1
|
Grebe S, Porcar-Castell A, Riikonen A, Paakkarinen V, Aro EM. Accounting for photosystem I photoinhibition sheds new light on seasonal acclimation strategies of boreal conifers. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:3973-3992. [PMID: 38572950 PMCID: PMC11233416 DOI: 10.1093/jxb/erae145] [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: 12/30/2023] [Accepted: 05/30/2024] [Indexed: 04/05/2024]
Abstract
The photosynthetic acclimation of boreal evergreen conifers is controlled by regulatory and photoprotective mechanisms that allow conifers to cope with extreme environmental changes. However, the underlying dynamics of photosystem II (PSII) and photosystem I (PSI) remain unresolved. Here, we investigated the dynamics of PSII and PSI during the spring recovery of photosynthesis in Pinus sylvestris and Picea abies using a combination of chlorophyll a fluorescence, P700 difference absorbance measurements, and quantification of key thylakoid protein abundances. In particular, we derived a new set of PSI quantum yield equations, correcting for the effects of PSI photoinhibition. Using the corrected equations, we found that the seasonal dynamics of PSII and PSI photochemical yields remained largely in balance, despite substantial seasonal changes in the stoichiometry of PSII and PSI core complexes driven by PSI photoinhibition. Similarly, the previously reported seasonal up-regulation of cyclic electron flow was no longer evident, after accounting for PSI photoinhibition. Overall, our results emphasize the importance of considering the dynamics of PSII and PSI to elucidate the seasonal acclimation of photosynthesis in overwintering evergreens. Beyond the scope of conifers, our corrected PSI quantum yields expand the toolkit for future studies aimed at elucidating the dynamic regulation of PSI.
Collapse
Affiliation(s)
- Steffen Grebe
- Molecular Plant Biology, Department of Life Technologies, University of Turku, 20014 Turku, Finland
- Optics of Photosynthesis Laboratory, Viikki Plant Science Center, Institute for Atmospheric and Earth System Research/Forest Sciences, University of Helsinki, 00014 Helsinki, Finland
| | - Albert Porcar-Castell
- Optics of Photosynthesis Laboratory, Viikki Plant Science Center, Institute for Atmospheric and Earth System Research/Forest Sciences, University of Helsinki, 00014 Helsinki, Finland
| | - Anu Riikonen
- Optics of Photosynthesis Laboratory, Viikki Plant Science Center, Institute for Atmospheric and Earth System Research/Forest Sciences, University of Helsinki, 00014 Helsinki, Finland
| | - Virpi Paakkarinen
- Molecular Plant Biology, Department of Life Technologies, University of Turku, 20014 Turku, Finland
| | - Eva-Mari Aro
- Molecular Plant Biology, Department of Life Technologies, University of Turku, 20014 Turku, Finland
| |
Collapse
|
2
|
Tikhonov AN. The cytochrome b 6f complex: plastoquinol oxidation and regulation of electron transport in chloroplasts. PHOTOSYNTHESIS RESEARCH 2024; 159:203-227. [PMID: 37369875 DOI: 10.1007/s11120-023-01034-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 06/12/2023] [Indexed: 06/29/2023]
Abstract
In oxygenic photosynthetic systems, the cytochrome b6f (Cytb6f) complex (plastoquinol:plastocyanin oxidoreductase) is a heart of the hub that provides connectivity between photosystems (PS) II and I. In this review, the structure and function of the Cytb6f complex are briefly outlined, being focused on the mechanisms of a bifurcated (two-electron) oxidation of plastoquinol (PQH2). In plant chloroplasts, under a wide range of experimental conditions (pH and temperature), a diffusion of PQH2 from PSII to the Cytb6f does not limit the intersystem electron transport. The overall rate of PQH2 turnover is determined mainly by the first step of the bifurcated oxidation of PQH2 at the catalytic site Qo, i.e., the reaction of electron transfer from PQH2 to the Fe2S2 cluster of the high-potential Rieske iron-sulfur protein (ISP). This point has been supported by the quantum chemical analysis of PQH2 oxidation within the framework of a model system including the Fe2S2 cluster of the ISP and surrounding amino acids, the low-potential heme b6L, Glu78 and 2,3,5-trimethylbenzoquinol (the tail-less analog of PQH2). Other structure-function relationships and mechanisms of electron transport regulation of oxygenic photosynthesis associated with the Cytb6f complex are briefly outlined: pH-dependent control of the intersystem electron transport and the regulatory balance between the operation of linear and cyclic electron transfer chains.
Collapse
Affiliation(s)
- Alexander N Tikhonov
- Department of Biophysics, Faculty of Physics, M.V. Lomonosov Moscow State University, Moscow, Russian Federation, 119991.
| |
Collapse
|
3
|
Garty Y, Bussi Y, Levin-Zaidman S, Shimoni E, Kirchhoff H, Charuvi D, Nevo R, Reich Z. Thylakoid membrane stacking controls electron transport mode during the dark-to-light transition by adjusting the distances between PSI and PSII. NATURE PLANTS 2024; 10:512-524. [PMID: 38396112 DOI: 10.1038/s41477-024-01628-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 01/23/2024] [Indexed: 02/25/2024]
Abstract
The balance between linear electron transport (LET) and cyclic electron transport (CET) plays an essential role in plant adaptation and protection against photo-induced damage. This balance is largely maintained by phosphorylation-driven alterations in the PSII-LHCII assembly and thylakoid membrane stacking. During the dark-to-light transition, plants shift this balance from CET, which prevails to prevent overreduction of the electron transport chain and consequent photo-induced damage, towards LET, which enables efficient CO2 assimilation and biomass production. Using freeze-fracture cryo-scanning electron microscopy and transmission electron microscopy of Arabidopsis leaves, we reveal unique membrane regions possessing characteristics of both stacked and unstacked regions of the thylakoid network that form during this transition. A notable consequence of the morphological attributes of these regions, which we refer to as 'stacked thylakoid doublets', is an overall increase in the proximity and connectivity of the two photosystems (PSI and PSII) that drive LET. This, in turn, reduces diffusion distances and barriers for the mobile carriers that transfer electrons between the two PSs, thereby maximizing LET and optimizing the plant's ability to utilize light energy. The mechanics described here for the shift between CET and LET during the dark-to-light transition are probably also used during chromatic adaptation mediated by state transitions.
Collapse
Affiliation(s)
- Yuval Garty
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Yuval Bussi
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Smadar Levin-Zaidman
- Department of Chemical Research Support, Weizmann Institute of Science, Rehovot, Israel
| | - Eyal Shimoni
- Department of Chemical Research Support, Weizmann Institute of Science, Rehovot, Israel
| | - Helmut Kirchhoff
- Institute of Biological Chemistry, Washington State University, Pullman, WA, USA
| | - Dana Charuvi
- Institute of Plant Sciences, Agricultural Research Organization, Volcani Institute, Rishon LeZion, Israel
| | - Reinat Nevo
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel.
| | - Ziv Reich
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel.
| |
Collapse
|
4
|
Chaturvedi AK, Dym O, Levin Y, Fluhr R. PGR5-LIKE PHOTOSYNTHETIC PHENOTYPE1A redox states alleviate photoinhibition during changes in light intensity. PLANT PHYSIOLOGY 2024; 194:1059-1074. [PMID: 37787609 DOI: 10.1093/plphys/kiad518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 09/06/2023] [Accepted: 09/11/2023] [Indexed: 10/04/2023]
Abstract
Plants have evolved photosynthetic regulatory mechanisms to maintain homeostasis in response to light changes during diurnal transitions and those caused by passing clouds or by wind. One such adaptation directs photosynthetic electron flow to a cyclic pathway to alleviate excess energy surges. Here, we assign a function to regulatory cysteines of PGR5-like protein 1A (PGRL1A), a constituent of the PROTON GRADIENT REGULATION5 (PGR5)-dependent cyclic electron flow (CEF) pathway. During step increases from darkness to low light intensity in Arabidopsis (Arabidopsis thaliana), the intermolecular disulfide of the PGRL1A 59-kDa complex was reduced transiently within seconds to the 28-kDa form. In contrast, step increases from darkness to high light stimulated a stable, partially reduced redox state in PGRL1A. Mutations of 2 cysteines in PGRL1A, Cys82 and Cys183, resulted in a constitutively pseudo-reduced state. The mutant displayed higher proton motive force (PMF) and nonphotochemical quenching (NPQ) than the wild type (WT) and showed altered donor and acceptor dynamic flow around PSI. These changes were found to correspond with the redox state of PGRL1A. Continuous light regimes did not affect mutant growth compared to the WT. However, under fluctuating regimes of high light, the mutant showed better growth than the WT. In contrast, in fluctuating regimes of low light, the mutant displayed a growth penalty that can be attributed to constant stimulation of CEF under low light. Treatment with photosynthetic inhibitors indicated that PGRL1A redox state control depends on the penultimate Fd redox state. Our results showed that redox state changes in PGRL1A are crucial to optimize photosynthesis.
Collapse
Affiliation(s)
- Amit Kumar Chaturvedi
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Orly Dym
- Department of Life Science Core Facilities, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Yishai Levin
- The Nancy and Stephen Grand Israel National Center for Personalized Medicine, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Robert Fluhr
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 76100, Israel
| |
Collapse
|
5
|
Zorz J, Paquette AJ, Gillis T, Kouris A, Khot V, Demirkaya C, De La Hoz Siegler H, Strous M, Vadlamani A. Coordinated proteome change precedes cell lysis and death in a mat-forming cyanobacterium. THE ISME JOURNAL 2023; 17:2403-2414. [PMID: 37914776 PMCID: PMC10689466 DOI: 10.1038/s41396-023-01545-3] [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: 05/25/2023] [Revised: 10/12/2023] [Accepted: 10/16/2023] [Indexed: 11/03/2023]
Abstract
Cyanobacteria form dense multicellular communities that experience transient conditions in terms of access to light and oxygen. These systems are productive but also undergo substantial biomass turnover through cell death, supplementing heightened heterotrophic respiration. Here we use metagenomics and metaproteomics to survey the molecular response of a mat-forming cyanobacterium undergoing mass cell lysis after exposure to dark and anoxic conditions. A lack of evidence for viral, bacterial, or eukaryotic antagonism contradicts commonly held beliefs on the causative agent for cyanobacterial death during dense growth. Instead, proteogenomics data indicated that lysis likely resulted from a genetically programmed response triggered by a failure to maintain osmotic pressure in the wake of severe energy limitation. Cyanobacterial DNA was rapidly degraded, yet cyanobacterial proteins remained abundant. A subset of proteins, including enzymes involved in amino acid metabolism, peptidases, toxin-antitoxin systems, and a potentially self-targeting CRISPR-Cas system, were upregulated upon lysis, indicating possible involvement in the programmed cell death response. We propose this natural form of cell death could provide new pathways for controlling harmful algal blooms and for sustainable bioproduct production.
Collapse
Affiliation(s)
- Jackie Zorz
- Department of Earth, Energy, and Environment, University of Calgary, Calgary, AB, Canada.
| | - Alexandre J Paquette
- Department of Earth, Energy, and Environment, University of Calgary, Calgary, AB, Canada
| | - Timber Gillis
- Department of Earth, Energy, and Environment, University of Calgary, Calgary, AB, Canada
| | - Angela Kouris
- Department of Earth, Energy, and Environment, University of Calgary, Calgary, AB, Canada
- Synergia Biotech Inc., Calgary, AB, Canada
| | - Varada Khot
- Department of Earth, Energy, and Environment, University of Calgary, Calgary, AB, Canada
| | - Cigdem Demirkaya
- Department of Chemical and Petroleum Engineering, University of Calgary, Calgary, AB, Canada
| | | | - Marc Strous
- Department of Earth, Energy, and Environment, University of Calgary, Calgary, AB, Canada
| | - Agasteswar Vadlamani
- Department of Earth, Energy, and Environment, University of Calgary, Calgary, AB, Canada
- Synergia Biotech Inc., Calgary, AB, Canada
| |
Collapse
|
6
|
Kugler A, Stensjö K. Optimal energy and redox metabolism in the cyanobacterium Synechocystis sp. PCC 6803. NPJ Syst Biol Appl 2023; 9:47. [PMID: 37739963 PMCID: PMC10516873 DOI: 10.1038/s41540-023-00307-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Accepted: 09/01/2023] [Indexed: 09/24/2023] Open
Abstract
Understanding energy and redox homeostasis and carbon partitioning is crucial for systems metabolic engineering of cell factories. Carbon metabolism alone cannot achieve maximal accumulation of metabolites in production hosts, since an efficient production of target molecules requires energy and redox balance, in addition to carbon flow. The interplay between cofactor regeneration and heterologous production in photosynthetic microorganisms is not fully explored. To investigate the optimality of energy and redox metabolism, while overproducing alkenes-isobutene, isoprene, ethylene and 1-undecene, in the cyanobacterium Synechocystis sp. PCC 6803, we applied stoichiometric metabolic modelling. Our network-wide analysis indicates that the rate of NAD(P)H regeneration, rather than of ATP, controls ATP/NADPH ratio, and thereby bioproduction. The simulation also implies that energy and redox balance is interconnected with carbon and nitrogen metabolism. Furthermore, we show that an auxiliary pathway, composed of serine, one-carbon and glycine metabolism, supports cellular redox homeostasis and ATP cycling. The study revealed non-intuitive metabolic pathways required to enhance alkene production, which are mainly driven by a few key reactions carrying a high flux. We envision that the presented comparative in-silico metabolic analysis will guide the rational design of Synechocystis as a photobiological production platform of target chemicals.
Collapse
Affiliation(s)
- Amit Kugler
- Microbial Chemistry, Department of Chemistry-Ångström Laboratory, Uppsala University, Box 523, SE-751 20, Uppsala, Sweden
| | - Karin Stensjö
- Microbial Chemistry, Department of Chemistry-Ångström Laboratory, Uppsala University, Box 523, SE-751 20, Uppsala, Sweden.
| |
Collapse
|
7
|
Flannery SE, Pastorelli F, Emrich‐Mills TZ, Casson SA, Hunter CN, Dickman MJ, Jackson PJ, Johnson MP. STN7 is not essential for developmental acclimation of Arabidopsis to light intensity. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023; 114:1458-1474. [PMID: 36960687 PMCID: PMC10952155 DOI: 10.1111/tpj.16204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 03/12/2023] [Accepted: 03/15/2023] [Indexed: 06/17/2023]
Abstract
Plants respond to changing light intensity in the short term through regulation of light harvesting, electron transfer, and metabolism to mitigate redox stress. A sustained shift in light intensity leads to a long-term acclimation response (LTR). This involves adjustment in the stoichiometry of photosynthetic complexes through de novo synthesis and degradation of specific proteins associated with the thylakoid membrane. The light-harvesting complex II (LHCII) serine/threonine kinase STN7 plays a key role in short-term light harvesting regulation and was also suggested to be crucial to the LTR. Arabidopsis plants lacking STN7 (stn7) shifted to low light experience higher photosystem II (PSII) redox pressure than the wild type or those lacking the cognate phosphatase TAP38 (tap38), while the reverse is true at high light, where tap38 suffers more. In principle, the LTR should allow optimisation of the stoichiometry of photosynthetic complexes to mitigate these effects. We used quantitative label-free proteomics to assess how the relative abundance of photosynthetic proteins varied with growth light intensity in wild-type, stn7, and tap38 plants. All plants were able to adjust photosystem I, LHCII, cytochrome b6 f, and ATP synthase abundance with changing white light intensity, demonstrating neither STN7 nor TAP38 is crucial to the LTR per se. However, stn7 plants grown for several weeks at low light (LL) or moderate light (ML) still showed high PSII redox pressure and correspondingly lower PSII efficiency, CO2 assimilation, and leaf area compared to wild-type and tap38 plants, hence the LTR is unable to fully ameliorate these symptoms. In contrast, under high light growth conditions the mutants and wild type behaved similarly. These data are consistent with the paramount role of STN7-dependent LHCII phosphorylation in tuning PSII redox state for optimal growth in LL and ML conditions.
Collapse
Affiliation(s)
- Sarah E. Flannery
- Plants, Photosynthesis and Soil, School of BiosciencesUniversity of SheffieldFirth Court, Western BankSheffieldUK
| | - Federica Pastorelli
- Plants, Photosynthesis and Soil, School of BiosciencesUniversity of SheffieldFirth Court, Western BankSheffieldUK
| | - Thomas Z. Emrich‐Mills
- Plants, Photosynthesis and Soil, School of BiosciencesUniversity of SheffieldFirth Court, Western BankSheffieldUK
| | - Stuart A. Casson
- Plants, Photosynthesis and Soil, School of BiosciencesUniversity of SheffieldFirth Court, Western BankSheffieldUK
| | - C. Neil Hunter
- Plants, Photosynthesis and Soil, School of BiosciencesUniversity of SheffieldFirth Court, Western BankSheffieldUK
| | - Mark J. Dickman
- Department of Chemical and Biological EngineeringUniversity of SheffieldSheffieldUK
| | - Philip J. Jackson
- Plants, Photosynthesis and Soil, School of BiosciencesUniversity of SheffieldFirth Court, Western BankSheffieldUK
- Department of Chemical and Biological EngineeringUniversity of SheffieldSheffieldUK
| | - Matthew P. Johnson
- Plants, Photosynthesis and Soil, School of BiosciencesUniversity of SheffieldFirth Court, Western BankSheffieldUK
| |
Collapse
|
8
|
Degen GE, Jackson PJ, Proctor MS, Zoulias N, Casson SA, Johnson MP. High cyclic electron transfer via the PGR5 pathway in the absence of photosynthetic control. PLANT PHYSIOLOGY 2023; 192:370-386. [PMID: 36774530 PMCID: PMC10152662 DOI: 10.1093/plphys/kiad084] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Accepted: 01/24/2023] [Indexed: 05/03/2023]
Abstract
The light reactions of photosynthesis couple electron and proton transfers across the thylakoid membrane, generating NADPH, and proton motive force (pmf) that powers the endergonic synthesis of ATP by ATP synthase. ATP and NADPH are required for CO2 fixation into carbohydrates by the Calvin-Benson-Bassham cycle. The dominant ΔpH component of the pmf also plays a photoprotective role in regulating photosystem II light harvesting efficiency through nonphotochemical quenching (NPQ) and photosynthetic control via electron transfer from cytochrome b6f (cytb6f) to photosystem I. ΔpH can be adjusted by increasing the proton influx into the thylakoid lumen via upregulation of cyclic electron transfer (CET) or decreasing proton efflux via downregulation of ATP synthase conductivity (gH+). The interplay and relative contributions of these two elements of ΔpH control to photoprotection are not well understood. Here, we showed that an Arabidopsis (Arabidopsis thaliana) ATP synthase mutant hunger for oxygen in photosynthetic transfer reaction 2 (hope2) with 40% higher proton efflux has supercharged CET. Double crosses of hope2 with the CET-deficient proton gradient regulation 5 and ndh-like photosynthetic complex I lines revealed that PROTON GRADIENT REGULATION 5 (PGR5)-dependent CET is the major pathway contributing to higher proton influx. PGR5-dependent CET allowed hope2 to maintain wild-type levels of ΔpH, CO2 fixation and NPQ, however photosynthetic control remained absent and PSI was prone to photoinhibition. Therefore, high CET in the absence of ATP synthase regulation is insufficient for PSI photoprotection.
Collapse
Affiliation(s)
- Gustaf E Degen
- Plants, Photosynthesis and Soil, School of Biosciences, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK
| | - Philip J Jackson
- Plants, Photosynthesis and Soil, School of Biosciences, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK
- Department of Chemical and Biological Engineering, University of Sheffield, Sheffield S1 4NL, UK
| | - Matthew S Proctor
- Plants, Photosynthesis and Soil, School of Biosciences, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK
| | - Nicholas Zoulias
- Plants, Photosynthesis and Soil, School of Biosciences, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK
| | - Stuart A Casson
- Plants, Photosynthesis and Soil, School of Biosciences, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK
| | - Matthew P Johnson
- Plants, Photosynthesis and Soil, School of Biosciences, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK
| |
Collapse
|
9
|
Ozawa SI, Buchert F, Reuys R, Hippler M, Takahashi Y. Algal PETC-Pro171-Leu suppresses electron transfer in cytochrome b6f under acidic lumenal conditions. PLANT PHYSIOLOGY 2023; 191:1803-1817. [PMID: 36516417 PMCID: PMC10022631 DOI: 10.1093/plphys/kiac575] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 11/22/2022] [Indexed: 06/17/2023]
Abstract
Linear photosynthetic electron flow (LEF) produces NADPH and generates a proton electrochemical potential gradient across the thylakoid membrane to synthesize ATP, both of which are required for CO2 fixation. As cellular demand for ATP and NADPH varies, cyclic electron flow (CEF) between Photosystem I and the cytochrome b6f complex (b6f) produces extra ATP. b6f regulates LEF and CEF via photosynthetic control, which is a pH-dependent b6f slowdown of plastoquinol oxidation at the lumenal site. This protection mechanism is triggered at more alkaline lumen pH in the pgr1 (proton gradient regulation 1) mutant of the vascular plant Arabidopsis (Arabidopsis thaliana), which contains a Pro194Leu substitution in the b6f Rieske Iron-sulfur protein Photosynthetic Electron Transfer C (PETC) subunit. In this work, we introduced the equivalent pgr1 mutation in the green alga Chlamydomonas reinhardtii to generate PETC-P171L. Consistent with the pgr1 phenotype, PETC-P171L displayed impaired NPQ induction along with slower photoautotrophic growth under high light conditions. Our data provide evidence that the ΔpH component in PETC-P171L depends on oxygen availability. Only under low oxygen conditions was the ΔpH component sufficient to trigger a phenotype in algal PETC-P171L where the mutant b6f was more restricted to oxidize the plastoquinol pool and showed diminished electron flow through the b6f complex. These results demonstrate that photosynthetic control of different stringency are established in C. reinhardtii depending on the cellular metabolism, and the lumen pH-sensitive PETC-P171L was generated to read out various associated effects.
Collapse
Affiliation(s)
| | - Felix Buchert
- Institute of Plant Biology and Biotechnology, University of Münster, 48143 Münster, Germany
| | - Ruby Reuys
- Institute of Plant Biology and Biotechnology, University of Münster, 48143 Münster, Germany
| | - Michael Hippler
- Institute of Plant Science and Resources, Okayama University, Kurashiki 710-0046, Japan
- Institute of Plant Biology and Biotechnology, University of Münster, 48143 Münster, Germany
| | - Yuichiro Takahashi
- Research Institute for Interdisciplinary Science, Okayama University, Okayama 700-8530, Japan
| |
Collapse
|
10
|
Schansker G. Determining photosynthetic control, a probe for the balance between electron transport and Calvin-Benson cycle activity, with the DUAL-KLAS-NIR. PHOTOSYNTHESIS RESEARCH 2022; 153:191-204. [PMID: 35844008 DOI: 10.1007/s11120-022-00934-7] [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: 11/04/2021] [Accepted: 06/14/2022] [Indexed: 06/15/2023]
Abstract
Photosynthetic Control is defined as the control imposed on photosynthetic electron transport by the lumen-pH-sensitive re-oxidation of plastoquinol (PQH2) by cytochrome b6f. Photosynthetic Control leads at higher actinic light intensities to an electron transport chain with a (relatively) reduced photosystem (PS) II and PQ pool and a (relatively) oxidized PS I. Making Light Curves of more than 33 plant species with the recently introduced DUAL-KLAS-NIR (Chl a fluorescence + the redox states of plastocyanin (PC), P700, and ferredoxin (Fd)) the light intensity-dependent induction of Photosynthetic Control was probed and characterized. It was observed that PC became completely oxidized at light intensities ≤ 400 µmol photons m-2 s-1 (at lower light intensities in shade than in sun leaves). The relationship between qP and P700(red) was used to determine the extent of Photosynthetic Control. Instead of measuring the whole Light Curve, it was shown that a single moderate light intensity can be used to characterize the status of a leaf relative to that of other leaves. It was further found that in some shade-acclimated leaves Fd becomes again more oxidized at high light intensities indicating that electron transfer from the PQ pool to P700 cannot keep up with the outflow of electrons on the acceptor side of PS I. It was observed as well that for NPQ-induction a lower light intensity (less acidified lumen) was needed than for the induction of Photosynthetic Control. The measurements were also used to make a comparison between the parameters qP and qL, a comparison suggesting that qP was the more relevant parameter.
Collapse
Affiliation(s)
- Gert Schansker
- Heinz Walz GmbH, Eichenring 6, 91090, Effeltrich, Germany.
| |
Collapse
|
11
|
Suslichenko IS, Trubitsin BV, Vershubskii AV, Tikhonov AN. The noninvasive monitoring of the redox status of photosynthetic electron transport chains in Hibiscus rosa-sinensis and Tradescantia leaves. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2022; 185:233-243. [PMID: 35716433 DOI: 10.1016/j.plaphy.2022.06.002] [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: 01/30/2022] [Revised: 05/13/2022] [Accepted: 06/01/2022] [Indexed: 06/15/2023]
Abstract
We present an approach to the noninvasive determination of the electron capacity of the intersystem pool of electron carriers in chloroplasts in situ. As apt experimental models, we used the leaves of Hibiscus rosa-sinensis and Tradescantia species. Electron paramagnetic resonance and optical response of P700 (the primary electron donor in Photosystem I) were applied to measuring electron transport in chloroplasts. Electron capacities of the intersystem electron transport chain (ETC) were determined from redox transients of P700 upon chromatic transitions (white light → far-red light). During the induction period, we observed the nonmonotonic changes in the number of electron equivalents in the intersystem ETC per P700 (parameter Q). In Hibiscus rosa-sinensis, the light-induced rise of Q from ≈2.5 (in the dark) to Q ≈ 12 was followed by its decrease to Q ≈ 6. The data obtained are discussed in the context of pH-dependent regulation of electron transport in chloroplasts, which provides the well-balanced operation of the intersystem ETC. The decay of Q is explained by the attenuation of Photosystem II activity due to the lumen acidification and the acceleration of plastoquinol re-oxidation as a result of the Calvin-Benson cycle activation. Our computer model of electron and proton transport coupled to ATP synthesis in chloroplasts was used to analyze the up and down feedbacks responsible for pH-dependent regulation of electron transport in chloroplasts. The procedures introduced here may be important for subsequent works aimed at defining the plastoquinone participation in regulation of photosynthetic processes in chloroplasts in situ.
Collapse
Affiliation(s)
- Igor S Suslichenko
- Faculty of Physics, M.V. Lomonosov Moscow State University, Moscow, Russia
| | - Boris V Trubitsin
- Faculty of Physics, M.V. Lomonosov Moscow State University, Moscow, Russia
| | | | | |
Collapse
|
12
|
Ho TTH, Schwier C, Elman T, Fleuter V, Zinzius K, Scholz M, Yacoby I, Buchert F, Hippler M. Photosystem I light-harvesting proteins regulate photosynthetic electron transfer and hydrogen production. PLANT PHYSIOLOGY 2022; 189:329-343. [PMID: 35157085 PMCID: PMC9070821 DOI: 10.1093/plphys/kiac055] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 01/23/2022] [Indexed: 05/06/2023]
Abstract
Linear electron flow (LEF) and cyclic electron flow (CEF) compete for light-driven electrons transferred from the acceptor side of photosystem I (PSI). Under anoxic conditions, such highly reducing electrons also could be used for hydrogen (H2) production via electron transfer between ferredoxin and hydrogenase in the green alga Chlamydomonas reinhardtii. Partitioning between LEF and CEF is regulated through PROTON-GRADIENT REGULATION5 (PGR5). There is evidence that partitioning of electrons also could be mediated via PSI remodeling processes. This plasticity is linked to the dynamics of PSI-associated light-harvesting proteins (LHCAs) LHCA2 and LHCA9. These two unique light-harvesting proteins are distinct from all other LHCAs because they are loosely bound at the PSAL pole. Here, we investigated photosynthetic electron transfer and H2 production in single, double, and triple mutants deficient in PGR5, LHCA2, and LHCA9. Our data indicate that lhca2 and lhca9 mutants are efficient in photosynthetic electron transfer, that LHCA2 impacts the pgr5 phenotype, and that pgr5/lhca2 is a potent H2 photo-producer. In addition, pgr5/lhca2 and pgr5/lhca9 mutants displayed substantially different H2 photo-production kinetics. This indicates that the absence of LHCA2 or LHCA9 impacts H2 photo-production independently, despite both being attached at the PSAL pole, pointing to distinct regulatory capacities.
Collapse
Affiliation(s)
- Thi Thu Hoai Ho
- Institute of Plant Biology and Biotechnology, University of Münster, Münster 48143, Germany
- Faculty of Fisheries, University of Agriculture and Forestry, Hue University, Hue 530000, Vietnam
| | - Chris Schwier
- Institute of Plant Biology and Biotechnology, University of Münster, Münster 48143, Germany
| | - Tamar Elman
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Vera Fleuter
- Institute of Plant Biology and Biotechnology, University of Münster, Münster 48143, Germany
| | - Karen Zinzius
- Institute of Plant Biology and Biotechnology, University of Münster, Münster 48143, Germany
| | - Martin Scholz
- Institute of Plant Biology and Biotechnology, University of Münster, Münster 48143, Germany
| | - Iftach Yacoby
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Felix Buchert
- Institute of Plant Biology and Biotechnology, University of Münster, Münster 48143, Germany
| | | |
Collapse
|
13
|
Saint-Sorny M, Brzezowski P, Arrivault S, Alric J, Johnson X. Interactions Between Carbon Metabolism and Photosynthetic Electron Transport in a Chlamydomonas reinhardtii Mutant Without CO 2 Fixation by RuBisCO. FRONTIERS IN PLANT SCIENCE 2022; 13:876439. [PMID: 35574084 PMCID: PMC9096841 DOI: 10.3389/fpls.2022.876439] [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: 02/15/2022] [Accepted: 03/31/2022] [Indexed: 06/15/2023]
Abstract
A Chlamydomonas reinhardtii RuBisCO-less mutant, ΔrbcL, was used to study carbohydrate metabolism without fixation of atmospheric carbon. The regulatory mechanism(s) that control linear electron flow, known as "photosynthetic control," are amplified in ΔrbcL at the onset of illumination. With the aim to understand the metabolites that control this regulatory response, we have correlated the kinetics of primary carbon metabolites to chlorophyll fluorescence induction curves. We identify that ΔrbcL in the absence of acetate generates adenosine triphosphate (ATP) via photosynthetic electron transfer reactions. Also, metabolites of the Calvin Benson Bassham (CBB) cycle are responsive to the light. Indeed, ribulose 1,5-bisphosphate (RuBP), the last intermediate before carboxylation by Ribulose-1,5-bisphosphate carboxylase-oxygenase, accumulates significantly with time, and CBB cycle intermediates for RuBP regeneration, dihydroxyacetone phosphate (DHAP), pentose phosphates and ribose-5-phosphate (R5P) are rapidly accumulated in the first seconds of illumination, then consumed, showing that although the CBB is blocked, these enzymes are still transiently active. In opposition, in the presence of acetate, consumption of CBB cycle intermediates is strongly diminished, suggesting that the link between light and primary carbon metabolism is almost lost. Phosphorylated hexoses and starch accumulate significantly. We show that acetate uptake results in heterotrophic metabolism dominating phototrophic metabolism, with glyoxylate and tricarboxylic acid (TCA) cycle intermediates being the most highly represented metabolites, specifically succinate and malate. These findings allow us to hypothesize which metabolites and metabolic pathways are relevant to the upregulation of processes like cyclic electron flow that are implicated in photosynthetic control mechanisms.
Collapse
Affiliation(s)
- Maureen Saint-Sorny
- CEA, CNRS, UMR 7265, BIAM, CEA Cadarache, Aix-Marseille Université, Saint-Paul-lez-Durance, France
| | - Pawel Brzezowski
- CEA, CNRS, UMR 7265, BIAM, CEA Cadarache, Aix-Marseille Université, Saint-Paul-lez-Durance, France
| | | | - Jean Alric
- CEA, CNRS, UMR 7265, BIAM, CEA Cadarache, Aix-Marseille Université, Saint-Paul-lez-Durance, France
| | - Xenie Johnson
- CEA, CNRS, UMR 7265, BIAM, CEA Cadarache, Aix-Marseille Université, Saint-Paul-lez-Durance, France
| |
Collapse
|
14
|
Naciri R, Rajib W, Chtouki M, Zeroual Y, Oukarroum A. Potassium and phosphorus content ratio in hydroponic culture affects tomato plant growth and nutrient uptake. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2022; 28:763-774. [PMID: 35592482 PMCID: PMC9110585 DOI: 10.1007/s12298-022-01178-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 04/01/2022] [Accepted: 04/07/2022] [Indexed: 06/15/2023]
Abstract
Mineral nutrient deficiencies induce a cascade of physiological, morphological, and biochemical changes in plants which reduce vegetative growth. In this work, the impact of P and K concentration levels on tomato plant development grown in hydroponic culture was investigated. Root morphology, chlorophyll a fluorescence, phosphorus (P) and potassium (K) content, and shoot and root biomass were analyzed. Root morphology showed significant differences among the plants grown in hydroponic culture with different concentrations of P and K. Plant root/shoot dry biomass ratio decreased by 22 and 35% for P15K0 and P30K0, respectively, compared to the control (P30K232). The deficiency of P and K (individually or both) reduced significantly the root mass density parameter. For example, root mass density decreased by 38% at P15K0 treatment compared to control. Correlation analysis showed that the P and K content ratio in shoot and root was significantly and positively correlated with root volume. Deficiencies in K and P decreased the relative size of the PSI final electron acceptor pool and the electron flow on the acceptor side of PSI. Tomato growth response depend on the availability of P and K, however, interactions between these two nutrients could influence their uptake and utilization.
Collapse
Affiliation(s)
- Rachida Naciri
- University Mohammed VI Polytechnic (UM6P), Lot-660 Hay Moulay Rachid, 43150 Ben Guerir, Morocco
| | - Wiam Rajib
- University Mohammed VI Polytechnic (UM6P), Lot-660 Hay Moulay Rachid, 43150 Ben Guerir, Morocco
| | - Mohamed Chtouki
- University Mohammed VI Polytechnic (UM6P), Lot-660 Hay Moulay Rachid, 43150 Ben Guerir, Morocco
| | - Youssef Zeroual
- University Mohammed VI Polytechnic (UM6P), Lot-660 Hay Moulay Rachid, 43150 Ben Guerir, Morocco
| | - Abdallah Oukarroum
- University Mohammed VI Polytechnic (UM6P), Lot-660 Hay Moulay Rachid, 43150 Ben Guerir, Morocco
| |
Collapse
|
15
|
Murai K, Isobe H, Tezuka A, Nishio K. Continuous Variation of Secondary Structural Contents of Interfacial Peptides Induced by Hydrogel Fusion. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:3032-3039. [PMID: 35238564 DOI: 10.1021/acs.langmuir.1c01858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Three-dimensional assemblies formed by multi-biopolymers perform important biological functions by maintaining the vital activities of living organisms through biochemical reactions that occur at the interfaces of these structures. In this study, we investigated the mechanism of the continuous variation of the secondary structural contents of interfacial peptides induced by the fusion of hydrogels with different charges. The hydrogel fusion induced continuous pH changes at the interface through ionic diffusion from the hydrogel matrices, and the pH value increased rapidly during the early stage (0-200 min) of the fusion process. In addition, the secondary structural content of the interfacial peptides changed continuously between the β-sheet and random coil conformations during the early stage of the fusion process. The continuous variation in the secondary structural contents of the interfacial peptides was caused by (1) the protonation of peptide molecule amino acid side-chains in the region of pH change and (2) charge shielding due to the electrostatic interactions between the intramolecular peptides, intermolecular peptides, and intramolecular and intermolecular peptides.
Collapse
Affiliation(s)
- Kazuki Murai
- Department of Chemistry and Materials, Faculty of Textile Science and Technology, Shinshu University, 3-15-1 Tokida, Ueda, Nagano 386-8567, Japan
| | - Hiroto Isobe
- Department of Materials Science and Technology, Faculty of Advanced Engineering, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan
| | - Atsuya Tezuka
- Department of Chemistry and Materials, Faculty of Textile Science and Technology, Shinshu University, 3-15-1 Tokida, Ueda, Nagano 386-8567, Japan
| | - Keishi Nishio
- Department of Materials Science and Technology, Faculty of Advanced Engineering, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan
| |
Collapse
|
16
|
Electron transfer via cytochrome b6f complex displays sensitivity to Antimycin A upon STT7 kinase activation. Biochem J 2022; 479:111-127. [PMID: 34981811 DOI: 10.1042/bcj20210802] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 12/23/2021] [Accepted: 01/04/2022] [Indexed: 11/17/2022]
Abstract
The cytochrome b6f complex (b6f) has been initially considered as the ferredoxin-plastoquinone reductase (FQR) during cyclic electron flow (CEF) with photosystem I that is inhibited by antimycin A (AA). The binding of AA to the b6f Qi-site is aggravated by heme-ci, which challenged the FQR function of b6f during CEF. Alternative models suggest that PROTON GRADIENT REGULATION5 (PGR5) is involved in a b6f-independent, AA-sensitive FQR. Here, we show in Chlamydomonas reinhardtii that the b6f is conditionally inhibited by AA in vivo and that the inhibition did not require PGR5. Instead, activation of the STT7 kinase upon anaerobic treatment induced the AA sensitivity of b6f which was absent in stt7-1. However, a lock in State 2 due to persisting phosphorylation in the phosphatase double mutant pph1;pbcp did not increase AA sensitivity of electron transfer. The latter required a redox poise, supporting the view that state transitions and CEF are not coercively coupled. This suggests that the b6f-interacting kinase is required for structure-function modulation of the Qi-site under CEF favoring conditions. We propose that PGR5 and STT7 independently sustain AA-sensitive FQR activity of the b6f. Accordingly, PGR5-mediated electron injection into an STT7-modulated Qi-site drives a Mitchellian Q cycle in CEF conditions.
Collapse
|
17
|
Ilíková I, Ilík P, Opatíková M, Arshad R, Nosek L, Karlický V, Kučerová Z, Roudnický P, Pospíšil P, Lazár D, Bartoš J, Kouřil R. Towards spruce-type photosystem II: consequences of the loss of light-harvesting proteins LHCB3 and LHCB6 in Arabidopsis. PLANT PHYSIOLOGY 2021; 187:2691-2715. [PMID: 34618099 PMCID: PMC8644234 DOI: 10.1093/plphys/kiab396] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 07/26/2021] [Indexed: 05/28/2023]
Abstract
The largest stable photosystem II (PSII) supercomplex in land plants (C2S2M2) consists of a core complex dimer (C2), two strongly (S2) and two moderately (M2) bound light-harvesting protein (LHCB) trimers attached to C2 via monomeric antenna proteins LHCB4-6. Recently, we have shown that LHCB3 and LHCB6, presumably essential for land plants, are missing in Norway spruce (Picea abies), which results in a unique structure of its C2S2M2 supercomplex. Here, we performed structure-function characterization of PSII supercomplexes in Arabidopsis (Arabidopsis thaliana) mutants lhcb3, lhcb6, and lhcb3 lhcb6 to examine the possibility of the formation of the "spruce-type" PSII supercomplex in angiosperms. Unlike in spruce, in Arabidopsis both LHCB3 and LHCB6 are necessary for stable binding of the M trimer to PSII core. The "spruce-type" PSII supercomplex was observed with low abundance only in the lhcb3 plants and its formation did not require the presence of LHCB4.3, the only LHCB4-type protein in spruce. Electron microscopy analysis of grana membranes revealed that the majority of PSII in lhcb6 and namely in lhcb3 lhcb6 mutants were arranged into C2S2 semi-crystalline arrays, some of which appeared to structurally restrict plastoquinone diffusion. Mutants without LHCB6 were characterized by fast induction of non-photochemical quenching and, on the contrary to the previous lhcb6 study, by only transient slowdown of electron transport between PSII and PSI. We hypothesize that these functional changes, associated with the arrangement of PSII into C2S2 arrays in thylakoids, may be important for the photoprotection of both PSI and PSII upon abrupt high-light exposure.
Collapse
Affiliation(s)
- Iva Ilíková
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of
the Region Haná for Biotechnological and Agricultural Research, 783 71
Olomouc, Czech Republic
| | - Petr Ilík
- Department of Biophysics, Centre of the Region Haná for Biotechnological and
Agricultural Research, Palacký University, 783 71 Olomouc, Czech Republic
| | - Monika Opatíková
- Department of Biophysics, Centre of the Region Haná for Biotechnological and
Agricultural Research, Palacký University, 783 71 Olomouc, Czech Republic
| | - Rameez Arshad
- Department of Biophysics, Centre of the Region Haná for Biotechnological and
Agricultural Research, Palacký University, 783 71 Olomouc, Czech Republic
- Electron Microscopy Group, Groningen Biomolecular Sciences and Biotechnology
Institute, University of Groningen, Nijenborgh 7, 9747 AG Groningen,
The Netherlands
| | - Lukáš Nosek
- Department of Biophysics, Centre of the Region Haná for Biotechnological and
Agricultural Research, Palacký University, 783 71 Olomouc, Czech Republic
| | - Václav Karlický
- Department of Physics, Faculty of Science, University of Ostrava,
710 00 Ostrava, Czech Republic
- Global Change Research Institute of the Czech Academy of
Sciences, 603 00 Brno, Czech Republic
| | - Zuzana Kučerová
- Department of Biophysics, Centre of the Region Haná for Biotechnological and
Agricultural Research, Palacký University, 783 71 Olomouc, Czech Republic
| | - Pavel Roudnický
- Central European Institute of Technology, Masaryk University, 625
00 Brno, Czech Republic
| | - Pavel Pospíšil
- Department of Biophysics, Centre of the Region Haná for Biotechnological and
Agricultural Research, Palacký University, 783 71 Olomouc, Czech Republic
| | - Dušan Lazár
- Department of Biophysics, Centre of the Region Haná for Biotechnological and
Agricultural Research, Palacký University, 783 71 Olomouc, Czech Republic
| | - Jan Bartoš
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of
the Region Haná for Biotechnological and Agricultural Research, 783 71
Olomouc, Czech Republic
| | - Roman Kouřil
- Department of Biophysics, Centre of the Region Haná for Biotechnological and
Agricultural Research, Palacký University, 783 71 Olomouc, Czech Republic
| |
Collapse
|
18
|
Trinh MDL, Hashimoto A, Kono M, Takaichi S, Nakahira Y, Masuda S. Lack of plastid-encoded Ycf10, a homolog of the nuclear-encoded DLDG1 and the cyanobacterial PxcA, enhances the induction of non-photochemical quenching in tobacco. PLANT DIRECT 2021; 5:e368. [PMID: 34938941 PMCID: PMC8671777 DOI: 10.1002/pld3.368] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 11/22/2021] [Accepted: 11/23/2021] [Indexed: 05/05/2023]
Abstract
pH homeostasis in the chloroplast is crucial for the control of photosynthesis and other metabolic processes in plants. Recently, nuclear-encoded Day-Length-dependent Delayed Greening1 (DLDG1) and Fluctuating-Light Acclimation Protein1 (FLAP1) that are required for the light-inducible optimization of plastidial pH in Arabidopsis thaliana were identified. DLDG1 and FLAP1 homologs are specifically conserved in oxygenic phototrophs, and a DLDG1 homolog, Ycf10, is encoded in the chloroplast genome in plant cells. However, the function of Ycf10 and its physiological significance are unknown. To address this, we constructed ycf10 tobacco Nicotiana tabacum mutants and characterized their phenotypes. The ycf10 tobacco mutants grown under continuous-light conditions showed a pale-green phenotype only in developing leaves, and it was suppressed in short-day conditions. The ycf10 mutants also induced excessive non-photochemical quenching (NPQ) compared with those in the wild-type at the induction stage of photosynthesis. These phenotypes resemble those of Arabidopsis dldg1 mutants, suggesting that they have similar functions. However, there are distinct differences between the two mutant phenotypes: The highly induced NPQ in tobacco ycf10 and the Arabidopsis dldg1 mutants are diminished and enhanced, respectively, with increasing duration of the fluctuating actinic-light illumination. Ycf10 and DLDG1 were previously shown to localize in chloroplast envelope-membranes, suggesting that Ycf10 and DLDG1 differentially control H+ exchange across these membranes in a light-dependent manner to control photosynthesis.
Collapse
Affiliation(s)
- Mai Duy Luu Trinh
- Department of Life Science and TechnologyTokyo Institute of TechnologyYokohamaJapan
| | - Akira Hashimoto
- Department of Life Science and TechnologyTokyo Institute of TechnologyYokohamaJapan
| | - Masaru Kono
- Department of Biological Science, Graduate School of ScienceThe University of TokyoTokyoJapan
| | - Shinichi Takaichi
- Department of Molecular MicrobiologyTokyo University of AgricultureTokyoJapan
| | | | - Shinji Masuda
- Department of Life Science and TechnologyTokyo Institute of TechnologyYokohamaJapan
| |
Collapse
|
19
|
Khan N, Essemine J, Hamdani S, Qu M, Lyu MJA, Perveen S, Stirbet A, Govindjee G, Zhu XG. Natural variation in the fast phase of chlorophyll a fluorescence induction curve (OJIP) in a global rice minicore panel. PHOTOSYNTHESIS RESEARCH 2021; 150:137-158. [PMID: 33159615 DOI: 10.1007/s11120-020-00794-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 10/26/2020] [Indexed: 06/11/2023]
Abstract
Photosynthesis can be probed through Chlorophyll a fluorescence induction (FI), which provides detailed insight into the electron transfer process in Photosystem II, and beyond. Here, we have systematically studied the natural variation of the fast phase of the FI, i.e. the OJIP phase, in rice. The OJIP phase of the Chl a fluorescence induction curve is referred to as "fast transient" lasting for less than a second; it is obtained after a dark-adapted sample is exposed to saturating light. In the OJIP curve, "O" stands for "origin" (minimal fluorescence), "P" for "peak" (maximum fluorescence), and J and I for inflection points between the O and P levels. Further, Fo is the fluorescence intensity at the "O" level, whereas Fm is the intensity at the P level, and Fv (= Fm - Fo) is the variable fluorescence. We surveyed a set of quantitative parameters derived from the FI curves of 199 rice accessions, grown under both field condition (FC) and growth room condition (GC). Our results show a significant variation between Japonica (JAP) and Indica (IND) subgroups, under both the growth conditions, in almost all the parameters derived from the OJIP curves. The ratio of the variable to the maximum (Fv/Fm) and of the variable to the minimum (Fv/Fo) fluorescence, the performance index (PIabs), as well as the amplitude of the I-P phase (AI-P) show higher values in JAP compared to that in the IND subpopulation. In contrast, the amplitude of the O-J phase (AO-J) and the normalized area above the OJIP curve (Sm) show an opposite trend. The performed genetic analysis shows that plants grown under GC appear much more affected by environmental factors than those grown in the field. We further conducted a genome-wide association study (GWAS) using 11 parameters derived from plants grown in the field. In total, 596 non-unique significant loci based on these parameters were identified by GWAS. Several photosynthesis-related proteins were identified to be associated with different OJIP parameters. We found that traits with high correlation are usually associated with similar genomic regions. Specifically, the thermal phase of FI, which includes the amplitudes of the J-I and I-P subphases (AJ-I and AI-P) of the OJIP curve, is, in turn, associated with certain common genomic regions. Our study is the first one dealing with the natural variations in rice, with the aim to characterize potential candidate genes controlling the magnitude and half-time of each of the phases in the OJIP FI curve.
Collapse
Affiliation(s)
- Naveed Khan
- CAS Key Laboratory of Computational Biology, CAS-MPG Partner Institute for Computational Biology, Institute of Nutrition and Health, University of Chinese Academy of Science, Chinese Academy of Sciences, Shanghai, 200031, China
- State Key Laboratory for Plant Molecular Genetics and Center of Excellence for Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Jemaa Essemine
- State Key Laboratory for Plant Molecular Genetics and Center of Excellence for Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Saber Hamdani
- State Key Laboratory for Plant Molecular Genetics and Center of Excellence for Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Mingnan Qu
- State Key Laboratory for Plant Molecular Genetics and Center of Excellence for Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Ming-Ju Amy Lyu
- State Key Laboratory for Plant Molecular Genetics and Center of Excellence for Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Shahnaz Perveen
- State Key Laboratory for Plant Molecular Genetics and Center of Excellence for Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | | | - 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
| | - Xin-Guang Zhu
- State Key Laboratory for Plant Molecular Genetics and Center of Excellence for Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200031, China.
| |
Collapse
|
20
|
Shi Q, Zhang SB, Wang JH, Huang W. Pre-illumination at high light significantly alleviates the over-reduction of photosystem I under fluctuating light. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2021; 312:111053. [PMID: 34620448 DOI: 10.1016/j.plantsci.2021.111053] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 08/29/2021] [Accepted: 09/04/2021] [Indexed: 06/13/2023]
Abstract
Photosystem I (PSI) is the primary target of photoinhibition under fluctuating light (FL). In angiosperms, cyclic electron flow (CEF) around PSI is thought to be the main player protecting PSI under FL. The activation of CEF is linked to the thylakoid stacking, which is in turn affected by light intensity. However, it is unknown how pre-illumination affects the CEF activation and PSI redox state under FL. To address this question, we conducted a spectroscopic analysis under FL in Bletilla striata and Morus alba after pre-illumination at moderate light (ML, 611 μmol photons m-2 s-1) or high light (HL, 1455 μmol photons m-2 s-1). Our results indicated that both species displayed a transient over-reduction of PSI after a transition from low to high light, but the extent of PSI over-reduction under FL was largely alleviated by pre-illumination at HL when compared with pre-illumination under ML. Furthermore, pre-illumination at HL accelerated the activation rate of CEF but did not affect the activation of non-photochemical quenching and linear electron flow from photosystem II under FL. Therefore, such increased CEF activity by pre-illumination under HL alleviated PSI over-reduction under FL by facilitating the electron sink downstream of PSI. Taking together, pre-illumination at HL protects PSI under FL through acceptor-side regulation.
Collapse
Affiliation(s)
- Qi- Shi
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China
| | - Shi-Bao Zhang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China
| | - Ji-Hua Wang
- Flower Research Institute of Yunnan Academy of Agricultural Sciences, Kunming, 650205, Yunnan, China
| | - Wei Huang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China.
| |
Collapse
|
21
|
Mathiot C, Alric J. Standard units for ElectroChromic Shift measurements in plant biology. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:6467-6473. [PMID: 34089606 DOI: 10.1093/jxb/erab261] [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: 01/27/2021] [Accepted: 06/04/2021] [Indexed: 06/12/2023]
Abstract
The absorbance shift of pigments is proportional to the membrane potential (Δψ) in plants, green algae, and many photosynthetic bacteria. It is currently denoted as ElectroChromic Shift (ECS) at 515-520 nm for plant carotenoids. It is increasingly being used for phenotyping plants for traits related to photosynthesis or chloroplast metabolism because it is a non-invasive technique and also because more instruments are now commercially available from various manufacturers. The ECS technique is currently used to monitor the post-illumination decay of the proton-motive force (pmf), but it has a more general use for quantitative studies on photosynthetic energy transduction. Here we briefly summarize the basic knowledge on ECS, emphasize the full potential of this technique, and propose a quantitative analysis of the photosynthetic performance with the definition of a transmission coefficient for electrons along the photosynthetic chain.
Collapse
Affiliation(s)
- Charlie Mathiot
- Aix Marseille Univ, CEA, CNRS, BIAM, UMR 7265, Photosynthesis and Environment, F-13108 Saint Paul-Lez-Durance, France
- Groupe Biomasse 3G, CEA Tech, CEA Cadarache, F-13108 Saint-Paul-Lez-Durance, France
| | - Jean Alric
- Aix Marseille Univ, CEA, CNRS, BIAM, UMR 7265, Photosynthesis and Environment, F-13108 Saint Paul-Lez-Durance, France
| |
Collapse
|
22
|
Cruz JA, Avenson TJ. Photosynthesis: a multiscopic view. JOURNAL OF PLANT RESEARCH 2021; 134:665-682. [PMID: 34170422 DOI: 10.1007/s10265-021-01321-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 06/11/2021] [Indexed: 06/13/2023]
Abstract
A recurring analogy for photosynthesis research is the fable of the blind men and the elephant. Photosynthesis has many complex working parts, which has driven the need to study each of them individually, with an inherent understanding that a more complete picture will require systematic integration of these views. However, unlike the blind men, who are limited to using their hands, researchers have developed over the past decades a repertoire of methods for studying these components, many of which capitalize on unique features intrinsic to each. More recent concerns about food security and clean, renewable energy have increased support for applied photosynthesis research, with the idea of either improving photosynthetic performance as a desired trait in select species or using photosynthetic measurements as a phenotyping tool in breeding efforts or for high precision crop management. In this review, we spotlight the migration of approaches for studying photosynthesis from the laboratory into field environments, highlight some recent advances and speculate on areas where further development would be fruitful, with an eye towards how applied photosynthesis research can have impacts at local and global scales.
Collapse
Affiliation(s)
- Jeffrey A Cruz
- Plant Research Laboratories, Michigan State University, 612 Wilson Road, MI, S-206, Lansing, USA.
- Department of Biochemistry and Molecular Biology, Michigan State University, Lansing, MI, USA.
| | - Thomas J Avenson
- Department of Plant Sciences, University of Cambridge, CB2 9EW, Cambridge, UK
| |
Collapse
|
23
|
Sarewicz M, Pintscher S, Pietras R, Borek A, Bujnowicz Ł, Hanke G, Cramer WA, Finazzi G, Osyczka A. Catalytic Reactions and Energy Conservation in the Cytochrome bc1 and b6f Complexes of Energy-Transducing Membranes. Chem Rev 2021; 121:2020-2108. [PMID: 33464892 PMCID: PMC7908018 DOI: 10.1021/acs.chemrev.0c00712] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Indexed: 12/16/2022]
Abstract
This review focuses on key components of respiratory and photosynthetic energy-transduction systems: the cytochrome bc1 and b6f (Cytbc1/b6f) membranous multisubunit homodimeric complexes. These remarkable molecular machines catalyze electron transfer from membranous quinones to water-soluble electron carriers (such as cytochromes c or plastocyanin), coupling electron flow to proton translocation across the energy-transducing membrane and contributing to the generation of a transmembrane electrochemical potential gradient, which powers cellular metabolism in the majority of living organisms. Cytsbc1/b6f share many similarities but also have significant differences. While decades of research have provided extensive knowledge on these enzymes, several important aspects of their molecular mechanisms remain to be elucidated. We summarize a broad range of structural, mechanistic, and physiological aspects required for function of Cytbc1/b6f, combining textbook fundamentals with new intriguing concepts that have emerged from more recent studies. The discussion covers but is not limited to (i) mechanisms of energy-conserving bifurcation of electron pathway and energy-wasting superoxide generation at the quinol oxidation site, (ii) the mechanism by which semiquinone is stabilized at the quinone reduction site, (iii) interactions with substrates and specific inhibitors, (iv) intermonomer electron transfer and the role of a dimeric complex, and (v) higher levels of organization and regulation that involve Cytsbc1/b6f. In addressing these topics, we point out existing uncertainties and controversies, which, as suggested, will drive further research in this field.
Collapse
Affiliation(s)
- Marcin Sarewicz
- Department
of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Sebastian Pintscher
- Department
of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Rafał Pietras
- Department
of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Arkadiusz Borek
- Department
of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Łukasz Bujnowicz
- Department
of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Guy Hanke
- School
of Biological and Chemical Sciences, Queen
Mary University of London, London E1 4NS, U.K.
| | - William A. Cramer
- Department
of Biological Sciences, Purdue University, West Lafayette, Indiana 47907 United States
| | - Giovanni Finazzi
- Laboratoire
de Physiologie Cellulaire et Végétale, Université Grenoble Alpes, Centre National Recherche Scientifique,
Commissariat Energie Atomique et Energies Alternatives, Institut National
Recherche l’agriculture, l’alimentation et l’environnement, 38054 Grenoble Cedex 9, France
| | - Artur Osyczka
- Department
of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| |
Collapse
|
24
|
Clowez S, Renicke C, Pringle JR, Grossman AR. Impact of Menthol on Growth and Photosynthetic Function of Breviolum Minutum (Dinoflagellata, Dinophyceae, Symbiodiniaceae) and Interactions with its Aiptasia Host. JOURNAL OF PHYCOLOGY 2021; 57:245-257. [PMID: 33025575 DOI: 10.1111/jpy.13081] [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: 06/01/2019] [Revised: 09/01/2020] [Accepted: 09/19/2020] [Indexed: 06/11/2023]
Abstract
Environmental change, including global warming and chemical pollution, can compromise cnidarian-(e.g., coral-) dinoflagellate symbioses and cause coral bleaching. Understanding the mechanisms that regulate these symbioses will inform strategies for sustaining healthy coral-reef communities. A model system for corals is the symbiosis between the sea anemone Exaiptasia pallida (common name Aiptasia) and its dinoflagellate partners (family Symbiodiniaceae). To complement existing studies of the interactions between these organisms, we examined the impact of menthol, a reagent often used to render cnidarians aposymbiotic, on the dinoflagellate Breviolum minutum, both in culture and in hospite. In both environments, the growth and photosynthesis of this alga were compromised at either 100 or 300 µM menthol. We observed reduction in PSII and PSI functions, the abundances of reaction-center proteins, and, at 300 µM menthol, of total cellular proteins. Interestingly, for free-living algae exposed to 100 µM menthol, an initial decline in growth, photosynthetic activities, pigmentation, and protein abundances reversed after 5-15 d, eventually approaching control levels. This behavior was observed in cells maintained in continuous light, but not in cells experiencing a light-dark regimen, suggesting that B. minutum can detoxify menthol or acclimate and repair damaged photosynthetic complexes in a light- and/or energy-dependent manner. Extended exposures of cultured algae to 300 µM menthol ultimately resulted in algal death. Most symbiotic anemones were also unable to survive this menthol concentration for 30 d. Additionally, cells impaired for photosynthesis by pre-treatment with 300 µM menthol exhibited reduced efficiency in re-populating the anemone host.
Collapse
Affiliation(s)
- Sophie Clowez
- Department of Plant Biology, Carnegie Institution for Science, 260 Panama Street, Stanford, California, 94305, USA
| | - Christian Renicke
- Department of Genetics, Stanford University, Stanford, California, 94305, USA
| | - John R Pringle
- Department of Genetics, Stanford University, Stanford, California, 94305, USA
| | - Arthur R Grossman
- Department of Plant Biology, Carnegie Institution for Science, 260 Panama Street, Stanford, California, 94305, USA
| |
Collapse
|
25
|
Malone LA, Proctor MS, Hitchcock A, Hunter CN, Johnson MP. Cytochrome b 6f - Orchestrator of photosynthetic electron transfer. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2021; 1862:148380. [PMID: 33460588 DOI: 10.1016/j.bbabio.2021.148380] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 01/06/2021] [Accepted: 01/09/2021] [Indexed: 11/18/2022]
Abstract
Cytochrome b6f (cytb6f) lies at the heart of the light-dependent reactions of oxygenic photosynthesis, where it serves as a link between photosystem II (PSII) and photosystem I (PSI) through the oxidation and reduction of the electron carriers plastoquinol (PQH2) and plastocyanin (Pc). A mechanism of electron bifurcation, known as the Q-cycle, couples electron transfer to the generation of a transmembrane proton gradient for ATP synthesis. Cytb6f catalyses the rate-limiting step in linear electron transfer (LET), is pivotal for cyclic electron transfer (CET) and plays a key role as a redox-sensing hub involved in the regulation of light-harvesting, electron transfer and photosynthetic gene expression. Together, these characteristics make cytb6f a judicious target for genetic manipulation to enhance photosynthetic yield, a strategy which already shows promise. In this review we will outline the structure and function of cytb6f with a particular focus on new insights provided by the recent high-resolution map of the complex from Spinach.
Collapse
Affiliation(s)
- Lorna A Malone
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK
| | - Matthew S Proctor
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK
| | - Andrew Hitchcock
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK
| | - C Neil Hunter
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK
| | - Matthew P Johnson
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK.
| |
Collapse
|
26
|
Theune ML, Hildebrandt S, Steffen-Heins A, Bilger W, Gutekunst K, Appel J. In-vivo quantification of electron flow through photosystem I - Cyclic electron transport makes up about 35% in a cyanobacterium. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2020; 1862:148353. [PMID: 33346012 DOI: 10.1016/j.bbabio.2020.148353] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 11/23/2020] [Accepted: 12/08/2020] [Indexed: 12/15/2022]
Abstract
Photosynthetic electron flow, driven by photosystem I and II, provides chemical energy for carbon fixation. In addition to a linear mode a second cyclic route exists, which only involves photosystem I. The exact contributions of linear and cyclic transport are still a matter of debate. Here, we describe the development of a method that allows quantification of electron flow in absolute terms through photosystem I in a photosynthetic organism for the first time. Specific in-vivo protocols allowed to discern the redox states of plastocyanin, P700 and the FeS-clusters including ferredoxin at the acceptor site of PSI in the cyanobacterium Synechocystis sp. PCC 6803 with the near-infrared spectrometer Dual-KLAS/NIR. P700 absorbance changes determined with the Dual-KLAS/NIR correlated linearly with direct determinations of PSI concentrations using EPR. Dark-interval relaxation kinetics measurements (DIRKPSI) were applied to determine electron flow through PSI. Counting electrons from hydrogen oxidation as electron donor to photosystem I in parallel to DIRKPSI measurements confirmed the validity of the method. Electron flow determination by classical PSI yield measurements overestimates electron flow at low light intensities and saturates earlier compared to DIRKPSI. Combination of DIRKPSI with oxygen evolution measurements yielded a proportion of 35% of surplus electrons passing PSI compared to PSII. We attribute these electrons to cyclic electron transport, which is twice as high as assumed for plants. Counting electrons flowing through the photosystems allowed determination of the number of quanta required for photosynthesis to 11 per oxygen produced, which is close to published values.
Collapse
Affiliation(s)
- Marius L Theune
- Department of Biology, Botanical Institute, Christian-Albrechts-University, 24118 Kiel, Germany
| | - Sarah Hildebrandt
- Department of Biology, Botanical Institute, Christian-Albrechts-University, 24118 Kiel, Germany
| | - Anja Steffen-Heins
- Division of Food Technology, Institute of Human Nutrition and Food Science, Christian-Albrechts-University, 24118 Kiel, Germany
| | - Wolfgang Bilger
- Department of Biology, Botanical Institute, Christian-Albrechts-University, 24118 Kiel, Germany
| | - Kirstin Gutekunst
- Department of Biology, Botanical Institute, Christian-Albrechts-University, 24118 Kiel, Germany
| | - Jens Appel
- Department of Biology, Botanical Institute, Christian-Albrechts-University, 24118 Kiel, Germany.
| |
Collapse
|
27
|
PGR5 is required for efficient Q cycle in the cytochrome b6f complex during cyclic electron flow. Biochem J 2020; 477:1631-1650. [PMID: 32267468 DOI: 10.1042/bcj20190914] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 03/23/2020] [Accepted: 04/07/2020] [Indexed: 01/07/2023]
Abstract
Proton gradient regulation 5 (PGR5) is involved in the control of photosynthetic electron transfer, but its mechanistic role is not yet clear. Several models have been proposed to explain phenotypes such as a diminished steady-state proton motive force (pmf) and increased photodamage of photosystem I (PSI). Playing a regulatory role in cyclic electron flow (CEF) around PSI, PGR5 contributes indirectly to PSI protection by enhancing photosynthetic control, which is a pH-dependent down-regulation of electron transfer at the cytochrome b6f complex (b6f). Here, we re-evaluated the role of PGR5 in the green alga Chlamydomonas reinhardtii and conclude that pgr5 possesses a dysfunctional b6f. Our data indicate that the b6f low-potential chain redox activity likely operated in two distinct modes - via the canonical Q cycle during linear electron flow and via an alternative Q cycle during CEF, which allowed efficient oxidation of the low-potential chain in the WT b6f. A switch between the two Q cycle modes was dependent on PGR5 and relied on unknown stromal electron carrier(s), which were a general requirement for b6f activity. In CEF-favoring conditions, the electron transfer bottleneck in pgr5 was the b6f, in which insufficient low-potential chain redox tuning might account for the mutant pmf phenotype. By attributing a ferredoxin-plastoquinone reductase activity to the b6f and investigating a PGR5 cysteine mutant, a current model of CEF is challenged.
Collapse
|
28
|
Okegawa Y, Motohashi K. M-Type Thioredoxins Regulate the PGR5/PGRL1-Dependent Pathway by Forming a Disulfide-Linked Complex with PGRL1. THE PLANT CELL 2020; 32:3866-3883. [PMID: 33037145 PMCID: PMC7721319 DOI: 10.1105/tpc.20.00304] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 09/16/2020] [Accepted: 10/07/2020] [Indexed: 05/11/2023]
Abstract
In addition to linear electron transport, photosystem I cyclic electron transport (PSI-CET) contributes to photosynthesis and photoprotection. In Arabidopsis (Arabidopsis thaliana), PSI-CET consists of two partially redundant pathways, one of which is the PROTON GRADIENT REGULATION5 (PGR5)/PGR5-LIKE PHOTOSYNTHETIC PHENOTYPE1 (PGRL1)-dependent pathway. Although the physiological significance of PSI-CET is widely recognized, the regulatory mechanism behind these pathways remains largely unknown. Here, we report on the regulation of the PGR5/PGRL1-dependent pathway by the m-type thioredoxins (Trx m). Genetic and phenotypic characterizations of multiple mutants indicated the physiological interaction between Trx m and the PGR5/PGRL1-dependent pathway in vivo. Using purified Trx proteins and ruptured chloroplasts, in vitro, we showed that the reduced form of Trx m specifically decreased the PGR5/PGRL1-dependent plastoquinone reduction. In planta, Trx m4 directly interacted with PGRL1 via disulfide complex formation. Analysis of the transgenic plants expressing PGRL1 Cys variants demonstrated that Cys-123 of PGRL1 is required for Trx m4-PGRL1 complex formation. Furthermore, the Trx m4-PGRL1 complex was transiently dissociated during the induction of photosynthesis. We propose that Trx m directly regulates the PGR5/PGRL1-dependent pathway by complex formation with PGRL1.
Collapse
Affiliation(s)
- Yuki Okegawa
- Department of Frontier Life Sciences, Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo Motoyama, Kita-Ku, Kyoto 603-8555, Japan
- Center for Plant Sciences, Kyoto Sangyo University, Kamigamo Motoyama, Kita-Ku, Kyoto 603-8555, Japan
| | - Ken Motohashi
- Department of Frontier Life Sciences, Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo Motoyama, Kita-Ku, Kyoto 603-8555, Japan
- Center for Plant Sciences, Kyoto Sangyo University, Kamigamo Motoyama, Kita-Ku, Kyoto 603-8555, Japan
| |
Collapse
|
29
|
Storti M, Segalla A, Mellon M, Alboresi A, Morosinotto T. Regulation of electron transport is essential for photosystem I stability and plant growth. THE NEW PHYTOLOGIST 2020; 228:1316-1326. [PMID: 32367526 DOI: 10.1111/nph.16643] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 04/27/2020] [Indexed: 06/11/2023]
Abstract
Photosynthetic electron transport is regulated by cyclic and pseudocyclic electron flow (CEF and PCEF) to maintain the balance between light availability and metabolic demands. CEF transfers electrons from photosystem I to the plastoquinone pool with two mechanisms, dependent either on PGR5/PGRL1 or on the type I NADH dehydrogenase-like (NDH) complex. PCEF uses electrons from photosystem I to reduce oxygen and in many groups of photosynthetic organisms, but remarkably not in angiosperms, it is catalyzed by flavodiiron proteins (FLVs). In this study, Physcomitrella patens plants depleted in PGRL1, NDH and FLVs in different combinations were generated and characterized, showing that all these mechanisms are active in this moss. Surprisingly, in contrast to flowering plants, Physcomitrella patens can cope with the simultaneous inactivation of PGR5- and NDH-dependent CEF but, when FLVs are also depleted, plants show strong growth reduction and photosynthetic activity is drastically reduced. The results demonstrate that mechanisms for modulation of photosynthetic electron transport have large functional overlap but are together indispensable to protect photosystem I from damage and they are an essential component for photosynthesis in any light regime.
Collapse
Affiliation(s)
- Mattia Storti
- Department of Biology, University of Padova, Padova, 35121, Italy
| | - Anna Segalla
- Department of Biology, University of Padova, Padova, 35121, Italy
| | - Marco Mellon
- Department of Biology, University of Padova, Padova, 35121, Italy
| | | | | |
Collapse
|
30
|
Tan Y, Zhang QS, Zhao W, Liu Z, Ma MY, Zhong MY, Wang MX. The highly efficient NDH-dependent photosystem I cyclic electron flow pathway in the marine angiosperm Zostera marina. PHOTOSYNTHESIS RESEARCH 2020; 144:49-62. [PMID: 32152819 DOI: 10.1007/s11120-020-00732-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 03/03/2020] [Indexed: 05/13/2023]
Abstract
Zostera marina, a fully submerged marine angiosperm with a unique evolutionary history associated with its terrestrial origin, has distinct photochemical characteristics caused by its oxygen-evolving complex (OEC) being prone to deactivation in visible light. Based on the present phylogenetic analysis, the chloroplast NADPH dehydrogenase-like (NDH) complex was found to be completed in of Z. marina, unlike other marine plants, suggesting its crucial role. Thus, the responses of electron transport to irradiation were investigated through multiple chlorophyll fluorescence techniques and Western blot analysis. Moreover, the respective contribution of the two photosystem I cyclic electron flow (PSI-CEF) pathways to the generation of trans-thylakoid proton gradient (∆pH) was also examined using inhibitors. The contributions of the two PSI-CEF pathways to ∆pH were similar; furthermore, there was a trade-off between the two pathways under excess irradiation: the PGR5/L1-dependent PSI-CEF decreased gradually following its activation during the initial illumination, while NDH-dependent PSI-CEF was activated gradually with exposure duration. OEC inactivation was continuously under excess irradiation, which exhibits a positive linear correlation with the activation of NDH-dependent PSI-CEF. We suggest that PGR5/L1-dependent PSI-CEF was preferentially activated to handle the excess electron caused by the operation of OEC during the initial illumination. Subsequently, the increasing OEC inactivation with exposure duration resulted in a deficit of electrons. Limited electrons from PSI might preferentially synthesize NADPH, which could support the function of NDH-dependent PSI-CEF to generate ∆pH and ATP via reducing ferredoxin, thereby maintaining OEC stability.
Collapse
Affiliation(s)
- Ying Tan
- Ocean School, Yantai University, Yantai, 264005, People's Republic of China
| | - Quan Sheng Zhang
- Ocean School, Yantai University, Yantai, 264005, People's Republic of China.
| | - Wei Zhao
- Ocean School, Yantai University, Yantai, 264005, People's Republic of China
| | - Zhe Liu
- Ocean School, Yantai University, Yantai, 264005, People's Republic of China
| | - Ming Yu Ma
- Ocean School, Yantai University, Yantai, 264005, People's Republic of China
| | - Ming Yu Zhong
- Ocean School, Yantai University, Yantai, 264005, People's Republic of China
| | - Meng Xin Wang
- Ocean School, Yantai University, Yantai, 264005, People's Republic of China
| |
Collapse
|
31
|
Sela A, Piskurewicz U, Megies C, Mène-Saffrané L, Finazzi G, Lopez-Molina L. Embryonic Photosynthesis Affects Post-Germination Plant Growth. PLANT PHYSIOLOGY 2020; 182:2166-2181. [PMID: 32060052 PMCID: PMC7140907 DOI: 10.1104/pp.20.00043] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 01/28/2020] [Indexed: 05/02/2023]
Abstract
Photosynthesis is the fundamental process fueling plant vegetative growth and development. The progeny of plants relies on maternal photosynthesis, via food reserves in the seed, to supply the necessary energy for seed germination and early seedling establishment. Intriguingly, before seed maturation, Arabidopsis (Arabidopsis thaliana) embryos are also photosynthetically active, the biological significance of which remains poorly understood. Investigating this system is genetically challenging because mutations perturbing photosynthesis are expected to affect both embryonic and vegetative tissues. Here, we isolated a temperature-sensitive mutation affecting CPN60α2, which encodes a subunit of the chloroplast chaperonin complex CPN60. When exposed to cold temperatures, cpn60α2 mutants accumulate less chlorophyll in newly produced tissues, thus allowing the specific disturbance of embryonic photosynthesis. Analyses of cpn60α2 mutants were combined with independent genetic and pharmacological approaches to show that embryonic photosynthetic activity is necessary for normal skoto- and photomorphogenesis in juvenile seedlings as well as long-term adult plant development. Our results reveal the importance of embryonic photosynthetic activity for normal adult plant growth, development, and health.
Collapse
Affiliation(s)
- Ayala Sela
- Department of Botany and Plant Biology, University of Geneva, 1211 Geneva, Switzerland
| | - Urszula Piskurewicz
- Department of Botany and Plant Biology, University of Geneva, 1211 Geneva, Switzerland
| | - Christian Megies
- Department of Botany and Plant Biology, University of Geneva, 1211 Geneva, Switzerland
| | | | - Giovanni Finazzi
- Université Grenoble Alpes, Centre National de la Recherche Scientifique, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Institut National de la Recherche Agronomique, Interdisciplinary Research Institute of Grenoble - Cell & Plant Physiology Laboratory, 38000 Grenoble, France
| | - Luis Lopez-Molina
- Department of Botany and Plant Biology, University of Geneva, 1211 Geneva, Switzerland
- Institute of Genetics and Genomics in Geneva, University of Geneva, 1211 Geneva, Switzerland
| |
Collapse
|
32
|
Walker BJ, Kramer DM, Fisher N, Fu X. Flexibility in the Energy Balancing Network of Photosynthesis Enables Safe Operation under Changing Environmental Conditions. PLANTS (BASEL, SWITZERLAND) 2020; 9:E301. [PMID: 32121540 PMCID: PMC7154899 DOI: 10.3390/plants9030301] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 02/13/2020] [Accepted: 02/15/2020] [Indexed: 12/11/2022]
Abstract
Given their ability to harness chemical energy from the sun and generate the organic compounds necessary for life, photosynthetic organisms have the unique capacity to act simultaneously as their own power and manufacturing plant. This dual capacity presents many unique challenges, chiefly that energy supply must be perfectly balanced with energy demand to prevent photodamage and allow for optimal growth. From this perspective, we discuss the energy balancing network using recent studies and a quantitative framework for calculating metabolic ATP and NAD(P)H demand using measured leaf gas exchange and assumptions of metabolic demand. We focus on exploring how the energy balancing network itself is structured to allow safe and flexible energy supply. We discuss when the energy balancing network appears to operate optimally and when it favors high capacity instead. We also present the hypothesis that the energy balancing network itself can adapt over longer time scales to a given metabolic demand and how metabolism itself may participate in this energy balancing.
Collapse
Affiliation(s)
- Berkley J. Walker
- Plant Research Laboratory, Michigan State University, East Lansing, MI 48823, USA; (D.M.K.); (N.F.); (X.F.)
- Department of Plant Biology, Michigan State University, East Lansing, MI 48823, USA
| | - David M. Kramer
- Plant Research Laboratory, Michigan State University, East Lansing, MI 48823, USA; (D.M.K.); (N.F.); (X.F.)
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48823, USA
| | - Nicholas Fisher
- Plant Research Laboratory, Michigan State University, East Lansing, MI 48823, USA; (D.M.K.); (N.F.); (X.F.)
| | - Xinyu Fu
- Plant Research Laboratory, Michigan State University, East Lansing, MI 48823, USA; (D.M.K.); (N.F.); (X.F.)
| |
Collapse
|
33
|
McKenzie SD, Ibrahim IM, Aryal UK, Puthiyaveetil S. Stoichiometry of protein complexes in plant photosynthetic membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2020; 1861:148141. [DOI: 10.1016/j.bbabio.2019.148141] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 11/21/2019] [Accepted: 12/05/2019] [Indexed: 12/14/2022]
|
34
|
Kono M, Kawaguchi H, Mizusawa N, Yamori W, Suzuki Y, Terashima I. Far-Red Light Accelerates Photosynthesis in the Low-Light Phases of Fluctuating Light. PLANT & CELL PHYSIOLOGY 2020; 61:192-202. [PMID: 31617558 DOI: 10.1093/pcp/pcz191] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 09/26/2019] [Indexed: 05/09/2023]
Abstract
It is well known that far-red light (FR; >700 nm) drives PSI photochemistry, but its effect on photosynthetic performance has received little attention. In this study, the effects of the addition of FR to red fluctuating light (FL) have on photosynthesis were examined in the leaves of Arabidopsis thaliana. Light-activated leaves were illuminated with FL [alternating high light/low light (HL/LL) at 800/30 μmol m-2 s-1] for 10-15 min without or with FR at intensities that reflected natural conditions. The CO2 assimilation rates upon the transition from HL to LL were significantly greater with FR than without FR. The enhancement of photosynthesis by FR was small under the steady-state conditions and in the HL phases of FL. Proton conductivity through the thylakoid membrane (gH+) in the LL phases of FL, estimated from the dark relaxation kinetics of the electrochromic absorbance shift, was greater with FR than without FR. The relaxation of non-photochemical quenching (NPQ) in the PSII antenna system and the increase in PSII photochemistry in the LL phases accelerated in the presence of FR. Similar FR-effects in FL were confirmed in typical sun and shade plants. On the basis of these results, we concluded that FR exerted beneficial effects on photosynthesis in FL by exciting PSI and accelerating NPQ relaxation and PSII-yield increase. This was probably because of the increased gH+, which would reflect faster ΔpH dissipation and ATP synthesis.
Collapse
Affiliation(s)
- Masaru Kono
- Department of Biological Sciences, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033 Japan
| | - Hikaru Kawaguchi
- Faculty of Science, Kanagawa University, 2946 Tsuchiya, Hiratsuka, Kanagawa, 259-1293 Japan
| | - Naoki Mizusawa
- Department of Frontier Bioscience, Hosei University, Koganei, Tokyo, 184-8584 Japan
- Research Center for Micro-Nano Technology, Hosei University, Koganei, Tokyo, 184-0003 Japan
| | - Wataru Yamori
- Department of Biological Sciences, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033 Japan
| | - Yoshihiro Suzuki
- Faculty of Science, Kanagawa University, 2946 Tsuchiya, Hiratsuka, Kanagawa, 259-1293 Japan
| | - Ichiro Terashima
- Department of Biological Sciences, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033 Japan
| |
Collapse
|
35
|
Harada K, Arizono T, Sato R, Trinh MDL, Hashimoto A, Kono M, Tsujii M, Uozumi N, Takaichi S, Masuda S. DAY-LENGTH-DEPENDENT DELAYED-GREENING1, the Arabidopsis Homolog of the Cyanobacterial H+-Extrusion Protein, Is Essential for Chloroplast pH Regulation and Optimization of Non-Photochemical Quenching. PLANT & CELL PHYSIOLOGY 2019; 60:2660-2671. [PMID: 31665522 DOI: 10.1093/pcp/pcz203] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 10/22/2019] [Indexed: 05/21/2023]
Abstract
Plants convert solar energy into chemical energy through photosynthesis, which supports almost all life activities on earth. Because the intensity and quality of sunlight can change dramatically throughout the day, various regulatory mechanisms help plants adjust their photosynthetic output accordingly, including the regulation of light energy accumulation to prevent the generation of damaging reactive oxygen species. Non-photochemical quenching (NPQ) is a regulatory mechanism that dissipates excess light energy, but how it is regulated is not fully elucidated. In this study, we report a new NPQ-regulatory protein named Day-Length-dependent Delayed-Greening1 (DLDG1). The Arabidopsis DLDG1 associates with the chloroplast envelope membrane, and the dldg1 mutant had a large NPQ value compared with wild type. The mutant also had a pale-green phenotype in developing leaves but only under continuous light; this phenotype was not observed when dldg1 was cultured in the dark for ≥8 h/d. DLDG1 is a homolog of the plasma membrane-localizing cyanobacterial proton-extrusion-protein A that is required for light-induced H+ extrusion and also shows similarity in its amino-acid sequence to that of Ycf10 encoded in the plastid genome. Arabidopsis DLDG1 enhances the growth-retardation phenotype of the Escherichia coli K+/H+ antiporter mutant, and the everted membrane vesicles of the E. coli expressing DLDG1 show the K+/H+ antiport activity. Our findings suggest that DLDG1 functionally interacts with Ycf10 to control H+ homeostasis in chloroplasts, which is important for the light-acclimation response, by optimizing the extent of NPQ.
Collapse
Affiliation(s)
- Kyohei Harada
- School of Life Science & Technology, Tokyo Institute of Technology, Yokohama, 226-8501 Japan
| | - Takatoshi Arizono
- School of Life Science & Technology, Tokyo Institute of Technology, Yokohama, 226-8501 Japan
| | - Ryoichi Sato
- School of Life Science & Technology, Tokyo Institute of Technology, Yokohama, 226-8501 Japan
| | - Mai Duy Luu Trinh
- School of Life Science & Technology, Tokyo Institute of Technology, Yokohama, 226-8501 Japan
| | - Akira Hashimoto
- School of Life Science & Technology, Tokyo Institute of Technology, Yokohama, 226-8501 Japan
| | - Masaru Kono
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, 113-0033 Japan
| | - Masaru Tsujii
- Department of Biomolecular Engineering, Graduate School of Engineering, Tohoku University, Sendai, 980-8579 Japan
| | - Nobuyuki Uozumi
- Department of Biomolecular Engineering, Graduate School of Engineering, Tohoku University, Sendai, 980-8579 Japan
| | - Shinichi Takaichi
- Department of Molecular Microbiology, Faculty of Life Science, Tokyo University of Agriculture, Tokyo, 156-8502 Japan
| | - Shinji Masuda
- School of Life Science & Technology, Tokyo Institute of Technology, Yokohama, 226-8501 Japan
- Center for Biological Resources & Informatics, Tokyo Institute of Technology, Yokohama, 226-8501 Japan
| |
Collapse
|
36
|
Harada K, Arizono T, Sato R, Trinh MDL, Hashimoto A, Kono M, Tsujii M, Uozumi N, Takaichi S, Masuda S. DAY-LENGTH-DEPENDENT DELAYED-GREENING1, the Arabidopsis Homolog of the Cyanobacterial H+-Extrusion Protein, Is Essential for Chloroplast pH Regulation and Optimization of Non-Photochemical Quenching. PLANT & CELL PHYSIOLOGY 2019; 60:2660-2671. [PMID: 31665522 DOI: 10.1101/731653] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 10/22/2019] [Indexed: 05/24/2023]
Abstract
Plants convert solar energy into chemical energy through photosynthesis, which supports almost all life activities on earth. Because the intensity and quality of sunlight can change dramatically throughout the day, various regulatory mechanisms help plants adjust their photosynthetic output accordingly, including the regulation of light energy accumulation to prevent the generation of damaging reactive oxygen species. Non-photochemical quenching (NPQ) is a regulatory mechanism that dissipates excess light energy, but how it is regulated is not fully elucidated. In this study, we report a new NPQ-regulatory protein named Day-Length-dependent Delayed-Greening1 (DLDG1). The Arabidopsis DLDG1 associates with the chloroplast envelope membrane, and the dldg1 mutant had a large NPQ value compared with wild type. The mutant also had a pale-green phenotype in developing leaves but only under continuous light; this phenotype was not observed when dldg1 was cultured in the dark for ≥8 h/d. DLDG1 is a homolog of the plasma membrane-localizing cyanobacterial proton-extrusion-protein A that is required for light-induced H+ extrusion and also shows similarity in its amino-acid sequence to that of Ycf10 encoded in the plastid genome. Arabidopsis DLDG1 enhances the growth-retardation phenotype of the Escherichia coli K+/H+ antiporter mutant, and the everted membrane vesicles of the E. coli expressing DLDG1 show the K+/H+ antiport activity. Our findings suggest that DLDG1 functionally interacts with Ycf10 to control H+ homeostasis in chloroplasts, which is important for the light-acclimation response, by optimizing the extent of NPQ.
Collapse
Affiliation(s)
- Kyohei Harada
- School of Life Science & Technology, Tokyo Institute of Technology, Yokohama, 226-8501 Japan
| | - Takatoshi Arizono
- School of Life Science & Technology, Tokyo Institute of Technology, Yokohama, 226-8501 Japan
| | - Ryoichi Sato
- School of Life Science & Technology, Tokyo Institute of Technology, Yokohama, 226-8501 Japan
| | - Mai Duy Luu Trinh
- School of Life Science & Technology, Tokyo Institute of Technology, Yokohama, 226-8501 Japan
| | - Akira Hashimoto
- School of Life Science & Technology, Tokyo Institute of Technology, Yokohama, 226-8501 Japan
| | - Masaru Kono
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, 113-0033 Japan
| | - Masaru Tsujii
- Department of Biomolecular Engineering, Graduate School of Engineering, Tohoku University, Sendai, 980-8579 Japan
| | - Nobuyuki Uozumi
- Department of Biomolecular Engineering, Graduate School of Engineering, Tohoku University, Sendai, 980-8579 Japan
| | - Shinichi Takaichi
- Department of Molecular Microbiology, Faculty of Life Science, Tokyo University of Agriculture, Tokyo, 156-8502 Japan
| | - Shinji Masuda
- School of Life Science & Technology, Tokyo Institute of Technology, Yokohama, 226-8501 Japan
- Center for Biological Resources & Informatics, Tokyo Institute of Technology, Yokohama, 226-8501 Japan
| |
Collapse
|
37
|
Tacchino F, Succurro A, Ebenhöh O, Gerace D. Optimal efficiency of the Q-cycle mechanism around physiological temperatures from an open quantum systems approach. Sci Rep 2019; 9:16657. [PMID: 31723177 PMCID: PMC6853958 DOI: 10.1038/s41598-019-52842-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 10/14/2019] [Indexed: 01/17/2023] Open
Abstract
The Q-cycle mechanism entering the electron and proton transport chain in oxygenic photosynthesis is an example of how biological processes can be efficiently investigated with elementary microscopic models. Here we address the problem of energy transport across the cellular membrane from an open quantum system theoretical perspective. We model the cytochrome \documentclass[12pt]{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$${b}_{6}\,f$$\end{document}b6f protein complex under cyclic electron flow conditions starting from a simplified kinetic model, which is hereby revisited in terms of a Markovian quantum master equation formulation and spin-boson Hamiltonian treatment. We apply this model to theoretically demonstrate an optimal thermodynamic efficiency of the Q-cycle around ambient and physiologically relevant temperature conditions. Furthermore, we determine the quantum yield of this complex biochemical process after setting the electrochemical potentials to values well established in the literature. The present work suggests that the theory of quantum open systems can successfully push forward our theoretical understanding of complex biological systems working close to the quantum/classical boundary.
Collapse
Affiliation(s)
| | - Antonella Succurro
- Institute of Quantitative and Theoretical Biology, Heinrich Heine University, 40225, Düsseldorf, Germany.,Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich Heine University, 40225, Düsseldorf, Germany.,Life and Medical Sciences (LIMES) Institute and West German Genome Center, University of Bonn, Bonn, Germany
| | - Oliver Ebenhöh
- Institute of Quantitative and Theoretical Biology, Heinrich Heine University, 40225, Düsseldorf, Germany.,Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich Heine University, 40225, Düsseldorf, Germany
| | - Dario Gerace
- Department of Physics, University of Pavia, I-27100, Pavia, Italy.
| |
Collapse
|
38
|
Probing the electric field across thylakoid membranes in cyanobacteria. Proc Natl Acad Sci U S A 2019; 116:21900-21906. [PMID: 31591197 DOI: 10.1073/pnas.1913099116] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In plants, algae, and some photosynthetic bacteria, the ElectroChromic Shift (ECS) of photosynthetic pigments, which senses the electric field across photosynthetic membranes, is widely used to quantify the activity of the photosynthetic chain. In cyanobacteria, ECS signals have never been used for physiological studies, although they can provide a unique tool to study the architecture and function of the respiratory and photosynthetic electron transfer chains, entangled in the thylakoid membranes. Here, we identified bona fide ECS signals, likely corresponding to carotenoid band shifts, in the model cyanobacteria Synechococcus elongatus PCC7942 and Synechocystis sp. PCC6803. These band shifts, most likely originating from pigments located in photosystem I, have highly similar spectra in the 2 species and can be best measured as the difference between the absorption changes at 500 to 505 nm and the ones at 480 to 485 nm. These signals respond linearly to the electric field and display the basic kinetic features of ECS as characterized in other organisms. We demonstrate that these probes are an ideal tool to study photosynthetic physiology in vivo, e.g., the fraction of PSI centers that are prebound by plastocyanin/cytochrome c 6 in darkness (about 60% in both cyanobacteria, in our experiments), the conductivity of the thylakoid membrane (largely reflecting the activity of the ATP synthase), or the steady-state rates of the photosynthetic electron transport pathways.
Collapse
|
39
|
Regulation of photosynthetic cyclic electron flow pathways by adenylate status in higher plant chloroplasts. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2019; 1860:148081. [PMID: 31520615 DOI: 10.1016/j.bbabio.2019.148081] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 09/01/2019] [Accepted: 09/08/2019] [Indexed: 01/08/2023]
Abstract
Cylic electron flow (CEF) around Photosystem I in photosynthetic eukaryotes is likely to be necessary to augment ATP production, rapidly- and precisely balancing the plastid ATP/NADPH energy budget to meet the demands of downstream metabolism. Many regulatory aspects of this process are unclear. Here we demonstrate that the higher plant plastid NADH/Fd:plastoquinone reductase (NDH) and proposed PGR5/PGRL1 ferredoxin:plastoquinone reductase (FQR) pathways of CEF are strongly, rapidly and reversibly inhibited in vitro by ATP with Ki values of 670 μM and 240 μM respectively, within the range of physiological changes in ATP concentrations. Control experiments ruled out effects on secondary reactions, e.g. FNR- and cytochrome b6f activity, nonphotochemical quenching of chlorophyll fluorescence etc., supporting the view that ATP is an inhibitor of CEF and its associated pmf generation and subsequent ATP production. The effects are specific to ATP, with the ATP analog AMP-PNP showing little inhibitory effect, and ADP inhibiting only at higher concentrations. For the FQR pathway, inhibition was found to be classically competitive with Fd, and the NDH pathway showing partial competition with Fd. We propose a straightforward model for regulation of CEF in plants in which CEF is activated under conditions when stromal ATP low, but is downregulated as ATP levels build up, allowing for effective ATP homeostasis. The differences in Ki values suggest a two-tiered regulatory system, where the highly efficient proton pumping NDH is activated with moderate decreases in ATP, with the less energetically-efficient FQR pathway being activated under more severe ATP depletion.
Collapse
|
40
|
Scholz M, Gäbelein P, Xue H, Mosebach L, Bergner SV, Hippler M. Light-dependent N-terminal phosphorylation of LHCSR3 and LHCB4 are interlinked in Chlamydomonas reinhardtii. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 99:877-894. [PMID: 31033075 PMCID: PMC6851877 DOI: 10.1111/tpj.14368] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 03/15/2019] [Accepted: 04/16/2019] [Indexed: 05/08/2023]
Abstract
Phosphorylation dynamics of LHCSR3 were investigated in Chlamydomonas reinhardtii by quantitative proteomics and genetic engineering. LHCSR3 protein expression and phosphorylation were induced in high light. Our data revealed synergistic and dynamic N-terminal LHCSR3 phosphorylation. Phosphorylated and nonphosphorylated LHCSR3 associated with PSII-LHCII supercomplexes. The phosphorylation status of LHCB4 was closely linked to the phosphorylation of multiple sites at the N-terminus of LHCSR3, indicating that LHCSR3 phosphorylation may operate as a molecular switch modulating LHCB4 phosphorylation, which in turn is important for PSII-LHCII disassembly. Notably, LHCSR3 phosphorylation diminished under prolonged high light, which coincided with onset of CEF. Hierarchical clustering of significantly altered proteins revealed similar expression profiles of LHCSR3, CRX, and FNR. This finding indicated the existence of a functional link between LHCSR3 protein abundance and phosphorylation, photosynthetic electron flow, and the oxidative stress response.
Collapse
Affiliation(s)
- Martin Scholz
- Institute of Plant Biology and BiotechnologyUniversity of MünsterSchlossplatz 8Münster48143Germany
| | - Philipp Gäbelein
- Institute of Plant Biology and BiotechnologyUniversity of MünsterSchlossplatz 8Münster48143Germany
| | - Huidan Xue
- Institute of Plant Biology and BiotechnologyUniversity of MünsterSchlossplatz 8Münster48143Germany
| | - Laura Mosebach
- Institute of Plant Biology and BiotechnologyUniversity of MünsterSchlossplatz 8Münster48143Germany
| | - Sonja Verena Bergner
- Institute of Plant Biology and BiotechnologyUniversity of MünsterSchlossplatz 8Münster48143Germany
- Present address:
Max Planck Institute of Molecular Plant PhysiologyAm Mühlenberg 1Potsdam‐Golm14476Germany
| | - Michael Hippler
- Institute of Plant Biology and BiotechnologyUniversity of MünsterSchlossplatz 8Münster48143Germany
| |
Collapse
|
41
|
Du J, Qiu B, Pedrosa Gomes M, Juneau P, Dai G. Influence of light intensity on cadmium uptake and toxicity in the cyanobacteria Synechocystis sp. PCC6803. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2019; 211:163-172. [PMID: 30991162 DOI: 10.1016/j.aquatox.2019.03.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2018] [Revised: 03/18/2019] [Accepted: 03/24/2019] [Indexed: 05/02/2023]
Abstract
The mechanisms of cadmium toxicity to cyanobacterial photosynthesis have been extensively studied, but the response mechanisms to combinations of different cadmium concentrations and different light intensities are not yet well understood. The two principal objectives of the present work were to: 1) study the short term (5 h) toxic effects of cadmium on Synechocystis PCC6803 under three different culturing light intensity conditions; and, 2) investigate the effects of light history on Cd toxicity to Synechocystis. The maximal (ФM) and operational (Ф'M) photosystem II quantum yields, photosystem I quantum yield [Y (I)], cyclic electron flow, relative photochemical quenching (qPrel), relative non-photochemical quenching (qNrel), relative unquenched fluorescence (UQFrel), pigment contents, and cadmium uptake were evaluated when Synechocystis cells were treated with cadmium for 5 h under three different light conditions. We demonstrated that cadmium toxicity was enhanced with increasing growth light intensities due to increased cadmium uptake under higher light exposures, and the photoprotective mechanisms could not cope with cadmium and light stress under high light conditions. We also investigated Cd toxicity to Synechocystis adapted to three growth light intensities and subsequently shifted to different light intensity conditions to compare the effects of light regime shift on cadmium toxicity. We observed increased cadmium toxicity when the cells were transferred from low light to high light conditions. Interestingly, Synechocystis cells grown at high light intensities were more tolerant to cadmium than cells grown at low light intensities after the same light regime shift, due to the development of photoprotective mechanisms.
Collapse
Affiliation(s)
- Juan Du
- College of Life Sciences, Central China Normal University, Wuhan, 430079, Hubei, PR China
| | - Baosheng Qiu
- College of Life Sciences, Central China Normal University, Wuhan, 430079, Hubei, PR China
| | - Marcelo Pedrosa Gomes
- Laboratório de Fisiologia de Plantas sob Estresse, Departamento de Botânica, Setor de Ciências Biológicas, Universidade Federal do Paraná, Avenida Coronel Francisco H. dos Santos, 100, Centro Politécnico Jardim das Américas, C.P. 19031, 81531-980, Curitiba, Paraná, Brazil
| | - Philippe Juneau
- Departement des Sciences Biologiques - GRIL-TOXEN, Ecotoxicology of Aquatic Microorganisms Laboratory, Université du Québec à Montréal, Succ. Centre-Ville, C.P. 8888, H3C 3P8, Montréal, Québec, Canada.
| | - Guozheng Dai
- College of Life Sciences, Central China Normal University, Wuhan, 430079, Hubei, PR China.
| |
Collapse
|
42
|
Borisova-Mubarakshina MM, Vetoshkina DV, Ivanov BN. Antioxidant and signaling functions of the plastoquinone pool in higher plants. PHYSIOLOGIA PLANTARUM 2019; 166:181-198. [PMID: 30706486 DOI: 10.1111/ppl.12936] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 01/23/2019] [Accepted: 01/25/2019] [Indexed: 05/25/2023]
Abstract
The review covers data representing the plastoquinone pool as the component integrated in plant antioxidant defense and plant signaling. The main goal of the review is to discuss the evidence describing the plastoquinone-involved biochemical reactions, which are incorporated in maintaining the sustainability of higher plants to stress conditions. In this context, the analysis of the reactions of various redox forms of plastoquinone with oxygen species is presented. The review describes how these reactions can constitute both the antioxidant and signaling functions of the pool. Special attention is paid to the reaction of superoxide anion radicals with plastohydroquinone molecules, producing hydrogen peroxide as signal molecules. Attention is also given to the processes affecting the redox state of the plastoquinone pool because the redox state of the pool is of special importance for antioxidant defense and signaling.
Collapse
Affiliation(s)
| | - Daria V Vetoshkina
- Institute of Basic Biological Problems of the Russian Academy of Sciences, Pushchino, Russia
| | - Boris N Ivanov
- Institute of Basic Biological Problems of the Russian Academy of Sciences, Pushchino, Russia
| |
Collapse
|
43
|
Nawrocki W, Bailleul B, Cardol P, Rappaport F, Wollman FA, Joliot P. Maximal cyclic electron flow rate is independent of PGRL1 in Chlamydomonas. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2019; 1860:425-432. [DOI: 10.1016/j.bbabio.2019.01.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Revised: 12/08/2018] [Accepted: 01/25/2019] [Indexed: 11/30/2022]
|
44
|
Belyaeva NE, Bulychev AA, Riznichenko GY, Rubin AB. Analyzing both the fast and the slow phases of chlorophyll a fluorescence and P700 absorbance changes in dark-adapted and preilluminated pea leaves using a Thylakoid Membrane model. PHOTOSYNTHESIS RESEARCH 2019; 140:1-19. [PMID: 30810971 DOI: 10.1007/s11120-019-00627-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 02/12/2019] [Indexed: 05/25/2023]
Abstract
The dark-to-light transitions enable energization of the thylakoid membrane (TM), which is reflected in fast and slow (OJIPSMT or OABCDE) stages of fluorescence induction (FI) and P700 oxidoreduction changes (ΔA810). A Thylakoid Membrane model (T-M model), in which special emphasis has been placed on ferredoxin-NADP+-oxidoreductase (FNR) activation and energy-dependent qE quenching, was applied for quantifying the kinetics of FI and ΔA810. Pea leaves were kept in darkness for 15 min and then the FI and ΔA810 signals were measured upon actinic illumination, applied either directly or after a 10-s light pulse coupled with a subsequent 10-s dark interval. On the time scale from 40 µs to 30 s, the parallel T-M model fittings to both FI and ΔA810 signals were obtained. The parameters of FNR activation and the buildup of qE quenching were found to differ for dark-adapted and preilluminated leaves. At the onset of actinic light, photosystem II (PSII) acceptors were oxidized (neutral) after dark adaptation, while the redox states with closed and/or semiquinone QA(-)QB(-) forms were supposedly generated after preillumination, and did not relax within the 10 s dark interval. In qE simulations, a pH-dependent Hill relationship was used. The rate constant of heat losses in PSII antenna kD(t) was found to increase from the basic value kDconst, at the onset of illumination, to its maximal level kDvar due to lumenal acidification. In dark-adapted leaves, a low value of kDconst of ∼ 2 × 106 s-1 was found. Simulations on the microsecond to 30 s time scale revealed that the slow P-S-M-T phases of the fluorescence induction were sensitive to light-induced FNR activation and high-energy qE quenching. Thus, the corresponding time-dependent rate constants kD(t) and kFNR(t) change substantially upon the release of electron transport on the acceptor side of PSI and during the NPQ development. The transitions between the cyclic and linear electron transport modes have also been quantified in this paper.
Collapse
Affiliation(s)
- N E Belyaeva
- Department of Biophysics, Biology Faculty of the M.V. Lomonosov, Moscow State University, Moscow, Russia, 119234.
| | - A A Bulychev
- Department of Biophysics, Biology Faculty of the M.V. Lomonosov, Moscow State University, Moscow, Russia, 119234
| | - G Yu Riznichenko
- Department of Biophysics, Biology Faculty of the M.V. Lomonosov, Moscow State University, Moscow, Russia, 119234
| | - A B Rubin
- Department of Biophysics, Biology Faculty of the M.V. Lomonosov, Moscow State University, Moscow, Russia, 119234
| |
Collapse
|
45
|
Nawrocki WJ, Bailleul B, Picot D, Cardol P, Rappaport F, Wollman FA, Joliot P. The mechanism of cyclic electron flow. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2019; 1860:433-438. [PMID: 30827891 DOI: 10.1016/j.bbabio.2018.12.005] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Revised: 12/08/2018] [Accepted: 12/08/2018] [Indexed: 12/16/2022]
Abstract
Apart from the canonical light-driven linear electron flow (LEF) from water to CO2, numerous regulatory and alternative electron transfer pathways exist in chloroplasts. One of them is the cyclic electron flow around Photosystem I (CEF), contributing to photoprotection of both Photosystem I and II (PSI, PSII) and supplying extra ATP to fix atmospheric carbon. Nonetheless, CEF remains an enigma in the field of functional photosynthesis as we lack understanding of its pathway. Here, we address the discrepancies between functional and genetic/biochemical data in the literature and formulate novel hypotheses about the pathway and regulation of CEF based on recent structural and kinetic information.
Collapse
Affiliation(s)
- W J Nawrocki
- Institut de Biologie Physico-Chimique, UMR 7141 CNRS-UPMC, 13 rue P. et M. Curie, 75005 Paris, France; Laboratoire de Génétique et Physiologie des Microalgues, Institut de Botanique, Université de Liège, 4, Chemin de la Vallée, B-4000 Liège, Belgium.
| | - B Bailleul
- Institut de Biologie Physico-Chimique, UMR 7141 CNRS-UPMC, 13 rue P. et M. Curie, 75005 Paris, France
| | - D Picot
- Institut de Biologie Physico-Chimique, UMR 7099 CNRS-UPMC, 13 rue P. et M. Curie, 75005 Paris, France
| | - P Cardol
- Laboratoire de Génétique et Physiologie des Microalgues, Institut de Botanique, Université de Liège, 4, Chemin de la Vallée, B-4000 Liège, Belgium
| | - F Rappaport
- Institut de Biologie Physico-Chimique, UMR 7141 CNRS-UPMC, 13 rue P. et M. Curie, 75005 Paris, France
| | - F-A Wollman
- Institut de Biologie Physico-Chimique, UMR 7141 CNRS-UPMC, 13 rue P. et M. Curie, 75005 Paris, France
| | - P Joliot
- Institut de Biologie Physico-Chimique, UMR 7141 CNRS-UPMC, 13 rue P. et M. Curie, 75005 Paris, France
| |
Collapse
|
46
|
Takagi D, Ifuku K, Nishimura T, Miyake C. Antimycin A inhibits cytochrome b 559-mediated cyclic electron flow within photosystem II. PHOTOSYNTHESIS RESEARCH 2019; 139:487-498. [PMID: 29790043 DOI: 10.1007/s11120-018-0519-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 05/15/2018] [Indexed: 05/27/2023]
Abstract
The light reactions of photosynthesis are known to comprise both linear and cyclic electron flow in order to convert light energy into chemical energy in the form of NADPH and ATP. Antimycin A (AA) has been proposed as an inhibitor of ferredoxin-dependent cyclic electron flow around photosystem I (CEF-PSI) in photosynthesis research. However, its precise inhibitory mechanism and target site had not been elucidated yet. Here we show that AA inhibits the cyclic (alternative) electron flow via cytochrome b559 (Cyt b559) within photosystem II (CEF-PSII). When AA was applied to thylakoid membranes isolated from spinach leaves, the high potential form of Cyt b559, which was reduced in the dark, was transformed into the lower potential forms and readily oxidized by molecular oxygen. In the absence of AA, the reduced Cyt b559 was oxidized by P680+ upon light illumination and re-reduced in the dark, mainly by the electron from the QB site on the acceptor side of PSII. In contrast, AA suppressed the oxidation of Cyt b559 and induced its reduction under the illumination. This inhibition of Cyt b559 oxidation by AA enhanced photoinhibition of PSII. Based on the above results, we propose caution regarding the use of AA for evaluating CEF-PSI per se and concurrently propose that AA provides for new insights into, and interpretations of, the physiological importance of Cyt b559, rather than that of CEF-PSI in photosynthetic organisms.
Collapse
Affiliation(s)
- Daisuke Takagi
- Department of Biological and Environmental Science, Faculty of Agriculture, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, 657-8511, Japan.
| | - Kentaro Ifuku
- Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Taishi Nishimura
- Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Chikahiro Miyake
- Department of Biological and Environmental Science, Faculty of Agriculture, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, 657-8511, Japan
| |
Collapse
|
47
|
Mishra KB, Mishra A, Kubásek J, Urban O, Heyer AG. Low temperature induced modulation of photosynthetic induction in non-acclimated and cold-acclimated Arabidopsis thaliana: chlorophyll a fluorescence and gas-exchange measurements. PHOTOSYNTHESIS RESEARCH 2019; 139:123-143. [PMID: 30306531 DOI: 10.1007/s11120-018-0588-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 09/24/2018] [Indexed: 05/23/2023]
Abstract
Cold acclimation modifies the photosynthetic machinery and enables plants to survive at sub-zero temperatures, whereas in warm habitats, many species suffer even at non-freezing temperatures. We have measured chlorophyll a fluorescence (ChlF) and CO2 assimilation to investigate the effects of cold acclimation, and of low temperatures, on a cold-sensitive Arabidopsis thaliana accession C24. Upon excitation with low intensity (40 µmol photons m- 2 s- 1) ~ 620 nm light, slow (minute range) ChlF transients, at ~ 22 °C, showed two waves in the SMT phase (S, semi steady-state; M, maximum; T, terminal steady-state), whereas CO2 assimilation showed a linear increase with time. Low-temperature treatment (down to - 1.5 °C) strongly modulated the SMT phase and stimulated a peak in the CO2 assimilation induction curve. We show that the SMT phase, at ~ 22 °C, was abolished when measured under high actinic irradiance, or when 3-(3, 4-dichlorophenyl)-1, 1- dimethylurea (DCMU, an inhibitor of electron flow) or methyl viologen (MV, a Photosystem I (PSI) electron acceptor) was added to the system. Our data suggest that stimulation of the SMT wave, at low temperatures, has multiple reasons, which may include changes in both photochemical and biochemical reactions leading to modulations in non-photochemical quenching (NPQ) of the excited state of Chl, "state transitions," as well as changes in the rate of cyclic electron flow through PSI. Further, we suggest that cold acclimation, in accession C24, promotes "state transition" and protects photosystems by preventing high excitation pressure during low-temperature exposure.
Collapse
Affiliation(s)
- Kumud B Mishra
- Global Change Research Institute, Czech Academy of Sciences, Bělidla 986/4a, 603 00, Brno, Czech Republic.
- Department of Experimental Biology, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic.
| | - Anamika Mishra
- Global Change Research Institute, Czech Academy of Sciences, Bělidla 986/4a, 603 00, Brno, Czech Republic
| | - Jiří Kubásek
- Global Change Research Institute, Czech Academy of Sciences, Bělidla 986/4a, 603 00, Brno, Czech Republic
| | - Otmar Urban
- Global Change Research Institute, Czech Academy of Sciences, Bělidla 986/4a, 603 00, Brno, Czech Republic
| | - Arnd G Heyer
- Department of Plant Biotechnology, Institute of Biomaterials and Biomolecular Systems, University of Stuttgart, Pfaffenwaldring 57, 70567, Stuttgart, Germany
| |
Collapse
|
48
|
Nikkanen L, Toivola J, Trotta A, Diaz MG, Tikkanen M, Aro E, Rintamäki E. Regulation of cyclic electron flow by chloroplast NADPH-dependent thioredoxin system. PLANT DIRECT 2018; 2:e00093. [PMID: 31245694 PMCID: PMC6508795 DOI: 10.1002/pld3.93] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 09/12/2018] [Accepted: 10/15/2018] [Indexed: 05/18/2023]
Abstract
Linear electron transport in the thylakoid membrane drives photosynthetic NADPH and ATP production, while cyclic electron flow (CEF) around photosystem I only promotes the translocation of protons from stroma to thylakoid lumen. The chloroplast NADH dehydrogenase-like complex (NDH) participates in one CEF route transferring electrons from ferredoxin back to the plastoquinone pool with concomitant proton pumping to the lumen. CEF has been proposed to balance the ratio of ATP/NADPH production and to control the redox poise particularly in fluctuating light conditions, but the mechanisms regulating the NDH complex remain unknown. We have investigated potential regulation of the CEF pathways by the chloroplast NADPH-thioredoxin reductase (NTRC) in vivo by using an Arabidopsis knockout line of NTRC as well as lines overexpressing NTRC. Here, we present biochemical and biophysical evidence showing that NTRC stimulates the activity of NDH-dependent CEF and is involved in the regulation of generation of proton motive force, thylakoid conductivity to protons, and redox balance between the thylakoid electron transfer chain and the stroma during changes in light conditions. Furthermore, protein-protein interaction assays suggest a putative thioredoxin-target site in close proximity to the ferredoxin-binding domain of NDH, thus providing a plausible mechanism for redox regulation of the NDH ferredoxin:plastoquinone oxidoreductase activity.
Collapse
Affiliation(s)
- Lauri Nikkanen
- Molecular Plant BiologyDepartment of BiochemistryUniversity of TurkuTurkuFinland
| | - Jouni Toivola
- Molecular Plant BiologyDepartment of BiochemistryUniversity of TurkuTurkuFinland
| | - Andrea Trotta
- Molecular Plant BiologyDepartment of BiochemistryUniversity of TurkuTurkuFinland
| | - Manuel Guinea Diaz
- Molecular Plant BiologyDepartment of BiochemistryUniversity of TurkuTurkuFinland
| | - Mikko Tikkanen
- Molecular Plant BiologyDepartment of BiochemistryUniversity of TurkuTurkuFinland
| | - Eva‐Mari Aro
- Molecular Plant BiologyDepartment of BiochemistryUniversity of TurkuTurkuFinland
| | - Eevi Rintamäki
- Molecular Plant BiologyDepartment of BiochemistryUniversity of TurkuTurkuFinland
| |
Collapse
|
49
|
Ksas B, Légeret B, Ferretti U, Chevalier A, Pospíšil P, Alric J, Havaux M. The plastoquinone pool outside the thylakoid membrane serves in plant photoprotection as a reservoir of singlet oxygen scavengers. PLANT, CELL & ENVIRONMENT 2018; 41:2277-2287. [PMID: 29601642 DOI: 10.1111/pce.13202] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2017] [Revised: 03/14/2018] [Accepted: 03/15/2018] [Indexed: 05/05/2023]
Abstract
The Arabidopsis vte1 mutant is devoid of tocopherol and plastochromanol (PC-8). When exposed to excess light energy, vte1 produced more singlet oxygen (1 O2 ) and suffered from extensive oxidative damage compared with the wild type. Here, we show that overexpressing the solanesyl diphosphate synthase 1 (SPS1) gene in vte1 induced a marked accumulation of total plastoquinone (PQ-9) and rendered the vte1 SPS1oex plants tolerant to photooxidative stress, indicating that PQ-9 can replace tocopherol and PC-8 in photoprotection. High total PQ-9 levels were associated with a noticeable decrease in 1 O2 production and higher levels of Hydroxyplastoquinone (PQ-C), a 1 O2 -specific PQ-9 oxidation product. The extra PQ-9 molecules in the vte1 SPS1oex plants were stored in the plastoglobules and the chloroplast envelopes, rather than in the thylakoid membranes, whereas PQ-C was found almost exclusively in the thylakoid membranes. Upon exposure of wild-type plants to high light, the thylakoid PQ-9 pool decreased, whereas the extrathylakoid pool remained unchanged. In vte1 and vte1 SPS1oex plants, the PQ-9 losses in high light were strongly amplified, affecting also the extrathylakoid pool, and PQ-C was found in high amounts in the thylakoids. We conclude that the thylakoid PQ-9 pool acts as a 1 O2 scavenger and is replenished from the extrathylakoid stock.
Collapse
Affiliation(s)
- Brigitte Ksas
- CEA Cadarache, CNRS UMR 7265 Biologie Végétale et Microbiologie Environnementales, Aix Marseille Université, Laboratoire d'Ecophysiologie Moléculaire des Plantes, 13108, Saint-Paul-lez-Durance, France
| | - Bertrand Légeret
- CEA Cadarache, CNRS UMR 7265 Biologie Végétale et Microbiologie Environnementales, Aix Marseille Université, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, 13108, Saint-Paul-lez-Durance, France
| | - Ursula Ferretti
- Department of Biophysics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Šlechtitelů 27, 783 71, Olomouc, Czech Republic
| | - Anne Chevalier
- CEA Cadarache, CNRS UMR 7265 Biologie Végétale et Microbiologie Environnementales, Aix Marseille Université, Laboratoire d'Ecophysiologie Moléculaire des Plantes, 13108, Saint-Paul-lez-Durance, France
| | - Pavel Pospíšil
- Department of Biophysics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Šlechtitelů 27, 783 71, Olomouc, Czech Republic
| | - Jean Alric
- CEA Cadarache, CNRS UMR 7265 Biologie Végétale et Microbiologie Environnementales, Aix Marseille Université, Laboratoire d'Ecophysiologie Moléculaire des Plantes, 13108, Saint-Paul-lez-Durance, France
| | - Michel Havaux
- CEA Cadarache, CNRS UMR 7265 Biologie Végétale et Microbiologie Environnementales, Aix Marseille Université, Laboratoire d'Ecophysiologie Moléculaire des Plantes, 13108, Saint-Paul-lez-Durance, France
| |
Collapse
|
50
|
Molecular mechanisms involved in plant photoprotection. Biochem Soc Trans 2018; 46:467-482. [DOI: 10.1042/bst20170307] [Citation(s) in RCA: 110] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2017] [Revised: 03/04/2018] [Accepted: 03/05/2018] [Indexed: 11/17/2022]
Abstract
Photosynthesis uses sunlight to convert water and carbon dioxide into biomass and oxygen. When in excess, light can be dangerous for the photosynthetic apparatus because it can cause photo-oxidative damage and decreases the efficiency of photosynthesis because of photoinhibition. Plants have evolved many photoprotective mechanisms in order to face reactive oxygen species production and thus avoid photoinhibition. These mechanisms include quenching of singlet and triplet excited states of chlorophyll, synthesis of antioxidant molecules and enzymes and repair processes for damaged photosystem II and photosystem I reaction centers. This review focuses on the mechanisms involved in photoprotection of chloroplasts through dissipation of energy absorbed in excess.
Collapse
|