1
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Smirnoff N, Wheeler GL. The ascorbate biosynthesis pathway in plants is known, but there is a way to go with understanding control and functions. J Exp Bot 2024; 75:2604-2630. [PMID: 38300237 PMCID: PMC11066809 DOI: 10.1093/jxb/erad505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Accepted: 01/29/2024] [Indexed: 02/02/2024]
Abstract
Ascorbate (vitamin C) is one of the most abundant primary metabolites in plants. Its complex chemistry enables it to function as an antioxidant, as a free radical scavenger, and as a reductant for iron and copper. Ascorbate biosynthesis occurs via the mannose/l-galactose pathway in green plants, and the evidence for this pathway being the major route is reviewed. Ascorbate accumulation is leaves is responsive to light, reflecting various roles in photoprotection. GDP-l-galactose phosphorylase (GGP) is the first dedicated step in the pathway and is important in controlling ascorbate synthesis. Its expression is determined by a combination of transcription and translation. Translation is controlled by an upstream open reading frame (uORF) which blocks translation of the main GGP-coding sequence, possibly in an ascorbate-dependent manner. GGP associates with a PAS-LOV protein, inhibiting its activity, and dissociation is induced by blue light. While low ascorbate mutants are susceptible to oxidative stress, they grow nearly normally. In contrast, mutants lacking ascorbate do not grow unless rescued by supplementation. Further research should investigate possible basal functions of ascorbate in severely deficient plants involving prevention of iron overoxidation in 2-oxoglutarate-dependent dioxygenases and iron mobilization during seed development and germination.
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Affiliation(s)
- Nicholas Smirnoff
- Biosciences, Faculty of Health and Life Sciences, Exeter EX4 4QD, UK
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2
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Conklin PL, Foyer CH, Hancock RD, Ishikawa T, Smirnoff N. Ascorbic acid metabolism and functions. J Exp Bot 2024; 75:2599-2603. [PMID: 38699987 PMCID: PMC11066792 DOI: 10.1093/jxb/erae143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Accepted: 03/28/2024] [Indexed: 05/05/2024]
Abstract
This Special Issue was assembled to mark the 25th anniversary of the proposal of the d -mannose/ l -galactose (Smirnoff-Wheeler) ascorbate biosynthesis pathway in plants ( Wheeler et al., 1998 ). The issue aims to assess the current state of knowledge and to identify outstanding questions about ascorbate metabolism and functions in plants.
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Affiliation(s)
- Patricia L Conklin
- Biological Sciences Department, Bowers Hall Rm 240, SUNY Cortland, Cortland, NY 13045, USA
| | - Christine H Foyer
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Edgbaston B15 2TT, UK
| | - Robert D Hancock
- Cell and Molecular Sciences, The James Hutton Institute, Invergowrie, Dundee, DD2 5DA, UK
| | - Takahiro Ishikawa
- Shimane University, 1060 Nishikawatsu, Matsue, Shimane 690-8504, Japan
| | - Nicholas Smirnoff
- Biosciences, Faculty of Health and Life Sciences, University of Exeter, Exeter EX4 4QD, UK
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3
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Arnaud D, Deeks MJ, Smirnoff N. RBOHF activates stomatal immunity by modulating both reactive oxygen species and apoplastic pH dynamics in Arabidopsis. Plant J 2023; 116:404-415. [PMID: 37421599 PMCID: PMC10952706 DOI: 10.1111/tpj.16380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 06/28/2023] [Accepted: 07/04/2023] [Indexed: 07/10/2023]
Abstract
Stomatal defences are important for plants to prevent pathogen entry and further colonisation of leaves. Apoplastic reactive oxygen species (ROS) generated by NADPH oxidases and apoplastic peroxidases play an important role in activating stomatal closure upon perception of bacteria. However, downstream events, particularly the factors influencing cytosolic hydrogen peroxide (H2 O2 ) signatures in guard cells are poorly understood. We used the H2 O2 sensor roGFP2-Orp1 and a ROS-specific fluorescein probe to study intracellular oxidative events during stomatal immune response using Arabidopsis mutants involved in the apoplastic ROS burst. Surprisingly, the NADPH oxidase mutant rbohF showed over-oxidation of roGFP2-Orp1 by a pathogen-associated molecular pattern (PAMP) in guard cells. However, stomatal closure was not tightly correlated with high roGFP2-Orp1 oxidation. In contrast, RBOHF was necessary for PAMP-mediated ROS production measured by a fluorescein-based probe in guard cells. Unlike previous reports, the rbohF mutant, but not rbohD, was impaired in PAMP-triggered stomatal closure resulting in defects in stomatal defences against bacteria. Interestingly, RBOHF also participated in PAMP-induced apoplastic alkalinisation. The rbohF mutants were also partly impaired in H2 O2 -mediated stomatal closure at 100 μm while higher H2 O2 concentration up to 1 mm did not promote stomatal closure in wild-type plants. Our results provide novel insights on the interplay between apoplastic and cytosolic ROS dynamics and highlight the importance of RBOHF in plant immunity.
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Affiliation(s)
- Dominique Arnaud
- Biosciences, Faculty of Health and Life SciencesUniversity of ExeterExeterEX4 4QDUK
| | - Michael J. Deeks
- Biosciences, Faculty of Health and Life SciencesUniversity of ExeterExeterEX4 4QDUK
| | - Nicholas Smirnoff
- Biosciences, Faculty of Health and Life SciencesUniversity of ExeterExeterEX4 4QDUK
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4
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Barton S, Padfield D, Masterson A, Buckling A, Smirnoff N, Yvon-Durocher G. Comparative experimental evolution reveals species-specific idiosyncrasies in marine phytoplankton adaptation to warming. Glob Chang Biol 2023; 29:5261-5275. [PMID: 37395481 DOI: 10.1111/gcb.16827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 05/30/2023] [Indexed: 07/04/2023]
Abstract
A number of experimental studies have demonstrated that phytoplankton can display rapid thermal adaptation in response to warmed environments. While these studies provide insight into the evolutionary responses of single species, they tend to employ different experimental techniques. Consequently, our ability to compare the potential for thermal adaptation across different, ecologically relevant, species remains limited. Here, we address this limitation by conducting simultaneous long-term warming experiments with the same experimental design on clonal isolates of three phylogenetically diverse species of marine phytoplankton; the cyanobacterium Synechococcus sp., the prasinophyte Ostreococcus tauri and the diatom Phaeodoactylum tricornutum. Over the same experimental time period, we observed differing levels of thermal adaptation in response to stressful supra-optimal temperatures. Synechococcus sp. displayed the greatest improvement in fitness (i.e., growth rate) and thermal tolerance (i.e., temperature limits of growth). Ostreococcus tauri was able to improve fitness and thermal tolerance, but to a lesser extent. Finally, Phaeodoactylum tricornutum showed no signs of adaptation. These findings could help us understand how the structure of phytoplankton communities may change in response to warming, and possible biogeochemical implications, as some species show relatively more rapid adaptive shifts in their thermal tolerance.
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Affiliation(s)
- Samuel Barton
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, UK
- Department of Earth Sciences, University of Oxford, Oxford, UK
| | - Daniel Padfield
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, UK
| | - Abigail Masterson
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, UK
| | - Angus Buckling
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, UK
| | - Nicholas Smirnoff
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - Gabriel Yvon-Durocher
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, UK
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5
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Arnaud D, Deeks MJ, Smirnoff N. Organelle-targeted biosensors reveal distinct oxidative events during pattern-triggered immune responses. Plant Physiol 2023; 191:2551-2569. [PMID: 36582183 PMCID: PMC10069903 DOI: 10.1093/plphys/kiac603] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 12/02/2022] [Accepted: 12/02/2022] [Indexed: 05/19/2023]
Abstract
Reactive oxygen species are produced in response to pathogens and pathogen-associated molecular patterns, as exemplified by the rapid extracellular oxidative burst dependent on the NADPH oxidase isoform RESPIRATORY BURST OXIDASE HOMOLOG D (RBOHD) in Arabidopsis (Arabidopsis thaliana). We used the H2O2 biosensor roGFP2-Orp1 and the glutathione redox state biosensor GRX1-roGFP2 targeted to various organelles to reveal unsuspected oxidative events during the pattern-triggered immune response to flagellin (flg22) and after inoculation with Pseudomonas syringae. roGFP2-Orp1 was oxidized in a biphasic manner 1 and 6 h after treatment, with a more intense and faster response in the cytosol compared to chloroplasts, mitochondria, and peroxisomes. Peroxisomal and cytosolic GRX1-roGFP2 were also oxidized in a biphasic manner. Interestingly, our results suggested that bacterial effectors partially suppress the second phase of roGFP2-Orp1 oxidation in the cytosol. Pharmacological and genetic analyses indicated that the pathogen-associated molecular pattern-induced cytosolic oxidation required the BRI1-ASSOCIATED RECEPTOR KINASE (BAK1) and BOTRYTIS-INDUCED KINASE 1 (BIK1) signaling components involved in the immune response but was largely independent of NADPH oxidases RBOHD and RESPIRATORY BURST OXIDASE HOMOLOG F (RBOHF) and apoplastic peroxidases peroxidase 33 (PRX33) and peroxidase 34 (PRX34). The initial apoplastic oxidative burst measured with luminol was followed by a second oxidation burst, both of which preceded the two waves of cytosolic oxidation. In contrast to the cytosolic oxidation, these bursts were RBOHD-dependent. Our results reveal complex oxidative sources and dynamics during the pattern-triggered immune response, including that cytosolic oxidation is largely independent of the preceding extracellular oxidation events.
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Affiliation(s)
- Dominique Arnaud
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, UK
| | - Michael J Deeks
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, UK
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6
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Lamanchai K, Smirnoff N, Salmon DL, Ngernmuen A, Roytrakul S, Leetanasaksakul K, Kittisenachai S, Jantasuriyarat C. OsVTC1-1 Gene Silencing Promotes a Defense Response in Rice and Enhances Resistance to Magnaporthe oryzae. Plants (Basel) 2022; 11:2189. [PMID: 36079570 PMCID: PMC9460107 DOI: 10.3390/plants11172189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 08/13/2022] [Accepted: 08/23/2022] [Indexed: 06/15/2023]
Abstract
Rice blast disease is a serious disease in rice caused by Magnaporthe oryzae (M. oryzae). Ascorbic acid (AsA), or vitamin C, is a strong antioxidant that prevents oxidative damage to cellular components and plays an essential role in plant defense response. GDP-D-mannose pyrophosphorylase (GMP or VTC1) is an enzyme that generates GDP-D-mannose for AsA, cell wall, and glycoprotein synthesis. The OsVTC1 gene has three homologs in the rice genome: OsVTC1-1, OsVTC1-3, and OsVTC1-8. Using OsVTC1-1 RNAi lines, this study investigated the role of the OsVTC1-1 gene during rice blast fungus inoculation. The OsVTC1-1 RNAi inoculated with rice blast fungus induced changes to cell wall monosaccharides, photosynthetic efficiency, reactive oxygen species (ROS) accumulation, and malondialdehyde (MDA) content. Additionally, the OsVTC1-1 RNAi lines were shown to be more resistant to rice blast fungus than the wild type. Genes and proteins related to defense response, plant hormone synthesis, and signaling pathways, especially salicylic acid and jasmonic acid, were up-regulated in the OsVTC1-1 RNAi lines after rice blast inoculation. These results suggest that the OsVTC1-1 gene regulates rice blast resistance through several defense mechanisms, including hormone synthesis and signaling pathways.
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Affiliation(s)
- Kanyanat Lamanchai
- Department of Genetics, Faculty of Science, Kasetsart University, Chatuchak, Bangkok 10900, Thailand
| | - Nicholas Smirnoff
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, UK
| | - Deborah L. Salmon
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, UK
| | - Athipat Ngernmuen
- Department of Zoology, Faculty of Science, Kasetsart University, Chatuchak, Bangkok 10900, Thailand
| | - Sittiruk Roytrakul
- Functional Proteomics Technology, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113 Paholyothin Road, Klong 1, Klong Luang, Pathumthani 12120, Thailand
| | - Kantinan Leetanasaksakul
- Functional Proteomics Technology, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113 Paholyothin Road, Klong 1, Klong Luang, Pathumthani 12120, Thailand
| | - Suthathip Kittisenachai
- Functional Proteomics Technology, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113 Paholyothin Road, Klong 1, Klong Luang, Pathumthani 12120, Thailand
| | - Chatchawan Jantasuriyarat
- Department of Genetics, Faculty of Science, Kasetsart University, Chatuchak, Bangkok 10900, Thailand
- Center for Advanced Studies in Tropical Natural Resources, National Research University-Kasetsart (CASTNAR, NRU-KU), Kasetsart University, Chatuchak, Bangkok 10900, Thailand
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7
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Schaum CE, Buckling A, Smirnoff N, Yvon-Durocher G. Evolution of thermal tolerance and phenotypic plasticity under rapid and slow temperature fluctuations. Proc Biol Sci 2022; 289:20220834. [PMID: 35919998 PMCID: PMC9346350 DOI: 10.1098/rspb.2022.0834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Global warming is associated with an increase in sea surface temperature and its variability. The consequences of evolving in variable, fluctuating environments are explored by a large body of theory: when populations evolve in fluctuating environments the frequency of fluctuations determines the shapes of tolerance curves (indicative of habitats that organisms can inhabit) and trait reaction norms (the phenotypes that organisms display across these environments). Despite this well-established theoretical backbone, predicting how trait and tolerance curves will evolve in organisms at the foundation of marine ecosystems remains a challenge. Here, we used a globally distributed phytoplankton, Thalassiosira pseudonana, and show that fluctuations in temperature on scales of 3–4 generations rapidly selected for populations with enhanced trait plasticity and elevated thermal tolerance. Fluctuations spanning 30–40 generations selected for the formation of two stable, genetically and physiologically distinct populations, one evolving high trait plasticity and enhanced thermal tolerance, and the other, akin to samples evolved under constant warming, with lower trait plasticity and a smaller increase in thermal tolerance.
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Affiliation(s)
- C-E Schaum
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, Cornwall TR10 9EZ, UK.,Centre for Earth Systems and Sustainability (CEN)/ Institute for Marine Ecosystems and Fishery Science (IMF), Hamburg University, 22767 Hamburg, Germany
| | - A Buckling
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, Cornwall TR10 9EZ, UK
| | - N Smirnoff
- Biosciences, College of Life and Environmental Sciences, Geoffrey Pope Building University of Exeter, Exeter EX4 4QD, UK
| | - G Yvon-Durocher
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, Cornwall TR10 9EZ, UK
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8
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Hancock RD, Smirnoff N, Lunn JE. Journal of Experimental Botany 70th anniversary: plant metabolism in a changing world. J Exp Bot 2021; 72:5939-5941. [PMID: 34473301 PMCID: PMC8411604 DOI: 10.1093/jxb/erab352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Affiliation(s)
- Robert D Hancock
- Cell and Molecular Sciences, The James Hutton Institute, Dundee DD2 5DA, UK
| | - Nicholas Smirnoff
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, UK
| | - John E Lunn
- Max Planck Institute of Molecular Plant Physiology, D-14476 Potsdam-Golm, Germany
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9
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Geigenberger P, Smirnoff N, Van Breusegem F, Dietz KJ, Noctor G. Plant redox biology-on the move. Plant Physiol 2021; 186:1-3. [PMID: 33710325 PMCID: PMC8154049 DOI: 10.1093/plphys/kiab103] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 02/23/2021] [Indexed: 05/10/2023]
Affiliation(s)
- Peter Geigenberger
- Ludwig Maximilians University of Munich, Faculty of Biology, LMU Biocenter, Grosshaderner Str. 2-4, 82152 Planegg-Martinsried, Germany
| | - Nicholas Smirnoff
- Biosciences, College of Life and Environmental Sciences, University of Exeter,Geoffrey Pope Building, Stocker Road, Exeter EX4 4QD, UK
| | - Frank Van Breusegem
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Center for Plant Systems Biology, VIB, Technologiepark-Zwijnaarde 71, 9052 Ghent, Belgium
| | - Karl-Josef Dietz
- University of Bielefeld, Faculty of Biology, Biochemistry and Physiology of Plants, 33615 Bielefeld, Germany
| | - Graham Noctor
- Institut Universitaire de France (IUF), Université Paris-Saclay, CNRS, INRAE, Univ Evry, Institute of Plant Sciences Paris-Saclay (IPS2), 91405, Orsay, France
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10
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Feroz H, Ferlez B, Oh H, Mohammadiarani H, Ren T, Baker CS, Gajewski JP, Lugar DJ, Gaudana SB, Butler P, Hühn J, Lamping M, Parak WJ, Blatt MR, Kerfeld CA, Smirnoff N, Vashisth H, Golbeck JH, Kumar M. Liposome-based measurement of light-driven chloride transport kinetics of halorhodopsin. Biochim Biophys Acta Biomembr 2021; 1863:183637. [PMID: 33930372 DOI: 10.1016/j.bbamem.2021.183637] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 04/14/2021] [Accepted: 04/22/2021] [Indexed: 11/30/2022]
Abstract
We report a simple and direct fluorimetric vesicle-based method for measuring the transport rate of the light-driven ions pumps as specifically applied to the chloride pump, halorhodopsin, from Natronomonas pharaonis (pHR). Previous measurements were cell-based and methods to determine average single channel permeability challenging. We used a water-in-oil emulsion method for directional pHR reconstitution into two different types of vesicles: lipid vesicles and asymmetric lipid-block copolymer vesicles. We then used stopped-flow experiments combined with fluorescence correlation spectroscopy to determine per protein Cl- transport rates. We obtained a Cl- transport rate of 442 (±17.7) Cl-/protein/s in egg phosphatidyl choline (PC) lipid vesicles and 413 (±26) Cl-/protein/s in hybrid block copolymer/lipid (BCP/PC) vesicles with polybutadine-polyethylene oxide (PB12PEO8) on the outer leaflet and PC in the inner leaflet at a photon flux of 1450 photons/protein/s. Normalizing to a per photon basis, this corresponds to 0.30 (±0.07) Cl-/photon and 0.28 (±0.04) Cl-/photon for pure PC and BCP/PC hybrid vesicles respectively, both of which are in agreement with recently reported turnover of ~500 Cl-/protein/s from flash photolysis experiments and with voltage-clamp measurements of 0.35 (±0.16) Cl-/photon in pHR-expressing oocytes as well as with a pHR quantum efficiency of ~30%.
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Affiliation(s)
- Hasin Feroz
- Department of Chemical Engineering, The Pennsylvania State University, University Park, PA, USA
| | - Bryan Ferlez
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA
| | - Hyeonji Oh
- Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, USA
| | | | - Tingwei Ren
- Department of Chemical Engineering, The Pennsylvania State University, University Park, PA, USA
| | - Carol S Baker
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA
| | - John P Gajewski
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA
| | - Daniel J Lugar
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA
| | - Sandeep B Gaudana
- MSU-DOE Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA
| | - Peter Butler
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, USA
| | - Jonas Hühn
- Department of Physics and Chemistry, Philipps University of Marburg, Marburg, Germany
| | - Matthias Lamping
- Department of Physics and Chemistry, Philipps University of Marburg, Marburg, Germany
| | - Wolfgang J Parak
- Center of Hybrid Nanostructures (CHyN), Universität Hamburg, Hamburg, Germany
| | - Michael R Blatt
- Laboratory of Plant Physiology and Biophysics, Institute of Molecular Cell and Systems Biology, Bower Building, University of Glasgow, Glasgow G12 8QQ, UK
| | - Cheryl A Kerfeld
- MSU-DOE Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA; Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA, USA; Environmental Genomics and Systems Biology and Molecular Biophysics and Integrated Bioimaging Divisions, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | | | - Harish Vashisth
- Department of Chemical Engineering, The University of New Hampshire, Durham, NH, USA
| | - John H Golbeck
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA; Department of Chemistry, The Pennsylvania State University, University Park, PA, USA
| | - Manish Kumar
- Department of Civil, Architectural and Environmental Engineering, The University of Texas at Austin, Austin, TX, USA.
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11
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Fenech M, Amorim-Silva V, Esteban del Valle A, Arnaud D, Ruiz-Lopez N, Castillo AG, Smirnoff N, Botella MA. The role of GDP-l-galactose phosphorylase in the control of ascorbate biosynthesis. Plant Physiol 2021; 185:1574-1594. [PMID: 33793952 PMCID: PMC8133566 DOI: 10.1093/plphys/kiab010] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 12/28/2020] [Indexed: 05/03/2023]
Abstract
The enzymes involved in l-ascorbate biosynthesis in photosynthetic organisms (the Smirnoff-Wheeler [SW] pathway) are well established. Here, we analyzed their subcellular localizations and potential physical interactions and assessed their role in the control of ascorbate synthesis. Transient expression of C terminal-tagged fusions of SW genes in Nicotiana benthamiana and Arabidopsis thaliana mutants complemented with genomic constructs showed that while GDP-d-mannose epimerase is cytosolic, all the enzymes from GDP-d-mannose pyrophosphorylase (GMP) to l-galactose dehydrogenase (l-GalDH) show a dual cytosolic/nuclear localization. All transgenic lines expressing functional SW protein green fluorescent protein fusions driven by their endogenous promoters showed a high accumulation of the fusion proteins, with the exception of those lines expressing GDP-l-galactose phosphorylase (GGP) protein, which had very low abundance. Transient expression of individual or combinations of SW pathway enzymes in N. benthamiana only increased ascorbate concentration if GGP was included. Although we did not detect direct interaction between the different enzymes of the pathway using yeast-two hybrid analysis, consecutive SW enzymes, as well as the first and last enzymes (GMP and l-GalDH) associated in coimmunoprecipitation studies. This association was supported by gel filtration chromatography, showing the presence of SW proteins in high-molecular weight fractions. Finally, metabolic control analysis incorporating known kinetic characteristics showed that previously reported feedback repression at the GGP step, combined with its relatively low abundance, confers a high-flux control coefficient and rationalizes why manipulation of other enzymes has little effect on ascorbate concentration.
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Affiliation(s)
- Mario Fenech
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora” (IHSM-UMA-CSIC), Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos s/n, E-29071 Málaga, Spain
| | - Vítor Amorim-Silva
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora” (IHSM-UMA-CSIC), Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos s/n, E-29071 Málaga, Spain
| | - Alicia Esteban del Valle
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora” (IHSM-UMA-CSIC), Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos s/n, E-29071 Málaga, Spain
| | - Dominique Arnaud
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, UK
| | - Noemi Ruiz-Lopez
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora” (IHSM-UMA-CSIC), Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos s/n, E-29071 Málaga, Spain
| | - Araceli G Castillo
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora” (IHSM-UMA-CSIC), Departamento de Genética, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos s/n, E-29071 Málaga, Spain
| | - Nicholas Smirnoff
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, UK
| | - Miguel A Botella
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora” (IHSM-UMA-CSIC), Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos s/n, E-29071 Málaga, Spain
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12
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Helliwell KE, Kleiner FH, Hardstaff H, Chrachri A, Gaikwad T, Salmon D, Smirnoff N, Wheeler GL, Brownlee C. Spatiotemporal patterns of intracellular Ca 2+ signalling govern hypo-osmotic stress resilience in marine diatoms. New Phytol 2021; 230:155-170. [PMID: 33486789 DOI: 10.1111/nph.17162] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Accepted: 12/11/2020] [Indexed: 05/15/2023]
Abstract
Diatoms are globally important phytoplankton that dominate coastal and polar-ice assemblages. These environments exhibit substantial changes in salinity over dynamic spatiotemporal regimes. Rapid sensory systems are vital to mitigate the harmful consequences of osmotic stress. Population-based analyses have suggested that Ca2+ signalling is involved in diatom osmotic sensing. However, mechanistic insight of the role of osmotic Ca2+ signalling is limited. Here, we show that Phaeodactylum Ca2+ elevations are essential for surviving hypo-osmotic shock. Moreover, employing novel single-cell imaging techniques we have characterised real-time Ca2+ signalling responses in single diatom cells to environmental osmotic perturbations. We observe that intracellular spatiotemporal patterns of osmotic-induced Ca2+ elevations encode vital information regarding the nature of the osmotic stimulus. Localised Ca2+ signals evoked by mild or gradual hypo-osmotic shocks are propagated globally from the apical cell tips, enabling fine-tuned cell volume regulation across the whole cell. Finally, we demonstrate that diatoms adopt Ca2+ -independent and dependent mechanisms for osmoregulation. We find that efflux of organic osmolytes occurs in a Ca2+ -independent manner, but this response is insufficient to mitigate cell damage during hypo-osmotic shock. By comparison, Ca2+ -dependent signalling is necessary to prevent cell bursting via precise coordination of K+ transport, and therefore is likely to underpin survival in dynamic osmotic environments.
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Affiliation(s)
- Katherine E Helliwell
- The Laboratory, Marine Biological Association, Citadel Hill, Plymouth, PL1 2PB, UK
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4QD, UK
| | - Friedrich H Kleiner
- The Laboratory, Marine Biological Association, Citadel Hill, Plymouth, PL1 2PB, UK
- School of Ocean and Earth Science, University of Southampton, Southampton, SO14 3ZH, UK
| | - Hayley Hardstaff
- The Laboratory, Marine Biological Association, Citadel Hill, Plymouth, PL1 2PB, UK
| | - Abdul Chrachri
- The Laboratory, Marine Biological Association, Citadel Hill, Plymouth, PL1 2PB, UK
| | - Trupti Gaikwad
- The Laboratory, Marine Biological Association, Citadel Hill, Plymouth, PL1 2PB, UK
| | - Deborah Salmon
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4QD, UK
| | - Nicholas Smirnoff
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4QD, UK
| | - Glen L Wheeler
- The Laboratory, Marine Biological Association, Citadel Hill, Plymouth, PL1 2PB, UK
| | - Colin Brownlee
- The Laboratory, Marine Biological Association, Citadel Hill, Plymouth, PL1 2PB, UK
- School of Ocean and Earth Science, University of Southampton, Southampton, SO14 3ZH, UK
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13
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Abstract
The chloroplast has recently emerged as pivotal to co-ordinating plant defence responses and as a target of plant pathogens. Beyond its central position in oxygenic photosynthesis and primary metabolism - key targets in the complex virulence strategies of diverse pathogens - the chloroplast integrates, decodes and responds to environmental signals. The capacity of chloroplasts to synthesize phytohormones and a diverse range of secondary metabolites, combined with retrograde and reactive oxygen signalling, provides exquisite flexibility to both perceive and respond to biotic stresses. These processes also represent a plethora of opportunities for pathogens to evolve strategies to directly or indirectly target 'chloroplast immunity'. This review covers the contribution of the chloroplast to pathogen associated molecular pattern and effector triggered immunity as well as systemic acquired immunity. We address phytohormone modulation of immunity and surmise how chloroplast-derived reactive oxygen species underpin chloroplast immunity through indirect evidence inferred from genetic modification of core chloroplast components and direct pathogen targeting of the chloroplast. We assess the impact of transcriptional reprogramming of nuclear-encoded chloroplast genes during disease and defence and look at future research challenges.
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Affiliation(s)
- George R Littlejohn
- School of Biological and Marine Sciences, University of Plymouth, Plymouth, PL4 8AA, UK
| | - Susan Breen
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | - Nicholas Smirnoff
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4QD, UK
| | - Murray Grant
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
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14
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Bömer M, Pérez‐Salamó I, Florance HV, Salmon D, Dudenhoffer J, Finch P, Cinar A, Smirnoff N, Harvey A, Devoto A. Jasmonates induce Arabidopsis bioactivities selectively inhibiting the growth of breast cancer cells through CDC6 and mTOR. New Phytol 2021; 229:2120-2134. [PMID: 33124043 PMCID: PMC8022592 DOI: 10.1111/nph.17031] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 09/26/2020] [Indexed: 06/11/2023]
Abstract
Phytochemicals are used often in vitro and in vivo in cancer research. The plant hormones jasmonates (JAs) control the synthesis of specialized metabolites through complex regulatory networks. JAs possess selective cytotoxicity in mixed populations of cancer and normal cells. Here, direct incubation of leaf explants from the non-medicinal plant Arabidopsis thaliana with human breast cancer cells, selectively suppresses cancer cell growth. High-throughput LC-MS identified Arabidopsis metabolites. Protein and transcript levels of cell cycle regulators were examined in breast cancer cells. A synergistic effect by methyljasmonate (MeJA) and by compounds upregulated in the metabolome of MeJA-treated Arabidopsis leaves, on the breast cancer cell cycle, is associated with Cell Division Cycle 6 (CDC6), Cyclin-dependent kinase 2 (CDK2), Cyclins D1 and D3, indicating that key cell cycle components mediate cell viability reduction. Bioactives such as indoles, quinolines and cis-(+)-12-oxophytodienoic acid, in synergy, could act as anticancer compounds. Our work suggests a universal role for MeJA-treatment of Arabidopsis in altering the DNA replication regulator CDC6, supporting conservation, across kingdoms, of cell cycle regulation, through the crosstalk between the mechanistic target of rapamycin, mTOR and JAs. This study has important implications for the identification of metabolites with anti-cancer bioactivities in plants with no known medicinal pedigree and it will have applications in developing disease treatments.
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Affiliation(s)
- Moritz Bömer
- Department of Biological SciencesPlant Molecular Science and Centre of Systems and Synthetic BiologyRoyal Holloway University of LondonEghamTW20 0EXUK
- Natural Resources InstituteUniversity of GreenwichCentral AvenueChatham MaritimeME4 4TBUK
| | - Imma Pérez‐Salamó
- Department of Biological SciencesPlant Molecular Science and Centre of Systems and Synthetic BiologyRoyal Holloway University of LondonEghamTW20 0EXUK
| | - Hannah V. Florance
- BiosciencesCollege of Life and Environmental SciencesUniversity of ExeterGeoffrey Pope Building, Stocker RoadExeterEX4 4QDUK
| | - Deborah Salmon
- BiosciencesCollege of Life and Environmental SciencesUniversity of ExeterGeoffrey Pope Building, Stocker RoadExeterEX4 4QDUK
| | | | - Paul Finch
- Department of Biological SciencesPlant Molecular Science and Centre of Systems and Synthetic BiologyRoyal Holloway University of LondonEghamTW20 0EXUK
| | - Aycan Cinar
- Institute of Environment, Health and SocietiesBrunel University LondonKingston LaneUxbridgeUB8 3PHUK
| | - Nicholas Smirnoff
- BiosciencesCollege of Life and Environmental SciencesUniversity of ExeterGeoffrey Pope Building, Stocker RoadExeterEX4 4QDUK
| | - Amanda Harvey
- Institute of Environment, Health and SocietiesBrunel University LondonKingston LaneUxbridgeUB8 3PHUK
| | - Alessandra Devoto
- Department of Biological SciencesPlant Molecular Science and Centre of Systems and Synthetic BiologyRoyal Holloway University of LondonEghamTW20 0EXUK
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15
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Haque T, Eaves DJ, Lin Z, Zampronio CG, Cooper HJ, Bosch M, Smirnoff N, Franklin-Tong VE. Self-Incompatibility Triggers Irreversible Oxidative Modification of Proteins in Incompatible Pollen. Plant Physiol 2020; 183:1391-1404. [PMID: 32321844 PMCID: PMC7333688 DOI: 10.1104/pp.20.00066] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 04/07/2020] [Indexed: 06/08/2023]
Abstract
Self-incompatibility (SI) is used by many angiosperms to prevent self-fertilization and inbreeding. In common poppy (Papaver rhoeas), interaction of cognate pollen and pistil S-determinants triggers programmed cell death (PCD) of incompatible pollen. We previously identified that reactive oxygen species (ROS) signal to SI-PCD. ROS-induced oxidative posttranslational modifications (oxPTMs) can regulate protein structure and function. Here, we have identified and mapped oxPTMs triggered by SI in incompatible pollen. Notably, SI-induced pollen had numerous irreversible oxidative modifications, while untreated pollen had virtually none. Our data provide a valuable analysis of the protein targets of ROS in the context of SI-induction and comprise a benchmark because currently there are few reports of irreversible oxPTMs in plants. Strikingly, cytoskeletal proteins and enzymes involved in energy metabolism are a prominent target of ROS. Oxidative modifications to a phosphomimic form of a pyrophosphatase result in a reduction of its activity. Therefore, our results demonstrate irreversible oxidation of pollen proteins during SI and provide evidence that this modification can affect protein function. We suggest that this reduction in cellular activity could lead to PCD.
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Affiliation(s)
- Tamanna Haque
- School of Biosciences, College of Life and Environmental Sciences, School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Deborah J Eaves
- School of Biosciences, College of Life and Environmental Sciences, School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Zongcheng Lin
- School of Biosciences, College of Life and Environmental Sciences, School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Cleidiane G Zampronio
- School of Biosciences, College of Life and Environmental Sciences, School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Helen J Cooper
- School of Biosciences, College of Life and Environmental Sciences, School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Maurice Bosch
- Institute of Biological, Environmental and Rural Sciences (IBERS), Aberystwyth University, Gogerddan, Aberystwyth SY23 3EB, United Kingdom
| | - Nicholas Smirnoff
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, United Kingdom
| | - Vernonica E Franklin-Tong
- School of Biosciences, College of Life and Environmental Sciences, School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
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16
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Mullineaux PM, Exposito-Rodriguez M, Laissue PP, Smirnoff N, Park E. Spatial chloroplast-to-nucleus signalling involving plastid-nuclear complexes and stromules. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190405. [PMID: 32362250 PMCID: PMC7209948 DOI: 10.1098/rstb.2019.0405] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Communication between chloroplasts and the nucleus in response to various environmental cues may be mediated by various small molecules. Signalling specificity could be enhanced if the physical contact between these organelles facilitates direct transfer and prevents interference from other subcellular sources of the same molecules. Plant cells have plastid-nuclear complexes, which provide close physical contact between these organelles. Plastid-nuclear complexes have been proposed to facilitate transfer of photosynthesis-derived H2O2 to the nucleus in high light. Stromules (stroma filled tubular plastid extensions) may provide an additional conduit for transfer of a wider range of signalling molecules, including proteins. However, plastid-nuclear complexes and stromules have been hitherto treated as distinct phenomena. We suggest that plastid-nuclear complexes and stromules work in a coordinated manner so that, according to environmental conditions or developmental state, the two modes of connection contribute to varying extents. We hypothesize that this association is dynamic and that there may be a link between plastid-nuclear complexes and the development of stromules. Furthermore, the changes in contact could alter signalling specificity by allowing an extended or different range of signalling molecules to be delivered to the nucleus. This article is part of the theme issue 'Retrograde signalling from endosymbiotic organelles'.
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Affiliation(s)
- Philip M Mullineaux
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, UK
| | | | | | - Nicholas Smirnoff
- College of Life and Environmental Sciences, Biosciences, University of Exeter, Exeter EX4 4QD, UK
| | - Eunsook Park
- Plant Immunity Research Center, College of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea.,Department of Molecular Biology, College of Agriculture and Natural Resources, University of Wyoming, Laramie WY 82071, USA
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17
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Bunbury F, Helliwell KE, Mehrshahi P, Davey MP, Salmon DL, Holzer A, Smirnoff N, Smith AG. Responses of a Newly Evolved Auxotroph of Chlamydomonas to B 12 Deprivation. Plant Physiol 2020; 183:167-178. [PMID: 32079734 PMCID: PMC7210614 DOI: 10.1104/pp.19.01375] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 02/04/2020] [Indexed: 05/10/2023]
Abstract
The corrinoid B12 is synthesized only by prokaryotes yet is widely required by eukaryotes as an enzyme cofactor. Microalgae have evolved B12 dependence on multiple occasions, and we previously demonstrated that experimental evolution of the non-B12-requiring alga Chlamydomonas reinhardtii in media supplemented with B12 generated a B12-dependent mutant (hereafter metE7). This clone provides a unique opportunity to study the physiology of a nascent B12 auxotroph. Our analyses demonstrate that B12 deprivation of metE7 disrupts C1 metabolism, causes an accumulation of starch and triacylglycerides, and leads to a decrease in photosynthetic pigments, proteins, and free amino acids. B12 deprivation also caused a substantial increase in reactive oxygen species, which preceded rapid cell death. Survival could be improved without compromising growth by simultaneously depriving the cells of nitrogen, suggesting a type of cross protection. Significantly, we found further improvements in survival under B12 limitation and an increase in B12 use efficiency after metE7 underwent a further period of experimental evolution, this time in coculture with a B12-producing bacterium. Therefore, although an early B12-dependent alga would likely be poorly adapted to coping with B12 deprivation, association with B12-producers can ensure long-term survival whilst also providing a suitable environment for evolving mechanisms to tolerate B12 limitation better.
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Affiliation(s)
- Freddy Bunbury
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, United Kingdom
| | - Katherine E Helliwell
- Marine Biological Association of the United Kingdom, Citadel Hill, Plymouth EX4 4PY, United Kingdom
- School of Biosciences, University of Exeter, Exeter, PL1 2PB, United Kingdom
| | - Payam Mehrshahi
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, United Kingdom
| | - Matthew P Davey
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, United Kingdom
| | - Deborah L Salmon
- School of Biosciences, University of Exeter, Exeter, PL1 2PB, United Kingdom
| | - Andre Holzer
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, United Kingdom
| | - Nicholas Smirnoff
- School of Biosciences, University of Exeter, Exeter, PL1 2PB, United Kingdom
| | - Alison G Smith
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, United Kingdom
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18
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Barton S, Jenkins J, Buckling A, Schaum CE, Smirnoff N, Raven JA, Yvon-Durocher G. Evolutionary temperature compensation of carbon fixation in marine phytoplankton. Ecol Lett 2020; 23:722-733. [PMID: 32059265 PMCID: PMC7078849 DOI: 10.1111/ele.13469] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 01/11/2020] [Indexed: 12/01/2022]
Abstract
The efficiency of carbon sequestration by the biological pump could decline in the coming decades because respiration tends to increase more with temperature than photosynthesis. Despite these differences in the short‐term temperature sensitivities of photosynthesis and respiration, it remains unknown whether the long‐term impacts of global warming on metabolic rates of phytoplankton can be modulated by evolutionary adaptation. We found that respiration was consistently more temperature dependent than photosynthesis across 18 diverse marine phytoplankton, resulting in universal declines in the rate of carbon fixation with short‐term increases in temperature. Long‐term experimental evolution under high temperature reversed the short‐term stimulation of metabolic rates, resulting in increased rates of carbon fixation. Our findings suggest that thermal adaptation may therefore have an ameliorating impact on the efficiency of phytoplankton as primary mediators of the biological carbon pump.
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Affiliation(s)
- Samuel Barton
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, Cornwall, TR10 9FE, UK
| | - James Jenkins
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, Cornwall, TR10 9FE, UK
| | - Angus Buckling
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, Cornwall, TR10 9FE, UK
| | - C-Elisa Schaum
- Institute for Hydrobiology and Fisheries, Section Oceanography, Hamburg University, 22767, Hamburg, Germany
| | - Nicholas Smirnoff
- Biosciences, College of Life and Environmental Sciences, Geoffrey Pope Building University of Exeter, Exeter, EX4 4QD, UK
| | - John A Raven
- Division of Plant Science, University of Dundee at the James Hutton Institute, Invergowrie, Dundee, DD2 5DA, UK.,Climate Change Cluster, University of Technology Sydney, Ultimo, NSW, 2007, Australia.,School of Biology, University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia
| | - Gabriel Yvon-Durocher
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, Cornwall, TR10 9FE, UK
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19
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Alegre ML, Steelheart C, Baldet P, Rothan C, Just D, Okabe Y, Ezura H, Smirnoff N, Gergoff Grozeff GE, Bartoli CG. Deficiency of GDP-L-galactose phosphorylase, an enzyme required for ascorbic acid synthesis, reduces tomato fruit yield. Planta 2020; 251:54. [PMID: 31970534 DOI: 10.1007/s00425-020-03345-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2019] [Accepted: 01/10/2020] [Indexed: 05/26/2023]
Abstract
Reduced GDP-L-galactose phosphorylase expression and deficiency of ascorbic acid content lead to decreased fruit set and yield in tomato plants. Reduced GDP-L-galactose phosphorylase expression and deficiency of ascorbic acid content lead to decreased fruit set and yield in tomato plants. GDP-L-galactose phosphorylase (GGP) catalyzes the first step committed to ascorbic acid synthesis. The participation of GDP-L-galactose phosphorylase and ascorbate in tomato fruit production and quality was studied in this work using two SlGGP1 deficient EMS Micro-Tom mutants. The SlGGP1 mutants display decreased concentrations of ascorbate in roots, leaves, flowers, and fruit. The initiation of anthesis is delayed in ggp1 plants but the number of flowers is similar to wild type. The number of fruits is reduced in ggp1 mutants with an increased individual weight. However, the whole fruit biomass accumulation is reduced in both mutant lines. Fruits of the ggp1 plants produce more ethylene and show higher firmness and soluble solids content than the wild type after the breaker stage. Leaf CO2 uptake decreases about 50% in both ggp1 mutants at saturating light conditions; however, O2 production in an enriched CO2 atmosphere is only 19% higher in wild type leaves. Leaf conductance that is largely reduced in both mutants may be the main limitation for photosynthesis. Sink-source assays and hormone concentration were measured to determine restrictions to fruit yield. Manipulation of leaf area/fruit number relationship demonstrates that the number of fruits and not the provision of photoassimilates from the source restricts biomass accumulation in the ggp1 lines. The lower gibberellins concentration measured in the flowers would contribute to the lower fruit set, thus impacting in tomato yield. Taken as a whole these results demonstrate that ascorbate biosynthetic pathway critically participates in tomato development and fruit production.
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Affiliation(s)
- Matías L Alegre
- INFIVE, Facultades de Ciencias Agrarias y Forestales y Ciencias Naturales, Universidad Nacional de La Plata-CCT CONICET, La Plata, Argentina
| | - Charlotte Steelheart
- INFIVE, Facultades de Ciencias Agrarias y Forestales y Ciencias Naturales, Universidad Nacional de La Plata-CCT CONICET, La Plata, Argentina
| | - Pierre Baldet
- UMR 1332 Biologie du Fruit Et Pathologie, Institut National de la Recherche Agronomique (INRA), Université de Bordeaux, 33140, Villenave d'Ornon, France
| | - Christophe Rothan
- UMR 1332 Biologie du Fruit Et Pathologie, Institut National de la Recherche Agronomique (INRA), Université de Bordeaux, 33140, Villenave d'Ornon, France
| | - Daniel Just
- UMR 1332 Biologie du Fruit Et Pathologie, Institut National de la Recherche Agronomique (INRA), Université de Bordeaux, 33140, Villenave d'Ornon, France
| | - Yoshihiro Okabe
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8572, Japan
- Tsukuba Plant Innovation Research Center, University of Tsukuba, Tsukuba, Ibaraki, 305-8572, Japan
| | - Hiroshi Ezura
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8572, Japan
- Tsukuba Plant Innovation Research Center, University of Tsukuba, Tsukuba, Ibaraki, 305-8572, Japan
| | - Nicholas Smirnoff
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4QD, UK
| | - Gustavo E Gergoff Grozeff
- INFIVE, Facultades de Ciencias Agrarias y Forestales y Ciencias Naturales, Universidad Nacional de La Plata-CCT CONICET, La Plata, Argentina
| | - Carlos G Bartoli
- INFIVE, Facultades de Ciencias Agrarias y Forestales y Ciencias Naturales, Universidad Nacional de La Plata-CCT CONICET, La Plata, Argentina.
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20
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Feroz H, Ferlez B, Lefoulon C, Ren T, Baker CS, Gajewski JP, Lugar DJ, Gaudana SB, Butler PJ, Hühn J, Lamping M, Parak WJ, Hibberd JM, Kerfeld CA, Smirnoff N, Blatt MR, Golbeck JH, Kumar M. Light-Driven Chloride Transport Kinetics of Halorhodopsin. Biophys J 2019; 115:353-360. [PMID: 30021110 DOI: 10.1016/j.bpj.2018.06.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 05/19/2018] [Accepted: 06/05/2018] [Indexed: 01/25/2023] Open
Abstract
Despite growing interest in light-driven ion pumps for use in optogenetics, current estimates of their transport rates span two orders of magnitude due to challenges in measuring slow transport processes and determining protein concentration and/or orientation in membranes in vitro. In this study, we report, to our knowledge, the first direct quantitative measurement of light-driven Cl- transport rates of the anion pump halorohodopsin from Natronomonas pharaonis (NpHR). We used light-interfaced voltage clamp measurements on NpHR-expressing oocytes to obtain a transport rate of 219 (± 98) Cl-/protein/s for a photon flux of 630 photons/protein/s. The measurement is consistent with the literature-reported quantum efficiency of ∼30% for NpHR, i.e., 0.3 isomerizations per photon absorbed. To reconcile our measurements with an earlier-reported 20 ms rate-limiting step, or 35 turnovers/protein/s, we conducted, to our knowledge, novel consecutive single-turnover flash experiments that demonstrate that under continuous illumination, NpHR bypasses this step in the photocycle.
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Affiliation(s)
- Hasin Feroz
- Department of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania
| | - Bryan Ferlez
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania
| | - Cecile Lefoulon
- Laboratory of Plant Physiology and Biophysics, Institute of Molecular Cell and Systems Biology, University of Glasgow, Glasgow, United Kingdom
| | - Tingwei Ren
- Department of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania
| | - Carol S Baker
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania
| | - John P Gajewski
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania
| | - Daniel J Lugar
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania
| | - Sandeep B Gaudana
- MSU-DOE Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan
| | - Peter J Butler
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, Pennsylvania
| | - Jonas Hühn
- Department of Physics and Chemistry, Philipps University of Marburg, Marburg, Germany
| | - Matthias Lamping
- Department of Physics and Chemistry, Philipps University of Marburg, Marburg, Germany
| | - Wolfgang J Parak
- Department of Physics and Chemistry, Philipps University of Marburg, Marburg, Germany
| | - Julian M Hibberd
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
| | - Cheryl A Kerfeld
- MSU-DOE Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan; Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, California; Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, California
| | | | - Michael R Blatt
- Laboratory of Plant Physiology and Biophysics, Institute of Molecular Cell and Systems Biology, University of Glasgow, Glasgow, United Kingdom
| | - John H Golbeck
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania; Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania
| | - Manish Kumar
- Department of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania.
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21
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Abstract
Prospects are reviewed for the use of synthetic enzyme complexes as a metabolic engineering tool.
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Affiliation(s)
- Nicholas Smirnoff
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter EX4 4QD, United Kingdom
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22
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Abstract
Contents Summary 1197 I. Introduction 1198 II. Measurement and imaging of H2 O2 1198 III. H2 O2 and O2·- toxicity 1199 IV. Production of H2 O2 : enzymes and subcellular locations 1200 V. H2 O2 transport 1205 VI. Control of H2 O2 concentration: how and where? 1205 VII. Metabolic functions of H2 O2 1207 VIII. H2 O2 signalling 1207 IX. Where next? 1209 Acknowledgements 1209 References 1209 SUMMARY: Hydrogen peroxide (H2 O2 ) is produced, via superoxide and superoxide dismutase, by electron transport in chloroplasts and mitochondria, plasma membrane NADPH oxidases, peroxisomal oxidases, type III peroxidases and other apoplastic oxidases. Intracellular transport is facilitated by aquaporins and H2 O2 is removed by catalase, peroxiredoxin, glutathione peroxidase-like enzymes and ascorbate peroxidase, all of which have cell compartment-specific isoforms. Apoplastic H2 O2 influences cell expansion, development and defence by its involvement in type III peroxidase-mediated polymer cross-linking, lignification and, possibly, cell expansion via H2 O2 -derived hydroxyl radicals. Excess H2 O2 triggers chloroplast and peroxisome autophagy and programmed cell death. The role of H2 O2 in signalling, for example during acclimation to stress and pathogen defence, has received much attention, but the signal transduction mechanisms are poorly defined. H2 O2 oxidizes specific cysteine residues of target proteins to the sulfenic acid form and, similar to other organisms, this modification could initiate thiol-based redox relays and modify target enzymes, receptor kinases and transcription factors. Quantification of the sources and sinks of H2 O2 is being improved by the spatial and temporal resolution of genetically encoded H2 O2 sensors, such as HyPer and roGFP2-Orp1. These H2 O2 sensors, combined with the detection of specific proteins modified by H2 O2 , will allow a deeper understanding of its signalling roles.
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Affiliation(s)
- Nicholas Smirnoff
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4QD, UK
| | - Dominique Arnaud
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4QD, UK
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23
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Schaum CE, Buckling A, Smirnoff N, Studholme DJ, Yvon-Durocher G. Publisher Correction: Environmental fluctuations accelerate molecular evolution of thermal tolerance in a marine diatom. Nat Commun 2018; 9:2813. [PMID: 30006505 PMCID: PMC6045655 DOI: 10.1038/s41467-018-05353-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- C-Elisa Schaum
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, Cornwall, TR10 9EZ, UK. .,Institute for Hydrobiology and Fisheries, Section Oceanography, Hamburg University, 22767, Hamburg, Germany.
| | - A Buckling
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, Cornwall, TR10 9EZ, UK
| | - N Smirnoff
- Biosciences, College of Life and Environmental Sciences, Geoffrey Pope Building University of Exeter, Exeter, EX4 4QD, UK
| | - D J Studholme
- Biosciences, College of Life and Environmental Sciences, Geoffrey Pope Building University of Exeter, Exeter, EX4 4QD, UK
| | - G Yvon-Durocher
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, Cornwall, TR10 9EZ, UK.
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Abstract
Ascorbic acid is synthesised by eukaryotes, the known exceptions being primates and some other animal groups which have lost functional gulonolactone oxidase. Prokaryotes do not synthesise ascorbate and do not need an ascorbate supply, so the functions that are essential for mammals and plants are not required or are substituted by other compounds. The ability of ascorbate to donate electrons enables it to act as a free radical scavenger and to reduce higher oxidation states of iron to Fe2+. These reactions are the basis of its biological activity along with the relative stability of the resulting resonance stabilised monodehydroascorbate radical. The importance of these properties is emphasised by the evolution of at least three biosynthetic pathways and production of an ascorbate analogue, erythroascorbate, by fungi. The iron reducing activity of ascorbate maintains the reactive centre Fe2+ of 2-oxoglutarate-dependent dioxygenases (2-ODDs) thus preventing inactivation. These enzymes have diverse functions and, recently, the possibility that ascorbate status in mammals could influence 2-ODDs involved in histone and DNA demethylation thereby influencing stem cell differentiation and cancer has been uncovered. Ascorbate is involved in iron uptake and transport in plants and animals. While the above biochemical functions are shared between mammals and plants, ascorbate peroxidase (APX) is an enzyme family limited to plants and photosynthetic protists. It provides these organisms with increased capacity to remove H2O2 produced by photosynthetic electron transport and photorespiration. The Fe reducing activity of ascorbate enables hydroxyl radical production (pro-oxidant effect) and the reactivity of dehydroascorbate (DHA) and reaction of its degradation products with proteins (dehydroascorbylation and glycation) is potentially damaging. Ascorbate status influences gene expression in plants and mammals but at present there is little evidence that it acts as a specific signalling molecule. It most likely acts indirectly by influencing the redox state of thiols and 2-ODD activity. However, the possibility that dehydroascorbylation is a regulatory post-translational protein modification could be explored.
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Affiliation(s)
- Nicholas Smirnoff
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter EX4 4QD, UK.
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25
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Mullineaux PM, Exposito-Rodriguez M, Laissue PP, Smirnoff N. ROS-dependent signalling pathways in plants and algae exposed to high light: Comparisons with other eukaryotes. Free Radic Biol Med 2018; 122:52-64. [PMID: 29410363 DOI: 10.1016/j.freeradbiomed.2018.01.033] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 01/27/2018] [Accepted: 01/31/2018] [Indexed: 01/09/2023]
Abstract
Like all aerobic organisms, plants and algae co-opt reactive oxygen species (ROS) as signalling molecules to drive cellular responses to changes in their environment. In this respect, there is considerable commonality between all eukaryotes imposed by the constraints of ROS chemistry, similar metabolism in many subcellular compartments, the requirement for a high degree of signal specificity and the deployment of thiol peroxidases as transducers of oxidising equivalents to regulatory proteins. Nevertheless, plants and algae carry out specialised signalling arising from oxygenic photosynthesis in chloroplasts and photoautotropism, which often induce an imbalance between absorption of light energy and the capacity to use it productively. A key means of responding to this imbalance is through communication of chloroplasts with the nucleus to adjust cellular metabolism. Two ROS, singlet oxygen (1O2) and hydrogen peroxide (H2O2), initiate distinct signalling pathways when photosynthesis is perturbed. 1O2, because of its potent reactivity means that it initiates but does not transduce signalling. In contrast, the lower reactivity of H2O2 means that it can also be a mobile messenger in a spatially-defined signalling pathway. How plants translate a H2O2 message to bring about changes in gene expression is unknown and therefore, we draw on information from other eukaryotes to propose a working hypothesis. The role of these ROS generated in other subcellular compartments of plant cells in response to HL is critically considered alongside other eukaryotes. Finally, the responses of animal cells to oxidative stress upon high irradiance exposure is considered for new comparisons between plant and animal cells.
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Affiliation(s)
- Philip M Mullineaux
- School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, UK.
| | | | | | - Nicholas Smirnoff
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter EX4 4QD, UK
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26
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Helliwell KE, Pandhal J, Cooper MB, Longworth J, Kudahl UJ, Russo DA, Tomsett EV, Bunbury F, Salmon DL, Smirnoff N, Wright PC, Smith AG. Quantitative proteomics of a B 12 -dependent alga grown in coculture with bacteria reveals metabolic tradeoffs required for mutualism. New Phytol 2018; 217:599-612. [PMID: 29034959 PMCID: PMC5765456 DOI: 10.1111/nph.14832] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 08/31/2017] [Indexed: 05/02/2023]
Abstract
The unicellular green alga Lobomonas rostrata requires an external supply of vitamin B12 (cobalamin) for growth, which it can obtain in stable laboratory cultures from the soil bacterium Mesorhizobium loti in exchange for photosynthate. We investigated changes in protein expression in the alga that allow it to engage in this mutualism. We used quantitative isobaric tagging (iTRAQ) proteomics to determine the L. rostrata proteome grown axenically with B12 supplementation or in coculture with M. loti. Data are available via ProteomeXchange (PXD005046). Using the related Chlamydomonas reinhardtii as a reference genome, 588 algal proteins could be identified. Enzymes of amino acid biosynthesis were higher in coculture than in axenic culture, and this was reflected in increased amounts of total cellular protein and several free amino acids. A number of heat shock proteins were also elevated. Conversely, photosynthetic proteins and those of chloroplast protein synthesis were significantly lower in L. rostrata cells in coculture. These observations were confirmed by measurement of electron transfer rates in cells grown under the two conditions. The results indicate that, despite the stability of the mutualism, L. rostrata experiences stress in coculture with M. loti, and must adjust its metabolism accordingly.
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Affiliation(s)
| | - Jagroop Pandhal
- Department of Chemical and Biological EngineeringUniversity of SheffieldMappin StreetSheffieldS1 3JDUK
| | - Matthew B. Cooper
- Department of Plant SciencesUniversity of CambridgeCambridgeCB2 3EAUK
| | - Joseph Longworth
- Department of Chemical and Biological EngineeringUniversity of SheffieldMappin StreetSheffieldS1 3JDUK
| | | | - David A. Russo
- Department of Chemical and Biological EngineeringUniversity of SheffieldMappin StreetSheffieldS1 3JDUK
| | | | - Freddy Bunbury
- Department of Plant SciencesUniversity of CambridgeCambridgeCB2 3EAUK
| | - Deborah L. Salmon
- BiosciencesCollege of Life and Environmental SciencesUniversity of ExeterExeterEX4 4QDUK
| | - Nicholas Smirnoff
- BiosciencesCollege of Life and Environmental SciencesUniversity of ExeterExeterEX4 4QDUK
| | - Phillip C. Wright
- Department of Chemical and Biological EngineeringUniversity of SheffieldMappin StreetSheffieldS1 3JDUK
| | - Alison G. Smith
- Department of Plant SciencesUniversity of CambridgeCambridgeCB2 3EAUK
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27
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Sambles CM, Salmon DL, Florance H, Howard TP, Smirnoff N, Nielsen LR, McKinney LV, Kjær ED, Buggs RJA, Studholme DJ, Grant M. Ash leaf metabolomes reveal differences between trees tolerant and susceptible to ash dieback disease. Sci Data 2017; 4:170190. [PMID: 29257137 PMCID: PMC5735976 DOI: 10.1038/sdata.2017.190] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 11/02/2017] [Indexed: 12/31/2022] Open
Abstract
European common ash, Fraxinus excelsior, is currently threatened by Ash dieback (ADB) caused by the fungus, Hymenoscyphus fraxineus. To detect and identify metabolites that may be products of pathways important in contributing to resistance against H. fraxineus, we performed untargeted metabolomic profiling on leaves from five high-susceptibility and five low-susceptibility F. excelsior individuals identified during Danish field trials. We describe in this study, two datasets. The first is untargeted LC-MS metabolomics raw data from ash leaves with high-susceptibility and low-susceptibility to ADB in positive and negative mode. These data allow the application of peak picking, alignment, gap-filling and retention-time correlation analyses to be performed in alternative ways. The second, a processed dataset containing abundances of aligned features across all samples enables further mining of the data. Here we illustrate the utility of this dataset which has previously been used to identify putative iridoid glycosides, well known anti-herbivory terpenoid derivatives, and show differential abundance in tolerant and susceptible ash samples.
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Affiliation(s)
- Christine M. Sambles
- Biosciences, Geoffrey Pope Building, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
- School of Life Sciences, Gibbet Hill Campus, University of Warwick, Coventry CV4 7AL, UK
| | - Deborah L. Salmon
- Biosciences, Geoffrey Pope Building, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| | - Hannah Florance
- SynthSys, Roger Land Building, Alexander Crum Brown Road, The King’s Buildings, Edinburgh EH9 3FF, UK
| | - Thomas P. Howard
- School of Biology, Devonshire Building, Newcastle University, Newcastle upon, Tyne NE1 7RU, UK
| | - Nicholas Smirnoff
- Biosciences, Geoffrey Pope Building, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| | - Lene R. Nielsen
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Rolighedsvej 23, Frederiksberg C 1958, Denmark
| | - Lea V. McKinney
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Rolighedsvej 23, Frederiksberg C 1958, Denmark
| | - Erik D. Kjær
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Rolighedsvej 23, Frederiksberg C 1958, Denmark
| | - Richard J. A. Buggs
- Royal Botanic Gardens Kew, Richmond, Surrey TW9 3AB, UK
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - David J. Studholme
- Biosciences, Geoffrey Pope Building, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| | - Murray Grant
- School of Life Sciences, Gibbet Hill Campus, University of Warwick, Coventry CV4 7AL, UK
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28
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Exposito-Rodriguez M, Laissue PP, Yvon-Durocher G, Smirnoff N, Mullineaux PM. Photosynthesis-dependent H 2O 2 transfer from chloroplasts to nuclei provides a high-light signalling mechanism. Nat Commun 2017; 8:49. [PMID: 28663550 PMCID: PMC5491514 DOI: 10.1038/s41467-017-00074-w] [Citation(s) in RCA: 205] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 05/26/2017] [Indexed: 12/30/2022] Open
Abstract
Chloroplasts communicate information by signalling to nuclei during acclimation to fluctuating light. Several potential operating signals originating from chloroplasts have been proposed, but none have been shown to move to nuclei to modulate gene expression. One proposed signal is hydrogen peroxide (H2O2) produced by chloroplasts in a light-dependent manner. Using HyPer2, a genetically encoded fluorescent H2O2 sensor, we show that in photosynthetic Nicotiana benthamiana epidermal cells, exposure to high light increases H2O2 production in chloroplast stroma, cytosol and nuclei. Critically, over-expression of stromal ascorbate peroxidase (H2O2 scavenger) or treatment with DCMU (photosynthesis inhibitor) attenuates nuclear H2O2 accumulation and high light-responsive gene expression. Cytosolic ascorbate peroxidase over-expression has little effect on nuclear H2O2 accumulation and high light-responsive gene expression. This is because the H2O2 derives from a sub-population of chloroplasts closely associated with nuclei. Therefore, direct H2O2 transfer from chloroplasts to nuclei, avoiding the cytosol, enables photosynthetic control over gene expression.Multiple plastid-derived signals have been proposed but not shown to move to the nucleus to promote plant acclimation to fluctuating light. Here the authors use a fluorescent hydrogen peroxide sensor to provide evidence that H2O2 is transferred directly from chloroplasts to nuclei to control nuclear gene expression.
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Affiliation(s)
- Marino Exposito-Rodriguez
- School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, UK
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, UK
| | | | - Gabriel Yvon-Durocher
- Environment and Sustainability Institute, University of Exeter, Penryn, Cornwall, TR10 9EZ, UK
| | - Nicholas Smirnoff
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, UK.
| | - Philip M Mullineaux
- School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, UK.
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29
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Bechtold U, Penfold CA, Jenkins DJ, Legaie R, Moore JD, Lawson T, Matthews JSA, Vialet-Chabrand SRM, Baxter L, Subramaniam S, Hickman R, Florance H, Sambles C, Salmon DL, Feil R, Bowden L, Hill C, Baker NR, Lunn JE, Finkenstädt B, Mead A, Buchanan-Wollaston V, Beynon J, Rand DA, Wild DL, Denby KJ, Ott S, Smirnoff N, Mullineaux PM. Time-Series Transcriptomics Reveals That AGAMOUS-LIKE22 Affects Primary Metabolism and Developmental Processes in Drought-Stressed Arabidopsis. Plant Cell 2016; 28:345-66. [PMID: 26842464 PMCID: PMC4790877 DOI: 10.1105/tpc.15.00910] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Revised: 01/14/2016] [Accepted: 02/02/2016] [Indexed: 05/18/2023]
Abstract
In Arabidopsis thaliana, changes in metabolism and gene expression drive increased drought tolerance and initiate diverse drought avoidance and escape responses. To address regulatory processes that link these responses, we set out to identify genes that govern early responses to drought. To do this, a high-resolution time series transcriptomics data set was produced, coupled with detailed physiological and metabolic analyses of plants subjected to a slow transition from well-watered to drought conditions. A total of 1815 drought-responsive differentially expressed genes were identified. The early changes in gene expression coincided with a drop in carbon assimilation, and only in the late stages with an increase in foliar abscisic acid content. To identify gene regulatory networks (GRNs) mediating the transition between the early and late stages of drought, we used Bayesian network modeling of differentially expressed transcription factor (TF) genes. This approach identified AGAMOUS-LIKE22 (AGL22), as key hub gene in a TF GRN. It has previously been shown that AGL22 is involved in the transition from vegetative state to flowering but here we show that AGL22 expression influences steady state photosynthetic rates and lifetime water use. This suggests that AGL22 uniquely regulates a transcriptional network during drought stress, linking changes in primary metabolism and the initiation of stress responses.
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Affiliation(s)
- Ulrike Bechtold
- School of Biological Sciences, University of Essex, Colchester CO4 3SQ, United Kingdom
| | | | - Dafyd J Jenkins
- Systems Biology Centre, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Roxane Legaie
- Systems Biology Centre, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Jonathan D Moore
- Systems Biology Centre, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Tracy Lawson
- School of Biological Sciences, University of Essex, Colchester CO4 3SQ, United Kingdom
| | - Jack S A Matthews
- School of Biological Sciences, University of Essex, Colchester CO4 3SQ, United Kingdom
| | | | - Laura Baxter
- Systems Biology Centre, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Sunitha Subramaniam
- School of Biological Sciences, University of Essex, Colchester CO4 3SQ, United Kingdom
| | - Richard Hickman
- Systems Biology Centre, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Hannah Florance
- College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, United Kingdom
| | - Christine Sambles
- College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, United Kingdom
| | - Deborah L Salmon
- College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, United Kingdom
| | - Regina Feil
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Laura Bowden
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Claire Hill
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Neil R Baker
- School of Biological Sciences, University of Essex, Colchester CO4 3SQ, United Kingdom
| | - John E Lunn
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Bärbel Finkenstädt
- Department of Statistics, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Andrew Mead
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Vicky Buchanan-Wollaston
- Systems Biology Centre, University of Warwick, Coventry CV4 7AL, United Kingdom School of Life Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Jim Beynon
- Systems Biology Centre, University of Warwick, Coventry CV4 7AL, United Kingdom School of Life Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - David A Rand
- Systems Biology Centre, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - David L Wild
- Systems Biology Centre, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Katherine J Denby
- Systems Biology Centre, University of Warwick, Coventry CV4 7AL, United Kingdom School of Life Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Sascha Ott
- Systems Biology Centre, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Nicholas Smirnoff
- College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, United Kingdom
| | - Philip M Mullineaux
- School of Biological Sciences, University of Essex, Colchester CO4 3SQ, United Kingdom
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30
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de Torres Zabala M, Zhai B, Jayaraman S, Eleftheriadou G, Winsbury R, Yang R, Truman W, Tang S, Smirnoff N, Grant M. Novel JAZ co-operativity and unexpected JA dynamics underpin Arabidopsis defence responses to Pseudomonas syringae infection. New Phytol 2016; 209:1120-34. [PMID: 26428397 PMCID: PMC4791170 DOI: 10.1111/nph.13683] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 08/19/2015] [Indexed: 05/21/2023]
Abstract
Pathogens target phytohormone signalling pathways to promote disease. Plants deploy salicylic acid (SA)-mediated defences against biotrophs. Pathogens antagonize SA immunity by activating jasmonate signalling, for example Pseudomonas syringae pv. tomato DC3000 produces coronatine (COR), a jasmonic acid (JA) mimic. This study found unexpected dynamics between SA, JA and COR and co-operation between JAZ jasmonate repressor proteins during DC3000 infection. We used a systems-based approach involving targeted hormone profiling, high-temporal-resolution micro-array analysis, reverse genetics and mRNA-seq. Unexpectedly, foliar JA did not accumulate until late in the infection process and was higher in leaves challenged with COR-deficient P. syringae or in the more resistant JA receptor mutant coi1. JAZ regulation was complex and COR alone was insufficient to sustainably induce JAZs. JAZs contribute to early basal and subsequent secondary plant defence responses. We showed that JAZ5 and JAZ10 specifically co-operate to restrict COR cytotoxicity and pathogen growth through a complex transcriptional reprogramming that does not involve the basic helix-loop-helix transcription factors MYC2 and related MYC3 and MYC4 previously shown to restrict pathogen growth. mRNA-seq predicts compromised SA signalling in a jaz5/10 mutant and rapid suppression of JA-related components on bacterial infection.
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Affiliation(s)
- Marta de Torres Zabala
- BiosciencesCollege of Life and Environmental SciencesUniversity of ExeterStocker RoadExeterEX4 4QDUK
| | - Bing Zhai
- College of Biological SciencesChina Agricultural UniversityBeijing100093China
| | - Siddharth Jayaraman
- BiosciencesCollege of Life and Environmental SciencesUniversity of ExeterStocker RoadExeterEX4 4QDUK
| | - Garoufalia Eleftheriadou
- BiosciencesCollege of Life and Environmental SciencesUniversity of ExeterStocker RoadExeterEX4 4QDUK
| | - Rebecca Winsbury
- BiosciencesCollege of Life and Environmental SciencesUniversity of ExeterStocker RoadExeterEX4 4QDUK
| | - Ron Yang
- BiosciencesCollege of Life and Environmental SciencesUniversity of ExeterStocker RoadExeterEX4 4QDUK
| | - William Truman
- Department of Plant BiologyUniversity of MinnesotaSaint PaulMN55108USA
| | - Saijung Tang
- College of Biological SciencesChina Agricultural UniversityBeijing100093China
| | - Nicholas Smirnoff
- BiosciencesCollege of Life and Environmental SciencesUniversity of ExeterStocker RoadExeterEX4 4QDUK
| | - Murray Grant
- BiosciencesCollege of Life and Environmental SciencesUniversity of ExeterStocker RoadExeterEX4 4QDUK
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31
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Lim B, Smirnoff N, Cobbett CS, Golz JF. Ascorbate-Deficient vtc2 Mutants in Arabidopsis Do Not Exhibit Decreased Growth. Front Plant Sci 2016; 7:1025. [PMID: 27468291 PMCID: PMC4943039 DOI: 10.3389/fpls.2016.01025] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 06/28/2016] [Indexed: 05/09/2023]
Abstract
In higher plants the L-galactose pathway represents the major route for ascorbate biosynthesis. The first committed step of this pathway is catalyzed by the enzyme GDP-L-galactose phosphorylase and is encoded by two paralogs in Arabidopsis - VITAMIN C2 (VTC2) and VTC5. The first mutant of this enzyme, vtc2-1, isolated via an EMS mutagenesis screen, has approximately 20-30% of wildtype ascorbate levels and has been reported to have decreased growth under standard laboratory conditions. Here, we show that a T-DNA insertion into the VTC2 causes a similar reduction in ascorbate levels, but does not greatly affect plant growth. Subsequent segregation analysis revealed the growth defects of vtc2-1 mutants segregate independently of the vtc2-1 mutation. These observations suggest that it is the presence of an independent cryptic mutation that affects growth of vtc2-1 mutants, and not the 70-80% decrease in ascorbate levels that has been assumed in past studies.
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Affiliation(s)
- Benson Lim
- School of BioSciences, University of Melbourne, ParkvilleVIC, Australia
| | - Nicholas Smirnoff
- Biosciences, College of Life and Environmental Sciences, University of ExeterExeter, UK
| | | | - John F. Golz
- School of BioSciences, University of Melbourne, ParkvilleVIC, Australia
- *Correspondence: John F. Golz, orcid.org/0000-0001-9478-5459
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32
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de Torres Zabala M, Littlejohn G, Jayaraman S, Studholme D, Bailey T, Lawson T, Tillich M, Licht D, Bölter B, Delfino L, Truman W, Mansfield J, Smirnoff N, Grant M. Chloroplasts play a central role in plant defence and are targeted by pathogen effectors. Nat Plants 2015; 1:15074. [PMID: 27250009 DOI: 10.1038/nplants.2015.74] [Citation(s) in RCA: 175] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 04/24/2015] [Indexed: 05/19/2023]
Abstract
Microbe associated molecular pattern (MAMP) receptors in plants recognize MAMPs and activate basal defences; however a complete understanding of the molecular and physiological mechanisms conferring immunity remains elusive. Pathogens suppress active defence in plants through the combined action of effector proteins. Here we show that the chloroplast is a key component of early immune responses. MAMP perception triggers the rapid, large-scale suppression of nuclear encoded chloroplast-targeted genes (NECGs). Virulent Pseudomonas syringae effectors reprogramme NECG expression in Arabidopsis, target the chloroplast and inhibit photosynthetic CO2 assimilation through disruption of photosystem II. This activity prevents a chloroplastic reactive oxygen burst. These physiological changes precede bacterial multiplication and coincide with pathogen-induced abscisic acid (ABA) accumulation. MAMP pretreatment protects chloroplasts from effector manipulation, whereas application of ABA or the inhibitor of photosynthetic electron transport, DCMU, abolishes the MAMP-induced chloroplastic reactive oxygen burst, and enhances growth of a P. syringae hrpA mutant that fails to secrete effectors.
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Affiliation(s)
- Marta de Torres Zabala
- Biosciences, College of Life and Environment Sciences, University of Exeter, Exeter EX4 4QD, UK
| | - George Littlejohn
- Biosciences, College of Life and Environment Sciences, University of Exeter, Exeter EX4 4QD, UK
| | - Siddharth Jayaraman
- Biosciences, College of Life and Environment Sciences, University of Exeter, Exeter EX4 4QD, UK
| | - David Studholme
- Biosciences, College of Life and Environment Sciences, University of Exeter, Exeter EX4 4QD, UK
| | - Trevor Bailey
- Biosciences, College of Life and Environment Sciences, University of Exeter, Exeter EX4 4QD, UK
| | - Tracy Lawson
- School of Biological Sciences, University of Essex, Colchester CO4 3SQ, UK
| | - Michael Tillich
- Max Planck Institute of Molecular Plant Physiology, Am Müehlenberg 1, Potsdam-Golm D-14476, Germany
| | - Dirk Licht
- Max Planck Institute of Molecular Plant Physiology, Am Müehlenberg 1, Potsdam-Golm D-14476, Germany
| | - Bettina Bölter
- Department of Biology I, Botany, Ludwig-Maximilians-Universität München, Groβhaderner Strase 2-4, Planegg-Martinsried D-82152, Germany
| | - Laura Delfino
- Department of Biology I, Botany, Ludwig-Maximilians-Universität München, Groβhaderner Strase 2-4, Planegg-Martinsried D-82152, Germany
| | - William Truman
- Department of Plant Biology, University of Minnesota, USA
| | - John Mansfield
- Department of Life Sciences, Imperial College, London SW7 2AZ, UK
| | - Nicholas Smirnoff
- Biosciences, College of Life and Environment Sciences, University of Exeter, Exeter EX4 4QD, UK
| | - Murray Grant
- Biosciences, College of Life and Environment Sciences, University of Exeter, Exeter EX4 4QD, UK
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Littlejohn GR, Mansfield JC, Parker D, Lind R, Perfect S, Seymour M, Smirnoff N, Love J, Moger J. In vivo chemical and structural analysis of plant cuticular waxes using stimulated Raman scattering microscopy. Plant Physiol 2015; 168:18-28. [PMID: 25783412 PMCID: PMC4424026 DOI: 10.1104/pp.15.00119] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 03/16/2015] [Indexed: 05/29/2023]
Abstract
The cuticle is a ubiquitous, predominantly waxy layer on the aerial parts of higher plants that fulfils a number of essential physiological roles, including regulating evapotranspiration, light reflection, and heat tolerance, control of development, and providing an essential barrier between the organism and environmental agents such as chemicals or some pathogens. The structure and composition of the cuticle are closely associated but are typically investigated separately using a combination of structural imaging and biochemical analysis of extracted waxes. Recently, techniques that combine stain-free imaging and biochemical analysis, including Fourier transform infrared spectroscopy microscopy and coherent anti-Stokes Raman spectroscopy microscopy, have been used to investigate the cuticle, but the detection sensitivity is severely limited by the background signals from plant pigments. We present a new method for label-free, in vivo structural and biochemical analysis of plant cuticles based on stimulated Raman scattering (SRS) microscopy. As a proof of principle, we used SRS microscopy to analyze the cuticles from a variety of plants at different times in development. We demonstrate that the SRS virtually eliminates the background interference compared with coherent anti-Stokes Raman spectroscopy imaging and results in label-free, chemically specific confocal images of cuticle architecture with simultaneous characterization of cuticle composition. This innovative use of the SRS spectroscopy may find applications in agrochemical research and development or in studies of wax deposition during leaf development and, as such, represents an important step in the study of higher plant cuticles.
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Affiliation(s)
- George R Littlejohn
- School of Biosciences, College of Life and Environmental Sciences (G.R.L., N.S., J.L.), and Department of Physics and Astronomy, College of Engineering, Mathematics, and Physical Sciences (J.C.M., J.M.), University of Exeter, Exeter, Devon EX4 4QD, United Kingdom;Biodomain Technology Group, Shell International Exploration and Production, Inc., Westhollow Technology Center, Houston, Texas 77082 (D.P.); andSyngenta, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, United Kingdom (R.L., S.P., M.S.)
| | - Jessica C Mansfield
- School of Biosciences, College of Life and Environmental Sciences (G.R.L., N.S., J.L.), and Department of Physics and Astronomy, College of Engineering, Mathematics, and Physical Sciences (J.C.M., J.M.), University of Exeter, Exeter, Devon EX4 4QD, United Kingdom;Biodomain Technology Group, Shell International Exploration and Production, Inc., Westhollow Technology Center, Houston, Texas 77082 (D.P.); andSyngenta, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, United Kingdom (R.L., S.P., M.S.)
| | - David Parker
- School of Biosciences, College of Life and Environmental Sciences (G.R.L., N.S., J.L.), and Department of Physics and Astronomy, College of Engineering, Mathematics, and Physical Sciences (J.C.M., J.M.), University of Exeter, Exeter, Devon EX4 4QD, United Kingdom;Biodomain Technology Group, Shell International Exploration and Production, Inc., Westhollow Technology Center, Houston, Texas 77082 (D.P.); andSyngenta, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, United Kingdom (R.L., S.P., M.S.)
| | - Rob Lind
- School of Biosciences, College of Life and Environmental Sciences (G.R.L., N.S., J.L.), and Department of Physics and Astronomy, College of Engineering, Mathematics, and Physical Sciences (J.C.M., J.M.), University of Exeter, Exeter, Devon EX4 4QD, United Kingdom;Biodomain Technology Group, Shell International Exploration and Production, Inc., Westhollow Technology Center, Houston, Texas 77082 (D.P.); andSyngenta, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, United Kingdom (R.L., S.P., M.S.)
| | - Sarah Perfect
- School of Biosciences, College of Life and Environmental Sciences (G.R.L., N.S., J.L.), and Department of Physics and Astronomy, College of Engineering, Mathematics, and Physical Sciences (J.C.M., J.M.), University of Exeter, Exeter, Devon EX4 4QD, United Kingdom;Biodomain Technology Group, Shell International Exploration and Production, Inc., Westhollow Technology Center, Houston, Texas 77082 (D.P.); andSyngenta, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, United Kingdom (R.L., S.P., M.S.)
| | - Mark Seymour
- School of Biosciences, College of Life and Environmental Sciences (G.R.L., N.S., J.L.), and Department of Physics and Astronomy, College of Engineering, Mathematics, and Physical Sciences (J.C.M., J.M.), University of Exeter, Exeter, Devon EX4 4QD, United Kingdom;Biodomain Technology Group, Shell International Exploration and Production, Inc., Westhollow Technology Center, Houston, Texas 77082 (D.P.); andSyngenta, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, United Kingdom (R.L., S.P., M.S.)
| | - Nicholas Smirnoff
- School of Biosciences, College of Life and Environmental Sciences (G.R.L., N.S., J.L.), and Department of Physics and Astronomy, College of Engineering, Mathematics, and Physical Sciences (J.C.M., J.M.), University of Exeter, Exeter, Devon EX4 4QD, United Kingdom;Biodomain Technology Group, Shell International Exploration and Production, Inc., Westhollow Technology Center, Houston, Texas 77082 (D.P.); andSyngenta, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, United Kingdom (R.L., S.P., M.S.)
| | - John Love
- School of Biosciences, College of Life and Environmental Sciences (G.R.L., N.S., J.L.), and Department of Physics and Astronomy, College of Engineering, Mathematics, and Physical Sciences (J.C.M., J.M.), University of Exeter, Exeter, Devon EX4 4QD, United Kingdom;Biodomain Technology Group, Shell International Exploration and Production, Inc., Westhollow Technology Center, Houston, Texas 77082 (D.P.); andSyngenta, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, United Kingdom (R.L., S.P., M.S.)
| | - Julian Moger
- School of Biosciences, College of Life and Environmental Sciences (G.R.L., N.S., J.L.), and Department of Physics and Astronomy, College of Engineering, Mathematics, and Physical Sciences (J.C.M., J.M.), University of Exeter, Exeter, Devon EX4 4QD, United Kingdom;Biodomain Technology Group, Shell International Exploration and Production, Inc., Westhollow Technology Center, Houston, Texas 77082 (D.P.); andSyngenta, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, United Kingdom (R.L., S.P., M.S.)
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Wheeler G, Ishikawa T, Pornsaksit V, Smirnoff N. Evolution of alternative biosynthetic pathways for vitamin C following plastid acquisition in photosynthetic eukaryotes. eLife 2015; 4. [PMID: 25768426 PMCID: PMC4396506 DOI: 10.7554/elife.06369] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 03/12/2015] [Indexed: 01/08/2023] Open
Abstract
Ascorbic acid (vitamin C) is an enzyme co-factor in eukaryotes that also plays a critical role in protecting photosynthetic eukaryotes against damaging reactive oxygen species derived from the chloroplast. Many animal lineages, including primates, have become ascorbate auxotrophs due to the loss of the terminal enzyme in their biosynthetic pathway, l-gulonolactone oxidase (GULO). The alternative pathways found in land plants and Euglena use a different terminal enzyme, l-galactonolactone dehydrogenase (GLDH). The evolutionary processes leading to these differing pathways and their contribution to the cellular roles of ascorbate remain unclear. Here we present molecular and biochemical evidence demonstrating that GULO was functionally replaced with GLDH in photosynthetic eukaryote lineages following plastid acquisition. GULO has therefore been lost repeatedly throughout eukaryote evolution. The formation of the alternative biosynthetic pathways in photosynthetic eukaryotes uncoupled ascorbate synthesis from hydrogen peroxide production and likely contributed to the rise of ascorbate as a major photoprotective antioxidant. DOI:http://dx.doi.org/10.7554/eLife.06369.001 Animals, plants, algae and other eukaryotic organisms all need vitamin C to enable many of their enzymes to work properly. Vitamin C also protects plant and algal cells from damage by molecules called reactive oxygen species (ROS), which can be produced when these cells harvest energy from sunlight in a process called photosynthesis. Photosynthesis occurs inside structures called chloroplasts, and has evolved on multiple occasions in eukaryotes when non-photosynthetic organisms acquired chloroplasts from other algae and then had to develop improved defences against ROS. There are several steps involved in the production of vitamin C. In many animals, an enzyme called GULO carries out the final step by converting a molecule known as an aldonolactone into vitamin C; this reaction also produces ROS as a waste product. The GULO enzyme is missing in humans, primates and some other groups of animals, so these organisms must get all the vitamin C they need from their diet. Plants and algae use a different enzyme—called GLDH—to make vitamin C from aldonolactone. GLDH is very similar to GULO, but it does not produce ROS as a waste product. It is not clear how the different pathways have evolved, or why some animals have lost the ability to make their own vitamin C. Here, Wheeler et al. used genetics and biochemistry to investigate the evolutionary origins of vitamin C production in a variety of eukaryotic organisms. This investigation revealed that although GULO is missing from the insects and several other groups of animals, it is present in the sponges and many other eukaryotes. This suggests that GULO evolved in early eukaryotic organisms and has since been lost by the different groups of animals. On the other hand, GLDH is only found in plants and the other eukaryotes that can photosynthesize. Wheeler et al.'s findings suggest that GULO has been lost and replaced by GLDH in all plants and algae following their acquisition of chloroplasts. GDLH allows plants and algae to make vitamin C without also producing ROS, which could explain why vitamin C has been able to take on an extra role in these organisms. The results allow us to better understand the functions of vitamin C in photosynthetic organisms and the processes associated with the acquisition of chloroplasts during evolution. DOI:http://dx.doi.org/10.7554/eLife.06369.002
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Affiliation(s)
- Glen Wheeler
- Marine Biological Association, Plymouth, United Kingdom
| | - Takahiro Ishikawa
- Department of Life Science and Biotechnology, Shimane University, Matsue, Japan
| | - Varissa Pornsaksit
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom
| | - Nicholas Smirnoff
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom
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Sultana N, Florance HV, Johns A, Smirnoff N. Ascorbate deficiency influences the leaf cell wall glycoproteome in Arabidopsis thaliana. Plant Cell Environ 2015; 38:375-84. [PMID: 24393051 DOI: 10.1111/pce.12267] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 12/04/2013] [Accepted: 12/07/2013] [Indexed: 05/10/2023]
Abstract
The cell wall forms the first line of interaction between the plant and the external environment. Based on the observation that ascorbate-deficient vtc mutants of Arabidopsis thaliana have increased cell wall peroxidase activity, the cell wall glycoproteome of vtc2-2 was investigated. Glycoproteins were purified from fully expanded leaves by Concanavalin A affinity chromatography and analysed by liquid chromatography quadrupole time-of-flight mass spectrometry. This procedure identified 63 proteins with predicted glycosylation sites and cell wall localization. Of these, 11 proteins were differentially expressed between vtc2-2 and wild type. In particular, PRX33/34 were identified as contributing to increased peroxidase activity in response to ascorbate deficiency. This is the same peroxidase previously shown to contribute to hydrogen peroxide generation and pathogen resistance. Three fasciclin-like arabinogalactan proteins (FLA1, 2 and 8) had lower abundance in vtc2-2. Inspection of published microarray data shows that these also have lower gene expression in vtc1 and vtc2-1 and are decreased in expression by pathogen challenge and oxidative stresses. Ascorbate deficiency therefore impacts expression of cell wall proteins involved in pathogen responses and these presumably contribute to the increased resistance of vtc mutants to biotrophic pathogens.
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Affiliation(s)
- Nighat Sultana
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, UK
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MacGregor DR, Kendall SL, Florance H, Fedi F, Moore K, Paszkiewicz K, Smirnoff N, Penfield S. Seed production temperature regulation of primary dormancy occurs through control of seed coat phenylpropanoid metabolism. New Phytol 2015; 205:642-52. [PMID: 25412428 DOI: 10.1111/nph.13090] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 08/22/2014] [Indexed: 05/21/2023]
Abstract
Environmental changes during seed production are important drivers of lot-to-lot variation in seed behaviour and enable wild species to time their life history with seasonal cues. Temperature during seed set is the dominant environmental signal determining the depth of primary dormancy, although the mechanisms though which temperature changes impart changes in dormancy state are still only partly understood. We used molecular, genetic and biochemical techniques to examine the mechanism through which temperature variation affects Arabidopsis thaliana seed dormancy. Here we show that, in Arabidopsis, low temperatures during seed maturation result in an increase in phenylpropanoid gene expression in seeds and that this correlates with higher concentrations of seed coat procyanidins. Lower maturation temperatures cause differences in coat permeability to tetrazolium, and mutants with increased seed coat permeability and/or low procyanidin concentrations are less able to enter strongly dormant states after exposure to low temperatures during seed maturation. Our data show that maternal temperature signalling regulates seed coat properties, and this is an important pathway through which the environmental signals control primary dormancy depth.
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Affiliation(s)
- Dana R MacGregor
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK; Department of Crop Genetics, John Innes Centre, Norwich Research Park, Colney Ln, Norwich, Norfolk, NR4, 7UH, UK
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Madadkar Haghjou M, Colville L, Smirnoff N. The induction of menadione stress tolerance in the marine microalga, Dunaliella viridis, through cold pretreatment and modulation of the ascorbate and glutathione pools. Plant Physiol Biochem 2014; 84:96-104. [PMID: 25240268 DOI: 10.1016/j.plaphy.2014.08.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Accepted: 08/27/2014] [Indexed: 06/03/2023]
Abstract
The effect of cold pretreatment on menadione tolerance was investigated in the cells of the marine microalga, Dunaliella viridis. In addition, the involvement of ascorbate and glutathione in the response to menadione stress was tested by treating cell suspensions with l-galactono-1,4-lactone, an ascorbate precursor, and buthionine sulfoximine, an inhibitor of glutathione synthesis. Menadione was highly toxic to non cold-pretreated cells, and caused a large decrease in cell number. Cold pretreatment alleviated menadione toxicity and cold pretreated cells accumulated lower levels of reactive oxygen species, and had enhanced antioxidant capacity due to increased levels of β-carotene, reduced ascorbate and total glutathione compared to non cold-pretreated cells. Cold pretreatment also altered the response to l-galactono-1,4-lactone and buthionine sulfoximine treatments. Combined l-galactono-1,4-lactone and menadione treatment was lethal in non-cold pretreated cells, but in cold-pretreated cells it had a positive effect on cell numbers compared to menadione alone. Overall, exposure of Dunaliella cells to cold stress enhanced tolerance to subsequent oxidative stress induced by menadione.
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Affiliation(s)
| | - Louise Colville
- Seed Conservation Department, Royal Botanic Gardens, Kew, Wakehurst Place, Ardingly, West Sussex RH17 6TN, UK
| | - Nicholas Smirnoff
- University of Exeter, School of Biosciences, Geoffrey Pope Building, Exeter EX4 4QD, UK
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38
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Abstract
It has been proposed that enzymes can associate into complexes (metabolons) that increase the efficiency of metabolic pathways by channelling substrates between enzymes. Metabolons may increase flux by increasing the local concentration of intermediates, decreasing the concentration of enzymes needed to maintain a given flux, directing the products of a pathway to a specific subcellular location or minimizing the escape of reactive intermediates. Metabolons can be formed by relatively loose non-covalent protein-protein interaction, anchorage to membranes, and (in bacteria) by encapsulation of enzymes in protein-coated microcompartments. Evidence that non-coated metabolons are effective at channelling substrates is scarce and difficult to obtain. In plants there is strong evidence that small proportions of glycolytic enzymes are associated with the outside of mitochondria and are effective in substrate channelling. More recently, synthetic metabolons, in which enzymes are scaffolded to synthetic proteins or nucleic acids, have been expressed in microorganisms and these provide evidence that scaffolded enzymes are more effective than free enzymes for metabolic engineering. This provides experimental evidence that metabolons may have a general advantage and opens the way to improving the outcome of metabolic engineering in plants by including synthetic metabolons in the toolbox.
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Affiliation(s)
- Chloe Singleton
- Biosciences, College of Environmental and Life Sciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter EX4 4QD, UK
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Cresswell JE, Robert FXL, Florance H, Smirnoff N. Clearance of ingested neonicotinoid pesticide (imidacloprid) in honey bees (Apis mellifera) and bumblebees (Bombus terrestris). Pest Manag Sci 2014; 70:332-7. [PMID: 23633150 DOI: 10.1002/ps.3569] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Revised: 03/13/2013] [Accepted: 04/30/2013] [Indexed: 05/04/2023]
Abstract
BACKGROUND Bees in agricultural landscapes are exposed to dietary pesticides such as imidacloprid when they feed from treated mass-flowering crops. Concern about the consequent impact on bees makes it important to understand their resilience. In the laboratory, the authors therefore fed adult worker bees on dosed syrup (125 μg L(-1) of imidacloprid, or 98 μg kg(-1)) either continuously or as a pulsed exposure and measured their behaviour (feeding and locomotory activity) and whole-body residues. RESULTS On dosed syrup, honey bees maintained much lower bodily levels of imidacloprid than bumblebees (<0.2 ng versus 2.4 ng of imidacloprid per bee). Dietary imidacloprid did not affect the behaviour of honey bees, but it reduced feeding and locomotory activity in bumblebees. After the pulsed exposure, bumblebees cleared bodily imidacloprid after 48 h and recovered behaviourally. CONCLUSION The differential behavioural resilience of the two species can be attributed to the observed differential in bodily residues. The ability of bumblebees to recover may be environmentally relevant in wild populations that face transitory exposures from the pulsed blooming of mass-flowering crops.
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Affiliation(s)
- James E Cresswell
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, UK; Centre for Pollination Studies, University of Calcutta, Kolkata, India
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Littlejohn GR, Mansfield JC, Christmas JT, Witterick E, Fricker MD, Grant MR, Smirnoff N, Everson RM, Moger J, Love J. An update: improvements in imaging perfluorocarbon-mounted plant leaves with implications for studies of plant pathology, physiology, development and cell biology. Front Plant Sci 2014; 5:140. [PMID: 24795734 PMCID: PMC4006058 DOI: 10.3389/fpls.2014.00140] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2013] [Accepted: 03/24/2014] [Indexed: 05/21/2023]
Abstract
Plant leaves are optically complex, which makes them difficult to image by light microscopy. Careful sample preparation is therefore required to enable researchers to maximize the information gained from advances in fluorescent protein labeling, cell dyes and innovations in microscope technologies and techniques. We have previously shown that mounting leaves in the non-toxic, non-fluorescent perfluorocarbon (PFC), perfluorodecalin (PFD) enhances the optical properties of the leaf with minimal impact on physiology. Here, we assess the use of the PFCs, PFD, and perfluoroperhydrophenanthrene (PP11) for in vivo plant leaf imaging using four advanced modes of microscopy: laser scanning confocal microscopy (LSCM), two-photon fluorescence microscopy, second harmonic generation microscopy, and stimulated Raman scattering (SRS) microscopy. For every mode of imaging tested, we observed an improved signal when leaves were mounted in PFD or in PP11, compared to mounting the samples in water. Using an image analysis technique based on autocorrelation to quantitatively assess LSCM image deterioration with depth, we show that PP11 outperformed PFD as a mounting medium by enabling the acquisition of clearer images deeper into the tissue. In addition, we show that SRS microscopy can be used to image PFCs directly in the mesophyll and thereby easily delimit the "negative space" within a leaf, which may have important implications for studies of leaf development. Direct comparison of on and off resonance SRS micrographs show that PFCs do not to form intracellular aggregates in live plants. We conclude that the application of PFCs as mounting media substantially increases advanced microscopy image quality of living mesophyll and leaf vascular bundle cells.
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Affiliation(s)
- George R. Littlejohn
- Division of Plant and Microbial Sciences, School of Biosciences, University of ExeterExeter, UK
- *Correspondence: George R. Littlejohn and John Love, Division of Plant and Microbial Sciences, School of Biosciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter EX4 4QD, UK e-mail: ;
| | | | | | - Eleanor Witterick
- Division of Plant and Microbial Sciences, School of Biosciences, University of ExeterExeter, UK
| | - Mark D. Fricker
- Department of Plant Sciences, University of OxfordOxford, UK
| | - Murray R. Grant
- Division of Plant and Microbial Sciences, School of Biosciences, University of ExeterExeter, UK
| | - Nicholas Smirnoff
- Division of Plant and Microbial Sciences, School of Biosciences, University of ExeterExeter, UK
| | | | - Julian Moger
- School of Physics, University of ExeterExeter, UK
| | - John Love
- Division of Plant and Microbial Sciences, School of Biosciences, University of ExeterExeter, UK
- *Correspondence: George R. Littlejohn and John Love, Division of Plant and Microbial Sciences, School of Biosciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter EX4 4QD, UK e-mail: ;
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Abstract
Despite the clear demand for open data sharing, its implementation within plant science is still limited. This is, at least in part, because open data-sharing raises several unanswered questions and challenges to current research practices. In this commentary, some of the challenges encountered by plant researchers at the bench when generating, interpreting, and attempting to disseminate their data have been highlighted. The difficulties involved in sharing sequencing, transcriptomics, proteomics, and metabolomics data are reviewed. The benefits and drawbacks of three data-sharing venues currently available to plant scientists are identified and assessed: (i) journal publication; (ii) university repositories; and (iii) community and project-specific databases. It is concluded that community and project-specific databases are the most useful to researchers interested in effective data sharing, since these databases are explicitly created to meet the researchers' needs, support extensive curation, and embody a heightened awareness of what it takes to make data reuseable by others. Such bottom-up and community-driven approaches need to be valued by the research community, supported by publishers, and provided with long-term sustainable support by funding bodies and government. At the same time, these databases need to be linked to generic databases where possible, in order to be discoverable to the majority of researchers and thus promote effective and efficient data sharing. As we look forward to a future that embraces open access to data and publications, it is essential that data policies, data curation, data integration, data infrastructure, and data funding are linked together so as to foster data access and research productivity.
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Affiliation(s)
- Sabina Leonelli
- Egenis & Department of Sociology, Philosophy and Anthropology, Byrne House, St Germans Road, Exeter EX4 4PJ, UK
- * To whom correspondence should be addressed. E-mail:
| | - Nicholas Smirnoff
- Geoffrey Pope Building, Biosciences, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| | - Jonathan Moore
- Warwick Systems Biology Centre, Senate House, University of Warwick, Coventry CV4 7AL, UK
| | - Charis Cook
- School of Life Sciences, Gibbet Hill Campus, University of Warwick, Coventry CV4 7AL, UK
| | - Ruth Bastow
- School of Life Sciences, Gibbet Hill Campus, University of Warwick, Coventry CV4 7AL, UK
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Exposito-Rodriguez M, Laissue PP, Littlejohn GR, Smirnoff N, Mullineaux PM. The Use of HyPer to Examine Spatial and Temporal Changes in H2O2 in High Light-Exposed Plants. Methods Enzymol 2013; 527:185-201. [DOI: 10.1016/b978-0-12-405882-8.00010-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Page M, Sultana N, Paszkiewicz K, Florance H, Smirnoff N. The influence of ascorbate on anthocyanin accumulation during high light acclimation in Arabidopsis thaliana: further evidence for redox control of anthocyanin synthesis. Plant Cell Environ 2012; 35:388-404. [PMID: 21631536 DOI: 10.1111/j.1365-3040.2011.02369.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Ascorbate and anthocyanins act as photoprotectants during exposure to high light (HL). They accumulate in Arabidopsis leaves in response to HL on a similar timescale, suggesting a potential relationship between them. Flavonoids and related metabolites were identified and profiled by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The ascorbate-deficient mutants vtc1, vtc2 and vtc3 accumulated less anthocyanin than wild-type (WT) during HL acclimation. In contrast, kaempferol glycoside accumulation was less affected by light and not decreased by ascorbate deficiency, while sinapoyl malate levels decreased during HL acclimation. Comparison of six Arabidopsis ecotypes showed a positive correlation between ascorbate and anthocyanin accumulation in HL. mRNA-Seq analysis showed that all flavonoid biosynthesis transcripts were increased by HL acclimation in WT. RT-PCR analysis showed that vtc1 and vtc2 were impaired in HL induction of transcripts of anthocyanin biosynthesis enzymes, and the transcription factors PAP1, GL3 and EGL3 that activate the pathway. Abscisic acid (ABA) and jasmonic acid (JA), hormones that could affect anthocyanin accumulation, were unaffected in vtc mutants. It is concluded that HL induction of anthocyanin synthesis involves a redox-sensitive process upstream of the known transcription factors. Because anthocyanins accumulate in preference to kaempferol glycosides and sinapoyl malate in HL, they might have specific properties that make them useful in HL acclimation.
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Affiliation(s)
- Mike Page
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, UK
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Gao Y, Nishikawa H, Badejo AA, Shibata H, Sawa Y, Nakagawa T, Maruta T, Shigeoka S, Smirnoff N, Ishikawa T. Expression of aspartyl protease and C3HC4-type RING zinc finger genes are responsive to ascorbic acid in Arabidopsis thaliana. J Exp Bot 2011; 62:3647-57. [PMID: 21421703 PMCID: PMC3130181 DOI: 10.1093/jxb/err068] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Ascorbate (AsA) is a redox buffer and enzyme cofactor with various proposed functions in stress responses and growth. The aim was to identify genes whose transcript levels respond to changes in leaf AsA. The AsA-deficient Arabidopsis mutant vtc2-1 was incubated with the AsA precursor L-galactono-1,4-lactone (L-GalL) to increase leaf AsA concentration. Differentially expressed genes screened by DNA microarray were further characterized for AsA responsiveness in wild-type plants. The analysis of 14 candidates by real-time PCR identified an aspartyl protease gene (ASP, At1g66180) and a C3HC4-type RING zinc finger gene (AtATL15, At1g22500) whose transcripts were rapidly responsive to increases in AsA pool size caused by L-GalL and AsA supplementation and light. Transgenic Arabidopsis plants expressing an AtATL15 promoter::luciferase reporter confirmed that the promoter is L-GalL, AsA, and light responsive. The expression patterns of ASP and AtATL15 suggest they have roles in growth regulation. The promoter of AtATL15 is responsive to AsA status and will provide a tool to investigate the functions of AsA in plants further.
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Affiliation(s)
- Yongshun Gao
- Department of Applied Bioscience and Biotechnology, Faculty of Life and Environmental Science, Shimane University, 1060 Nishikawatsu, Matsue, Shimane 690-8504, Japan
| | - Hitoshi Nishikawa
- Department of Applied Bioscience and Biotechnology, Faculty of Life and Environmental Science, Shimane University, 1060 Nishikawatsu, Matsue, Shimane 690-8504, Japan
| | - Adebanjo Ayobamidele Badejo
- Department of Applied Bioscience and Biotechnology, Faculty of Life and Environmental Science, Shimane University, 1060 Nishikawatsu, Matsue, Shimane 690-8504, Japan
| | - Hitoshi Shibata
- Department of Applied Bioscience and Biotechnology, Faculty of Life and Environmental Science, Shimane University, 1060 Nishikawatsu, Matsue, Shimane 690-8504, Japan
| | - Yoshihiro Sawa
- Department of Applied Bioscience and Biotechnology, Faculty of Life and Environmental Science, Shimane University, 1060 Nishikawatsu, Matsue, Shimane 690-8504, Japan
| | - Tsuyoshi Nakagawa
- Department of Molecular and Functional Genomics, Center for Integrated Research in Science, Shimane University, 1060 Nishikawatsu, Matsue, Shimane 690-8504, Japan
| | - Takanori Maruta
- Department of Advanced Bioscience, Faculty of Agriculture, Kinki University, 3327-204 Nakamachi, Nara 631-8505, Japan
| | - Shigeru Shigeoka
- Department of Advanced Bioscience, Faculty of Agriculture, Kinki University, 3327-204 Nakamachi, Nara 631-8505, Japan
| | - Nicholas Smirnoff
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter EX4 4QD, UK
| | - Takahiro Ishikawa
- Department of Applied Bioscience and Biotechnology, Faculty of Life and Environmental Science, Shimane University, 1060 Nishikawatsu, Matsue, Shimane 690-8504, Japan
- To whom correspondence should be addressed. E-mail:
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Wilkins KA, Bancroft J, Bosch M, Ings J, Smirnoff N, Franklin-Tong VE. Reactive oxygen species and nitric oxide mediate actin reorganization and programmed cell death in the self-incompatibility response of papaver. Plant Physiol 2011; 156:404-16. [PMID: 21386034 PMCID: PMC3091060 DOI: 10.1104/pp.110.167510] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Accepted: 03/04/2011] [Indexed: 05/17/2023]
Abstract
Pollen-pistil interactions are critical early events regulating pollination and fertilization. Self-incompatibility (SI) is an important mechanism to prevent self-fertilization and inbreeding in higher plants. Although data implicate the involvement of reactive oxygen species (ROS) and nitric oxide (NO) in pollen-pistil interactions and the regulation of pollen tube growth, there has been a lack of studies investigating ROS and NO signaling in pollen tubes in response to defined, physiologically relevant stimuli. We have used live-cell imaging to visualize ROS and NO in growing Papaver rhoeas pollen tubes using chloromethyl-2'7'-dichlorodihydrofluorescein diacetate acetyl ester and 4-amino-5-methylamino-2',7'-difluorofluorescein diacetate and demonstrate that SI induces relatively rapid and transient increases in ROS and NO, with each showing a distinctive "signature" within incompatible pollen tubes. Investigating how these signals integrate with the SI responses, we show that Ca(2+) increases are upstream of ROS and NO. As ROS/NO scavengers alleviated both the formation of SI-induced actin punctate foci and also the activation of a DEVDase/caspase-3-like activity, this demonstrates that ROS and NO act upstream of these key SI markers and suggests that they signal to these SI events. These data represent, to our knowledge, the first steps in understanding ROS/NO signaling triggered by this receptor-ligand interaction in pollen tubes.
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Proctor MCF, Smirnoff N. Ecophysiology of photosynthesis in bryophytes: major roles for oxygen photoreduction and non-photochemical quenching? Physiol Plant 2011; 141:130-40. [PMID: 20969578 DOI: 10.1111/j.1399-3054.2010.01424.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
CO(2) fixation in mosses saturates at moderate irradiances. Relative electron transport rate (RETR) inferred from chlorophyll fluorescence saturates at similar irradiance in shade species (e.g. Plagiomnium undulatum, Trichocolea tomentella), but many species of unshaded habitats (e.g. Andreaea rothii, Schistidium apocarpum, Sphagnum spp. and Frullania dilatata) show non-saturating RETR at high irradiance, with high non-photochemical quenching (NPQ). In P. undulatum and S. apocarpum, experiments in different gas mixtures showed O(2) and CO(2) as interchangeable electron sinks. Nitrogen + saturating CO(2) gave high RETR and depressed NPQ. In S. apocarpum, glycolaldehyde (inhibiting photosynthesis and photorespiration) depressed RETR in air more at low than at high irradiance; in CO(2) -free air RETR was maintained at all irradiances. Non-saturating electron flow was not suppressed in ambient CO(2) with 1% O(2) . The results indicate high capacity for oxygen photoreduction when CO(2) assimilation is limited. Non-saturating light-dependent H(2) O(2) production, insensitive to glycolaldehyde, suggests that electron transport is supported by oxygen photoreduction, perhaps via the Mehler-peroxidase reaction. Consistent with this, mosses were highly tolerant to paraquat, which generates superoxide at photosystem I (PSI). Protection against excess excitation energy in mosses involves high capacity for photosynthetic electron transport to oxygen and high NPQ, activated at high irradiance, alongside high reactive oxygen species (ROS) tolerance.
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Affiliation(s)
- Michael C F Proctor
- School of Biosciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QG, Devon, UK.
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Affiliation(s)
- Nicholas Smirnoff
- College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, United Kingdom.
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48
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Littlejohn GR, Gouveia JD, Edner C, Smirnoff N, Love J. Perfluorodecalin enhances in vivo confocal microscopy resolution of Arabidopsis thaliana mesophyll. New Phytol 2010; 186:1018-1025. [PMID: 20374500 DOI: 10.1111/j.1469-8137.2010.03244.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
*Air spaces in the leaf mesophyll generate deleterious optical effects that compromise confocal microscopy. *Leaves were mounted in the nontoxic, nonfluorescent perfluorocarbon, perfluorodecalin (PFD), and optical enhancement and physiological effect were assessed using confocal microscopy and chlorophyll fluorescence. *Mounting leaves of Arabidopsis thaliana in PFD significantly improved the optical qualities of the leaf, thereby enabling high-resolution laser scanning confocal imaging over twofold deeper into the mesophyll, compared with using water. Incubation in PFD had less physiological impact on the mounted specimen than water. *We conclude that the application of PFD as a mounting medium substantially increases confocal image resolution of living mesophyll and vascular bundle cells, with minimal physiological impact.
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Affiliation(s)
- George R Littlejohn
- School of Biosciences, The University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter EX4 4QD, UK
| | - João D Gouveia
- School of Biosciences, The University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter EX4 4QD, UK
| | - Christoph Edner
- School of Biosciences, The University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter EX4 4QD, UK
| | - Nicholas Smirnoff
- School of Biosciences, The University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter EX4 4QD, UK
| | - John Love
- School of Biosciences, The University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter EX4 4QD, UK
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Spelman K, Iiams-Hauser K, Cech NB, Taylor EW, Smirnoff N, Wenner CA. Role for PPARγ in IL-2 inhibition in T cells by Echinacea-derived undeca-2E-ene-8,10-diynoic acid isobutylamide. Int Immunopharmacol 2009; 9:1260-4. [DOI: 10.1016/j.intimp.2009.08.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2009] [Revised: 08/16/2009] [Accepted: 08/17/2009] [Indexed: 12/15/2022]
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Galvez-Valdivieso G, Fryer MJ, Lawson T, Slattery K, Truman W, Smirnoff N, Asami T, Davies WJ, Jones AM, Baker NR, Mullineaux PM. The high light response in Arabidopsis involves ABA signaling between vascular and bundle sheath cells. Plant Cell 2009; 21:2143-62. [PMID: 19638476 PMCID: PMC2729609 DOI: 10.1105/tpc.108.061507] [Citation(s) in RCA: 185] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2008] [Revised: 07/01/2009] [Accepted: 07/08/2009] [Indexed: 05/18/2023]
Abstract
Previously, it has been shown that Arabidopsis thaliana leaves exposed to high light accumulate hydrogen peroxide (H2O2) in bundle sheath cell (BSC) chloroplasts as part of a retrograde signaling network that induces ASCORBATE PEROXIDASE2 (APX2). Abscisic acid (ABA) signaling has been postulated to be involved in this network. To investigate the proposed role of ABA, a combination of physiological, pharmacological, bioinformatic, and molecular genetic approaches was used. ABA biosynthesis is initiated in vascular parenchyma and activates a signaling network in neighboring BSCs. This signaling network includes the Galpha subunit of the heterotrimeric G protein complex, the OPEN STOMATA1 protein kinase, and extracellular H2O2, which together coordinate with a redox-retrograde signal from BSC chloroplasts to activate APX2 expression. High light-responsive genes expressed in other leaf tissues are subject to a coordination of chloroplast retrograde signaling and transcellular signaling activated by ABA synthesized in vascular cells. ABA is necessary for the successful adjustment of the leaf to repeated episodes of high light. This process involves maintenance of photochemical quenching, which is required for dissipation of excess excitation energy.
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