szeged 6726, Hungary
| | - Imre Vass
- Biological Research Center, Institute of Plant Biology, Szeged 6726, Hungary
| | - Julian J Eaton-Rye
- Department of Biochemistry, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand
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29
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Gisriel CJ, Brudvig GW. Comparison of PsbQ and Psb27 in photosystem II provides insight into their roles. PHOTOSYNTHESIS RESEARCH 2022; 152:177-191. [PMID: 35001227 PMCID: PMC9271139 DOI: 10.1007/s11120-021-00888-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 11/24/2021] [Indexed: 06/14/2023]
Abstract
Photosystem II (PSII) catalyzes the oxidation of water at its active site that harbors a high-valent inorganic Mn4CaOx cluster called the oxygen-evolving complex (OEC). Extrinsic subunits generally serve to protect the OEC from reductants and stabilize the structure, but diversity in the extrinsic subunits exists between phototrophs. Recent cryo-electron microscopy experiments have provided new molecular structures of PSII with varied extrinsic subunits. We focus on the extrinsic subunit PsbQ, that binds to the mature PSII complex, and on Psb27, an extrinsic subunit involved in PSII biogenesis. PsbQ and Psb27 share a similar binding site and have a four-helix bundle tertiary structure, suggesting they are related. Here, we use sequence alignments, structural analyses, and binding simulations to compare PsbQ and Psb27 from different organisms. We find no evidence that PsbQ and Psb27 are related despite their similar structures and binding sites. Evolutionary divergence within PsbQ homologs from different lineages is high, probably due to their interactions with other extrinsic subunits that themselves exhibit vast diversity between lineages. This may result in functional variation as exemplified by large differences in their calculated binding energies. Psb27 homologs generally exhibit less divergence, which may be due to stronger evolutionary selection for certain residues that maintain its function during PSII biogenesis and this is consistent with their more similar calculated binding energies between organisms. Previous experimental inconsistencies, low confidence binding simulations, and recent structural data suggest that Psb27 is likely to exhibit flexibility that may be an important characteristic of its activity. The analysis provides insight into the functions and evolution of PsbQ and Psb27, and an unusual example of proteins with similar tertiary structures and binding sites that probably serve different roles.
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Affiliation(s)
| | - Gary W Brudvig
- Department of Chemistry, Yale University, New Haven, CT, 06520, USA.
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, 06520, USA.
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30
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Yocum CF. Photosystem 2 and the oxygen evolving complex: a brief overview. PHOTOSYNTHESIS RESEARCH 2022; 152:97-105. [PMID: 35294671 DOI: 10.1007/s11120-022-00910-1] [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: 11/24/2021] [Accepted: 02/28/2022] [Indexed: 06/14/2023]
Abstract
These special issues of photosynthesis research present papers documenting progress in revealing the many aspects of photosystem 2, a unique, one-of-a-kind complex system that can reduce a plastoquinone to a plastoquinol on every second flash of light and oxidize 2 H2O to an O2 on every fourth flash. This overview is a brief personal assessment of the progress observed by the author over a four-decade research career, including a discussion of some remaining unsolved issues. It will come as no surprise to readers that there are remaining questions given the complexity of PS2, and the efforts that have been needed so far to uncover its secrets. In fact, most readers will have their own lists of outstanding questions.
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Affiliation(s)
- Charles F Yocum
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, 48109, USA.
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31
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Shi Y, Ke X, Yang X, Liu Y, Hou X. Plants response to light stress. J Genet Genomics 2022; 49:735-747. [DOI: 10.1016/j.jgg.2022.04.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 04/13/2022] [Accepted: 04/26/2022] [Indexed: 11/30/2022]
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Advances in the Understanding of the Lifecycle of Photosystem II. Microorganisms 2022; 10:microorganisms10050836. [PMID: 35630282 PMCID: PMC9145668 DOI: 10.3390/microorganisms10050836] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 04/14/2022] [Accepted: 04/16/2022] [Indexed: 02/04/2023] Open
Abstract
Photosystem II is a light-driven water-plastoquinone oxidoreductase present in cyanobacteria, algae and plants. It produces molecular oxygen and protons to drive ATP synthesis, fueling life on Earth. As a multi-subunit membrane-protein-pigment complex, Photosystem II undergoes a dynamic cycle of synthesis, damage, and repair known as the Photosystem II lifecycle, to maintain a high level of photosynthetic activity at the cellular level. Cyanobacteria, oxygenic photosynthetic bacteria, are frequently used as model organisms to study oxygenic photosynthetic processes due to their ease of growth and genetic manipulation. The cyanobacterial PSII structure and function have been well-characterized, but its lifecycle is under active investigation. In this review, advances in studying the lifecycle of Photosystem II in cyanobacteria will be discussed, with a particular emphasis on new structural findings enabled by cryo-electron microscopy. These structural findings complement a rich and growing body of biochemical and molecular biology research into Photosystem II assembly and repair.
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33
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Su X, Cao D, Pan X, Shi L, Liu Z, Dall'Osto L, Bassi R, Zhang X, Li M. Supramolecular assembly of chloroplast NADH dehydrogenase-like complex with photosystem I from Arabidopsis thaliana. MOLECULAR PLANT 2022; 15:454-467. [PMID: 35123031 DOI: 10.1016/j.molp.2022.01.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 01/27/2022] [Accepted: 01/30/2022] [Indexed: 06/14/2023]
Abstract
Cyclic electron transport/flow (CET/CEF) in chloroplasts is a regulatory process essential for the optimization of plant photosynthetic efficiency. A crucial CEF pathway is catalyzed by a membrane-embedded NADH dehydrogenase-like (NDH) complex that contains at least 29 protein subunits and associates with photosystem I (PSI) to form the NDH-PSI supercomplex. Here, we report the 3.9 Å resolution structure of the Arabidopsis thaliana NDH-PSI (AtNDH-PSI) supercomplex. We constructed structural models for 26 AtNDH subunits, among which 11 are unique to chloroplasts and stabilize the core part of the NDH complex. In the supercomplex, one NDH can bind up to two PSI-light-harvesting complex I (PSI-LHCI) complexes at both sides of its membrane arm. Two minor LHCIs, Lhca5 and Lhca6, each present in one PSI-LHCI, interact with NDH and contribute to supercomplex formation and stabilization. Collectively, our study reveals the structural details of the AtNDH-PSI supercomplex assembly and provides a molecular basis for further investigation of the regulatory mechanism of CEF in plants.
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Affiliation(s)
- Xiaodong Su
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, P.R. China; University of Chinese Academy of Sciences, Beijing 100049, P.R. China
| | - Duanfang Cao
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, P.R. China
| | - Xiaowei Pan
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, P.R. China; College of Life Science, Capital Normal University, Beijing 100101, P.R. China.
| | - Lifang Shi
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, P.R. China
| | - Zhenfeng Liu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, P.R. China; University of Chinese Academy of Sciences, Beijing 100049, P.R. China
| | - Luca Dall'Osto
- Dipartimento di Biotecnologie, Università di Verona, 37134 Verona, Italy
| | - Roberto Bassi
- Dipartimento di Biotecnologie, Università di Verona, 37134 Verona, Italy
| | - Xinzheng Zhang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, P.R. China; University of Chinese Academy of Sciences, Beijing 100049, P.R. China; Center for Biological Imaging, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, P.R. China.
| | - Mei Li
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, P.R. China.
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Li M, Long B, Dai SY, Golden JW, Wang X, Yuan JS. Altered Carbon Partitioning Enhances CO 2 to Terpene Conversion in Cyanobacteria. BIODESIGN RESEARCH 2022; 2022:9897425. [PMID: 37850123 PMCID: PMC10521692 DOI: 10.34133/2022/9897425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 01/11/2022] [Indexed: 10/19/2023] Open
Abstract
Photosynthetic terpene production represents one of the most carbon and energy-efficient routes for converting CO2 into hydrocarbon. In photosynthetic organisms, metabolic engineering has led to limited success in enhancing terpene productivity, partially due to the low carbon partitioning. In this study, we employed systems biology analysis to reveal the strong competition for carbon substrates between primary metabolism (e.g., sucrose, glycogen, and protein synthesis) and terpene biosynthesis in Synechococcus elongatus PCC 7942. We then engineered key "source" and "sink" enzymes. The "source" limitation was overcome by knocking out either sucrose or glycogen biosynthesis to significantly enhance limonene production via altered carbon partitioning. Moreover, a fusion enzyme complex with geranyl diphosphate synthase (GPPS) and limonene synthase (LS) was designed to further improve pathway kinetics and substrate channeling. The synergy between "source" and "sink" achieved a limonene titer of 21.0 mg/L. Overall, the study demonstrates that balancing carbon flux between primary and secondary metabolism can be an effective approach to enhance terpene bioproduction in cyanobacteria. The design of "source" and "sink" synergy has significant potential in improving natural product yield in photosynthetic species.
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Affiliation(s)
- Man Li
- Synthetic and Systems Biology Innovation Hub, Texas A&M University, College Station, Texas 77843, USA
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas 77843, USA
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of ScienceChina
| | - Bin Long
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas 77843, USA
| | - Susie Y. Dai
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas 77843, USA
| | - James W. Golden
- Section of Molecular Biology, University of California San Diego, La Jolla, CA 92093, USA
| | - Xin Wang
- Synthetic and Systems Biology Innovation Hub, Texas A&M University, College Station, Texas 77843, USA
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas 77843, USA
- Department of Microbiology, Miami University, Oxford, Ohio 45056, USA
| | - Joshua S. Yuan
- Synthetic and Systems Biology Innovation Hub, Texas A&M University, College Station, Texas 77843, USA
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas 77843, USA
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Biswas S, Eaton-Rye JJ. PsbX maintains efficient electron transport in Photosystem II and reduces susceptibility to high light in Synechocystis sp. PCC 6803. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2022; 1863:148519. [PMID: 34890576 DOI: 10.1016/j.bbabio.2021.148519] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 11/15/2021] [Accepted: 11/30/2021] [Indexed: 12/13/2022]
Abstract
PsbX is a 4.1 kDa intrinsic Photosystem II (PS II) protein, found together with the low-molecular-weight proteins, PsbY and PsbJ, in proximity to cytochrome b559. The function of PsbX is not yet fully characterized but PsbX may play a role in the exchange of the secondary plastoquinone electron acceptor QB with the quinone pool in the thylakoid membrane. To study the role of PsbX, we have constructed a PsbX-lacking strain of Synechocystis sp. PCC 6803. Our studies indicate that the absence of PsbX causes sensitivity to high light and impairs electron transport within PS II. In addition to a change in the QB-binding pocket, PsbX-lacking cells exhibited sensitivity to sodium formate, suggesting altered binding of the bicarbonate ligand to the non-heme iron between the sequential plastoquinone electron acceptors QA and QB. Experiments using 35S-methionine revealed high-light-treated PsbX-lacking cells restore PS II activity during recovery under low light by an increase in the turnover of PS II-associated core proteins. These labeling experiments indicate the recovery after exposure to high light requires both selective removal and replacement of the D1 protein and de novo PS II assembly.
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Affiliation(s)
- Sandeep Biswas
- Department of Biochemistry, University of Otago, New Zealand
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Spaniol B, Lang J, Venn B, Schake L, Sommer F, Mustas M, Geimer S, Wollman FA, Choquet Y, Mühlhaus T, Schroda M. Complexome profiling on the Chlamydomonas lpa2 mutant reveals insights into PSII biogenesis and new PSII associated proteins. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:245-262. [PMID: 34436580 PMCID: PMC8730698 DOI: 10.1093/jxb/erab390] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 08/24/2021] [Indexed: 05/27/2023]
Abstract
While the composition and function of the major thylakoid membrane complexes are well understood, comparatively little is known about their biogenesis. The goal of this work was to shed more light on the role of auxiliary factors in the biogenesis of photosystem II (PSII). Here we have identified the homolog of LOW PSII ACCUMULATION 2 (LPA2) in Chlamydomonas. A Chlamydomonas reinhardtii lpa2 mutant grew slower in low light, was hypersensitive to high light, and exhibited aberrant structures in thylakoid membrane stacks. Chlorophyll fluorescence (Fv/Fm) was reduced by 38%. Synthesis and stability of newly made PSII core subunits D1, D2, CP43, and CP47 were not impaired. However, complexome profiling revealed that in the mutant CP43 was reduced to ~23% and D1, D2, and CP47 to ~30% of wild type levels. Levels of PSI and the cytochrome b6f complex were unchanged, while levels of the ATP synthase were increased by ~29%. PSII supercomplexes, dimers, and monomers were reduced to ~7%, ~26%, and ~60% of wild type levels, while RC47 was increased ~6-fold and LHCII by ~27%. We propose that LPA2 catalyses a step during PSII assembly without which PSII monomers and further assemblies become unstable and prone to degradation. The LHCI antenna was more disconnected from PSI in the lpa2 mutant, presumably as an adaptive response to reduce excitation of PSI. From the co-migration profiles of 1734 membrane-associated proteins, we identified three novel putative PSII associated proteins with potential roles in regulating PSII complex dynamics, assembly, and chlorophyll breakdown.
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Affiliation(s)
- Benjamin Spaniol
- Molekulare Biotechnologie & Systembiologie, TU Kaiserslautern, Paul-Ehrlich Straße 23, D-67663 Kaiserslautern, Germany
| | - Julia Lang
- Molekulare Biotechnologie & Systembiologie, TU Kaiserslautern, Paul-Ehrlich Straße 23, D-67663 Kaiserslautern, Germany
| | - Benedikt Venn
- Computational Systems Biology, TU Kaiserslautern, Paul-Ehrlich Straße 23, D-67663 Kaiserslautern, Germany
| | - Lara Schake
- Molekulare Biotechnologie & Systembiologie, TU Kaiserslautern, Paul-Ehrlich Straße 23, D-67663 Kaiserslautern, Germany
| | - Frederik Sommer
- Molekulare Biotechnologie & Systembiologie, TU Kaiserslautern, Paul-Ehrlich Straße 23, D-67663 Kaiserslautern, Germany
| | - Matthieu Mustas
- Biologie du Chloroplaste et Perception de la Lumière chez les Microalgues, Institut de Biologie Physico-Chimique, UMR CNRS/UPMC 7141, Paris, France
| | - Stefan Geimer
- Zellbiologie/Elektronenmikroskopie, Universität Bayreuth, 95440 Bayreuth, Germany
| | - Francis-André Wollman
- Biologie du Chloroplaste et Perception de la Lumière chez les Microalgues, Institut de Biologie Physico-Chimique, UMR CNRS/UPMC 7141, Paris, France
| | - Yves Choquet
- Biologie du Chloroplaste et Perception de la Lumière chez les Microalgues, Institut de Biologie Physico-Chimique, UMR CNRS/UPMC 7141, Paris, France
| | - Timo Mühlhaus
- Computational Systems Biology, TU Kaiserslautern, Paul-Ehrlich Straße 23, D-67663 Kaiserslautern, Germany
| | - Michael Schroda
- Molekulare Biotechnologie & Systembiologie, TU Kaiserslautern, Paul-Ehrlich Straße 23, D-67663 Kaiserslautern, Germany
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Gisriel CJ, Wang J, Liu J, Flesher DA, Reiss KM, Huang HL, Yang KR, Armstrong WH, Gunner MR, Batista VS, Debus RJ, Brudvig GW. High-resolution cryo-electron microscopy structure of photosystem II from the mesophilic cyanobacterium, Synechocystis sp. PCC 6803. Proc Natl Acad Sci U S A 2022; 119:e2116765118. [PMID: 34937700 PMCID: PMC8740770 DOI: 10.1073/pnas.2116765118] [Citation(s) in RCA: 59] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/18/2021] [Indexed: 12/15/2022] Open
Abstract
Photosystem II (PSII) enables global-scale, light-driven water oxidation. Genetic manipulation of PSII from the mesophilic cyanobacterium Synechocystis sp. PCC 6803 has provided insights into the mechanism of water oxidation; however, the lack of a high-resolution structure of oxygen-evolving PSII from this organism has limited the interpretation of biophysical data to models based on structures of thermophilic cyanobacterial PSII. Here, we report the cryo-electron microscopy structure of PSII from Synechocystis sp. PCC 6803 at 1.93-Å resolution. A number of differences are observed relative to thermophilic PSII structures, including the following: the extrinsic subunit PsbQ is maintained, the C terminus of the D1 subunit is flexible, some waters near the active site are partially occupied, and differences in the PsbV subunit block the Large (O1) water channel. These features strongly influence the structural picture of PSII, especially as it pertains to the mechanism of water oxidation.
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Affiliation(s)
| | - Jimin Wang
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520
| | - Jinchan Liu
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520
| | - David A Flesher
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520
| | - Krystle M Reiss
- Department of Chemistry, Yale University, New Haven, CT 06520
| | - Hao-Li Huang
- Department of Chemistry, Yale University, New Haven, CT 06520
| | - Ke R Yang
- Department of Chemistry, Yale University, New Haven, CT 06520
| | | | - M R Gunner
- Department of Physics, City College of New York, New York, NY 100031
| | | | - Richard J Debus
- Department of Biochemistry, University of California, Riverside, CA 92521
| | - Gary W Brudvig
- Department of Chemistry, Yale University, New Haven, CT 06520;
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520
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Choo P, Forsman JA, Hui L, Khaing EP, Summerfield TC, Eaton-Rye JJ. The PsbJ protein is required for photosystem II activity in centers lacking the PsbO and PsbV lumenal subunits. PHOTOSYNTHESIS RESEARCH 2022; 151:103-111. [PMID: 34273062 DOI: 10.1007/s11120-021-00862-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 07/02/2021] [Indexed: 06/13/2023]
Abstract
Photosystem II (PS II) of oxygenic photosynthesis is found in the thylakoid membranes of plastids and cyanobacteria. The mature PS II complex comprises a central core of four membrane proteins that bind the majority of the redox-active cofactors. In cyanobacteria the central core is surrounded by 13 low-molecular-weight (LMW) subunits which each consist of one or two transmembrane helices. Three additional hydrophilic subunits known as PsbO, PsbU and PsbV are found associated with hydrophilic loops belonging to the core proteins protruding into the thylakoid lumen. During biogenesis the majority of the LMW subunits are known to initially associate with individual pre-assembly complexes consisting of one or more of the core proteins; however, the point at which the PsbJ LMW subunit binds to PS II is not known. The majority of models for PS II biogenesis propose that the three extrinsic proteins and PsbJ bind in the final stages of PS II assembly. We have investigated the impact of creating the double mutants ∆PsbJ:∆PsbO, ∆PsbJ:∆PsbU and ∆PsbJ:∆PsbV to investigate potential cooperation between these subunits in the final stages of biogenesis. Our results indicate that PsbJ can bind to PS II in the absence of any one of the extrinsic proteins. However, unlike their respective single mutants, the ∆PsbJ:∆PsbO and ∆PsbJ:∆PsbV strains were not photoautotrophic and were unable to support oxygen evolution suggesting a functional oxygen-evolving complex could not assemble in these strains. In contrast, the PS II centers formed in the ∆PsbJ:∆PsbU strain were capable of photoautotrophic growth and could support oxygen evolution when whole-chain electron transport was supported by the addition of bicarbonate.
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Affiliation(s)
- Priscilla Choo
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | - Jack A Forsman
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
- Department of Botany, University of Otago, Dunedin, New Zealand
| | - Liangliang Hui
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | - Ei Phyo Khaing
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
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Narzi D, Guidoni L. Structural and dynamic insights into Mn 4Ca cluster-depleted Photosystem II. Phys Chem Chem Phys 2021; 23:27428-27436. [PMID: 34860219 DOI: 10.1039/d1cp02367e] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In the first steps of natural oxygenic photosynthesis, sunlight is used to oxidize water molecules to protons, electrons and molecular oxygen. This reaction takes place on the Mn4Ca cluster located in the reaction centre of Photosystem II (PSII), where the cluster is assembled and continuously repaired through a process known as photoactivation. Understanding the molecular details of such a process has important implications in different fields, in particular inspiring synthesis and repair strategies for artificial photosynthesis devices. In this regard, a detailed structural and dynamic characterization of Photosystem II lacking a Mn4Ca cluster, namely apo PSII, is a prerequisite for the full comprehension of the photoactivation. Recently, the structure of the apo PSII was resolved at 2.55 Å resolution [Zhang et al., eLife, 2017, 6, e26933], suggesting a pre-organized structure of the protein cavity hosting the cluster. Anyway, the question of whether these findings are a feature of the method used remains open. Here, by means of classical Molecular Dynamics simulations, we characterized the structural and dynamic features of the apo PSII for different protonation states of the cluster cavity. Albeit an overall conformational stability common to all investigated systems, we found significant deviations in the conformation of the side chains of the active site with respect to the X-ray positions. Our findings suggest that not all residues acting as Mn ligands are pre-organized prior to the Mn4Ca formation and previous local conformational changes are required in order to bind the first Mn ion in the high-affinity binding site.
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Affiliation(s)
- Daniele Narzi
- Department of Physical and Chemical Science, Università dellAquila, LAquila, Italy.
| | - Leonardo Guidoni
- Department of Physical and Chemical Science, Università dellAquila, LAquila, Italy.
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Wen X, Yang Z, Ding S, Yang H, Zhang L, Lu C, Lu Q. Analysis of the changes of electron transfer and heterogeneity of photosystem II in Deg1-reduced Arabidopsis plants. PHOTOSYNTHESIS RESEARCH 2021; 150:159-177. [PMID: 33993381 DOI: 10.1007/s11120-021-00842-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 05/04/2021] [Indexed: 05/07/2023]
Abstract
Deg1 protease functions in protease and chaperone of PSII complex components, but few works were performed to study the effects of Deg1 on electron transport activities on the donor and acceptor side of PSII and its correlation with the photoprotection of PSII during photoinhibition. Therefore, we performed systematic and comprehensive investigations of electron transfers on the donor and acceptor sides of photosystem II (PSII) in the Deg1-reduced transgenic lines deg1-2 and deg1-4. Both the maximal quantum efficiency of PSII photochemistry (Fv/Fm) and the actual PSII efficiency (ΦPSII) decreased significantly in the transgenic plants. Increases in nonphotochemical quenching (NPQ) and the dissipated energy flux per reaction center (DI0/RC) were also shown in the transgenic plants. Along with the decreased D1, CP47, and CP43 content, these results suggested photoinhibition under growth light conditions in transgenic plants. Decreased Deg1 caused inhibition of electron transfer on the PSII reducing side, leading to a decline in the number of QB-reducing centers and accumulation of QB-nonreducing centers. The Tm of the Q band shifted from 5.7 °C in the wild-type plant to 10.4 °C and 14.2 °C in the deg1-2 and deg1-4 plants, respectively, indicating an increase in the stability of S2QA¯ in transgenic plants. PSIIα in the transgenic plants largely reduced, while PSIIβ and PSIIγ increased with the decline in the Deg1 levels in transgenic plants suggesting PSIIα centers gradually converted into PSIIβ and PSIIγ centers in the transgenic plants. Besides, the connectivity of PSIIα and PSIIβ was downregulated in transgenic plants. Our results reveal that downregulation of Deg1 protein levels induced photoinhibition in transgenic plants, leading to loss of PSII activities on both the donor and acceptor sides in transgenic plants. These results give a new insight into the regulation role of Deg1 in PSII electron transport.
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Affiliation(s)
- Xiaogang Wen
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100093, China
| | - Zhipan Yang
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Shunhua Ding
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Huixia Yang
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Lixin Zhang
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, 85 Minglun Street, Kaifeng, 475001, China
| | - Congming Lu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, 271018, China.
| | - Qingtao Lu
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
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Huang YW, Sun CI, Hu CC, Tsai CH, Meng M, Lin NS, Hsu YH. NbPsbO1 Interacts Specifically with the Bamboo Mosaic Virus (BaMV) Subgenomic RNA (sgRNA) Promoter and Is Required for Efficient BaMV sgRNA Transcription. J Virol 2021; 95:e0083121. [PMID: 34379502 PMCID: PMC8475527 DOI: 10.1128/jvi.00831-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 07/28/2021] [Indexed: 11/26/2022] Open
Abstract
Many positive-strand (+) RNA viruses produce subgenomic RNAs (sgRNAs) in the infection cycle through the combined activities of viral replicase and host proteins. However, knowledge about host proteins involved in direct sgRNA promoter recognition is limited. Here, in the partially purified replicase complexes from Bamboo mosaic virus (BaMV)-infected tissue, we have identified the Nicotiana benthamiana photosystem II oxygen-evolving complex protein, NbPsbO1, which specifically interacted with the promoter of sgRNA but not that of genomic RNA (gRNA). Silencing of NbPsbO1 expression suppressed BaMV accumulation in N. benthamiana protoplasts without affecting viral gRNA replication. Overexpression of wild-type NbPsbO1 stimulated BaMV sgRNA accumulation. Fluorescent microscopy examination revealed that the fluorescence associated with NbPsbO1 was redistributed from chloroplast granal thylakoids to stroma in BaMV-infected cells. Overexpression of a mislocalized mutant of NbPsbO1, dTPPsbO1-T7, inhibited BaMV RNA accumulation in N. benthamiana, whereas overexpression of an NbPsbO1 derivative, sPsbO1-T7, designed to be targeted to chloroplast stroma, upregulated the sgRNA level. Furthermore, depletion of NbPsbO1 in BaMV RdRp preparation significantly inhibited sgRNA synthesis in vitro but exerted no effect on (+) or (-) gRNA synthesis, which indicates that NbPsbO1 is required for efficient sgRNA synthesis. These results reveal a novel role for NbPsbO1 in the selective enhancement of BaMV sgRNA transcription, most likely via direct interaction with the sgRNA promoter. IMPORTANCE Production of subgenomic RNAs (sgRNAs) for efficient translation of downstream viral proteins is one of the major strategies adapted for viruses that contain a multicistronic RNA genome. Both viral genomic RNA (gRNA) replication and sgRNA transcription rely on the combined activities of viral replicase and host proteins, which recognize promoter regions for the initiation of RNA synthesis. However, compared to the cis-acting elements involved in the regulation of sgRNA synthesis, the host factors involved in sgRNA promoter recognition mostly remain to be elucidated. Here, we found a chloroplast protein, NbPsbO1, which specifically interacts with Bamboo mosaic virus (BaMV) sgRNA promoter. We showed that NbPsbO1 is relocated to the BaMV replication site in BaMV-infected cells and demonstrated that NbPsbO1 is required for efficient BaMV sgRNA transcription but exerts no effect on gRNA replication. This study provides a new insight into the regulating mechanism of viral gRNA and sgRNA synthesis.
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Affiliation(s)
- Ying Wen Huang
- Graduate Institute of Biotechnology, National Chung Hisng University, Taichung, Taiwan
- Advanced Plant Biotechnology Center, National Chung Hsing University, Taichung, Taiwan
| | - Chu I Sun
- Graduate Institute of Biotechnology, National Chung Hisng University, Taichung, Taiwan
| | - Chung Chi Hu
- Graduate Institute of Biotechnology, National Chung Hisng University, Taichung, Taiwan
- Advanced Plant Biotechnology Center, National Chung Hsing University, Taichung, Taiwan
| | - Ching Hsiu Tsai
- Graduate Institute of Biotechnology, National Chung Hisng University, Taichung, Taiwan
- Advanced Plant Biotechnology Center, National Chung Hsing University, Taichung, Taiwan
| | - Menghsiao Meng
- Graduate Institute of Biotechnology, National Chung Hisng University, Taichung, Taiwan
| | - Na Sheng Lin
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
| | - Yau Heiu Hsu
- Graduate Institute of Biotechnology, National Chung Hisng University, Taichung, Taiwan
- Advanced Plant Biotechnology Center, National Chung Hsing University, Taichung, Taiwan
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Cecchin M, Jeong J, Son W, Kim M, Park S, Zuliani L, Cazzaniga S, Pompa A, Young Kang C, Bae S, Ballottari M, Jin E. LPA2 protein is involved in photosystem II assembly in Chlamydomonas reinhardtii. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 107:1648-1662. [PMID: 34218480 PMCID: PMC8518032 DOI: 10.1111/tpj.15405] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 06/23/2021] [Accepted: 06/30/2021] [Indexed: 06/13/2023]
Abstract
Photosynthetic eukaryotes require the proper assembly of photosystem II (PSII) in order to strip electrons from water and fuel carbon fixation reactions. In Arabidopsis thaliana, one of the PSII subunits (CP43/PsbC) was suggested to be assembled into the PSII complex via its interaction with an auxiliary protein called Low PSII Accumulation 2 (LPA2). However, the original articles describing the role of LPA2 in PSII assembly have been retracted. To investigate the function of LPA2 in the model organism for green algae, Chlamydomonas reinhardtii, we generated knockout lpa2 mutants by using the CRISPR-Cas9 target-specific genome editing system. Biochemical analyses revealed the thylakoidal localization of LPA2 protein in the wild type (WT), whereas lpa2 mutants were characterized by a drastic reduction in the levels of D1, D2, CP47 and CP43 proteins. Consequently, reduced PSII supercomplex accumulation, chlorophyll content per cell, PSII quantum yield and photosynthetic oxygen evolution were measured in the lpa2 mutants, leading to the almost complete impairment of photoautotrophic growth. Pulse-chase experiments demonstrated that the absence of LPA2 protein caused reduced PSII assembly and reduced PSII turnover. Taken together, our data indicate that, in C. reinhardtii, LPA2 is required for PSII assembly and proper function.
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Affiliation(s)
- Michela Cecchin
- Dipartimento di BiotecnologieUniversità di VeronaStrada le Grazie 15Verona37134Italy
| | - Jooyeon Jeong
- Department of Life ScienceHanyang University222, Wangsimni‐ro, Seongdong‐guSeoul04763Korea
| | - Woojae Son
- Department of ChemistryHanyang University222, Wangsimni‐ro, Seongdong‐guSeoul04763Korea
| | - Minjae Kim
- Department of Life ScienceHanyang University222, Wangsimni‐ro, Seongdong‐guSeoul04763Korea
| | - Seunghye Park
- Department of Life ScienceHanyang University222, Wangsimni‐ro, Seongdong‐guSeoul04763Korea
| | - Luca Zuliani
- Dipartimento di BiotecnologieUniversità di VeronaStrada le Grazie 15Verona37134Italy
| | - Stefano Cazzaniga
- Dipartimento di BiotecnologieUniversità di VeronaStrada le Grazie 15Verona37134Italy
| | - Andrea Pompa
- Dipartimento di Scienze BiomolecolariUniversità degli studi di UrbinoVia Aurelio Saffi, 2Urbino61029Italy
- Istituto di Bioscienze e BiorisorseConsiglio Nazionale delle RicercheVia Madonna Alta, 130Perugia06128Italy
| | - Chan Young Kang
- Department of ChemistryHanyang University222, Wangsimni‐ro, Seongdong‐guSeoul04763Korea
| | - Sangsu Bae
- Department of ChemistryHanyang University222, Wangsimni‐ro, Seongdong‐guSeoul04763Korea
| | - Matteo Ballottari
- Dipartimento di BiotecnologieUniversità di VeronaStrada le Grazie 15Verona37134Italy
| | - EonSeon Jin
- Department of Life ScienceHanyang University222, Wangsimni‐ro, Seongdong‐guSeoul04763Korea
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Wang Y, Xie Z, Wang X, Peng X, Zheng J. Fluorescent carbon-dots enhance light harvesting and photosynthesis by overexpressing PsbP and PsiK genes. J Nanobiotechnology 2021; 19:260. [PMID: 34454524 PMCID: PMC8403421 DOI: 10.1186/s12951-021-01005-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 08/18/2021] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Fluorescent carbon-dots (CDs) with multifaceted advantages have provided hope for improvement of crop growth. Near infrared (NIR) CDs would be more competitive and promising than short-wavelength emissive CDs, which are not directly utilized by chloroplast. The molecular targets and underlying mechanism of these stimulative effects are rarely mentioned. RESULTS NIR-CDs with good mono-dispersity and hydrophily were easily prepared by a one-step microwave-assisted carbonization manner, which showed obvious UV absorptive and far-red emissive properties. The chloroplast-CDs complexes could accelerate the electron transfer from photosystem II (PS II) to photosystem I (PS I). NIR-CDs exhibited a concentration-dependent promotion effect on N. benthamiana growth by strengthening photosynthesis. We firstly demonstrated that potential mechanisms behind the photosynthesis-stimulating activity might be related to up-regulated expression of the photosynthesis and chloroplast synthesis related genes, among which PsbP and PsiK genes are the key regulators. CONCLUSION These results illustrated that NIR-CDs showed great potential in the applications to increase crop yields through ultraviolet light harvesting and elevated photosynthesis efficiency. This work would provide a theoretical basis for the understanding and applications of the luminescent nanomaterials (not limited to CDs) in the sunlight conversion-related sustainable agriculture.
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Affiliation(s)
- Yuhui Wang
- Cixi Institute of Biomedical Engineering, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315300, People's Republic of China
| | - Zhuomi Xie
- Ningbo Research Institute of Zhejiang University, Ningbo, 315100, People's Republic of China
- Fujian Agriculture and Forestry University, Fuzhou, 350028, People's Republic of China
| | - Xiuhua Wang
- Cixi Institute of Biomedical Engineering, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315300, People's Republic of China
| | - Xin Peng
- Ningbo Research Institute of Zhejiang University, Ningbo, 315100, People's Republic of China.
| | - Jianping Zheng
- Cixi Institute of Biomedical Engineering, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315300, People's Republic of China.
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Forsman JA, Eaton-Rye JJ. The hydrophobicity of mutations targeting D1:Val219 modifies formate and diuron binding in the quinone-Fe-acceptor complex of Photosystem II. PHYSIOLOGIA PLANTARUM 2021; 172:2217-2225. [PMID: 34050526 DOI: 10.1111/ppl.13469] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Revised: 05/10/2021] [Accepted: 05/26/2021] [Indexed: 06/12/2023]
Abstract
The D1:Val219 residue of Photosystem II in the cyanobacterium Synechocystis sp. PCC 6803 was mutated to alanine or isoleucine, creating the V219A and V219I mutants, respectively. Oxygen evolution was slowed in these mutants, while chlorophyll a fluorescence induction assays indicated slowed electron transfer. As previously observed [Erickson J.M., Rahire, M., Rochaix, J.-D. and Mets. L. (1985) Science, 228, 204-207], the V219I mutant was resistant to 3,4-dichloro-1,1-dimethyl urea (DCMU); however, the V219A strain displayed no DCMU resistance. Additionally, the V219A strain was less sensitive to the addition of formate than the control, while the V219I strain was more sensitive to formate. Both mutant strains were susceptible to photodamage and required protein synthesis for recovery. We hypothesize that the sensitivity to DCMU and the extent of bicarbonate-reversible formate-induced inhibition, as well as the capacity for recovery in cells following photodamage, are influenced by the hydrophobicity of the environment associated with the Val219 residue in D1.
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Affiliation(s)
- Jack A Forsman
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
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Structural insights into a dimeric Psb27-photosystem II complex from a cyanobacterium Thermosynechococcus vulcanus. Proc Natl Acad Sci U S A 2021; 118:2018053118. [PMID: 33495333 DOI: 10.1073/pnas.2018053118] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Photosystem II (PSII) is a multisubunit pigment-protein complex and catalyzes light-driven water oxidation, leading to the conversion of light energy into chemical energy and the release of molecular oxygen. Psb27 is a small thylakoid lumen-localized protein known to serve as an assembly factor for the biogenesis and repair of the PSII complex. The exact location and binding fashion of Psb27 in the intermediate PSII remain elusive. Here, we report the structure of a dimeric Psb27-PSII complex purified from a psbV deletion mutant (ΔPsbV) of the cyanobacterium Thermosynechococcus vulcanus, solved by cryo-electron microscopy. Our structure showed that Psb27 is associated with CP43 at the luminal side, with specific interactions formed between Helix 2 and Helix 3 of Psb27 and a loop region between Helix 3 and Helix 4 of CP43 (loop C) as well as the large, lumen-exposed and hydrophilic E-loop of CP43. The binding of Psb27 imposes some conflicts with the N-terminal region of PsbO and also induces some conformational changes in CP43, CP47, and D2. This makes PsbO unable to bind in the Psb27-PSII. Conformational changes also occurred in D1, PsbE, PsbF, and PsbZ; this, together with the conformational changes occurred in CP43, CP47, and D2, may prevent the binding of PsbU and induce dissociation of PsbJ. This structural information provides important insights into the regulation mechanism of Psb27 in the biogenesis and repair of PSII.
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Sharma D, Afzal S, Singh NK. Nanopriming with phytosynthesized zinc oxide nanoparticles for promoting germination and starch metabolism in rice seeds. J Biotechnol 2021; 336:64-75. [PMID: 34116127 DOI: 10.1016/j.jbiotec.2021.06.014] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 12/31/2020] [Accepted: 06/04/2021] [Indexed: 10/21/2022]
Abstract
The application of zinc oxide nanoparticles (ZnO NPs) in agricultural field is emerging and relatively new. In this work, a simple, cost-efficient, non-toxic and eco-friendly method for the green synthesis of ZnO NPs by Senna occidentalis leaf extract has been described. Techniques used to characterize nanoparticles (NPs) were X-ray diffractometer (XRD), UV visible spectroscopy, Particle size analyzer (PSA), Fourier transform infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM). In this study, green synthesized ZnO NPs at 20-40 mg/l solution was used to prime aged seeds of early flowering homozygous mutant (BM6) of Pusa basmati (Oryza sativa), which enhanced germination performance and seedling vigor significantly as compared to zinc sulphate (ZnSO4) priming and conventional hydropriming. The effect of treatment was analyzed by measuring biophysical and biochemical parameter of germinating rice seeds. The seeds treated with ZnO NPs of 20 mg/l concentration showed more than 50 % stimulation in dry weight, relative water uptake of seeds and radicle length of seedling in comparison to other priming solution and control (hydro-primed). Significant growth was also observed in plumule length and fresh weight of seeds in ZnO NPs at 20 mg/l concentration in comparison to control and other priming treatments. At the same concentration of ZnO NPs, there was 23 % stimulation reported in total soluble sugar content and 45 % stimulation in amylase activity. There was also a substantial increase in antioxidant enzymes i.e. superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) activity. Seed priming represents an innovative user-friendly approach to enhance the germination rate, starch metabolic process and triggered zinc acquisition of rice aged seed as an alternative to the conventional priming method.
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Affiliation(s)
- Deepa Sharma
- Department of Biotechnology, Motilal Nehru National Institute of Technology Allahabad, Prayagraj, 211004, India
| | - Shadma Afzal
- Department of Biotechnology, Motilal Nehru National Institute of Technology Allahabad, Prayagraj, 211004, India
| | - Nand K Singh
- Department of Biotechnology, Motilal Nehru National Institute of Technology Allahabad, Prayagraj, 211004, India.
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Tahura S, Kabir AH. Physiological responses and genome-wide characterization of TaNRAMP1 gene in Mn-deficient wheat. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2021; 162:280-290. [PMID: 33714143 DOI: 10.1016/j.plaphy.2021.02.038] [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: 12/18/2020] [Accepted: 02/24/2021] [Indexed: 05/28/2023]
Abstract
Manganese (Mn) is an essential micronutrient for plants. This study elucidates the physiological consequences and characterization of TaNRAMP1 transporter in Mn-starved wheat. The cellular integrity, redox status, chlorophyll score, and Fv/Fm were severely affected, accompanied by decreased Mn concentration in root and shoot in Mn-deficient wheat. However, Fe concentration and root phytosiderophore release were not affected, contradicting the interactions of Fe status with Mn under Mn shortage. The genome-wide identification of TaNRAMP1 (natural resistance-associated macrophage protein 1), known as high-affinity Mn transporter, showed several polymorphisms within genome A, B, and D. The expression of TaNRAMP1 significantly decreased in roots of genome A and B but was constitutively expressed in genome D due to Mn-deficiency. The TaNRAMP1 was located in the plasma membrane and showed six motifs matched to Nramp (divalent metal transport). Further, TaNRAMP1 showed a close partnership with cation transporter associated with P-type ATPase/cation transport network. In the RNASeq platform, TaNRAMP1, located in all three genomes, showed the highest expression potential in microspore. Besides, only TaNRAMP1 in genome D was upregulated due to heat and drought stress but showed downregulation in response to excess sulfur and Puccinia triticina infection in all three genomes. The cis-regulatory analysis implies the transcriptional regulation of TaNRAMP1 linked to methyl jasmonate and abscisic acid synthesis. Furthermore, TaNRAMP1 proteins showed similar physicochemical properties, but the C-terminus position of genome D was different than genome A and B. This is the first study on the responses and genome-wide characterization of TaNRAMP1 in Mn-starved wheat.
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Affiliation(s)
- Sharaban Tahura
- Molecular Plant Physiology Laboratory, Department of Botany, University of Rajshahi, Rajshahi, 6205, Bangladesh
| | - Ahmad Humayan Kabir
- Molecular Plant Physiology Laboratory, Department of Botany, University of Rajshahi, Rajshahi, 6205, Bangladesh.
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Fu HY, Ghandour R, Ruf S, Zoschke R, Bock R, Schöttler MA. The availability of neither D2 nor CP43 limits the biogenesis of photosystem II in tobacco. PLANT PHYSIOLOGY 2021; 185:1111-1130. [PMID: 33793892 PMCID: PMC8133689 DOI: 10.1093/plphys/kiaa052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 11/17/2020] [Indexed: 06/12/2023]
Abstract
The pathway of photosystem II (PSII) assembly is well understood, and multiple auxiliary proteins supporting it have been identified, but little is known about rate-limiting steps controlling PSII biogenesis. In the cyanobacterium Synechocystis PCC6803 and the green alga Chlamydomonas reinhardtii, indications exist that the biosynthesis of the chloroplast-encoded D2 reaction center subunit (PsbD) limits PSII accumulation. To determine the importance of D2 synthesis for PSII accumulation in vascular plants and elucidate the contributions of transcriptional and translational regulation, we modified the 5'-untranslated region of psbD via chloroplast transformation in tobacco (Nicotiana tabacum). A drastic reduction in psbD mRNA abundance resulted in a strong decrease in PSII content, impaired photosynthetic electron transport, and retarded growth under autotrophic conditions. Overexpression of the psbD mRNA also increased transcript abundance of psbC (the CP43 inner antenna protein), which is co-transcribed with psbD. Because translation efficiency remained unaltered, translation output of pbsD and psbC increased with mRNA abundance. However, this did not result in increased PSII accumulation. The introduction of point mutations into the Shine-Dalgarno-like sequence or start codon of psbD decreased translation efficiency without causing pronounced effects on PSII accumulation and function. These data show that neither transcription nor translation of psbD and psbC are rate-limiting for PSII biogenesis in vascular plants and that PSII assembly and accumulation in tobacco are controlled by different mechanisms than in cyanobacteria or in C. reinhardtii.
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Affiliation(s)
- Han-Yi Fu
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam, Germany
| | - Rabea Ghandour
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam, Germany
| | - Stephanie Ruf
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam, Germany
| | - Reimo Zoschke
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam, Germany
| | - Ralph Bock
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam, Germany
| | - Mark Aurel Schöttler
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam, Germany
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Podmaniczki A, Nagy V, Vidal-Meireles A, Tóth D, Patai R, Kovács L, Tóth SZ. Ascorbate inactivates the oxygen-evolving complex in prolonged darkness. PHYSIOLOGIA PLANTARUM 2021; 171:232-245. [PMID: 33215703 DOI: 10.1111/ppl.13278] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 11/03/2020] [Accepted: 11/09/2020] [Indexed: 06/11/2023]
Abstract
Ascorbate (Asc, vitamin C) is an essential metabolite participating in multiple physiological processes of plants, including environmental stress management and development. In this study, we acquired knowledge on the role of Asc in dark-induced leaf senescence using Arabidopsis thaliana as a model organism. One of the earliest effects of prolonged darkness is the inactivation of oxygen-evolving complexes (OEC) as demonstrated here by fast chlorophyll a fluorescence and thermoluminescence measurements. We found that inactivation of OEC due to prolonged darkness was attenuated in the Asc-deficient vtc2-4 mutant. On the other hand, the severe photosynthetic phenotype of a psbo1 knockout mutant, lacking the major extrinsic OEC subunit PSBO1, was further aggravated upon a 24-h dark treatment. The psbr mutant, devoid of the PSBR subunit of OEC, performed only slightly disturbed photosynthetic activity under normal growth conditions, whereas it showed a strongly diminished B thermoluminescence band upon dark treatment. We have also generated a double psbo1 vtc2 mutant, and it showed a slightly milder photosynthetic phenotype than the single psbo1 mutant. Our results, therefore, suggest that Asc leads to the inactivation of OEC in prolonged darkness by over-reducing the Mn-complex that is probably enabled by a dark-induced dissociation of the extrinsic OEC subunits. Our study is an example that Asc may negatively affect certain cellular processes and thus its concentration and localization need to be highly controlled.
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Affiliation(s)
- Anna Podmaniczki
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
- Doctoral School of Biology, University of Szeged, Szeged, Hungary
| | - Valéria Nagy
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
| | | | - Dávid Tóth
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
- Doctoral School of Biology, University of Szeged, Szeged, Hungary
| | - Roland Patai
- Institute of Biophysics, Biological Research Centre, Szeged, Hungary
| | - László Kovács
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
| | - Szilvia Z Tóth
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
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Xiao Y, Zhu Q, Yang Y, Wang W, Kuang T, Shen JR, Han G. Role of PsbV-Tyr137 in photosystem II studied by site-directed mutagenesis in the thermophilic cyanobacterium Thermosynechococcus vulcanus. PHOTOSYNTHESIS RESEARCH 2020; 146:41-54. [PMID: 32342261 DOI: 10.1007/s11120-020-00753-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Accepted: 04/19/2020] [Indexed: 05/07/2023]
Abstract
PsbV (cytochrome c550) is one of the three extrinsic proteins of photosystem II (PSII) and functions to maintain the stability and activity of the Mn4CaO5 cluster, the catalytic center for water oxidation. PsbV-Y137 is the C-terminal residue of PsbV and is located at the exit of a hydrogen-bond network mediated by the D1-Y161-H190 residue pair. In order to examine the function of PsbV-Y137, four mutants, PsbV-Y137A, PsbV-Y137F, PsbV-Y137G, and PsbV-Y137W, were generated with Thermosynechococcus vulcanus (T. vulcanus). These mutants showed growth rates similar to that of the wild-type strain (WT); however, their oxygen-evolving activities were different. At pH 6.5, the oxygen evolution rates of Y137F and Y137W were almost identical to that of WT, whereas the oxygen evolution rates of the Y137A, Y137G mutants were 64% and 61% of WT, respectively. However, the oxygen evolution in the latter two mutants decreased less at higher pHs, suggesting that higher pHs facilitated oxygen evolution probably by facilitating proton egress in these two mutants. Furthermore, thylakoid membranes isolated from the PsbV-Y137A, PsbV-Y137G mutants exhibited much lower levels of oxygen-evolving activity than that of WT, which was found to be caused by the release of PsbV. In addition, PSII complexes purified from the PsbV-Y137A and PsbV-Y137G mutants lost all of the three extrinsic proteins but instead bind Psb27, an assembly cofactor of PSII. These results demonstrate that the PsbV-Tyr137 residue is required for the stable binding of PsbV to PSII, and the hydrogen-bond network mediated by D1-Y161-H190 is likely to function in proton egress during water oxidation.
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Affiliation(s)
- Yanan Xiao
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, No. 20, Nanxincun, Xiangshan, Beijing, 100093, China
- University of Chinese Academy of Sciences, Yuquan Rd, Shijingshan District, Beijing, 100049, China
| | - Qingjun Zhu
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, No. 20, Nanxincun, Xiangshan, Beijing, 100093, China
- University of Chinese Academy of Sciences, Yuquan Rd, Shijingshan District, Beijing, 100049, China
| | - Yanyan Yang
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, No. 20, Nanxincun, Xiangshan, Beijing, 100093, China
| | - Wenda Wang
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, No. 20, Nanxincun, Xiangshan, Beijing, 100093, China
| | - Tingyun Kuang
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, No. 20, Nanxincun, Xiangshan, Beijing, 100093, China
| | - Jian-Ren Shen
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, No. 20, Nanxincun, Xiangshan, Beijing, 100093, China.
- The Innovative Academy of Seed Design, Chinese Academy of Sciences, No. 1 Beichen West Rd., Beijing, 100101, China.
- Research Institute of Interdisciplinary Science, Graduate School of Natural Science and Technology, Okayama University, Tsushima Naka 3-1-1, Okayama, 700-8530, Japan.
| | - Guangye Han
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, No. 20, Nanxincun, Xiangshan, Beijing, 100093, China.
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