1
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McQuillan JL, Cutolo EA, Evans C, Pandhal J. Proteomic characterization of a lutein-hyperaccumulating Chlamydomonas reinhardtii mutant reveals photoprotection-related factors as targets for increasing cellular carotenoid content. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:166. [PMID: 37925447 PMCID: PMC10625216 DOI: 10.1186/s13068-023-02421-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 10/28/2023] [Indexed: 11/06/2023]
Abstract
BACKGROUND Microalgae are emerging hosts for the sustainable production of lutein, a high-value carotenoid; however, to be commercially competitive with existing systems, their capacity for lutein sequestration must be augmented. Previous attempts to boost microalgal lutein production have focussed on upregulating carotenoid biosynthetic enzymes, in part due to a lack of metabolic engineering targets for expanding lutein storage. RESULTS Here, we isolated a lutein hyper-producing mutant of the model green microalga Chlamydomonas reinhardtii and characterized the metabolic mechanisms driving its enhanced lutein accumulation using label-free quantitative proteomics. Norflurazon- and high light-resistant C. reinhardtii mutants were screened to yield four mutant lines that produced significantly more lutein per cell compared to the CC-125 parental strain. Mutant 5 (Mut-5) exhibited a 5.4-fold increase in lutein content per cell, which to our knowledge is the highest fold increase of lutein in C. reinhardtii resulting from mutagenesis or metabolic engineering so far. Comparative proteomics of Mut-5 against its parental strain CC-125 revealed an increased abundance of light-harvesting complex-like proteins involved in photoprotection, among differences in pigment biosynthesis, central carbon metabolism, and translation. Further characterization of Mut-5 under varying light conditions revealed constitutive overexpression of the photoprotective proteins light-harvesting complex stress-related 1 (LHCSR1) and LHCSR3 and PSII subunit S regardless of light intensity, and increased accrual of total chlorophyll and carotenoids as light intensity increased. Although the photosynthetic efficiency of Mut-5 was comparatively lower than CC-125, the amplitude of non-photochemical quenching responses of Mut-5 was 4.5-fold higher than in CC-125 at low irradiance. CONCLUSIONS We used C. reinhardtii as a model green alga and identified light-harvesting complex-like proteins (among others) as potential metabolic engineering targets to enhance lutein accumulation in microalgae. These have the added value of imparting resistance to high light, although partially compromising photosynthetic efficiency. Further genetic characterization and engineering of Mut-5 could lead to the discovery of unknown players in photoprotective mechanisms and the development of a potent microalgal lutein production system.
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Affiliation(s)
- Josie L McQuillan
- Department of Chemical and Biological Engineering, University of Sheffield, Mappin Street, Sheffield, S1 3JD, UK.
| | - Edoardo Andrea Cutolo
- Laboratory of Photosynthesis and Bioenergy, Department of Biotechnology, University of Verona, Strada le Grazie 15, 37134, Verona, Italy
| | - Caroline Evans
- Department of Chemical and Biological Engineering, University of Sheffield, Mappin Street, Sheffield, S1 3JD, UK
| | - Jagroop Pandhal
- Department of Chemical and Biological Engineering, University of Sheffield, Mappin Street, Sheffield, S1 3JD, UK.
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2
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Li Y, Jian Y, Mao Y, Meng F, Shao Z, Wang T, Zheng J, Wang Q, Liu L. "Omics" insights into plastid behavior toward improved carotenoid accumulation. FRONTIERS IN PLANT SCIENCE 2022; 13:1001756. [PMID: 36275568 PMCID: PMC9583013 DOI: 10.3389/fpls.2022.1001756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Accepted: 09/21/2022] [Indexed: 06/16/2023]
Abstract
Plastids are a group of diverse organelles with conserved carotenoids synthesizing and sequestering functions in plants. They optimize the carotenoid composition and content in response to developmental transitions and environmental stimuli. In this review, we describe the turbulence and reforming of transcripts, proteins, and metabolic pathways for carotenoid metabolism and storage in various plastid types upon organogenesis and external influences, which have been studied using approaches including genomics, transcriptomics, proteomics, and metabonomics. Meanwhile, the coordination of plastid signaling and carotenoid metabolism including the effects of disturbed carotenoid biosynthesis on plastid morphology and function are also discussed. The "omics" insight extends our understanding of the interaction between plastids and carotenoids and provides significant implications for designing strategies for carotenoid-biofortified crops.
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Affiliation(s)
- Yuanyuan Li
- Key Laboratory of Horticultural Plant Growth and Development, Ministry of Agriculture, Department of Horticulture, Zhejiang University, Hangzhou, China
| | - Yue Jian
- Key Laboratory of Horticultural Plant Growth and Development, Ministry of Agriculture, Department of Horticulture, Zhejiang University, Hangzhou, China
| | - Yuanyu Mao
- Key Laboratory of Horticultural Plant Growth and Development, Ministry of Agriculture, Department of Horticulture, Zhejiang University, Hangzhou, China
| | - Fanliang Meng
- Key Laboratory of Horticultural Plant Growth and Development, Ministry of Agriculture, Department of Horticulture, Zhejiang University, Hangzhou, China
| | - Zhiyong Shao
- Key Laboratory of Horticultural Plant Growth and Development, Ministry of Agriculture, Department of Horticulture, Zhejiang University, Hangzhou, China
| | - Tonglin Wang
- Hangzhou Academy of Agricultural Sciences, Hangzhou, China
| | - Jirong Zheng
- Hangzhou Academy of Agricultural Sciences, Hangzhou, China
| | - Qiaomei Wang
- Key Laboratory of Horticultural Plant Growth and Development, Ministry of Agriculture, Department of Horticulture, Zhejiang University, Hangzhou, China
| | - Lihong Liu
- Key Laboratory of Horticultural Plant Growth and Development, Ministry of Agriculture, Department of Horticulture, Zhejiang University, Hangzhou, China
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3
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Arzac MI, Fernández-Marín B, García-Plazaola JI. More than just lipid balls: quantitative analysis of plastoglobule attributes and their stress-related responses. PLANTA 2022; 255:62. [PMID: 35141783 PMCID: PMC8828631 DOI: 10.1007/s00425-022-03848-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 01/28/2022] [Indexed: 05/15/2023]
Abstract
Plastoglobules are ubiquitous under non-stress conditions and their morphology, closely related to their composition, changes differently depending on the specific stress that the plant undergoes. Plastoglobules are lipoprotein structures attached to thylakoid membranes, which participate in chloroplast metabolism and stress responses. Their structure contains a coating lipid monolayer and a hydrophobic core that differ in composition. Their function in chloroplasts has been studied focussing on their composition. However, we currently lack a comprehensive study that quantitatively evaluates the occurrence and morphology of plastoglobules. Following a literature search strategy, we quantified the main morphological attributes of plastoglobules from photosynthetic chloroplasts of more than 1000 TEM images published over the last 53 years, covering more than 100 taxa and 15 stress types. The analysis shows that plastoglobules under non-stress conditions are spherical, with an average diameter of 100-200 nm and cover less than 3% of the chloroplast cross-section area. This percentage rises under almost every type of stress, particularly in senescence. Interestingly, an apparent trade-off between increasing either the number or the diameter of plastoglobules governs this response. Our results show that plastoglobules are ubiquitous in chloroplasts of higher plants under non-stress conditions. Besides, provided the specific molecular composition of the core and coat of plastoglobules, we conclude that specific stress-related variation in plastoglobules attributes may allow inferring precise responses of the chloroplast metabolism.
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Affiliation(s)
- Miren I. Arzac
- Department Plant Biology and Ecology, University of the Basque Country (UPV/EHU), Barrio Sarriena s/n, 48940 Leioa, Spain
| | - Beatriz Fernández-Marín
- Department Botany, Ecology and Plant Physiology, University of La Laguna (ULL), 38200 Tenerife, Spain
| | - José I. García-Plazaola
- Department Plant Biology and Ecology, University of the Basque Country (UPV/EHU), Barrio Sarriena s/n, 48940 Leioa, Spain
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4
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Opriș O, Lung I, Soran ML, Ciorîță A, Copolovici L. Investigating the effects of non-steroidal anti-inflammatory drugs (NSAIDs) on the composition and ultrastructure of green leafy vegetables with important nutritional values. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2020; 151:342-351. [PMID: 32272352 DOI: 10.1016/j.plaphy.2020.03.046] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 03/26/2020] [Accepted: 03/28/2020] [Indexed: 06/11/2023]
Abstract
The global presence of pharmaceuticals in the environment has been particularly considered a concerning problem with unknown consequences. Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most frequently prescribed drugs in the world, and as a result, they are commonly found in different environmental compartments. In the present work, we studied the effects of NSAIDs (diclofenac, ibuprofen, and naproxen) on the composition and ultrastructure of Atriplex patula L., S. oleracea, and Lactuca sativa L., three green leafy vegetables with significant nutritional value. Contaminant solutions of NSAIDs were applied every two days using concentrations of 0.1 mg L-1, 0.5 mg L-1, and 1 mg L-1. After eight weeks of exposure of the green leafy vegetables to the selected NSAIDs, the chlorophylls (a + b), carotenoids (zeaxanthin, lutein, and ß-carotene), total polyphenol and total flavonoid contents, antioxidant capacity, and the ultrastructural modifications were determined. The obtained results indicated a moderate reduction in the assimilating pigments, total polyphenol and flavonoid contents. In addition, ultrastructural damages of the chloroplasts and cell walls were observed in the leaves of the selected vegetables, which were exposed to abiotic stress-induced by NSAIDs. All data collectively suggest that this group of drugs induced harmful effects on plants, and implicitly they may also negatively affected human health on the long term.
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Affiliation(s)
- Ocsana Opriș
- National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat, 400293, Cluj-Napoca, Romania
| | - Ildikó Lung
- National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat, 400293, Cluj-Napoca, Romania.
| | - Maria-Loredana Soran
- National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat, 400293, Cluj-Napoca, Romania
| | - Alexandra Ciorîță
- National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat, 400293, Cluj-Napoca, Romania; "Babeș-Bolyai" University, Faculty of Biology and Geology, 5-7 Clinicilor, 400006, Cluj-Napoca, Romania
| | - Lucian Copolovici
- National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat, 400293, Cluj-Napoca, Romania; Faculty of Food Engineering, Tourism and Environmental Protection and Institute of Research, Innovation and Development in Technical and Natural Sciences of "Aurel Vlaicu" University, 2 Elena Drăgoi, 310330, Arad, Romania
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5
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Surducan V, Surducan E, Neamtu C, Mot AC, Ciorîță A. Effects of Long-Term Exposure to Low-Power 915 MHz Unmodulated Radiation on Phaseolus vulgaris L. Bioelectromagnetics 2020; 41:200-212. [PMID: 32030775 DOI: 10.1002/bem.22253] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 01/21/2020] [Indexed: 11/10/2022]
Abstract
The morphophysiological response of Phaseolus vulgaris L. to low-power electromagnetic radiation was investigated in order to assess the potential harmful effects of long-term continuous exposure. The plants were grown in two separate electromagnetic field (EMF) shielded rooms, in a controlled, greenhouse-like environment. One batch was continuously irradiated during the growth period (from sowing to maturity) and the other one was used as a reference. An unmodulated signal at 915 MHz (the central frequency between the uplink and downlink of the GSM900 mobile communications band) was used, with a maximum power density of 10 mW/m2 measured near the plants. The plants were analyzed using ultraviolet-visible, statistical, morphometric, and electron microscopy methods. Significant differences were observed regarding the height of the plants, number of inflorescences, and chlorophyll and carotenoid content, all closely connected with the ultrastructural changes observed in the leaves. The irradiated batch grew higher (19% increase in plant height, 20% increase in stem and leaves' dry mass), with 18% fewer inflorescences, and extremely long roots (34% increase in dry mass). The ultrastructure of the irradiated leaves showed irregular cells and a higher content of plastoglobules in the chloroplasts. All results indicate that the irradiated plants suffered significant morphological modifications during their long-term exposure to the specific EM radiation. Bioelectromagnetics. © 2020 Bioelectromagnetics Society.
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Affiliation(s)
- Vasile Surducan
- National Institute for Research and Development of Isotopic and Molecular Technologies (INCDTIM), Cluj-Napoca, Romania
| | - Emanoil Surducan
- National Institute for Research and Development of Isotopic and Molecular Technologies (INCDTIM), Cluj-Napoca, Romania
| | - Camelia Neamtu
- National Institute for Research and Development of Isotopic and Molecular Technologies (INCDTIM), Cluj-Napoca, Romania
| | - Augustin C Mot
- National Institute for Research and Development of Isotopic and Molecular Technologies (INCDTIM), Cluj-Napoca, Romania.,Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, Cluj-Napoca, Romania
| | - Alexandra Ciorîță
- National Institute for Research and Development of Isotopic and Molecular Technologies (INCDTIM), Cluj-Napoca, Romania.,Faculty of Biology and Geology, Babes-Bolyai University, Cluj-Napoca, Romania
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6
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Lee K, Lehmann M, Paul MV, Wang L, Luckner M, Wanner G, Geigenberger P, Leister D, Kleine T. Lack of FIBRILLIN6 in Arabidopsis thaliana affects light acclimation and sulfate metabolism. THE NEW PHYTOLOGIST 2020; 225:1715-1731. [PMID: 31596965 DOI: 10.1111/nph.16246] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 10/02/2019] [Indexed: 06/10/2023]
Abstract
Arabidopsis thaliana contains 13 fibrillins (FBNs), which are all localized to chloroplasts. FBN1 and FBN2 are involved in photoprotection of photosystem II, and FBN4 and FBN5 are thought to be involved in plastoquinone transport and biosynthesis, respectively. The functions of the other FBNs remain largely unknown. To gain insight into the function of FBN6, we performed coexpression and Western analyses, conducted fluorescence and transmission electron microscopy, stained reactive oxygen species (ROS), measured photosynthetic parameters and glutathione levels, and applied transcriptomics and metabolomics. Using coexpression analyses, FBN6 was identified as a photosynthesis-associated gene. FBN6 is localized to thylakoid and envelope membranes, and its knockout results in stunted plants. The delayed-growth phenotype cannot be attributed to altered basic photosynthesis parameters or a reduced CO2 assimilation rate. Under moderate light stress, primary leaves of fbn6 plants begin to bleach and contain enlarged plastoglobules. RNA sequencing and metabolomics analyses point to an alteration in sulfate reduction in fbn6. Indeed, glutathione content is higher in fbn6, which in turn confers cadmium tolerance of fbn6 seedlings. We conclude that loss of FBN6 leads to perturbation of ROS homeostasis. FBN6 enables plants to cope with moderate light stress and affects cadmium tolerance.
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Affiliation(s)
- Kwanuk Lee
- Plant Molecular Biology (Botany), Department Biology I, Ludwig-Maximilians-University München, 82152, Martinsried, Germany
| | - Martin Lehmann
- Plant Molecular Biology (Botany), Department Biology I, Ludwig-Maximilians-University München, 82152, Martinsried, Germany
| | - Melanie V Paul
- Plant Metabolism, Department Biology I, Ludwig-Maximilians-University München, 82152, Martinsried, Germany
| | - Liangsheng Wang
- Plant Molecular Biology (Botany), Department Biology I, Ludwig-Maximilians-University München, 82152, Martinsried, Germany
| | - Manja Luckner
- Ultrastrukturforschung, Department Biology I, Ludwig-Maximilians-University München, 81252, Planegg-Martinsried, Germany
| | - Gerhard Wanner
- Ultrastrukturforschung, Department Biology I, Ludwig-Maximilians-University München, 81252, Planegg-Martinsried, Germany
| | - Peter Geigenberger
- Plant Metabolism, Department Biology I, Ludwig-Maximilians-University München, 82152, Martinsried, Germany
| | - Dario Leister
- Plant Molecular Biology (Botany), Department Biology I, Ludwig-Maximilians-University München, 82152, Martinsried, Germany
| | - Tatjana Kleine
- Plant Molecular Biology (Botany), Department Biology I, Ludwig-Maximilians-University München, 82152, Martinsried, Germany
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7
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Schaeffer SM, Christian R, Castro-Velasquez N, Hyden B, Lynch-Holm V, Dhingra A. Comparative ultrastructure of fruit plastids in three genetically diverse genotypes of apple (Malus × domestica Borkh.) during development. PLANT CELL REPORTS 2017; 36:1627-1640. [PMID: 28698906 PMCID: PMC5693628 DOI: 10.1007/s00299-017-2179-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 07/03/2017] [Indexed: 05/02/2023]
Abstract
Comparative ultrastructural developmental time-course analysis has identified discrete stages at which the fruit plastids undergo structural and consequently functional transitions to facilitate subsequent development-guided understanding of the complex plastid biology. Plastids are the defining organelle for a plant cell and are critical for myriad metabolic functions. The role of leaf plastid, chloroplast, is extensively documented; however, fruit plastids-chromoplasts-are poorly understood, especially in the context of the diverse metabolic processes operating in these diverse plant organs. Recently, in a comparative study of the predicted plastid-targeted proteomes across seven plant species, we reported that each plant species is predicted to harbor a unique set of plastid-targeted proteins. However, the temporal and developmental context of these processes remains unknown. In this study, an ultrastructural analysis approach was used to characterize fruit plastids in the epidermal and collenchymal cell layers at 11 developmental timepoints in three genotypes of apple (Malus × domestica Borkh.): chlorophyll-predominant 'Granny Smith', carotenoid-predominant 'Golden Delicious', and anthocyanin-predominant 'Top Red Delicious'. Plastids transitioned from a proplastid-like plastid to a chromoplast-like plastid in epidermis cells, while in the collenchyma cells, they transitioned from a chloroplast-like plastid to a chloro-chromo-amyloplast plastid. Plastids in the collenchyma cells of the three genotypes demonstrated a diverse array of structures and features. This study enabled the identification of discrete developmental stages during which specific functions are most likely being performed by the plastids as indicated by accumulation of plastoglobuli, starch granules, and other sub-organeller structures. Information regarding the metabolically active developmental stages is expected to facilitate biologically relevant omics studies to unravel the complex biochemistry of plastids in perennial non-model systems.
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Affiliation(s)
- Scott M Schaeffer
- Department of Horticulture, Washington State University, Pullman, WA, USA
- Molecular Plant Science Graduate Program, Washington State University, Pullman, WA, USA
- Indigo Agriculture, 500 Rutherford Ave, Suite 201, Charlestown, MA, 02129, USA
| | - Ryan Christian
- Department of Horticulture, Washington State University, Pullman, WA, USA
- Molecular Plant Science Graduate Program, Washington State University, Pullman, WA, USA
| | | | - Brennan Hyden
- Department of Horticulture, Washington State University, Pullman, WA, USA
| | - Valerie Lynch-Holm
- Franchesci Microscopy and Imaging Center, Washington State University, Pullman, WA, USA
| | - Amit Dhingra
- Department of Horticulture, Washington State University, Pullman, WA, USA.
- Molecular Plant Science Graduate Program, Washington State University, Pullman, WA, USA.
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8
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Sofer L, Cabanillas DG, Gayral M, Téplier R, Pouzoulet J, Ducousso M, Dufin L, Bréhélin C, Ziegler-Graff V, Brault V, Revers F. Identification of host factors potentially involved in RTM-mediated resistance during potyvirus long distance movement. Arch Virol 2017; 162:1855-1865. [PMID: 28251380 DOI: 10.1007/s00705-017-3292-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 01/29/2017] [Indexed: 12/28/2022]
Abstract
The long distance movement of potyviruses is a poorly understood step of the viral cycle. Only factors inhibiting this process, referred to as "Restricted TEV Movement" (RTM), have been identified in Arabidopsis thaliana. On the virus side, the potyvirus coat protein (CP) displays determinants required for long-distance movement and for RTM-based resistance breaking. However, the potyvirus CP was previously shown not to interact with the RTM proteins. We undertook the identification of Arabidopsis factors which directly interact with either the RTM proteins or the CP of lettuce mosaic virus (LMV). An Arabidopsis cDNA library generated from companion cells was screened with LMV CP and RTM proteins using the yeast two-hybrid system. Fourteen interacting proteins were identified. Two of them were shown to interact with CP and the RTM proteins suggesting that a multiprotein complex could be formed between the RTM proteins and virions or viral ribonucleoprotein complexes. Co-localization experiments in Nicotiana benthamiana showed that most of the viral and cellular protein pairs co-localized at the periphery of chloroplasts which suggests a putative role for plastids in this process.
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Affiliation(s)
- Luc Sofer
- BFP, INRA, University of Bordeaux, 33140, Villenave d'Ornon, France
| | - Daniel Garcia Cabanillas
- BFP, INRA, University of Bordeaux, 33140, Villenave d'Ornon, France
- Institut National de la Recherche Scientifique-Institut Armand-Frappier, Laval, QC, H7V 1B7, Canada
| | - Mathieu Gayral
- BFP, INRA, University of Bordeaux, 33140, Villenave d'Ornon, France
| | - Rachèle Téplier
- BFP, INRA, University of Bordeaux, 33140, Villenave d'Ornon, France
| | - Jérôme Pouzoulet
- BFP, INRA, University of Bordeaux, 33140, Villenave d'Ornon, France
- Department of Botany and Plant Sciences, University of California, Riverside, CA, 92521, USA
| | - Marie Ducousso
- BFP, INRA, University of Bordeaux, 33140, Villenave d'Ornon, France
- UMR 0385 BGPI, Virus Insecte Plante, INRA, Campus international de Bailllarguet, Montpellier, France
| | - Laurène Dufin
- BFP, INRA, University of Bordeaux, 33140, Villenave d'Ornon, France
| | - Claire Bréhélin
- UMR 5200, Laboratory of Membrane Biogenesis, CNRS, University of Bordeaux, 33140, Villenave d'Ornon, France
| | - Véronique Ziegler-Graff
- Institut de Biologie Moléculaire des Plantes, Laboratoire propre du CNRS conventionné avec l'Université de Strasbourg, 12 rue du Général Zimmer, 67084, Strasbourg, France
| | | | - Frédéric Revers
- BFP, INRA, University of Bordeaux, 33140, Villenave d'Ornon, France.
- BIOGECO, INRA, University of Bordeaux, 33615, Pessac, France.
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9
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Cai Y, McClinchie E, Price A, Nguyen TN, Gidda SK, Watt SC, Yurchenko O, Park S, Sturtevant D, Mullen RT, Dyer JM, Chapman KD. Mouse fat storage-inducing transmembrane protein 2 (FIT2) promotes lipid droplet accumulation in plants. PLANT BIOTECHNOLOGY JOURNAL 2017; 15:824-836. [PMID: 27987528 PMCID: PMC5466434 DOI: 10.1111/pbi.12678] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 12/01/2016] [Accepted: 12/02/2016] [Indexed: 05/23/2023]
Abstract
Fat storage-inducing transmembrane protein 2 (FIT2) is an endoplasmic reticulum (ER)-localized protein that plays an important role in lipid droplet (LD) formation in animal cells. However, no obvious homologue of FIT2 is found in plants. Here, we tested the function of FIT2 in plant cells by ectopically expressing mouse (Mus musculus) FIT2 in Nicotiana tabacum suspension-cultured cells, Nicotiana benthamiana leaves and Arabidopsis thaliana plants. Confocal microscopy indicated that the expression of FIT2 dramatically increased the number and size of LDs in leaves of N. benthamiana and Arabidopsis, and lipidomics analysis and mass spectrometry imaging confirmed the accumulation of neutral lipids in leaves. FIT2 also increased seed oil content by ~13% in some stable, overexpressing lines of Arabidopsis. When expressed transiently in leaves of N. benthamiana or suspension cells of N. tabacum, FIT2 localized specifically to the ER and was often concentrated at certain regions of the ER that resembled ER-LD junction sites. FIT2 also colocalized at the ER with other proteins known to be involved in triacylglycerol biosynthesis or LD formation in plants, but not with ER resident proteins involved in electron transfer or ER-vesicle exit sites. Collectively, these results demonstrate that mouse FIT2 promotes LD accumulation in plants, a surprising functional conservation in the context of a plant cell given the apparent lack of FIT2 homologues in higher plants. These results suggest also that FIT2 expression represents an effective synthetic biology strategy for elaborating neutral lipid compartments in plant tissues for potential biofuel or bioproduct purposes.
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Affiliation(s)
- Yingqi Cai
- Center for Plant Lipid ResearchUniversity of North TexasDentonTXUSA
| | | | - Ann Price
- Center for Plant Lipid ResearchUniversity of North TexasDentonTXUSA
| | - Thuy N. Nguyen
- Department of Molecular and Cellular BiologyUniversity of GuelphGuelphONCanada
- Present address: Department of Molecular GeneticsUniversity of TorontoTorontoONCanada
| | - Satinder K. Gidda
- Department of Molecular and Cellular BiologyUniversity of GuelphGuelphONCanada
| | - Samantha C. Watt
- Department of Molecular and Cellular BiologyUniversity of GuelphGuelphONCanada
| | - Olga Yurchenko
- US Arid‐Land Agricultural Research CenterUSDA‐ARSMaricopaAZUSA
| | - Sunjung Park
- US Arid‐Land Agricultural Research CenterUSDA‐ARSMaricopaAZUSA
- Present address: Biology DepartmentCentral Arizona CollegeMaricopaAZ85138USA
| | - Drew Sturtevant
- Center for Plant Lipid ResearchUniversity of North TexasDentonTXUSA
| | - Robert T. Mullen
- Department of Molecular and Cellular BiologyUniversity of GuelphGuelphONCanada
| | - John M. Dyer
- US Arid‐Land Agricultural Research CenterUSDA‐ARSMaricopaAZUSA
| | - Kent D. Chapman
- Center for Plant Lipid ResearchUniversity of North TexasDentonTXUSA
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10
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Mortimer CL, Misawa N, Perez-Fons L, Robertson FP, Harada H, Bramley PM, Fraser PD. The Formation and Sequestration of Nonendogenous Ketocarotenoids in Transgenic Nicotiana glauca. PLANT PHYSIOLOGY 2017; 173:1617-1635. [PMID: 28153925 PMCID: PMC5338661 DOI: 10.1104/pp.16.01297] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 01/18/2017] [Indexed: 05/02/2023]
Abstract
Ketolated and hydroxylated carotenoids are high-value compounds with industrial, food, and feed applications. Chemical synthesis is currently the production method of choice for these compounds, with no amenable plant sources readily available. In this study, the 4,4' β-oxygenase (crtW) and 3,3' β-hydroxylase (crtZ) genes from Brevundimonas sp. SD-212 were expressed under constitutive transcriptional control in Nicotiana glauca, which has an emerging potential as a biofuel and biorefining feedstock. The transgenic lines produced significant levels of nonendogenous carotenoids in all tissues. In leaf and flower, the carotenoids (∼0.5% dry weight) included 0.3% and 0.48%, respectively, of nonendogenous ketolated and hydroxylated carotenoids. These were 4-ketolutein, echinenone (and its 3-hydroxy derivatives), canthaxanthin, phoenicoxanthin, 4-ketozeaxanthin, and astaxanthin. Stable, homozygous genotypes expressing both transgenes inherited the chemotype. Subcellular fractionation of vegetative tissues and microscopic analysis revealed the presence of ketocarotenoids in thylakoid membranes, not predominantly in the photosynthetic complexes but in plastoglobules. Despite ketocarotenoid production and changes in cellular ultrastructure, intermediary metabolite levels were not dramatically affected. The study illustrates the utility of Brevundimonas sp. SD-212 CRTZ and CRTW to produce ketocarotenoids in a plant species that is being evaluated as a biorefining feedstock, the adaptation of the plastid to sequester nonendogenous carotenoids, and the robustness of plant metabolism to these changes.
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Affiliation(s)
- Cara L Mortimer
- School of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, United Kingdom (C.L.M., L.P.-F., F.P.R., P.M.B., P.D.F.); and
- Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, Suematsu, Nonoichi-machi, Ishikawa 921-8836, Japan (N.M., H.H.)
| | - Norihiko Misawa
- School of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, United Kingdom (C.L.M., L.P.-F., F.P.R., P.M.B., P.D.F.); and
- Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, Suematsu, Nonoichi-machi, Ishikawa 921-8836, Japan (N.M., H.H.)
| | - Laura Perez-Fons
- School of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, United Kingdom (C.L.M., L.P.-F., F.P.R., P.M.B., P.D.F.); and
- Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, Suematsu, Nonoichi-machi, Ishikawa 921-8836, Japan (N.M., H.H.)
| | - Francesca P Robertson
- School of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, United Kingdom (C.L.M., L.P.-F., F.P.R., P.M.B., P.D.F.); and
- Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, Suematsu, Nonoichi-machi, Ishikawa 921-8836, Japan (N.M., H.H.)
| | - Hisashi Harada
- School of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, United Kingdom (C.L.M., L.P.-F., F.P.R., P.M.B., P.D.F.); and
- Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, Suematsu, Nonoichi-machi, Ishikawa 921-8836, Japan (N.M., H.H.)
| | - Peter M Bramley
- School of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, United Kingdom (C.L.M., L.P.-F., F.P.R., P.M.B., P.D.F.); and
- Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, Suematsu, Nonoichi-machi, Ishikawa 921-8836, Japan (N.M., H.H.)
| | - Paul D Fraser
- School of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, United Kingdom (C.L.M., L.P.-F., F.P.R., P.M.B., P.D.F.); and
- Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, Suematsu, Nonoichi-machi, Ishikawa 921-8836, Japan (N.M., H.H.)
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11
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Brocard L, Immel F, Coulon D, Esnay N, Tuphile K, Pascal S, Claverol S, Fouillen L, Bessoule JJ, Bréhélin C. Proteomic Analysis of Lipid Droplets from Arabidopsis Aging Leaves Brings New Insight into Their Biogenesis and Functions. FRONTIERS IN PLANT SCIENCE 2017; 8:894. [PMID: 28611809 PMCID: PMC5447075 DOI: 10.3389/fpls.2017.00894] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 05/12/2017] [Indexed: 05/18/2023]
Abstract
Lipid droplets (LDs) are cell compartments specialized for oil storage. Although their role and biogenesis are relatively well documented in seeds, little is known about their composition, structure and function in senescing leaves where they also accumulate. Here, we used a label free quantitative mass spectrometry approach to define the LD proteome of aging Arabidopsis leaves. We found that its composition is highly different from that of seed/cotyledon and identified 28 proteins including 9 enzymes of the secondary metabolism pathways involved in plant defense response. With the exception of the TRIGALACTOSYLDIACYLGLYCEROL2 protein, we did not identify enzymes implicated in lipid metabolism, suggesting that growth of leaf LDs does not occur by local lipid synthesis but rather through contact sites with the endoplasmic reticulum (ER) or other membranes. The two most abundant proteins of the leaf LDs are the CALEOSIN3 and the SMALL RUBBER PARTICLE1 (AtSRP1); both proteins have structural functions and participate in plant response to stress. CALEOSIN3 and AtSRP1 are part of larger protein families, yet no other members were enriched in the LD proteome suggesting a specific role of both proteins in aging leaves. We thus examined the function of AtSRP1 at this developmental stage and found that AtSRP1 modulates the expression of CALEOSIN3 in aging leaves. Furthermore, AtSRP1 overexpression induces the accumulation of triacylglycerol with an unusual composition compared to wild-type. We demonstrate that, although AtSRP1 expression is naturally increased in wild type senescing leaves, its overexpression in senescent transgenic lines induces an over-accumulation of LDs organized in clusters at restricted sites of the ER. Conversely, atsrp1 knock-down mutants displayed fewer but larger LDs. Together our results reveal that the abundancy of AtSRP1 regulates the neo-formation of LDs during senescence. Using electron tomography, we further provide evidence that LDs in leaves share tenuous physical continuity as well as numerous contact sites with the ER membrane. Thus, our data suggest that leaf LDs are functionally distinct from seed LDs and that their biogenesis is strictly controlled by AtSRP1 at restricted sites of the ER.
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Affiliation(s)
- Lysiane Brocard
- Plant Imaging Platform, Bordeaux Imaging Center, UMS 3420 Centre National de la Recherche Scientifique, US4 Institut National de la Santé et de la Recherche Médicale, University of BordeauxBordeaux, France
| | - Françoise Immel
- Laboratory of Membrane Biogenesis, Centre National de la Recherche Scientifique, UMR 5200Villenave d'Ornon, France
- Laboratory of Membrane Biogenesis, University of Bordeaux, UMR 5200Villenave d'Ornon, France
| | - Denis Coulon
- Laboratory of Membrane Biogenesis, Centre National de la Recherche Scientifique, UMR 5200Villenave d'Ornon, France
- Laboratory of Membrane Biogenesis, University of Bordeaux, UMR 5200Villenave d'Ornon, France
- Bordeaux INPTalence, France
| | - Nicolas Esnay
- Laboratory of Membrane Biogenesis, Centre National de la Recherche Scientifique, UMR 5200Villenave d'Ornon, France
- Laboratory of Membrane Biogenesis, University of Bordeaux, UMR 5200Villenave d'Ornon, France
| | - Karine Tuphile
- Laboratory of Membrane Biogenesis, Centre National de la Recherche Scientifique, UMR 5200Villenave d'Ornon, France
- Laboratory of Membrane Biogenesis, University of Bordeaux, UMR 5200Villenave d'Ornon, France
| | - Stéphanie Pascal
- Laboratory of Membrane Biogenesis, Centre National de la Recherche Scientifique, UMR 5200Villenave d'Ornon, France
- Laboratory of Membrane Biogenesis, University of Bordeaux, UMR 5200Villenave d'Ornon, France
| | - Stéphane Claverol
- Proteome Platform, Functional Genomic Center of Bordeaux, University of BordeauxBordeaux, France
| | - Laëtitia Fouillen
- Laboratory of Membrane Biogenesis, Centre National de la Recherche Scientifique, UMR 5200Villenave d'Ornon, France
- Laboratory of Membrane Biogenesis, University of Bordeaux, UMR 5200Villenave d'Ornon, France
| | - Jean-Jacques Bessoule
- Laboratory of Membrane Biogenesis, Centre National de la Recherche Scientifique, UMR 5200Villenave d'Ornon, France
- Laboratory of Membrane Biogenesis, University of Bordeaux, UMR 5200Villenave d'Ornon, France
| | - Claire Bréhélin
- Laboratory of Membrane Biogenesis, Centre National de la Recherche Scientifique, UMR 5200Villenave d'Ornon, France
- Laboratory of Membrane Biogenesis, University of Bordeaux, UMR 5200Villenave d'Ornon, France
- *Correspondence: Claire Bréhélin
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Kelly AA, Feussner I. Oil is on the agenda: Lipid turnover in higher plants. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:1253-1268. [PMID: 27155216 DOI: 10.1016/j.bbalip.2016.04.021] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 04/23/2016] [Accepted: 04/25/2016] [Indexed: 12/13/2022]
Abstract
Lipases hydrolyze ester bonds within lipids. This process is called lipolysis. They are key players in lipid turnover and involved in numerous metabolic pathways, many of which are shared between organisms like the mobilization of neutral or storage lipids or lipase-mediated membrane lipid homeostasis. Some reactions though are predominantly present in certain organisms, such as the production of signaling molecules (endocannabinoids) by diacylglycerol (DAG) and monoacylglycerol (MAG) lipases in mammals and plants or the jasmonate production in flowering plants. This review aims at giving an overview of the different functional classes of lipases and respective well-known activities, with a focus on the most recent findings in plant biology for selected classes. Here we will put an emphasis on the physiological role and contribution of lipases to the turnover of neutral lipids found in seed oil and other vegetative tissue as candidates for increasing the economical values of crop plants. This article is part of a Special Issue entitled: Plant Lipid Biology edited by Kent D. Chapman and Ivo Feussner.
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Affiliation(s)
- Amélie A Kelly
- Georg-August-University, Albrecht-von-Haller-Institute for Plant Sciences, Justus-von-Liebig Weg 11, 37077 Göttingen, Germany
| | - Ivo Feussner
- Georg-August-University, Albrecht-von-Haller-Institute for Plant Sciences, Justus-von-Liebig Weg 11, 37077 Göttingen, Germany; Georg-August-University, Göttingen Center for Molecular Biosciences (GZMB), Justus-von-Liebig Weg 11, 37077 Göttingen, Germany; Georg-August-University, International Center for Advanced Studies of Energy Conversion (ICASEC), Justus-von-Liebig Weg 11, 37077 Göttingen, Germany
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13
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Belgio E, Ungerer P, Ruban AV. Light-harvesting superstructures of green plant chloroplasts lacking photosystems. PLANT, CELL & ENVIRONMENT 2015; 38:2035-47. [PMID: 25737144 DOI: 10.1111/pce.12528] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 02/23/2015] [Indexed: 05/26/2023]
Abstract
The light-harvesting antenna of higher plant photosystem II (LHCII) is the major photosynthetic membrane component encoded by an entire family of homologous nuclear genes. On the contrary, the great majority of proteins of photosystems and electron transport components are encoded by the chloroplast genome. In this work, we succeeded in gradually inhibiting the expression of the chloroplast genes that led to the disappearance of the photosystem complexes, mimicking almost total photoinhibition. The treated plants, despite displaying only some early signs of senescence, sustained their metabolism and growth for several weeks. The only major remaining membrane component was LHCII antenna that formed superstructures - stacks of dozens of thylakoids or supergrana. Freeze-fracture electron microscopy revealed specific organization, directly displaying frequently bifurcated membranes with reduced or totally absent photosystem II (PSII) reaction centre complexes. Our findings show that it is possible to accumulate large amounts of light-harvesting membranes, organized into three-dimensional structures, in the absence of reaction centre complexes. This points to the reciprocal role of LHCII and PSII in self-assembly of the three-dimensional matrix of the photosynthetic membrane, dictating its size and flexible adaptation to the light environment.
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Affiliation(s)
- Erica Belgio
- School of Biological and Chemical Sciences, Queen Mary University of London, London, E1 4NS, UK
| | - Petra Ungerer
- School of Biological and Chemical Sciences, Queen Mary University of London, London, E1 4NS, UK
| | - Alexander V Ruban
- School of Biological and Chemical Sciences, Queen Mary University of London, London, E1 4NS, UK
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14
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Rottet S, Besagni C, Kessler F. The role of plastoglobules in thylakoid lipid remodeling during plant development. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1847:889-99. [PMID: 25667966 DOI: 10.1016/j.bbabio.2015.02.002] [Citation(s) in RCA: 99] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Revised: 01/30/2015] [Accepted: 02/03/2015] [Indexed: 12/16/2022]
Abstract
Photosynthesis is the key bioenergetic process taking place in the chloroplast. The components of the photosynthetic machinery are embedded in a highly dynamic matrix, the thylakoid membrane. This membrane has the capacity to adapt during developmental transitions and under stress conditions. The galactolipids are the major polar lipid components of the thylakoid membrane conferring bilayer properties, while neutral thylakoid lipids such as the prenyllipids and carotenoids contribute to essential functions such as electron transport and photoprotection. Despite a large number of studies, the intriguing processes of thylakoid membrane biogenesis and dynamics remain unsolved. Plastoglobules, thylakoid-associated lipid droplets, appear to actively participate in thylakoid function from biogenesis to senescence. Recruitment of specific proteins enables the plastoglobules to act in metabolite synthesis, repair and disposal under changing environmental conditions and developmental stages. In this review, we describe plastoglobules as thylakoid membrane microdomains and discuss their involvement in lipid remodeling during stress and in the conversion from one plastid type to another. This article is part of a Special Issue entitled: Chloroplast Biogenesis.
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Affiliation(s)
- Sarah Rottet
- Laboratory of Plant Physiology, University of Neuchâtel, 2000 Neuchâtel, Switzerland
| | - Céline Besagni
- Laboratory of Plant Physiology, University of Neuchâtel, 2000 Neuchâtel, Switzerland
| | - Felix Kessler
- Laboratory of Plant Physiology, University of Neuchâtel, 2000 Neuchâtel, Switzerland.
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15
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Davidi L, Levin Y, Ben-Dor S, Pick U. Proteome analysis of cytoplasmatic and plastidic β-carotene lipid droplets in Dunaliella bardawil. PLANT PHYSIOLOGY 2015; 167:60-79. [PMID: 25404729 PMCID: PMC4281002 DOI: 10.1104/pp.114.248450] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The halotolerant green alga Dunaliella bardawil is unique in that it accumulates under stress two types of lipid droplets: cytoplasmatic lipid droplets (CLD) and β-carotene-rich (βC) plastoglobuli. Recently, we isolated and analyzed the lipid and pigment compositions of these lipid droplets. Here, we describe their proteome analysis. A contamination filter and an enrichment filter were utilized to define core proteins. A proteome database of Dunaliella salina/D. bardawil was constructed to aid the identification of lipid droplet proteins. A total of 124 and 42 core proteins were identified in βC-plastoglobuli and CLD, respectively, with only eight common proteins. Dunaliella spp. CLD resemble cytoplasmic droplets from Chlamydomonas reinhardtii and contain major lipid droplet-associated protein and enzymes involved in lipid and sterol metabolism. The βC-plastoglobuli proteome resembles the C. reinhardtii eyespot and Arabidopsis (Arabidopsis thaliana) plastoglobule proteomes and contains carotene-globule-associated protein, plastid-lipid-associated protein-fibrillins, SOUL heme-binding proteins, phytyl ester synthases, β-carotene biosynthesis enzymes, and proteins involved in membrane remodeling/lipid droplet biogenesis: VESICLE-INDUCING PLASTID PROTEIN1, synaptotagmin, and the eyespot assembly proteins EYE3 and SOUL3. Based on these and previous results, we propose models for the biogenesis of βC-plastoglobuli and the biosynthesis of β-carotene within βC-plastoglobuli and hypothesize that βC-plastoglobuli evolved from eyespot lipid droplets.
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Affiliation(s)
- Lital Davidi
- Department of Biological Chemistry (L.D., U.P.), Nancy and Stephen Grand Israel National Center for Personalized Medicine (Y.L.), and Biological Services Unit (S.B.-D.), Weizmann Institute of Science, Rehovot 76100, Israel
| | - Yishai Levin
- Department of Biological Chemistry (L.D., U.P.), Nancy and Stephen Grand Israel National Center for Personalized Medicine (Y.L.), and Biological Services Unit (S.B.-D.), Weizmann Institute of Science, Rehovot 76100, Israel
| | - Shifra Ben-Dor
- Department of Biological Chemistry (L.D., U.P.), Nancy and Stephen Grand Israel National Center for Personalized Medicine (Y.L.), and Biological Services Unit (S.B.-D.), Weizmann Institute of Science, Rehovot 76100, Israel
| | - Uri Pick
- Department of Biological Chemistry (L.D., U.P.), Nancy and Stephen Grand Israel National Center for Personalized Medicine (Y.L.), and Biological Services Unit (S.B.-D.), Weizmann Institute of Science, Rehovot 76100, Israel
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16
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Delfosse K, Wozny MR, Jaipargas EA, Barton KA, Anderson C, Mathur J. Fluorescent Protein Aided Insights on Plastids and their Extensions: A Critical Appraisal. FRONTIERS IN PLANT SCIENCE 2015; 6:1253. [PMID: 26834765 PMCID: PMC4719081 DOI: 10.3389/fpls.2015.01253] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2015] [Accepted: 12/21/2015] [Indexed: 05/20/2023]
Abstract
Multi-colored fluorescent proteins targeted to plastids have provided new insights on the dynamic behavior of these organelles and their interactions with other cytoplasmic components and compartments. Sub-plastidic components such as thylakoids, stroma, the inner and outer membranes of the plastid envelope, nucleoids, plastoglobuli, and starch grains have been efficiently highlighted in living plant cells. In addition, stroma filled membrane extensions called stromules have drawn attention to the dynamic nature of the plastid and its interactions with the rest of the cell. Use of dual and triple fluorescent protein combinations has begun to reveal plastid interactions with mitochondria, the nucleus, the endoplasmic reticulum and F-actin and suggests integral roles of plastids in retrograde signaling, cell to cell communication as well as plant-pathogen interactions. While the rapid advances and insights achieved through fluorescent protein based research on plastids are commendable it is necessary to endorse meaningful observations but subject others to closer scrutiny. Here, in order to develop a better and more comprehensive understanding of plastids and their extensions we provide a critical appraisal of recent information that has been acquired using targeted fluorescent protein probes.
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17
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Eitzinger N, Wagner V, Weisheit W, Geimer S, Boness D, Kreimer G, Mittag M. Proteomic Analysis of a Fraction with Intact Eyespots of Chlamydomonas reinhardtii and Assignment of Protein Methylation. FRONTIERS IN PLANT SCIENCE 2015; 6:1085. [PMID: 26697039 PMCID: PMC4678213 DOI: 10.3389/fpls.2015.01085] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 11/19/2015] [Indexed: 05/22/2023]
Abstract
Flagellate green algae possess a visual system, the eyespot. In Chlamydomonas reinhardtii it is situated at the edge of the chloroplast and consists of two carotenoid rich lipid globule layers subtended by thylakoid membranes (TM) that are attached to both chloroplast envelope membranes and a specialized area of the plasma membrane (PM). A former analysis of an eyespot fraction identified 203 proteins. To increase the understanding of eyespot related processes, knowledge of the protein composition of the membranes in its close vicinity is desirable. Here, we present a purification procedure that allows isolation of intact eyespots. This gain in intactness goes, however, hand in hand with an increase of contaminants from other organelles. Proteomic analysis identified 742 proteins. Novel candidates include proteins for eyespot development, retina-related proteins, ion pumps, and membrane-associated proteins, calcium sensing proteins as well as kinases, phosphatases and 14-3-3 proteins. Methylation of proteins at Arg or Lys is known as an important posttranslational modification involved in, e.g., signal transduction. Here, we identify several proteins from eyespot fractions that are methylated at Arg and/or Lys. Among them is the eyespot specific SOUL3 protein that influences the size and position of the eyespot and EYE2, a protein important for its development.
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Affiliation(s)
- Nicole Eitzinger
- Cell Biology, Department of Biology, Friedrich-Alexander-University Erlangen-NurembergErlangen, Germany
| | - Volker Wagner
- Institute of General Botany and Plant Physiology, Faculty of Biology and Pharmacy, Friedrich Schiller University JenaJena, Germany
| | - Wolfram Weisheit
- Institute of General Botany and Plant Physiology, Faculty of Biology and Pharmacy, Friedrich Schiller University JenaJena, Germany
| | - Stefan Geimer
- Cell Biology and Electron Microscopy, University of BayreuthBayreuth, Germany
| | - David Boness
- Cell Biology, Department of Biology, Friedrich-Alexander-University Erlangen-NurembergErlangen, Germany
| | - Georg Kreimer
- Cell Biology, Department of Biology, Friedrich-Alexander-University Erlangen-NurembergErlangen, Germany
| | - Maria Mittag
- Institute of General Botany and Plant Physiology, Faculty of Biology and Pharmacy, Friedrich Schiller University JenaJena, Germany
- *Correspondence: Maria Mittag,
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