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Shi K, Liu J, Liang H, Dong H, Zhang J, Wei Y, Zhou L, Wang S, Zhu J, Cao M, Jones CS, Ma D, Wang Z. An alfalfa MYB-like transcriptional factor MsMYBH positively regulates alfalfa seedling drought resistance and undergoes MsWAV3-mediated degradation. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2024; 66:683-699. [PMID: 38358036 DOI: 10.1111/jipb.13626] [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: 12/24/2023] [Accepted: 01/30/2024] [Indexed: 02/16/2024]
Abstract
Drought is a major threat to alfalfa (Medicago sativa L.) production. The discovery of important alfalfa genes regulating drought response will facilitate breeding for drought-resistant alfalfa cultivars. Here, we report a genome-wide association study of drought resistance in alfalfa. We identified and functionally characterized an MYB-like transcription factor gene (MsMYBH), which increases the drought resistance in alfalfa. Compared with the wild-types, the biomass and forage quality were enhanced in MsMYBH overexpressed plants. Combined RNA-seq, proteomics and chromatin immunoprecipitation analysis showed that MsMYBH can directly bind to the promoters of MsMCP1, MsMCP2, MsPRX1A and MsCARCAB to improve their expression. The outcomes of such interactions include better water balance, high photosynthetic efficiency and scavenge excess H2O2 in response to drought. Furthermore, an E3 ubiquitin ligase (MsWAV3) was found to induce MsMYBH degradation under long-term drought, via the 26S proteasome pathway. Furthermore, variable-number tandem repeats in MsMYBH promoter were characterized among a collection of germplasms, and the variation is associated with promoter activity. Collectively, our findings shed light on the functions of MsMYBH and provide a pivotal gene that could be leveraged for breeding drought-resistant alfalfa. This discovery also offers new insights into the mechanisms of drought resistance in alfalfa.
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Affiliation(s)
- Kun Shi
- College of Grassland Science and Technology, China Agricultural University, Beijing, 100193, China
| | - Jia Liu
- College of Grassland Science and Technology, China Agricultural University, Beijing, 100193, China
| | - Huan Liang
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Hongbin Dong
- College of Grassland Science and Technology, China Agricultural University, Beijing, 100193, China
| | - Jinli Zhang
- College of Grassland Science and Technology, China Agricultural University, Beijing, 100193, China
| | - Yuanhong Wei
- College of Grassland Science and Technology, China Agricultural University, Beijing, 100193, China
| | - Le Zhou
- College of Grassland Science and Technology, China Agricultural University, Beijing, 100193, China
| | - Shaopeng Wang
- College of Grassland Science and Technology, China Agricultural University, Beijing, 100193, China
| | - Jiahao Zhu
- College of Grassland Science and Technology, China Agricultural University, Beijing, 100193, China
| | - Mingshu Cao
- AgResearch Grasslands Research Centre, Palmerston North, 4442, New Zealand
| | - Chris S Jones
- International Livestock Research Institute, Nairobi, 00100, Kenya
| | - Dongmei Ma
- School of Ecology and Environment, Ningxia University, Yinchuan, 750021, China
| | - Zan Wang
- College of Grassland Science and Technology, China Agricultural University, Beijing, 100193, China
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Gray C, Wei T, Polívka T, Daskalakis V, Duffy CDP. Trivial Excitation Energy Transfer to Carotenoids Is an Unlikely Mechanism for Non-photochemical Quenching in LHCII. FRONTIERS IN PLANT SCIENCE 2021; 12:797373. [PMID: 35095968 PMCID: PMC8792765 DOI: 10.3389/fpls.2021.797373] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 12/20/2021] [Indexed: 05/04/2023]
Abstract
Higher plants defend themselves from bursts of intense light via the mechanism of Non-Photochemical Quenching (NPQ). It involves the Photosystem II (PSII) antenna protein (LHCII) adopting a conformation that favors excitation quenching. In recent years several structural models have suggested that quenching proceeds via energy transfer to the optically forbidden and short-lived S 1 states of a carotenoid. It was proposed that this pathway was controlled by subtle changes in the relative orientation of a small number of pigments. However, quantum chemical calculations of S 1 properties are not trivial and therefore its energy, oscillator strength and lifetime are treated as rather loose parameters. Moreover, the models were based either on a single LHCII crystal structure or Molecular Dynamics (MD) trajectories about a single minimum. Here we try and address these limitations by parameterizing the vibronic structure and relaxation dynamics of lutein in terms of observable quantities, namely its linear absorption (LA), transient absorption (TA) and two-photon excitation (TPE) spectra. We also analyze a number of minima taken from an exhaustive meta-dynamical search of the LHCII free energy surface. We show that trivial, Coulomb-mediated energy transfer to S 1 is an unlikely quenching mechanism, with pigment movements insufficiently pronounced to switch the system between quenched and unquenched states. Modulation of S 1 energy level as a quenching switch is similarly unlikely. Moreover, the quenching predicted by previous models is possibly an artifact of quantum chemical over-estimation of S 1 oscillator strength and the real mechanism likely involves short-range interaction and/or non-trivial inter-molecular states.
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Affiliation(s)
- Callum Gray
- Digital Environment Research Institute (DERI), Queen Mary University of London, London, United Kingdom
| | - Tiejun Wei
- Digital Environment Research Institute (DERI), Queen Mary University of London, London, United Kingdom
| | - Tomáš Polívka
- Department of Physics, Faculty of Science, University of South Bohemia, Ceske Budejovice, Czechia
| | - Vangelis Daskalakis
- Department of Chemical Engineering, Cyprus University of Technology, Limassol, Cyprus
| | - Christopher D. P. Duffy
- Digital Environment Research Institute (DERI), Queen Mary University of London, London, United Kingdom
- *Correspondence: Christopher D. P. Duffy
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Cloning and characterization of two chlorophyll A/B binding protein genes and analysis of their gene family in Camellia sinensis. Sci Rep 2020; 10:4602. [PMID: 32165676 PMCID: PMC7067855 DOI: 10.1038/s41598-020-61317-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 02/21/2020] [Indexed: 12/16/2022] Open
Abstract
In this study, two chlorophyll A/B binding protein (CAB) genes (CsCP1 and CsCP2) in tea plant were cloned. The proteins encoded by these genes belong to the external or internal antenna proteins of PS II, respectively. They may be the targets of physiological regulation for tea leaf cell PS II because they all contain multiple functional domains and modifiable sites. The CAB gene family in the tea genome consists of 25 homologous genes. We measured the expression patterns of ten genes in the CsCP1 and CsCP2 subfamily under six different stresses. CsCP1 expression was inhibited in response to 6 kinds of stress; CsCP2 expression was slightly upregulated only after cold stress and ABA treatment. However, the expression levels of CSA016997 and CSA030476 were upregulated significantly in the six stresses. The results suggested that the 10 CAB genes may have different functions in tea leaves. Moreover, changes in the expression of the 10 genes under stress appear to be related to ABA- and MeJA-dependent signalling pathways, and their responses to MeJA treatment is faster than those to ABA. In addition, we introduced our experiences for cloning the genes in the context of complex genomes.
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Wang W, Yu LJ, Xu C, Tomizaki T, Zhao S, Umena Y, Chen X, Qin X, Xin Y, Suga M, Han G, Kuang T, Shen JR. Structural basis for blue-green light harvesting and energy dissipation in diatoms. Science 2019; 363:363/6427/eaav0365. [DOI: 10.1126/science.aav0365] [Citation(s) in RCA: 103] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 12/31/2018] [Indexed: 01/23/2023]
Abstract
Diatoms are abundant photosynthetic organisms in aquatic environments and contribute 40% of its primary productivity. An important factor that contributes to the success of diatoms is their fucoxanthin chlorophyll a/c-binding proteins (FCPs), which have exceptional light-harvesting and photoprotection capabilities. Here, we report the crystal structure of an FCP from the marine diatom Phaeodactylum tricornutum, which reveals the binding of seven chlorophylls (Chls) a, two Chls c, seven fucoxanthins (Fxs), and probably one diadinoxanthin within the protein scaffold. Efficient energy transfer pathways can be found between Chl a and c, and each Fx is surrounded by Chls, enabling the energy transfer and quenching via Fx highly efficient. The structure provides a basis for elucidating the mechanisms of blue-green light harvesting, energy transfer, and dissipation in diatoms.
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Probing the pigment binding sites in LHCII with resonance Raman spectroscopy: The effect of mutations at S123. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:1490-1496. [DOI: 10.1016/j.bbabio.2016.06.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Revised: 05/31/2016] [Accepted: 06/02/2016] [Indexed: 11/15/2022]
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Liu C, Gao Z, Liu K, Sun R, Cui C, Holzwarth AR, Yang C. Simultaneous refolding of denatured PsbS and reconstitution with LHCII into liposomes of thylakoid lipids. PHOTOSYNTHESIS RESEARCH 2016; 127:109-16. [PMID: 26168990 DOI: 10.1007/s11120-015-0176-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 07/07/2015] [Indexed: 05/03/2023]
Abstract
The thylakoid membrane protein PsbS is critical for quenching excessive excitation energy in mechanisms that involve the light-harvesting complexes of photosystem II. Liposomes of thylakoid lipids have been shown to be a very good platform to study photosynthetic membrane proteins and their interactions. In this study, we simultaneously refolded and reconstituted functional pea PsbS into liposomes of thylakoid lipids starting from denatured expressed protein. Intrinsic fluorescence spectroscopy, trypsin digestion, and circular dichroism spectroscopy were used to characterize the native state of PsbS in the proteoliposomes. The functionality of refolded PsbS was further demonstrated by its effect on the fluorescence quenching of the major antenna system of photosystem II (LHCII) co-inserted into the liposomes. The fluorescence yield of native trimeric LHCII was lowered by PsbS by 50% at neutral pH and by a further 25% upon lowering the pH to 4.5. Furthermore, the acid-induced fluorescence reduction was completely reversed by addition of N,N'-dicyclohexylcarbodiimide, an inhibitor of protein protonation. These results indicate that reconstituted PsbS induces strong quenching of LHCII sensing changes in local pH via its protonation sites.
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Affiliation(s)
- Cheng Liu
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, People's Republic of China
| | - Zhimin Gao
- International Center for Bamboo and Rattan, State Forestry Administration Key Open Laboratory on Bamboo and Rattan Science and Technology, Beijing, 100102, People's Republic of China
| | - Kun Liu
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, People's Republic of China
| | - Ruixue Sun
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, People's Republic of China
| | - Chunbo Cui
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, People's Republic of China
| | - Alfred R Holzwarth
- Max-Planck-Institut für Chemische Energiekonversion, Stiftstrasse 34-36, 45470, Mülheim a. d. Ruhr, Germany
| | - Chunhong Yang
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, People's Republic of China.
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Malliarakis D, Tsiavos T, Ioannidis NE, Kotzabasis K. Spermine and lutein quench chlorophyll fluorescence in isolated PSII antenna complexes. JOURNAL OF PLANT PHYSIOLOGY 2015; 183:108-13. [PMID: 26121079 DOI: 10.1016/j.jplph.2015.06.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2015] [Revised: 06/08/2015] [Accepted: 06/11/2015] [Indexed: 05/03/2023]
Abstract
Non photochemical quenching is a spontaneous mechanism that protects plants and algae from photodamage. In the last two decades, carotenoids through the xanthophylls cycle have been proposed to play a key role in quenching of chlorophyll. More recently, the involvement of endogenous polyamines in energy-dependent component of non photochemical quenching has been suggested by several research groups. In the present contribution, the combined effect of spermine and the xanthophylls, zeaxanthin and lutein on the fluorescence of antenna complexes of photosystem II was tested in vitro. Lutein caused significant quenching on trimeric and monomeric antenna complexes, whereas zeaxanthin under our experimental conditions had negligible effect. Spermine has been shown to allow fluorescence quenching to be induced in isolated antenna in the absence of ΔpH and to accelerate quenching formation. The simultaneous treatment of spermine and lutein maximizes quenching even at relatively low concentrations.
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Affiliation(s)
- Dimitris Malliarakis
- Department of Biology, University of Crete, Voutes University Campus, GR-70013 Heraklion, Crete, Greece
| | - Theodoros Tsiavos
- Department of Biology, University of Crete, Voutes University Campus, GR-70013 Heraklion, Crete, Greece
| | - Nikolaos E Ioannidis
- Department of Biology, University of Crete, Voutes University Campus, GR-70013 Heraklion, Crete, Greece.
| | - Kiriakos Kotzabasis
- Department of Biology, University of Crete, Voutes University Campus, GR-70013 Heraklion, Crete, Greece.
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Liu C, Rao Y, Zhang L, Yang C. Identification of the roles of individual amino acid residues of the helix E of the major antenna of photosystem II (LHCII) by alanine scanning mutagenesis. J Biochem 2014; 156:203-10. [PMID: 24753330 DOI: 10.1093/jb/mvu028] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The functions of the helix E (W97-F105), an amphiphilic lumenal 310 helix of the major antenna of photosystem II (LHCII), are still unidentified. To elucidate the roles of individual amino acid residue of the helix E, alanine scanning mutagenesis has been performed to mutate every residue of this domain to alanine. The influence of every alanine substitution on the structure and function of LHCII has been investigated biochemically and spectroscopically. The results show that all mutations have little impact on the pigment binding and configuration. However, many mutants presented decreased thermo- or photo-stability compared with the wild type, highlighting the significance of this helix to the stability of LHCII. The most critical residue for stability is W97. The mutant W97A yielded very fragile trimeric pigment protein complexes. The structural analysis revealed that the hydrogen bonding and aromatic interactions between W97, F195, F194 and a water molecule contributed greatly to the stability of LHCII. Moreover, Q103A and F105A have been identified to be able to reinforce the tendency of aggregation in vitro. The structural analysis suggested that the enhancement in aggregation formation for Q103A and F105A might be attributed to the changing hydrophobicity of the region.
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Affiliation(s)
- Cheng Liu
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, P.R. China
| | - Yan Rao
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, P.R. China
| | - Lei Zhang
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, P.R. China
| | - Chunhong Yang
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, P.R. China
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Zhang L, Melø TB, Li H, Naqvi KR, Yang C. The inter-monomer interface of the major light-harvesting chlorophyll a/b complexes of photosystem II (LHCII) influences the chlorophyll triplet distribution. JOURNAL OF PLANT PHYSIOLOGY 2014; 171:42-8. [PMID: 24484957 DOI: 10.1016/j.jplph.2013.11.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 11/16/2013] [Accepted: 11/18/2013] [Indexed: 06/03/2023]
Abstract
Under strong light conditions, long-lived chlorophyll triplets ((3)Chls) are formed, which can sensitize singlet oxygen, a species harmful to the photosynthetic apparatus of plants. Plants have developed multiple photoprotective mechanisms to quench (3)Chl and scavenge singlet oxygen in order to sustain the photosynthetic activities. The lumenal loop of light-harvesting chlorophyll a/b complex of photosystem II (LHCII) plays important roles in regulating the pigment conformation and energy dissipation. In this study, site-directed mutagenesis analysis was applied to investigate triplet-triplet energy transfer and quenching of (3)Chl in LHCII. We mutated the amino acid at site 123 located in this region to Gly, Pro, Gln, Thr and Tyr, respectively, and recorded fluorescence excitation spectra, triplet-minus-singlet (TmS) spectra and kinetics of carotenoid triplet decay for wild type and all the mutants. A red-shift was evident in the TmS spectra of the mutants S123T and S123P, and all of the mutants except S123Y showed a decrease in the triplet energy transfer efficiency. We propose, on the basis of the available structural information, that these phenomena are related to the involvement, due to conformational changes in the lumenal region, of a long-wavelength lutein (Lut2) involved in quenching (3)Chl.
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Affiliation(s)
- Lei Zhang
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Thor Bernt Melø
- Department of Physics, Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | - Heng Li
- Department of Physics, Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | - K Razi Naqvi
- Department of Physics, Norwegian University of Science and Technology, 7491 Trondheim, Norway.
| | - Chunhong Yang
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
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Garab G. Hierarchical organization and structural flexibility of thylakoid membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2013; 1837:481-94. [PMID: 24333385 DOI: 10.1016/j.bbabio.2013.12.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Revised: 11/26/2013] [Accepted: 12/02/2013] [Indexed: 10/25/2022]
Abstract
Chloroplast thylakoid membranes accommodate densely packed protein complexes in ordered, often semi-crystalline arrays and are assembled into highly organized multilamellar systems, an organization warranting a substantial degree of stability. At the same time, they exhibit remarkable structural flexibility, which appears to play important - yet not fully understood - roles in different short-term adaptation mechanisms in response to rapidly changing environmental conditions. In this review I will focus on dynamic features of the hierarchically organized photosynthetic machineries at different levels of structural complexity: (i) isolated light harvesting complexes, (ii) molecular macroassemblies and supercomplexes, (iii) thylakoid membranes and (iv) their multilamellar membrane systems. Special attention will be paid to the most abundant systems, the major light harvesting antenna complex, LHCII, and to grana. Two physical mechanisms, which are less frequently treated in the literature, will receive special attention: (i) thermo-optic mechanism -elementary structural changes elicited by ultrafast local heat transients due to the dissipation of photon energy, which operates both in isolated antenna assemblies and the native thylakoid membranes, regulates important enzymatic functions and appears to play role in light adaptation and photoprotection mechanisms; and (ii) the mechanism by which non-bilayer lipids and lipid phases play key role in the functioning of xanthophyll cycle de-epoxidases and are proposed to regulate the protein-to-lipid ratio in thylakoid membranes and contribute to membrane dynamics. This article is part of a Special Issue entitled: Dynamic and ultrastructure of bioenergetic membranes and their components.
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Affiliation(s)
- Győző Garab
- Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, P.O. Box 521, H-6701 Szeged, Hungary.
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Proteomic analysis of 'Zaosu' pear (Pyrus bretschneideri Rehd.) and its red skin bud mutation. Proteome Sci 2012; 10:51. [PMID: 22931350 PMCID: PMC3602030 DOI: 10.1186/1477-5956-10-51] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Accepted: 07/17/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Breeding for strong red skin color is an important objective of the pear breeding program. There are few reports of proteome research in green skin pear and its red skin bud mutation. The manuscript at hand is one of the first studies dealing with 2D-PAGE-based analysis of pear fruits and leaves, establishing a suitable sample preparation and testing different 2D-PAGE protocols. Therefore, it may grant a basis for further studies on the pear proteome being the studies main goal. A proteomic analysis was conducted on leaves and fruits of 'Zaosu' pear (Pyrus bretschneideri Rehd.) and its red skin bud mutation in order to reveal their genetic differences in the protein level. RESULTS In the present study, the optimized two-dimensional (2-D) gel electrophoresis system of pear leaf and fruit was set up, and applied to analyze the leaves and fruit protein. The interesting peptide fragments were determined using 4800 Plus MALDI TOF/TOFTM Analyzer mass spectrometer, and the sequence obtained was blasted in NCBInr to identify the differentially-expressed protein. In the 1.5-fold differently-expressed proteins between 'Zaosu' pear and its mutant, 10 out of 35 proteins in fruit and 12 out of 24 ones in leaves were identified successfully. Among the 22 identified proteins, 7 protein spots were related to photosynthesis and energy metabolism; 4 were associated with environmental stress; 4 with disease defense; 2 with amino acid metabolism; 2 with cytoskeleton; 1 with antioxidant function; 1 with calcium metabolism; and 1 with unknown function. Moreover, related physiological index, such as chlorophyll content, Rubisco content and polyphone oxidase activity, were different between 'Zaosu' pear and its mutant. CONCLUSION A 2-D gel electrophoresis system of pear leaves and fruits was established, which was suitable for the analysis of proteome comparison. To the best of our knowledge, we have performed the first analysis of the proteomic changes in leaves and fruits of 'Zaosu' pear and its red skin bud mutation. Our study provides important information on the use of proteomic methods for studying protein regulation of 'Zaosu' pear and its red skin bud mutation.
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Pfannschmidt T, Yang C. The hidden function of photosynthesis: a sensing system for environmental conditions that regulates plant acclimation responses. PROTOPLASMA 2012; 249 Suppl 2:S125-36. [PMID: 22441589 DOI: 10.1007/s00709-012-0398-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Accepted: 03/12/2012] [Indexed: 05/03/2023]
Abstract
Plants convert light energy from the sun into chemical energy by photosynthesis. Since they are sessile, they have to deal with a wide range of conditions in their immediate environment. Many abiotic and biotic parameters exhibit considerable fluctuations which can have detrimental effects especially on the efficiency of photosynthetic light harvesting. During evolution, plants, therefore, evolved a number of acclimation processes which help them to adapt photosynthesis to such environmental changes. This includes protective mechanisms such as excess energy dissipation and processes supporting energy redistribution, e.g. state transitions or photosystem stoichiometry adjustment. Intriguingly, all these responses are triggered by photosynthesis itself via the interplay of its light reaction and the Calvin-Benson cycle with the residing environmental condition. Thus, besides its primary function in harnessing and converting light energy, photosynthesis acts as a sensing system for environmental changes that controls molecular acclimation responses which adapt the photosynthetic function to the environmental change. Important signalling parameters directly or indirectly affected by the environment are the pH gradient across the thylakoid membrane and the redox states of components of the photosynthetic electron transport chain and/or electron end acceptors coupled to it. Recent advances demonstrate that these signals control post-translational modifications of the photosynthetic protein complexes and also affect plastid and nuclear gene expression machineries as well as metabolic pathways providing a regulatory framework for an integrated response of the plant to the environment at all cellular levels.
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Affiliation(s)
- Thomas Pfannschmidt
- Junior Research Group Plant Acclimation To Environmental Changes, Protein Analysis by MS, Department of Plant Physiology, Institute of General Botany and Plant Physiology, Friedrich-Schiller-University Jena, Dornburger Str 159, 07743 Jena, Germany.
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Jajoo A, Szabó M, Zsiros O, Garab G. Low pH induced structural reorganization in thylakoid membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2012; 1817:1388-91. [PMID: 22248669 DOI: 10.1016/j.bbabio.2012.01.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Revised: 12/22/2011] [Accepted: 01/02/2012] [Indexed: 11/19/2022]
Abstract
By using low temperature fluorescence spectroscopy, it has been shown that exposing chloroplast thylakoid membranes to acidic pH reversibly decreases the fluorescence of photosystem II while the fluorescence of photosystem I increases [P. Singh-Rawal et al. (2010) Evidence that pH can drive state transitions in isolated thylakoid membranes from spinach, Photochem Photobiol Sci, 9 830-837]. In order to shed light on the origin of these changes, we performed circular dichroism (CD) spectroscopy on freshly isolated pea thylakoid membranes. We show that the magnitude of the psi-type CD, which is associated with the presence of chirally ordered macroarrays of the chromophores in intact thylakoid membranes, decreases gradually and reversibly upon gradually lowering the pH of the medium from 7.5 to 4.5 (psi, polymer or salt induced). The same treatment, as shown on thylakoid membranes washed in hypotonic low salt medium possessing no psi-type bands, induces no discernible change in the excitonic CD. These data show that while no change in the pigment-pigment interactions and thus in the molecular organization of the bulk protein complexes can be held responsible for the observed changes in the fluorescence, acidification of the medium significantly alters the macro-organization of the complexes, hence providing an explanation for the pH-induced redistribution of the excitation energy between the two photosystems. This article is part of a Special Issue entitled: Photosynthesis Research for Sustainability: from Natural to Artificial.
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Affiliation(s)
- Anjana Jajoo
- School of Life Science, Devi Ahilya University, Indore, India.
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Yao K, Liu C, Chen Y, Chen L, Li F, Liu K, Sun R, Wang P, Yang C. Integration of light-harvesting complexes into the polymer bulk heterojunction P3HT/PCBM device for efficient photovoltaic cells. ACTA ACUST UNITED AC 2012. [DOI: 10.1039/c2jm16616j] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Coetzer N, Gazendam I, Oelofse D, Berger DK. SSHscreen and SSHdb, generic software for microarray based gene discovery: application to the stress response in cowpea. PLANT METHODS 2010; 6:10. [PMID: 20359330 PMCID: PMC2859861 DOI: 10.1186/1746-4811-6-10] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2009] [Accepted: 04/01/2010] [Indexed: 05/25/2023]
Abstract
BACKGROUND Suppression subtractive hybridization is a popular technique for gene discovery from non-model organisms without an annotated genome sequence, such as cowpea (Vigna unguiculata (L.) Walp). We aimed to use this method to enrich for genes expressed during drought stress in a drought tolerant cowpea line. However, current methods were inefficient in screening libraries and management of the sequence data, and thus there was a need to develop software tools to facilitate the process. RESULTS Forward and reverse cDNA libraries enriched for cowpea drought response genes were screened on microarrays, and the R software package SSHscreen 2.0.1 was developed (i) to normalize the data effectively using spike-in control spot normalization, and (ii) to select clones for sequencing based on the calculation of enrichment ratios with associated statistics. Enrichment ratio 3 values for each clone showed that 62% of the forward library and 34% of the reverse library clones were significantly differentially expressed by drought stress (adjusted p value < 0.05). Enrichment ratio 2 calculations showed that > 88% of the clones in both libraries were derived from rare transcripts in the original tester samples, thus supporting the notion that suppression subtractive hybridization enriches for rare transcripts. A set of 118 clones were chosen for sequencing, and drought-induced cowpea genes were identified, the most interesting encoding a late embryogenesis abundant Lea5 protein, a glutathione S-transferase, a thaumatin, a universal stress protein, and a wound induced protein. A lipid transfer protein and several components of photosynthesis were down-regulated by the drought stress. Reverse transcriptase quantitative PCR confirmed the enrichment ratio values for the selected cowpea genes. SSHdb, a web-accessible database, was developed to manage the clone sequences and combine the SSHscreen data with sequence annotations derived from BLAST and Blast2GO. The self-BLAST function within SSHdb grouped redundant clones together and illustrated that the SSHscreen plots are a useful tool for choosing anonymous clones for sequencing, since redundant clones cluster together on the enrichment ratio plots. CONCLUSIONS We developed the SSHscreen-SSHdb software pipeline, which greatly facilitates gene discovery using suppression subtractive hybridization by improving the selection of clones for sequencing after screening the library on a small number of microarrays. Annotation of the sequence information and collaboration was further enhanced through a web-based SSHdb database, and we illustrated this through identification of drought responsive genes from cowpea, which can now be investigated in gene function studies. SSH is a popular and powerful gene discovery tool, and therefore this pipeline will have application for gene discovery in any biological system, particularly non-model organisms. SSHscreen 2.0.1 and a link to SSHdb are available from http://microarray.up.ac.za/SSHscreen.
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Affiliation(s)
- Nanette Coetzer
- ACGT Computational Biology and Bioinformatics Unit, Department of Biochemistry, University of Pretoria, 0002, South Africa
| | - Inge Gazendam
- Germplasm Development Division, Agricultural Research Council-Vegetable and Ornamental Plant Institute, Private Bag X293, Pretoria, 0001, South Africa
- Department of Plant Science, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, 0002, South Africa
| | - Dean Oelofse
- Germplasm Development Division, Agricultural Research Council-Vegetable and Ornamental Plant Institute, Private Bag X293, Pretoria, 0001, South Africa
| | - Dave K Berger
- Department of Plant Science, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, 0002, South Africa
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Gruszecki WI, Janik E, Luchowski R, Kernen P, Grudzinski W, Gryczynski I, Gryczynski Z. Supramolecular organization of the main photosynthetic antenna complex LHCII: a monomolecular layer study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:9384-9391. [PMID: 19382785 DOI: 10.1021/la900630a] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The light-harvesting pigment-protein complex LHCII is a main antenna complex of the photosynthetic apparatus of plants, responsible for collecting light energy and also for photoprotection against overexcitation-induced damage. Realization of both functions depends on molecular organization of the complex. Monolayer technique has been applied to address the problem of supramolecular organization of LHCII. Analysis of the isotherms of compression of monomolecular films formed at the argon-water interface shows that LHCII appears in two phases: one characterized by the specific molecular area characteristic of trimeric and one of monomeric organization of LHCII. Monolayers of LHCII were deposited by means of the Langmuir-Blodgett technique to solid supports and examined by means of AFM, FTIR, fluorescence spectroscopy, and fluorescence lifetime imaging microscopy (FLIM). FTIR analysis shows that organization of the trimers of LHCII within a monolayer is associated with formation of intermolecular hydrogen bonds between neighboring polypeptides. The linear-dichroism FTIR analysis reveals that polypeptide fragments involved in intermolecular interactions are oriented at an angle of 67 degrees with respect to the normal axis to the plane of the layer. Fluorescence and fluorescence lifetime analysis reveal that the organization of LHCII within monolayers is associated with formation of the low-lying excitonic energy levels that can be potentially responsible for excess excitation quenching. FLIM and AFM reveal heterogeneous organization of LHCII monolayers, in particular, formation of ring-like structures. The potential of LHCII to form molecular structures characterized by pigment excitonic interactions is discussed in terms of regulation of the photosynthetic accessory function and photoprotection against overexcitation-induced damage.
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Affiliation(s)
- Wiesław I Gruszecki
- Department of Biophysics, Institute of Physics, Maria Curie-Sklodowska University, 20-031 Lublin, Poland.
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Gundlach K, Werwie M, Wiegand S, Paulsen H. Filling the "green gap" of the major light-harvesting chlorophyll a/b complex by covalent attachment of Rhodamine Red. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2009; 1787:1499-504. [PMID: 19619502 DOI: 10.1016/j.bbabio.2009.07.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2009] [Revised: 07/10/2009] [Accepted: 07/13/2009] [Indexed: 11/16/2022]
Abstract
The major light-harvesting chlorophyll a/b complex (LHCII) greatly enhances the efficiency of photosynthesis in green plants. Recombinant LHCII can be assembled in vitro from its denatured, bacterially expressed apoprotein and plant pigments. This makes it an interesting candidate for biomimetic light-harvesting in photovoltaic applications. Due to its almost 20 pigments bound per apoprotein, LHCII absorbs efficiently in the blue and red spectral domains of visible light but less efficiently in the green domain, the so-called "green gap" in its absorption spectrum. Here we present a hybrid complex of recombinant LHCII with organic dyes that add to LHCII absorption in the green spectral region. One or three Rhodamine Red dye molecules were site-specifically attached to cysteine side chains in the apoprotein and did not interfere with LHCII assembly, function and stability. The dyes transferred their excitation energy virtually completely to the chlorophylls in LHCII, partially filling in the green gap. Thus, organic dyes can be used to increase the absorption cross section and, thus, the light-harvesting efficiency of recombinant LHCII.
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Affiliation(s)
- Kristina Gundlach
- Institut für Allgemeine Botanik, Johannes-Gutenberg-Universität Mainz, 55128 Mainz, Germany
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18
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Gruszecki WI, Gospodarek M, Grudziński W, Mazur R, Gieczewska K, Garstka M. Light-induced Change of Configuration of the LHCII-Bound Xanthophyll (Tentatively Assigned to Violaxanthin): A Resonance Raman Study. J Phys Chem B 2009; 113:2506-12. [DOI: 10.1021/jp8101755] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Wiesław I. Gruszecki
- Department of Biophysics, Institute of Physics, Maria Curie-Skłodowska University, 20-031 Lublin, Poland, Institute of Physics, Technical University of Lublin, Lublin, Poland, Department of Metabolic Regulation and Department of Plant Anatomy and Cytology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland
| | - Małgorzata Gospodarek
- Department of Biophysics, Institute of Physics, Maria Curie-Skłodowska University, 20-031 Lublin, Poland, Institute of Physics, Technical University of Lublin, Lublin, Poland, Department of Metabolic Regulation and Department of Plant Anatomy and Cytology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland
| | - Wojciech Grudziński
- Department of Biophysics, Institute of Physics, Maria Curie-Skłodowska University, 20-031 Lublin, Poland, Institute of Physics, Technical University of Lublin, Lublin, Poland, Department of Metabolic Regulation and Department of Plant Anatomy and Cytology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland
| | - Radosław Mazur
- Department of Biophysics, Institute of Physics, Maria Curie-Skłodowska University, 20-031 Lublin, Poland, Institute of Physics, Technical University of Lublin, Lublin, Poland, Department of Metabolic Regulation and Department of Plant Anatomy and Cytology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland
| | - Katarzyna Gieczewska
- Department of Biophysics, Institute of Physics, Maria Curie-Skłodowska University, 20-031 Lublin, Poland, Institute of Physics, Technical University of Lublin, Lublin, Poland, Department of Metabolic Regulation and Department of Plant Anatomy and Cytology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland
| | - Maciej Garstka
- Department of Biophysics, Institute of Physics, Maria Curie-Skłodowska University, 20-031 Lublin, Poland, Institute of Physics, Technical University of Lublin, Lublin, Poland, Department of Metabolic Regulation and Department of Plant Anatomy and Cytology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland
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Yang C, Lambrev P, Chen Z, Jávorfi T, Kiss AZ, Paulsen H, Garab G. The negatively charged amino acids in the lumenal loop influence the pigment binding and conformation of the major light-harvesting chlorophyll a/b complex of photosystem II. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2008; 1777:1463-70. [PMID: 18809373 DOI: 10.1016/j.bbabio.2008.08.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2008] [Revised: 08/21/2008] [Accepted: 08/25/2008] [Indexed: 10/21/2022]
Abstract
The major chlorophyll (Chl) a/b complexes of photosystem II (LHCIIb), in addition to their primary light-harvesting function, play key roles in the organization of the granal ultrastructure of the thylakoid membranes and in various regulatory processes. These functions depend on the structural stability and flexibility of the complexes. The lumenal side of LHCIIb is exposed to broadly variable pH environments, due to the build-up and decay of the pH gradient during photosynthesis. Therefore, the negatively charged amino acids in the lumenal loop might be of paramount importance for adjusting the structure and functions of LHCIIb. In order to clarify the structural roles of these residues, we investigated the pigment stoichiometries, absorption, linear and circular dichroism spectra of the reconstituted LHCIIb complexes, in which the negatively charged amino acids in the lumenal loop were exchanged to neutral ones (E94G, E107V and D111V). The mutations influenced the pigment binding and the molecular architecture of the complexes. Exchanging E94 to G destabilized the 3(10) helix in the lumenal loop structure and led to an acquired pH sensitivity of the LHCIIb structure. We conclude that these amino acids are important not only for pigment binding in the complexes, but also in stabilizing the conformation of LHCIIb at different pHs.
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Affiliation(s)
- Chunhong Yang
- Key Laboratory of Photosynthesis and Environmental Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, PR China.
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