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Wrobel TJ, Brilhaus D, Stefanski A, Stühler K, Weber APM, Linka N. Mapping the castor bean endosperm proteome revealed a metabolic interaction between plastid, mitochondria, and peroxisomes to optimize seedling growth. FRONTIERS IN PLANT SCIENCE 2023; 14:1182105. [PMID: 37868318 PMCID: PMC10588648 DOI: 10.3389/fpls.2023.1182105] [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: 03/08/2023] [Accepted: 08/07/2023] [Indexed: 10/24/2023]
Abstract
In this work, we studied castor-oil plant Ricinus communis as a classical system for endosperm reserve breakdown. The seeds of castor beans consist of a centrally located embryo with the two thin cotyledons surrounded by the endosperm. The endosperm functions as major storage tissue and is packed with nutritional reserves, such as oil, proteins, and starch. Upon germination, mobilization of the storage reserves requires inter-organellar interplay of plastids, mitochondria, and peroxisomes to optimize growth for the developing seedling. To understand their metabolic interactions, we performed a large-scale organellar proteomic study on castor bean endosperm. Organelles from endosperm of etiolated seedlings were isolated and subjected to liquid chromatography-tandem mass spectrometry (LC-MS/MS). Computer-assisted deconvolution algorithms were applied to reliably assign the identified proteins to their correct subcellular localization and to determine the abundance of the different organelles in the heterogeneous protein samples. The data obtained were used to build a comprehensive metabolic model for plastids, mitochondria, and peroxisomes during storage reserve mobilization in castor bean endosperm.
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Affiliation(s)
- Thomas J. Wrobel
- Institute of Plant Biochemistry and Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich Heine University, Düsseldorf, Germany
| | - Dominik Brilhaus
- Institute of Plant Biochemistry and Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich Heine University, Düsseldorf, Germany
| | - Anja Stefanski
- Molecular Proteomics Laboratory, Biologisch-Medizinisches Forschungszentrum (BMFZ), Universitätsklinikum, Düsseldorf, Germany
| | - Kai Stühler
- Molecular Proteomics Laboratory, Biologisch-Medizinisches Forschungszentrum (BMFZ), Universitätsklinikum, Düsseldorf, Germany
| | - Andreas P. M. Weber
- Institute of Plant Biochemistry and Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich Heine University, Düsseldorf, Germany
| | - Nicole Linka
- Institute of Plant Biochemistry and Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich Heine University, Düsseldorf, Germany
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Bajguz A, Piotrowska-Niczyporuk A. Biosynthetic Pathways of Hormones in Plants. Metabolites 2023; 13:884. [PMID: 37623827 PMCID: PMC10456939 DOI: 10.3390/metabo13080884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 07/22/2023] [Accepted: 07/24/2023] [Indexed: 08/26/2023] Open
Abstract
Phytohormones exhibit a wide range of chemical structures, though they primarily originate from three key metabolic precursors: amino acids, isoprenoids, and lipids. Specific amino acids, such as tryptophan, methionine, phenylalanine, and arginine, contribute to the production of various phytohormones, including auxins, melatonin, ethylene, salicylic acid, and polyamines. Isoprenoids are the foundation of five phytohormone categories: cytokinins, brassinosteroids, gibberellins, abscisic acid, and strigolactones. Furthermore, lipids, i.e., α-linolenic acid, function as a precursor for jasmonic acid. The biosynthesis routes of these different plant hormones are intricately complex. Understanding of these processes can greatly enhance our knowledge of how these hormones regulate plant growth, development, and physiology. This review focuses on detailing the biosynthetic pathways of phytohormones.
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Affiliation(s)
- Andrzej Bajguz
- Department of Biology and Plant Ecology, Faculty of Biology, University of Bialystok, Ciolkowskiego 1J, 15-245 Bialystok, Poland;
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Pipitone R, Eicke S, Pfister B, Glauser G, Falconet D, Uwizeye C, Pralon T, Zeeman SC, Kessler F, Demarsy E. A multifaceted analysis reveals two distinct phases of chloroplast biogenesis during de-etiolation in Arabidopsis. eLife 2021; 10:e62709. [PMID: 33629953 PMCID: PMC7906606 DOI: 10.7554/elife.62709] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 02/04/2021] [Indexed: 11/18/2022] Open
Abstract
Light triggers chloroplast differentiation whereby the etioplast transforms into a photosynthesizing chloroplast and the thylakoid rapidly emerges. However, the sequence of events during chloroplast differentiation remains poorly understood. Using Serial Block Face Scanning Electron Microscopy (SBF-SEM), we generated a series of chloroplast 3D reconstructions during differentiation, revealing chloroplast number and volume and the extent of envelope and thylakoid membrane surfaces. Furthermore, we used quantitative lipid and whole proteome data to complement the (ultra)structural data, providing a time-resolved, multi-dimensional description of chloroplast differentiation. This showed two distinct phases of chloroplast biogenesis: an initial photosynthesis-enabling 'Structure Establishment Phase' followed by a 'Chloroplast Proliferation Phase' during cell expansion. Moreover, these data detail thylakoid membrane expansion during de-etiolation at the seedling level and the relative contribution and differential regulation of proteins and lipids at each developmental stage. Altogether, we establish a roadmap for chloroplast differentiation, a critical process for plant photoautotrophic growth and survival.
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Affiliation(s)
- Rosa Pipitone
- Plant Physiology Laboratory, University of NeuchâtelNeuchâtelSwitzerland
| | - Simona Eicke
- Institute of Molecular Plant Biology, Department of Biology, ETH ZurichZurichSwitzerland
| | - Barbara Pfister
- Institute of Molecular Plant Biology, Department of Biology, ETH ZurichZurichSwitzerland
| | - Gaetan Glauser
- Neuchâtel Platform of Analytical Chemistry, University of NeuchâtelNeuchâtelSwitzerland
| | - Denis Falconet
- Université Grenoble Alpes, CNRS, CEA, INRAE, IRIG-DBSCI-LPCVGrenobleFrance
| | - Clarisse Uwizeye
- Université Grenoble Alpes, CNRS, CEA, INRAE, IRIG-DBSCI-LPCVGrenobleFrance
| | - Thibaut Pralon
- Plant Physiology Laboratory, University of NeuchâtelNeuchâtelSwitzerland
| | - Samuel C Zeeman
- Institute of Molecular Plant Biology, Department of Biology, ETH ZurichZurichSwitzerland
| | - Felix Kessler
- Plant Physiology Laboratory, University of NeuchâtelNeuchâtelSwitzerland
| | - Emilie Demarsy
- Plant Physiology Laboratory, University of NeuchâtelNeuchâtelSwitzerland
- Department of Botany and Plant Biology, University of GenevaGenevaSwitzerland
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Hedden P. The Current Status of Research on Gibberellin Biosynthesis. PLANT & CELL PHYSIOLOGY 2020; 61:1832-1849. [PMID: 32652020 PMCID: PMC7758035 DOI: 10.1093/pcp/pcaa092] [Citation(s) in RCA: 123] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 06/21/2020] [Indexed: 05/23/2023]
Abstract
Gibberellins are produced by all vascular plants and several fungal and bacterial species that associate with plants as pathogens or symbionts. In the 60 years since the first experiments on the biosynthesis of gibberellic acid in the fungus Fusarium fujikuroi, research on gibberellin biosynthesis has advanced to provide detailed information on the pathways, biosynthetic enzymes and their genes in all three kingdoms, in which the production of the hormones evolved independently. Gibberellins function as hormones in plants, affecting growth and differentiation in organs in which their concentration is very tightly regulated. Current research in plants is focused particularly on the regulation of gibberellin biosynthesis and inactivation by developmental and environmental cues, and there is now considerable information on the molecular mechanisms involved in these processes. There have also been recent advances in understanding gibberellin transport and distribution and their relevance to plant development. This review describes our current understanding of gibberellin metabolism and its regulation, highlighting the more recent advances in this field.
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Affiliation(s)
- Peter Hedden
- Laboratory of Growth Regulators, Palack� University & Institute of Experimental Botany of the Czech Academy of Sciences, Šlechtitelů 27, 78371 Olomouc, Czech Republic
- Rothamsted Research, West Common, Harpenden, Hertfordshire AL5 2JQ, UK
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Medina CA, Hawkins C, Liu XP, Peel M, Yu LX. Genome-Wide Association and Prediction of Traits Related to Salt Tolerance in Autotetraploid Alfalfa ( Medicago sativa L.). Int J Mol Sci 2020; 21:ijms21093361. [PMID: 32397526 PMCID: PMC7247575 DOI: 10.3390/ijms21093361%20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 05/05/2020] [Accepted: 05/06/2020] [Indexed: 05/28/2023] Open
Abstract
Soil salinity is a growing problem in world production agriculture. Continued improvement in crop salt tolerance will require the implementation of innovative breeding strategies such as marker-assisted selection (MAS) and genomic selection (GS). Genetic analyses for yield and vigor traits under salt stress in alfalfa breeding populations with three different phenotypic datasets was assessed. Genotype-by-sequencing (GBS) developed markers with allele dosage and phenotypic data were analyzed by genome-wide association studies (GWAS) and GS using different models. GWAS identified 27 single nucleotide polymorphism (SNP) markers associated with salt tolerance. Mapping SNPs markers against the Medicago truncatula reference genome revealed several putative candidate genes based on their roles in response to salt stress. Additionally, eight GS models were used to estimate breeding values of the training population under salt stress. Highest prediction accuracies and root mean square errors were used to determine the best prediction model. The machine learning methods (support vector machine and random forest) performance best with the prediction accuracy of 0.793 for yield. The marker loci and candidate genes identified, along with optimized GS prediction models, were shown to be useful in improvement of alfalfa with enhanced salt tolerance. DNA markers and the outcome of the GS will be made available to the alfalfa breeding community in efforts to accelerate genetic gains, in the development of biotic stress tolerant and more productive modern-day alfalfa cultivars.
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Affiliation(s)
- Cesar Augusto Medina
- United States Department of Agriculture-Agricultural Research Service, Plant Germplasm Introduction and Testing Research, Prosser, WA 99350, USA; (C.A.M.); (C.H.); (X.-P.L.)
| | - Charles Hawkins
- United States Department of Agriculture-Agricultural Research Service, Plant Germplasm Introduction and Testing Research, Prosser, WA 99350, USA; (C.A.M.); (C.H.); (X.-P.L.)
- Current address: Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Xiang-Ping Liu
- United States Department of Agriculture-Agricultural Research Service, Plant Germplasm Introduction and Testing Research, Prosser, WA 99350, USA; (C.A.M.); (C.H.); (X.-P.L.)
- Current address: College of Animal Science & Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing 163316, Heilongjiang, China
| | - Michael Peel
- United States Department of Agriculture-Agricultural Research Service, Forage and Range Research Lab, Logan, UT 84322, USA;
| | - Long-Xi Yu
- United States Department of Agriculture-Agricultural Research Service, Plant Germplasm Introduction and Testing Research, Prosser, WA 99350, USA; (C.A.M.); (C.H.); (X.-P.L.)
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Medina CA, Hawkins C, Liu XP, Peel M, Yu LX. Genome-Wide Association and Prediction of Traits Related to Salt Tolerance in Autotetraploid Alfalfa ( Medicago sativa L.). Int J Mol Sci 2020; 21:E3361. [PMID: 32397526 PMCID: PMC7247575 DOI: 10.3390/ijms21093361] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 05/05/2020] [Accepted: 05/06/2020] [Indexed: 12/13/2022] Open
Abstract
Soil salinity is a growing problem in world production agriculture. Continued improvement in crop salt tolerance will require the implementation of innovative breeding strategies such as marker-assisted selection (MAS) and genomic selection (GS). Genetic analyses for yield and vigor traits under salt stress in alfalfa breeding populations with three different phenotypic datasets was assessed. Genotype-by-sequencing (GBS) developed markers with allele dosage and phenotypic data were analyzed by genome-wide association studies (GWAS) and GS using different models. GWAS identified 27 single nucleotide polymorphism (SNP) markers associated with salt tolerance. Mapping SNPs markers against the Medicago truncatula reference genome revealed several putative candidate genes based on their roles in response to salt stress. Additionally, eight GS models were used to estimate breeding values of the training population under salt stress. Highest prediction accuracies and root mean square errors were used to determine the best prediction model. The machine learning methods (support vector machine and random forest) performance best with the prediction accuracy of 0.793 for yield. The marker loci and candidate genes identified, along with optimized GS prediction models, were shown to be useful in improvement of alfalfa with enhanced salt tolerance. DNA markers and the outcome of the GS will be made available to the alfalfa breeding community in efforts to accelerate genetic gains, in the development of biotic stress tolerant and more productive modern-day alfalfa cultivars.
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Affiliation(s)
- Cesar Augusto Medina
- United States Department of Agriculture-Agricultural Research Service, Plant Germplasm Introduction and Testing Research, Prosser, WA 99350, USA; (C.A.M.); (C.H.); (X.-P.L.)
| | - Charles Hawkins
- United States Department of Agriculture-Agricultural Research Service, Plant Germplasm Introduction and Testing Research, Prosser, WA 99350, USA; (C.A.M.); (C.H.); (X.-P.L.)
- Current address: Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Xiang-Ping Liu
- United States Department of Agriculture-Agricultural Research Service, Plant Germplasm Introduction and Testing Research, Prosser, WA 99350, USA; (C.A.M.); (C.H.); (X.-P.L.)
- Current address: College of Animal Science & Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing 163316, Heilongjiang, China
| | - Michael Peel
- United States Department of Agriculture-Agricultural Research Service, Forage and Range Research Lab, Logan, UT 84322, USA;
| | - Long-Xi Yu
- United States Department of Agriculture-Agricultural Research Service, Plant Germplasm Introduction and Testing Research, Prosser, WA 99350, USA; (C.A.M.); (C.H.); (X.-P.L.)
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Reinbothe S, Bartsch S, Rossig C, Davis MY, Yuan S, Reinbothe C, Gray J. A Protochlorophyllide (Pchlide) a Oxygenase for Plant Viability. FRONTIERS IN PLANT SCIENCE 2019; 10:593. [PMID: 31156665 PMCID: PMC6530659 DOI: 10.3389/fpls.2019.00593] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 04/24/2019] [Indexed: 05/19/2023]
Abstract
Higher plants contain a small, 5-member family of Rieske non-heme oxygenases that comprise the inner plastid envelope protein TIC55, phaeophorbide a oxygenasee (PAO), chlorophyllide a oxygenase (CAO), choline monooxygenase, and a 52 kDa protein (PTC52) associated with the precursor NADPH:protochlorophyllide (Pchlide) oxidoreductase A (pPORA) A translocon (PTC). Some of these chloroplast proteins have documented roles in chlorophyll biosynthesis (CAO) and degradation (PAO and TIC55), whereas the function of PTC52 remains unresolved. Biochemical evidence provided here identifies PTC52 as Pchlide a oxygenase of the inner plastid envelope linking Pchlide b synthesis to pPORA import. Protochlorophyllide b is the preferred substrate of PORA and its lack no longer allows pPORA import. The Pchlide b-dependent import pathway of pPORA thus operates in etiolated seedlings and is switched off during greening. Using dexamethasone-induced RNA interference (RNAi) we tested if PTC52 is involved in controlling both, pPORA import and Pchlide homeostasis in planta. As shown here, RNAi plants deprived of PTC52 transcript and PTC52 protein were unable to import pPORA and died as a result of excess Pchlide a accumulation causing singlet oxygen formation during greening. In genetic studies, no homozygous ptc52 knock-out mutants could be obtained presumably as a result of embryo lethality, suggesting a role for PTC52 in the initial greening of plant embryos. Phylogenetic studies identified PTC52-like genes amongst unicellular photosynthetic bacteria and higher plants, suggesting that the biochemical function associated with PTC52 may have an ancient evolutionary origin. PTC52 also harbors conserved motifs with bacterial oxygenases such as the terminal oxygenase component of 3-ketosteroid 9-alpha-hydroxylase (KshA) from Rhodococcus rhodochrous. 3D-modeling of PTC52 structure permitted the prediction of amino acid residues that contribute to the substrate specificity of this enzyme. In vitro-mutagenesis was used to test the predicted PTC52 model and provide insights into the reaction mechanism of this Rieske non-heme oxygenase.
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Affiliation(s)
- Steffen Reinbothe
- Laboratoire de Génétique Moléculaire des Plantes and Biologie Environnementale et Systémique (BEeSy), Université Grenoble Alpes, Grenoble, France
- *Correspondence: Steffen Reinbothe, John Gray,
| | - Sandra Bartsch
- Laboratoire de Génétique Moléculaire des Plantes and Biologie Environnementale et Systémique (BEeSy), Université Grenoble Alpes, Grenoble, France
| | - Claudia Rossig
- Laboratoire de Génétique Moléculaire des Plantes and Biologie Environnementale et Systémique (BEeSy), Université Grenoble Alpes, Grenoble, France
| | | | - Shu Yuan
- College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Christiane Reinbothe
- Laboratoire de Génétique Moléculaire des Plantes and Biologie Environnementale et Systémique (BEeSy), Université Grenoble Alpes, Grenoble, France
| | - John Gray
- Department of Biological Sciences, The University of Toledo, Toledo, OH, United States
- *Correspondence: Steffen Reinbothe, John Gray,
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Eisenhut M, Hoecker N, Schmidt SB, Basgaran RM, Flachbart S, Jahns P, Eser T, Geimer S, Husted S, Weber APM, Leister D, Schneider A. The Plastid Envelope CHLOROPLAST MANGANESE TRANSPORTER1 Is Essential for Manganese Homeostasis in Arabidopsis. MOLECULAR PLANT 2018; 11:955-969. [PMID: 29734002 DOI: 10.1016/j.molp.2018.04.008] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 04/26/2018] [Accepted: 04/27/2018] [Indexed: 05/18/2023]
Abstract
The transition metal manganese (Mn) is indispensable for photoautotrophic growth since photosystem II (PSII) employs an inorganic Mn4CaO5 cluster for water splitting. Here, we show that the Arabidopsis membrane protein CHLOROPLAST MANGANESE TRANSPORTER1 (CMT1) is involved in chloroplast Mn homeostasis. CMT1 is the closest homolog of the previously characterized thylakoid Mn transporter PHOTOSYNTHESIS-AFFECTED MUTANT71 (PAM71). In contrast to PAM71, CMT1 resides at the chloroplast envelope and is ubiquitously expressed. Nonetheless, like PAM71, the expression of CMT1 can also alleviate the Mn-sensitive phenotype of yeast mutant Δpmr1. The cmt1 mutant is severely suppressed in growth, chloroplast ultrastructure, and PSII activity owing to a decrease in the amounts of pigments and thylakoid membrane proteins. The importance of CMT1 for chloroplast Mn homeostasis is demonstrated by the significant reduction in chloroplast Mn concentrations in cmt1-1, which exhibited reduced Mn binding in PSII complexes. Moreover, CMT1 expression is downregulated in Mn-surplus conditions. The pam71 cmt1-1double mutant resembles the cmt1-1 single mutant rather than pam71 in most respects. Taken together, our results suggest that CMT1 mediates Mn2+ uptake into the chloroplast stroma, and that CMT1 and PAM71 function sequentially in Mn delivery to PSII across the chloroplast envelope and the thylakoid membrane.
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Affiliation(s)
- Marion Eisenhut
- Biochemie der Pflanzen, Cluster of Excellence on Plant Science (CEPLAS), Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany.
| | - Natalie Hoecker
- Molekularbiologie der Pflanzen (Botanik), Department Biologie I, Ludwig-Maximilians-Universität München, 82152 Martinsried, Germany
| | - Sidsel Birkelund Schmidt
- Department of Plant and Environmental Sciences and Copenhagen Plant Science Centre (CPSC), Faculty of Science, University of Copenhagen, 1871 Frederiksberg, Denmark
| | - Rubek Merina Basgaran
- Biochemie der Pflanzen, Cluster of Excellence on Plant Science (CEPLAS), Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - Samantha Flachbart
- Biochemie der Pflanzen, Cluster of Excellence on Plant Science (CEPLAS), Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - Peter Jahns
- Biochemie der Pflanzen, Cluster of Excellence on Plant Science (CEPLAS), Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - Tabea Eser
- Molekularbiologie der Pflanzen (Botanik), Department Biologie I, Ludwig-Maximilians-Universität München, 82152 Martinsried, Germany
| | - Stefan Geimer
- Zellbiologie/Elektronenmikroskopie NW I/B1, Universität Bayreuth, 95447 Bayreuth, Germany
| | - Søren Husted
- Department of Plant and Environmental Sciences and Copenhagen Plant Science Centre (CPSC), Faculty of Science, University of Copenhagen, 1871 Frederiksberg, Denmark
| | - Andreas P M Weber
- Biochemie der Pflanzen, Cluster of Excellence on Plant Science (CEPLAS), Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - Dario Leister
- Molekularbiologie der Pflanzen (Botanik), Department Biologie I, Ludwig-Maximilians-Universität München, 82152 Martinsried, Germany
| | - Anja Schneider
- Molekularbiologie der Pflanzen (Botanik), Department Biologie I, Ludwig-Maximilians-Universität München, 82152 Martinsried, Germany.
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Zhu M, Lin J, Ye J, Wang R, Yang C, Gong J, Liu Y, Deng C, Liu P, Chen C, Cheng Y, Deng X, Zeng Y. A comprehensive proteomic analysis of elaioplasts from citrus fruits reveals insights into elaioplast biogenesis and function. HORTICULTURE RESEARCH 2018; 5:6. [PMID: 29423236 PMCID: PMC5802726 DOI: 10.1038/s41438-017-0014-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2017] [Revised: 12/07/2017] [Accepted: 12/10/2017] [Indexed: 05/02/2023]
Abstract
Elaioplasts of citrus peel are colorless plastids which accumulate significant amounts of terpenes. However, other functions of elaioplasts have not been fully characterized to date. Here, a LC-MS/MS shotgun technology was applied to identify the proteins from elaioplasts that were highly purified from young fruit peel of kumquat. A total of 655 putative plastid proteins were identified from elaioplasts according to sequence homology in silico and manual curation. Based on functional classification via Mapman, ~50% of the identified proteins fall into six categories, including protein metabolism, transport, and lipid metabolism. Of note, elaioplasts contained ATP synthase and ADP, ATP carrier proteins at high abundance, indicating important roles for ATP generation and transport in elaioplast biogenesis. Additionally, a comparison of proteins between citrus chromoplast and elaioplast proteomes suggest a high level of functional conservation. However, some distinctive protein profiles were also observed in both types of plastids notably for isoprene biosynthesis in elaioplasts, and carotenoid metabolism in chromoplasts. In conclusion, this comprehensive proteomic study provides new insights into the major metabolic pathways and unique characteristics of elaioplasts and chromoplasts in citrus fruit.
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Affiliation(s)
- Man Zhu
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan, 430070 China
- Institute of Citrus Science, Huazhong Agricultural University, Wuhan, 430070 China
| | - Jiajia Lin
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan, 430070 China
- Institute of Citrus Science, Huazhong Agricultural University, Wuhan, 430070 China
| | - Junli Ye
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan, 430070 China
- Institute of Citrus Science, Huazhong Agricultural University, Wuhan, 430070 China
| | - Rui Wang
- Shanghai Applied Protein Technology Co. Ltd, Shanghai, 200233 China
| | - Chao Yang
- Shanghai Applied Protein Technology Co. Ltd, Shanghai, 200233 China
| | - Jinli Gong
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan, 430070 China
- Institute of Citrus Science, Huazhong Agricultural University, Wuhan, 430070 China
| | - Yun Liu
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan, 430070 China
- Institute of Citrus Science, Huazhong Agricultural University, Wuhan, 430070 China
| | - Chongling Deng
- Guangxi Citrus Research Institute, Guangxi, 541004 China
| | - Ping Liu
- Guangxi Citrus Research Institute, Guangxi, 541004 China
| | - Chuanwu Chen
- Guangxi Citrus Research Institute, Guangxi, 541004 China
| | - Yunjiang Cheng
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan, 430070 China
- Institute of Citrus Science, Huazhong Agricultural University, Wuhan, 430070 China
| | - Xiuxin Deng
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan, 430070 China
- Institute of Citrus Science, Huazhong Agricultural University, Wuhan, 430070 China
| | - Yunliu Zeng
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan, 430070 China
- Institute of Citrus Science, Huazhong Agricultural University, Wuhan, 430070 China
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Broad W, Ling Q, Jarvis P. New Insights Into Roles of Ubiquitin Modification in Regulating Plastids and Other Endosymbiotic Organelles. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2016; 325:1-33. [PMID: 27241217 DOI: 10.1016/bs.ircmb.2016.02.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Recent findings have revealed important and diverse roles for the ubiquitin modification of proteins in the regulation of endosymbiotic organelles, which include the primary plastids of plants as well as complex plastids: the secondary endosymbiotic organelles of cryptophytes, alveolates, stramenopiles, and haptophytes. Ubiquitin modifications have a variety of potential consequences, both to the modified protein itself and to cellular regulation. The ubiquitin-proteasome system (UPS) can target individual proteins for selective degradation by the cytosolic 26S proteasome. Ubiquitin modifications can also signal the removal of whole endosymbiotic organelles, for example, via autophagy as has been well characterized in mitochondria. As plastids must import over 90% of their proteins from the cytosol, the observation that the UPS selectively targets the plastid protein import machinery is particularly significant. In this way, the UPS may influence the development and interconversions of different plastid types, as well as plastid responses to stress, by reconfiguring the organellar proteome. In complex plastids, the Symbiont-derived ERAD-Like Machinery (SELMA) has coopted the protein transport capabilities of the ER-Associated Degradation (ERAD) system, whereby misfolded proteins are retrotranslocated from ER for proteasomal degradation, uncoupling them from proteolysis: SELMA components have been retargeted to the second outermost plastid membrane to mediate protein import. In spite of this wealth of new information, there still remain a large number of unanswered questions and a need to define the roles of ubiquitin modification further in the regulation of plastids.
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Affiliation(s)
- W Broad
- Department of Plant Sciences, University of Oxford, Oxford, United Kingdom
| | - Q Ling
- Department of Plant Sciences, University of Oxford, Oxford, United Kingdom
| | - P Jarvis
- Department of Plant Sciences, University of Oxford, Oxford, United Kingdom.
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11
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Impaired Chloroplast Biogenesis in Immutans, an Arabidopsis Variegation Mutant, Modifies Developmental Programming, Cell Wall Composition and Resistance to Pseudomonas syringae. PLoS One 2016; 11:e0150983. [PMID: 27050746 PMCID: PMC4822847 DOI: 10.1371/journal.pone.0150983] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 02/21/2016] [Indexed: 12/20/2022] Open
Abstract
The immutans (im) variegation mutation of Arabidopsis has green- and white- sectored leaves due to action of a nuclear recessive gene. IM codes for PTOX, a plastoquinol oxidase in plastid membranes. Previous studies have revealed that the green and white sectors develop into sources (green tissues) and sinks (white tissues) early in leaf development. In this report we focus on white sectors, and show that their transformation into effective sinks involves a sharp reduction in plastid number and size. Despite these reductions, cells in the white sectors have near-normal amounts of plastid RNA and protein, and surprisingly, a marked amplification of chloroplast DNA. The maintenance of protein synthesis capacity in the white sectors might poise plastids for their development into other plastid types. The green and white im sectors have different cell wall compositions: whereas cell walls in the green sectors resemble those in wild type, cell walls in the white sectors have reduced lignin and cellulose microfibrils, as well as alterations in galactomannans and the decoration of xyloglucan. These changes promote susceptibility to the pathogen Pseudomonas syringae. Enhanced susceptibility can also be explained by repressed expression of some, but not all, defense genes. We suggest that differences in morphology, physiology and biochemistry between the green and white sectors is caused by a reprogramming of leaf development that is coordinated, in part, by mechanisms of retrograde (plastid-to-nucleus) signaling, perhaps mediated by ROS. We conclude that variegation mutants offer a novel system to study leaf developmental programming, cell wall metabolism and host-pathogen interactions.
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12
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Programmed chloroplast destruction during leaf senescence involves 13-lipoxygenase (13-LOX). Proc Natl Acad Sci U S A 2016; 113:3383-8. [PMID: 26969728 DOI: 10.1073/pnas.1525747113] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Leaf senescence is the terminal stage in the development of perennial plants. Massive physiological changes occur that lead to the shut down of photosynthesis and a cessation of growth. Leaf senescence involves the selective destruction of the chloroplast as the site of photosynthesis. Here, we show that 13-lipoxygenase (13-LOX) accomplishes a key role in the destruction of chloroplasts in senescing plants and propose a critical role of its NH2-terminal chloroplast transit peptide. The 13-LOX enzyme identified here accumulated in the plastid envelope and catalyzed the dioxygenation of unsaturated membrane fatty acids, leading to a selective destruction of the chloroplast and the release of stromal constituents. Because 13-LOX pathway products comprise compounds involved in insect deterrence and pathogen defense (volatile aldehydes and oxylipins), a mechanism of unmolested nitrogen and carbon relocation is suggested that occurs from leaves to seeds and roots during fall.
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13
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Abstract
Plastids are ubiquitously present in plants and are the organelles for carotenoid biosynthesis and storage. Based on their morphology and function, plastids are classified into various types, i.e. proplastids, etioplasts, chloroplasts, amyloplasts, and chromoplasts. All plastids, except proplastids, can synthesize carotenoids. However, plastid types have a profound effect on carotenoid accumulation and stability. In this chapter, we discuss carotenoid biosynthesis and regulation in various plastids with a focus on carotenoids in chromoplasts. Plastid transition related to carotenoid biosynthesis and the different capacity of various plastids to sequester carotenoids and the associated effect on carotenoid stability are described in light of carotenoid accumulation in plants.
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Affiliation(s)
- Li Li
- Robert W. Holley Center for Agriculture and Health, USDA-ARS, Plant Breeding and Genetics Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA.
| | - Hui Yuan
- Robert W. Holley Center for Agriculture and Health, USDA-ARS, Plant Breeding and Genetics Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA
| | - Yunliu Zeng
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan, China
| | - Qiang Xu
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan, China
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14
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Cell growth defect factor 1 is crucial for the plastid import of NADPH:protochlorophyllide oxidoreductase A in Arabidopsis thaliana. Proc Natl Acad Sci U S A 2015; 112:5838-43. [PMID: 25901327 DOI: 10.1073/pnas.1506339112] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Tetrapyrroles such as chlorophyll, heme, and bacteriochlorophyll play fundamental roles in the energy absorption and transduction of all photosynthetic organisms. They are synthesized via a complex pathway taking place in chloroplasts. Chlorophyll biosynthesis in angiosperms involves 16 steps of which only one is light-requiring and driven by the NADPH:protochlorophyllide oxidoreductase (POR). Three POR isoforms have been identified in Arabidopsis thaliana--designated PORA, PORB, and PORC--that are differentially expressed in etiolated, light-exposed, and light-adapted plants. All three isoforms are encoded by nuclear genes, are synthesized as larger precursors in the cytosol (pPORs), and are imported posttranslationally into the plastid compartment. Import of the precursor to the dark-specific isoform PORA (pPORA) is protochlorophyllide (Pchlide)-dependent and due to the operation of a unique translocon complex dubbed PTC (Pchlide-dependent translocon complex) in the plastid envelope. Here, we identified a ∼30-kDa protein that participates in pPORA import. The ∼30-kDa protein is identical to the previously identified CELL GROWTH DEFECT FACTOR 1 (CDF1) in Arabidopsis that is conserved in higher plants and Synechocystis. CDF1 operates in pPORA import and stabilization and hereby acts as a chaperone for PORA protein translocation. CDF1 permits tight interactions between Pchlide synthesized in the plastid envelope and the importing PORA polypeptide chain such that no photoexcitative damage occurs through the generation of singlet oxygen operating as a cell death inducer. Together, our results identify an ancient mechanism dating back to the endosymbiotic origin of chloroplasts as a key element of Pchlide-dependent pPORA import.
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15
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Chu CC, Li HM. Protein import into isolated pea root leucoplasts. FRONTIERS IN PLANT SCIENCE 2015; 6:690. [PMID: 26388889 PMCID: PMC4560022 DOI: 10.3389/fpls.2015.00690] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 08/20/2015] [Indexed: 05/06/2023]
Abstract
Leucoplasts are important organelles for the synthesis and storage of starch, lipids and proteins. However, molecular mechanism of protein import into leucoplasts and how it differs from that of import into chloroplasts remain unknown. We used pea seedlings for both chloroplast and leucoplast isolations to compare within the same species. We further optimized the isolation and import conditions to improve import efficiency and to permit a quantitative comparison between the two plastid types. The authenticity of the import was verified using a mitochondrial precursor protein. Our results show that, when normalized to Toc75, most translocon proteins are less abundant in leucoplasts than in chloroplasts. A precursor shown to prefer the receptor Toc132 indeed had relatively more similar import efficiencies between chloroplasts and leucoplasts compared to precursors that prefer Toc159. Furthermore we found two precursors that exhibited very high import efficiency into leucoplasts. Their transit peptides may be candidates for delivering transgenic proteins into leucoplasts and for analyzing motifs important for leucoplast import.
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Affiliation(s)
| | - Hsou-min Li
- *Correspondence: Hsou-min Li, Institute of Molecular Biology, Academia Sinica, Nankang, Taipei 11529, Taiwan,
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16
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Demarsy E, Lakshmanan AM, Kessler F. Border control: selectivity of chloroplast protein import and regulation at the TOC-complex. FRONTIERS IN PLANT SCIENCE 2014; 5:483. [PMID: 25278954 PMCID: PMC4166117 DOI: 10.3389/fpls.2014.00483] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Accepted: 09/01/2014] [Indexed: 05/25/2023]
Abstract
Plants have evolved complex and sophisticated molecular mechanisms to regulate their development and adapt to their surrounding environment. Particularly the development of their specific organelles, chloroplasts and other plastid-types, is finely tuned in accordance with the metabolic needs of the cell. The normal development and functioning of plastids require import of particular subsets of nuclear encoded proteins. Most preproteins contain a cleavable sequence at their N terminal (transit peptide) serving as a signal for targeting to the organelle and recognition by the translocation machinery TOC-TIC (translocon of outer membrane complex-translocon of inner membrane complex) spanning the dual membrane envelope. The plastid proteome needs constant remodeling in response to developmental and environmental factors. Therefore selective regulation of preprotein import plays a crucial role in plant development. In this review we describe the diversity of transit peptides and TOC receptor complexes, and summarize the current knowledge and potential directions for future research concerning regulation of the different Toc isoforms.
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Affiliation(s)
| | | | - Felix Kessler
- *Correspondence: Felix Kessler, Laboratory of Plant Physiology, Université de Neuchâtel, UniMail, Rue Emile Argand 11, 2000 Neuchâtel, Switzerland e-mail:
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17
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Sheng P, Tan J, Jin M, Wu F, Zhou K, Ma W, Heng Y, Wang J, Guo X, Zhang X, Cheng Z, Liu L, Wang C, Liu X, Wan J. Albino midrib 1, encoding a putative potassium efflux antiporter, affects chloroplast development and drought tolerance in rice. PLANT CELL REPORTS 2014; 33:1581-94. [PMID: 24917171 DOI: 10.1007/s00299-014-1639-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 05/17/2014] [Accepted: 05/26/2014] [Indexed: 05/21/2023]
Abstract
Mutation of the AM1 gene causes an albino midrib phenotype and enhances tolerance to drought in rice K(+) efflux antiporter (KEA) genes encode putative potassium efflux antiporters that are mainly located in plastid-containing organisms, ranging from lower green algae to higher flowering plants. However, little genetic evidence has been provided on the functions of KEA in chloroplast development. In this study, we isolated a rice mutant, albino midrib 1 (am1), with green- and white-variegation in the first few leaves, and albino midrib phenotype in older tissues. We found that AM1 encoded a putative KEA in chloroplast. AM1 was highly expressed in leaves, while lowly in roots. Chloroplast gene expression and proteins accumulation were affected during chlorophyll biosynthesis and photosynthesis in am1 mutants. Interestingly, AM1 was induced by salt and PEG, and am1 showed enhanced sensitivity to salinity in seed germination and increased tolerance to drought. Taken together, we concluded that KEAs were involved in chloroplast development and played important roles in drought tolerance.
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Affiliation(s)
- Peike Sheng
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, Hunan University, Changsha, 410082, Hunan, China
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18
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Pick TR, Weber APM. Unknown components of the plastidial permeome. FRONTIERS IN PLANT SCIENCE 2014; 5:410. [PMID: 25191333 PMCID: PMC4137279 DOI: 10.3389/fpls.2014.00410] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Accepted: 08/01/2014] [Indexed: 05/29/2023]
Abstract
Beyond their role in photosynthesis plastids provide a plethora of additional metabolic functions to plant cells. For example, they harbor complete biosynthetic pathways for the de novo synthesis of carotenoids, fatty acids, and amino acids. Furthermore plastids contribute important reactions to multi-compartmentalized pathways, such as photorespiration or plant hormone syntheses, and they depend on the import of essential molecules that they cannot synthesize themselves, such as ascorbic acid. This causes a high traffic of metabolites across the plastid envelope. Although it was recently shown that non-polar substrates could be exchanged between the plastid and the ER without involving transporters, various essential transport processes are mediated by highly selective but still unknown metabolite transporters. This review focuses on selected components of the plastidial permeome that are predicted to exist but that have not yet been identified as molecular entities, such as the transporters for isopentenyl diphosphate (IPP) or ascorbic acid.
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Affiliation(s)
| | - Andreas P. M. Weber
- *Correspondence: Andreas P. M. Weber, Institut für Biochemie der Pflanzen, Cluster of Excellence on Plant Sciences, Heinrich-Heine Universität Düsseldorf, Universitätstrasse 1, D-40225 Düsseldorf, Germany e-mail:
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19
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Plastidial transporters KEA1, -2, and -3 are essential for chloroplast osmoregulation, integrity, and pH regulation in Arabidopsis. Proc Natl Acad Sci U S A 2014; 111:7480-5. [PMID: 24794527 DOI: 10.1073/pnas.1323899111] [Citation(s) in RCA: 175] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Multiple K(+) transporters and channels and the corresponding mutants have been described and studied in the plasma membrane and organelle membranes of plant cells. However, knowledge about the molecular identity of chloroplast K(+) transporters is limited. Potassium transport and a well-balanced K(+) homeostasis were suggested to play important roles in chloroplast function. Because no loss-of-function mutants have been identified, the importance of K(+) transporters for chloroplast function and photosynthesis remains to be determined. Here, we report single and higher-order loss-of-function mutants in members of the cation/proton antiporters-2 antiporter superfamily KEA1, KEA2, and KEA3. KEA1 and KEA2 proteins are targeted to the inner envelope membrane of chloroplasts, whereas KEA3 is targeted to the thylakoid membrane. Higher-order but not single mutants showed increasingly impaired photosynthesis along with pale green leaves and severely stunted growth. The pH component of the proton motive force across the thylakoid membrane was significantly decreased in the kea1kea2 mutants, but increased in the kea3 mutant, indicating an altered chloroplast pH homeostasis. Electron microscopy of kea1kea2 leaf cells revealed dramatically swollen chloroplasts with disrupted envelope membranes and reduced thylakoid membrane density. Unexpectedly, exogenous NaCl application reversed the observed phenotypes. Furthermore, the kea1kea2 background enables genetic analyses of the functional significance of other chloroplast transporters as exemplified here in kea1kea2Na(+)/H(+) antiporter1 (nhd1) triple mutants. Taken together, the presented data demonstrate a fundamental role of inner envelope KEA1 and KEA2 and thylakoid KEA3 transporters in chloroplast osmoregulation, integrity, and ion and pH homeostasis.
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20
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Zeng Y, Pan Z, Wang L, Ding Y, Xu Q, Xiao S, Deng X. Phosphoproteomic analysis of chromoplasts from sweet orange during fruit ripening. PHYSIOLOGIA PLANTARUM 2014; 150:252-70. [PMID: 23786612 DOI: 10.1111/ppl.12080] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 05/18/2013] [Accepted: 05/27/2013] [Indexed: 05/18/2023]
Abstract
Like other types of plastids, chromoplasts have essential biosynthetic and metabolic activities which may be regulated via post-translational modifications, such as phosphorylation, of their resident proteins. We here report a proteome-wide mapping of in vivo phosphorylation sites in chromoplast-enriched samples prepared from sweet orange [Citrus sinensis (L.) Osbeck] at different ripening stages by titanium dioxide-based affinity chromatography for phosphoprotein enrichment with LC-MS/MS. A total of 109 plastid-localized phosphoprotein candidates were identified that correspond to 179 unique phosphorylation sites in 135 phosphopeptides. On the basis of Motif-X analysis, two distinct types of phosphorylation sites, one as proline-directed phosphorylation motif and the other as casein kinase II motif, can be generalized from these identified phosphopeptides. While most identified phosphoproteins show high homology to those already identified in plastids, approximately 22% of them are novel based on BLAST search using the public databases PhosPhAt and P(3) DB. A close comparative analysis showed that approximately 50% of the phosphoproteins identified in citrus chromoplasts find obvious counterparts in the chloroplast phosphoproteome, suggesting a rather high-level of conservation in basic metabolic activities in these two types of plastids. Not surprisingly, the phosphoproteome of citrus chromoplasts is also characterized by the lack of phosphoproteins involved in photosynthesis and by the presence of more phosphoproteins implicated in stress/redox responses. This study presents the first comprehensive phosphoproteomic analysis of chromoplasts and may help to understand how phosphorylation regulates differentiation of citrus chromoplasts during fruit ripening.
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Affiliation(s)
- Yunliu Zeng
- Key Laboratory of Horticultural Plant Biology of Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, PR China
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21
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Abstract
A genome-scale model (GSM) is an in silico metabolic model comprising hundreds or thousands of chemical reactions that constitute the metabolic inventory of a cell, tissue, or organism. A complete, accurate GSM, in conjunction with a simulation technique such as flux balance analysis (FBA), can be used to comprehensively predict cellular metabolic flux distributions for a given genotype and given environmental conditions. Apart from enabling a user to quantitatively visualize carbon flow through metabolic pathways, these flux predictions also facilitate the hypothesis of new network properties. By simulating the impacts of environmental stresses or genetic interventions on metabolism, GSMs can aid the formulation of nontrivial metabolic engineering strategies. GSMs for plants and other eukaryotes are significantly more complicated than those for prokaryotes due to their extensive compartmentalization and size. The reconstruction of a GSM involves creating an initial model, curating the model, and then rendering the model ready for FBA. Model reconstruction involves obtaining organism-specific reactions from the annotated genome sequence or organism-specific databases. Model curation involves determining metabolite protonation status or charge, ensuring that reactions are stoichiometrically balanced, assigning reactions to appropriate subcellular compartments, deleting generic reactions or creating specific versions of them, linking dead-end metabolites, and filling of pathway gaps to complete the model. Subsequently, the model requires the addition of transport, exchange, and biomass synthesis reactions to make it FBA-ready. This cycle of editing, refining, and curation has to be performed iteratively to obtain an accurate model. This chapter outlines the reconstruction and curation of GSMs with a focus on models of plant metabolism.
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22
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23
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Lee JY, Lee HS, Song JY, Jung YJ, Reinbothe S, Park YI, Lee SY, Pai HS. Cell growth defect factor1/chaperone-like protein of POR1 plays a role in stabilization of light-dependent protochlorophyllide oxidoreductase in Nicotiana benthamiana and Arabidopsis. THE PLANT CELL 2013; 25:3944-60. [PMID: 24151298 PMCID: PMC3877821 DOI: 10.1105/tpc.113.111096] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Revised: 09/11/2013] [Accepted: 09/30/2013] [Indexed: 05/20/2023]
Abstract
Angiosperms require light for chlorophyll biosynthesis because one reaction in the pathway, the reduction of protochlorophyllide (Pchlide) to chlorophyllide, is catalyzed by the light-dependent protochlorophyllide oxidoreductase (POR). Here, we report that Cell growth defect factor1 (Cdf1), renamed here as chaperone-like protein of POR1 (CPP1), an essential protein for chloroplast development, plays a role in the regulation of POR stability and function. Cdf1/CPP1 contains a J-like domain and three transmembrane domains, is localized in the thylakoid and envelope membranes, and interacts with POR isoforms in chloroplasts. CPP1 can stabilize POR proteins with its holdase chaperone activity. CPP1 deficiency results in diminished POR protein accumulation and defective chlorophyll synthesis, leading to photobleaching and growth inhibition of plants under light conditions. CPP1 depletion also causes reduced POR accumulation in etioplasts of dark-grown plants and as a result impairs the formation of prolamellar bodies, which subsequently affects chloroplast biogenesis upon illumination. Furthermore, in cyanobacteria, the CPP1 homolog critically regulates POR accumulation and chlorophyll synthesis under high-light conditions, in which the dark-operative Pchlide oxidoreductase is repressed by its oxygen sensitivity. These findings and the ubiquitous presence of CPP1 in oxygenic photosynthetic organisms suggest the conserved nature of CPP1 function in the regulation of POR.
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Affiliation(s)
- Jae-Yong Lee
- Department of Systems Biology, Yonsei University, Seoul 120-749, Korea
| | - Ho-Seok Lee
- Department of Systems Biology, Yonsei University, Seoul 120-749, Korea
| | - Ji-Young Song
- Department of Biological Science and Graduate School of Analytical Science and Technology, Chungnam National University, Daejeon 305-764, Korea
| | - Young Jun Jung
- Division of Applied Life Sciences, Gyeongsang National University, Jinju 660-701, Korea
| | - Steffen Reinbothe
- Biologie Environnementale et Systémique, Université Joseph Fourier LBFA, BP53F 38041 Grenoble cedex 9 France
| | - Youn-Il Park
- Department of Biological Science and Graduate School of Analytical Science and Technology, Chungnam National University, Daejeon 305-764, Korea
| | - Sang Yeol Lee
- Division of Applied Life Sciences, Gyeongsang National University, Jinju 660-701, Korea
| | - Hyun-Sook Pai
- Department of Systems Biology, Yonsei University, Seoul 120-749, Korea
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24
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Hildebrand M, Abbriano RM, Polle JEW, Traller JC, Trentacoste EM, Smith SR, Davis AK. Metabolic and cellular organization in evolutionarily diverse microalgae as related to biofuels production. Curr Opin Chem Biol 2013; 17:506-14. [PMID: 23538202 DOI: 10.1016/j.cbpa.2013.02.027] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Revised: 02/18/2013] [Accepted: 02/26/2013] [Indexed: 12/18/2022]
Abstract
Microalgae are among the most diverse organisms on the planet, and as a result of symbioses and evolutionary selection, the configuration of core metabolic networks is highly varied across distinct algal classes. The differences in photosynthesis, carbon fixation and processing, carbon storage, and the compartmentation of cellular and metabolic processes are substantial and likely to transcend into the efficiency of various steps involved in biofuel molecule production. By highlighting these differences, we hope to provide a framework for comparative analyses to determine the efficiency of the different arrangements or processes. This sets the stage for optimization on the based on information derived from evolutionary selection to diverse algal classes and to synthetic systems.
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Affiliation(s)
- Mark Hildebrand
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0202, USA.
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25
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Wang YQ, Yang Y, Fei Z, Yuan H, Fish T, Thannhauser TW, Mazourek M, Kochian LV, Wang X, Li L. Proteomic analysis of chromoplasts from six crop species reveals insights into chromoplast function and development. JOURNAL OF EXPERIMENTAL BOTANY 2013; 64:949-61. [PMID: 23314817 PMCID: PMC3580812 DOI: 10.1093/jxb/ers375] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Chromoplasts are unique plastids that accumulate massive amounts of carotenoids. To gain a general and comparative characterization of chromoplast proteins, this study performed proteomic analysis of chromoplasts from six carotenoid-rich crops: watermelon, tomato, carrot, orange cauliflower, red papaya, and red bell pepper. Stromal and membrane proteins of chromoplasts were separated by 1D gel electrophoresis and analysed using nLC-MS/MS. A total of 953-2262 proteins from chromoplasts of different crop species were identified. Approximately 60% of the identified proteins were predicted to be plastid localized. Functional classification using MapMan bins revealed large numbers of proteins involved in protein metabolism, transport, amino acid metabolism, lipid metabolism, and redox in chromoplasts from all six species. Seventeen core carotenoid metabolic enzymes were identified. Phytoene synthase, phytoene desaturase, ζ-carotene desaturase, 9-cis-epoxycarotenoid dioxygenase, and carotenoid cleavage dioxygenase 1 were found in almost all crops, suggesting relative abundance of them among the carotenoid pathway enzymes. Chromoplasts from different crops contained abundant amounts of ATP synthase and adenine nucleotide translocator, which indicates an important role of ATP production and transport in chromoplast development. Distinctive abundant proteins were observed in chromoplast from different crops, including capsanthin/capsorubin synthase and fibrillins in pepper, superoxide dismutase in watermelon, carrot, and cauliflower, and glutathione-S-transferease in papaya. The comparative analysis of chromoplast proteins among six crop species offers new insights into the general metabolism and function of chromoplasts as well as the uniqueness of chromoplasts in specific crop species. This work provides reference datasets for future experimental study of chromoplast biogenesis, development, and regulation in plants.
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Affiliation(s)
- Yong-Qiang Wang
- Department of Plant Breeding and Genetics, Cornell University, Ithaca, NY 14853, USA
- * These two authors contributed equally to this work
| | - Yong Yang
- USDA-ARS, Robert W. Holley Center for Agriculture and Health, Cornell University, Ithaca, NY 14853, USA
- To whom correspondence should be addressed. E-mail:
| | - Zhangjun Fei
- USDA-ARS, Robert W. Holley Center for Agriculture and Health, Cornell University, Ithaca, NY 14853, USA
- Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, NY 14853, USA
| | - Hui Yuan
- Department of Plant Breeding and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Tara Fish
- USDA-ARS, Robert W. Holley Center for Agriculture and Health, Cornell University, Ithaca, NY 14853, USA
| | - Theodore W. Thannhauser
- USDA-ARS, Robert W. Holley Center for Agriculture and Health, Cornell University, Ithaca, NY 14853, USA
| | - Michael Mazourek
- Department of Plant Breeding and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Leon V. Kochian
- USDA-ARS, Robert W. Holley Center for Agriculture and Health, Cornell University, Ithaca, NY 14853, USA
| | - Xiaowu Wang
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Li Li
- Department of Plant Breeding and Genetics, Cornell University, Ithaca, NY 14853, USA
- USDA-ARS, Robert W. Holley Center for Agriculture and Health, Cornell University, Ithaca, NY 14853, USA
- To whom correspondence should be addressed. E-mail:
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26
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Simm S, Papasotiriou DG, Ibrahim M, Leisegang MS, Müller B, Schorge T, Karas M, Mirus O, Sommer MS, Schleiff E. Defining the core proteome of the chloroplast envelope membranes. FRONTIERS IN PLANT SCIENCE 2013; 4:11. [PMID: 23390424 PMCID: PMC3565376 DOI: 10.3389/fpls.2013.00011] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Accepted: 01/15/2013] [Indexed: 05/20/2023]
Abstract
High-throughput protein localization studies require multiple strategies. Mass spectrometric analysis of defined cellular fractions is one of the complementary approaches to a diverse array of cell biological methods. In recent years, the protein content of different cellular (sub-)compartments was approached. Despite of all the efforts made, the analysis of membrane fractions remains difficult, in that the dissection of the proteomes of the envelope membranes of chloroplasts or mitochondria is often not reliable because sample purity is not always warranted. Moreover, proteomic studies are often restricted to single (model) species, and therefore limited in respect to differential individual evolution. In this study we analyzed the chloroplast envelope proteomes of different plant species, namely, the individual proteomes of inner and outer envelope (OE) membrane of Pisum sativum and the mixed envelope proteomes of Arabidopsis thaliana and Medicago sativa. The analysis of all three species yielded 341 identified proteins in total, 247 of them being unique. 39 proteins were genuine envelope proteins found in at least two species. Based on this and previous envelope studies we defined the core envelope proteome of chloroplasts. Comparing the general overlap of the available six independent studies (including ours) revealed only a number of 27 envelope proteins. Depending on the stringency of applied selection criteria we found 231 envelope proteins, while less stringent criteria increases this number to 649 putative envelope proteins. Based on the latter we provide a map of the outer and inner envelope core proteome, which includes many yet uncharacterized proteins predicted to be involved in transport, signaling, and response. Furthermore, a foundation for the functional characterization of yet unidentified functions of the inner and OE for further analyses is provided.
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Affiliation(s)
- Stefan Simm
- Institute of Molecular Cell Biology of Plants, Goethe UniversityFrankfurt, Germany
| | | | - Mohamed Ibrahim
- Institute of Molecular Cell Biology of Plants, Goethe UniversityFrankfurt, Germany
| | | | - Bernd Müller
- Department of Biology I, Ludwig-Maximilians-UniversityMunich, Germany
| | - Tobias Schorge
- Institute of Pharmaceutical Chemistry, Goethe UniversityFrankfurt, Germany
| | - Michael Karas
- Institute of Pharmaceutical Chemistry, Goethe UniversityFrankfurt, Germany
- Center of Membrane Proteomics, Goethe UniversityFrankfurt, Germany
- Cluster of Excellence ‘Macromolecular Complexes’, Goethe UniversityFrankfurt, Germany
| | - Oliver Mirus
- Institute of Molecular Cell Biology of Plants, Goethe UniversityFrankfurt, Germany
| | - Maik S. Sommer
- Institute of Molecular Cell Biology of Plants, Goethe UniversityFrankfurt, Germany
| | - Enrico Schleiff
- Institute of Molecular Cell Biology of Plants, Goethe UniversityFrankfurt, Germany
- Center of Membrane Proteomics, Goethe UniversityFrankfurt, Germany
- Cluster of Excellence ‘Macromolecular Complexes’, Goethe UniversityFrankfurt, Germany
- *Correspondence: Enrico Schleiff, Center of Membrane Proteomics, Cluster of Excellence ’Macromolecular Complexes’, Institute of Molecular Cell Biology of Plants, Goethe University, Max-von-Laue Strasse 9, Frankfurt 60438, Germany. e-mail:
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27
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Rolland N, Curien G, Finazzi G, Kuntz M, Maréchal E, Matringe M, Ravanel S, Seigneurin-Berny D. The Biosynthetic Capacities of the Plastids and Integration Between Cytoplasmic and Chloroplast Processes. Annu Rev Genet 2012; 46:233-64. [DOI: 10.1146/annurev-genet-110410-132544] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Norbert Rolland
- Laboratoire de Physiologie Cellulaire et Végétale, CNRS/Université Joseph Fourier Grenoble I/INRA/CEA, 38054 Grenoble Cedex 9, France; , , , , , , ,
| | - Gilles Curien
- Laboratoire de Physiologie Cellulaire et Végétale, CNRS/Université Joseph Fourier Grenoble I/INRA/CEA, 38054 Grenoble Cedex 9, France; , , , , , , ,
| | - Giovanni Finazzi
- Laboratoire de Physiologie Cellulaire et Végétale, CNRS/Université Joseph Fourier Grenoble I/INRA/CEA, 38054 Grenoble Cedex 9, France; , , , , , , ,
| | - Marcel Kuntz
- Laboratoire de Physiologie Cellulaire et Végétale, CNRS/Université Joseph Fourier Grenoble I/INRA/CEA, 38054 Grenoble Cedex 9, France; , , , , , , ,
| | - Eric Maréchal
- Laboratoire de Physiologie Cellulaire et Végétale, CNRS/Université Joseph Fourier Grenoble I/INRA/CEA, 38054 Grenoble Cedex 9, France; , , , , , , ,
| | - Michel Matringe
- Laboratoire de Physiologie Cellulaire et Végétale, CNRS/Université Joseph Fourier Grenoble I/INRA/CEA, 38054 Grenoble Cedex 9, France; , , , , , , ,
| | - Stéphane Ravanel
- Laboratoire de Physiologie Cellulaire et Végétale, CNRS/Université Joseph Fourier Grenoble I/INRA/CEA, 38054 Grenoble Cedex 9, France; , , , , , , ,
| | - Daphné Seigneurin-Berny
- Laboratoire de Physiologie Cellulaire et Végétale, CNRS/Université Joseph Fourier Grenoble I/INRA/CEA, 38054 Grenoble Cedex 9, France; , , , , , , ,
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28
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Huang M, Friso G, Nishimura K, Qu X, Olinares PDB, Majeran W, Sun Q, van Wijk KJ. Construction of Plastid Reference Proteomes for Maize and Arabidopsis and Evaluation of Their Orthologous Relationships; The Concept of Orthoproteomics. J Proteome Res 2012. [DOI: 10.1021/pr300952g] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Mingshu Huang
- Department
of Plant Biology and ‡Computational Biology Service Unit, Cornell University, Ithaca, New York 14853, United States
| | - Giulia Friso
- Department
of Plant Biology and ‡Computational Biology Service Unit, Cornell University, Ithaca, New York 14853, United States
| | - Kenji Nishimura
- Department
of Plant Biology and ‡Computational Biology Service Unit, Cornell University, Ithaca, New York 14853, United States
| | - Xian Qu
- Department
of Plant Biology and ‡Computational Biology Service Unit, Cornell University, Ithaca, New York 14853, United States
| | - Paul Dominic B. Olinares
- Department
of Plant Biology and ‡Computational Biology Service Unit, Cornell University, Ithaca, New York 14853, United States
| | - Wojciech Majeran
- Department
of Plant Biology and ‡Computational Biology Service Unit, Cornell University, Ithaca, New York 14853, United States
| | - Qi Sun
- Department
of Plant Biology and ‡Computational Biology Service Unit, Cornell University, Ithaca, New York 14853, United States
| | - Klaas J. van Wijk
- Department
of Plant Biology and ‡Computational Biology Service Unit, Cornell University, Ithaca, New York 14853, United States
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29
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Shi LX, Theg SM. The chloroplast protein import system: from algae to trees. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1833:314-31. [PMID: 23063942 DOI: 10.1016/j.bbamcr.2012.10.002] [Citation(s) in RCA: 138] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Revised: 09/07/2012] [Accepted: 10/01/2012] [Indexed: 01/15/2023]
Abstract
Chloroplasts are essential organelles in the cells of plants and algae. The functions of these specialized plastids are largely dependent on the ~3000 proteins residing in the organelle. Although chloroplasts are capable of a limited amount of semiautonomous protein synthesis - their genomes encode ~100 proteins - they must import more than 95% of their proteins after synthesis in the cytosol. Imported proteins generally possess an N-terminal extension termed a transit peptide. The importing translocons are made up of two complexes in the outer and inner envelope membranes, the so-called Toc and Tic machineries, respectively. The Toc complex contains two precursor receptors, Toc159 and Toc34, a protein channel, Toc75, and a peripheral component, Toc64/OEP64. The Tic complex consists of as many as eight components, namely Tic22, Tic110, Tic40, Tic20, Tic21 Tic62, Tic55 and Tic32. This general Toc/Tic import pathway, worked out largely in pea chloroplasts, appears to operate in chloroplasts in all green plants, albeit with significant modifications. Sub-complexes of the Toc and Tic machineries are proposed to exist to satisfy different substrate-, tissue-, cell- and developmental requirements. In this review, we summarize our understanding of the functions of Toc and Tic components, comparing these components of the import machinery in green algae through trees. We emphasize recent findings that point to growing complexities of chloroplast protein import process, and use the evolutionary relationships between proteins of different species in an attempt to define the essential core translocon components and those more likely to be responsible for regulation. This article is part of a Special Issue entitled: Protein Import and Quality Control in Mitochondria and Plastids.
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Affiliation(s)
- Lan-Xin Shi
- Department of Plant Biology, University of California-Davis, One Shields Avenue, Davis, CA 95616, USA.
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30
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Aranda-Sicilia MN, Cagnac O, Chanroj S, Sze H, Rodríguez-Rosales MP, Venema K. Arabidopsis KEA2, a homolog of bacterial KefC, encodes a K(+)/H(+) antiporter with a chloroplast transit peptide. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2012; 1818:2362-71. [PMID: 22551943 DOI: 10.1016/j.bbamem.2012.04.011] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Revised: 04/10/2012] [Accepted: 04/16/2012] [Indexed: 01/10/2023]
Abstract
KEA genes encode putative K(+) efflux antiporters that are predominantly found in algae and plants but are rare in metazoa; however, nothing is known about their functions in eukaryotic cells. Plant KEA proteins show homology to bacterial K(+) efflux (Kef) transporters, though two members in the Arabidopsis thaliana family, AtKEA1 and AtKEA2, have acquired an extra hydrophilic domain of over 500 residues at the amino terminus. We show that AtKEA2 is highly expressed in leaves, stems and flowers, but not in roots, and that an N-terminal peptide of the protein is targeted to chloroplasts in Arabidopsis cotyledons. The full-length AtKEA2 protein was inactive when expressed in yeast; however, a truncated AtKEA2 protein (AtsKEA2) lacking the N-terminal domain complemented disruption of the Na(+)(K(+))/H(+) antiporter Nhx1p to confer hygromycin resistance and tolerance to Na(+) or K(+) stress. To test transport activity, purified truncated AtKEA2 was reconstituted in proteoliposomes containing the fluorescent probe pyranine. Monovalent cations reduced an imposed pH gradient (acid inside) indicating AtsKEA2 mediated cation/H(+) exchange with preference for K(+)=Cs(+)>Li(+)>Na(+). When a conserved Asp(721) in transmembrane helix 6 that aligns to the cation binding Asp(164) of Escherichia coli NhaA was replaced with Ala, AtsKEA2 was completely inactivated. Mutation of a Glu(835) between transmembrane helix 8 and 9 in AtsKEA2 also resulted in loss of activity suggesting this region has a regulatory role. Thus, AtKEA2 represents the founding member of a novel group of eukaryote K(+)/H(+) antiporters that modulate monovalent cation and pH homeostasis in plant chloroplasts or plastids.
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31
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Pudelski B, Schock A, Hoth S, Radchuk R, Weber H, Hofmann J, Sonnewald U, Soll J, Philippar K. The plastid outer envelope protein OEP16 affects metabolic fluxes during ABA-controlled seed development and germination. JOURNAL OF EXPERIMENTAL BOTANY 2012; 63:1919-36. [PMID: 22155670 PMCID: PMC3295387 DOI: 10.1093/jxb/err375] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2011] [Revised: 10/15/2011] [Accepted: 10/21/2011] [Indexed: 05/20/2023]
Abstract
Previously, the OEP16.1 channel pore in the outer envelope membrane of mature pea (Pisum sativum) chloroplasts in vitro has been characterized to be selective for amino acids. Isolation of OEP16.2, a second OEP16 isoform from pea, in the current study allowed membrane localization and gene expression of OEP16 to be followed throughout seed development and germination of Arabidopsis thaliana and P. sativum. Thereby it can be shown on the transcript and protein level that the isoforms OEP16.1 and OEP16.2 in both plant species are alternating: whereas OEP16.1 is prominent in early embryo development and first leaves of the growing plantlet, OEP16.2 dominates in late seed development stages, which are associated with dormancy and desiccation, as well as early germination events. Further, OEP16.2 expression in seeds is under control of the phytohormone abscisic acid (ABA), leading to an ABA-hypersensitive phenotype of germinating oep16 knockout mutants. In consequence, the loss of OEP16 causes metabolic imbalance, in particular that of amino acids during seed development and early germination. It is thus concluded that in vivo OEP16 most probably functions in shuttling amino acids across the outer envelope of seed plastids.
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Affiliation(s)
- Birgit Pudelski
- Biochemie und Physiologie der Pflanzen, Department Biologie I, Botanik, Ludwig-Maximilians-Universität München, D-82152 Planegg-Martinsried, Germany
- Munich Centre for Integrated Protein Science CiPSM, Ludwig-Maximilians-Universität München, D-81377 München, Germany
| | - Annette Schock
- Biochemie und Physiologie der Pflanzen, Department Biologie I, Botanik, Ludwig-Maximilians-Universität München, D-82152 Planegg-Martinsried, Germany
- Munich Centre for Integrated Protein Science CiPSM, Ludwig-Maximilians-Universität München, D-81377 München, Germany
| | - Stefan Hoth
- Molekulare Pflanzenphysiologie, Department Biologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstrasse 5, D-91058 Erlangen, Germany
- Pflanzenphysiologie, Biozentrum Klein Flottbek, Universität Hamburg, Ohnhorststrabe 18, D-22609 Hamburg, Germany
| | - Ruslana Radchuk
- Leibniz-Institut für Pflanzengenetik und Kulturpflanzenforschung (IPK), Corrensstrasse 3, D-06466 Gatersleben, Germany
| | - Hans Weber
- Leibniz-Institut für Pflanzengenetik und Kulturpflanzenforschung (IPK), Corrensstrasse 3, D-06466 Gatersleben, Germany
| | - Jörg Hofmann
- Biochemie, Department Biologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstrasse 5, D-91058 Erlangen, Germany
| | - Uwe Sonnewald
- Biochemie, Department Biologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstrasse 5, D-91058 Erlangen, Germany
| | - Jürgen Soll
- Biochemie und Physiologie der Pflanzen, Department Biologie I, Botanik, Ludwig-Maximilians-Universität München, D-82152 Planegg-Martinsried, Germany
- Munich Centre for Integrated Protein Science CiPSM, Ludwig-Maximilians-Universität München, D-81377 München, Germany
| | - Katrin Philippar
- Biochemie und Physiologie der Pflanzen, Department Biologie I, Botanik, Ludwig-Maximilians-Universität München, D-82152 Planegg-Martinsried, Germany
- Munich Centre for Integrated Protein Science CiPSM, Ludwig-Maximilians-Universität München, D-81377 München, Germany
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32
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Breuers FKH, Bräutigam A, Geimer S, Welzel UY, Stefano G, Renna L, Brandizzi F, Weber APM. Dynamic Remodeling of the Plastid Envelope Membranes - A Tool for Chloroplast Envelope in vivo Localizations. FRONTIERS IN PLANT SCIENCE 2012; 3:7. [PMID: 22645566 PMCID: PMC3355811 DOI: 10.3389/fpls.2012.00007] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2011] [Accepted: 01/05/2012] [Indexed: 05/20/2023]
Abstract
Two envelope membranes delimit plastids, the defining organelles of plant cells. The inner and outer envelope membranes are unique in their protein and lipid composition. Several studies have attempted to establish the proteome of these two membranes; however, differentiating between them is difficult due to their close proximity. Here, we describe a novel approach to distinguish the localization of proteins between the two membranes using a straightforward approach based on live cell imaging coupled with transient expression. We base our approach on analyses of the distribution of GFP-fusions, which were aimed to verify outer envelope membrane proteomics data. To distinguish between outer envelope and inner envelope protein localization, we used AtTOC64-GFP and AtTIC40-GFP, as respective controls. During our analyses, we observed membrane proliferations and loss of chloroplast shape in conditions of protein over-expression. The morphology of the proliferations varied in correlation with the suborganellar distribution of the over-expressed proteins. In particular, while layers of membranes built up in the inner envelope membrane, the outer envelope formed long extensions into the cytosol. Using electron microscopy, we showed that these extensions were stromules, a dynamic feature of plastids. Since the behavior of the membranes is different and is related to the protein localization, we propose that in vivo studies based on the analysis of morphological differences of the membranes can be used to distinguish between inner and outer envelope localizations of proteins. To demonstrate the applicability of this approach, we demonstrated the localization of AtLACS9 to the outer envelope membrane. We also discuss protein impact on membrane behavior and regulation of protein insertion into membranes, and provide new hypotheses on the formation of stromules.
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Affiliation(s)
| | - Andrea Bräutigam
- Institute for Plant Biochemistry, Heinrich Heine University DüsseldorfDüsseldorf, Germany
| | - Stefan Geimer
- Electron Microscopy Laboratory, Institute for Cell Biology, University of BayreuthBayreuth, Germany
| | - Ulla Y. Welzel
- Electron Microscopy Laboratory, Institute for Cell Biology, University of BayreuthBayreuth, Germany
| | - Giovanni Stefano
- Plant Research Laboratory, Department of Energy, Michigan State UniversityEast Lansing, MI, USA
| | - Luciana Renna
- Plant Research Laboratory, Department of Energy, Michigan State UniversityEast Lansing, MI, USA
| | - Federica Brandizzi
- Plant Research Laboratory, Department of Energy, Michigan State UniversityEast Lansing, MI, USA
| | - Andreas P. M. Weber
- Institute for Plant Biochemistry, Heinrich Heine University DüsseldorfDüsseldorf, Germany
- *Correspondence: Andreas P. M. Weber, Institute for Plant Biochemistry, Heinrich Heine University, Geb. 26.03.01, Universitätsstrasse 1, D-40225 Düsseldorf, Germany. e-mail:
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33
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Yang Y, Jin H, Chen Y, Lin W, Wang C, Chen Z, Han N, Bian H, Zhu M, Wang J. A chloroplast envelope membrane protein containing a putative LrgB domain related to the control of bacterial death and lysis is required for chloroplast development in Arabidopsis thaliana. THE NEW PHYTOLOGIST 2012; 193:81-95. [PMID: 21916894 DOI: 10.1111/j.1469-8137.2011.03867.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
• A protein encoded by At1g32080 was consistently identified in proteomic studies of Arabidopsis chloroplast envelope membranes, but its function remained unclear. The protein, designated AtLrgB, may have evolved from a gene fusion of lrgA and lrgB. In bacteria, two homologous operons, lrgAB and cidAB, participate in an emerging mechanism to control cell death and lysis. • We aim to characterize AtLrgB using reverse genetics and cell biological and biochemical analysis. • AtLrgB is expressed in leaves, but not in roots. T-DNA insertion mutation of AtLrgB produced plants with interveinal chlorotic and premature necrotic leaves. Overexpression of full-length AtLrgB (or its LrgA and LrgB domains, separately), under the control of CaMV 35S promoter, produced plants exhibiting veinal chlorosis and delayed greening. At the end of light period, the T-DNA mutant had high starch and low sucrose contents in leaves, while the 35S:AtLrgB plants had low starch and high sucrose contents. Metabolite profiling revealed that AtLrgB appeared not to directly transport triose phosphate or hexose phosphates. In yeast cells, AtLrgB could augment nystatin-induced membrane permeability. • Our work indicates that AtLrgB is a new player in chloroplast development, carbon partitioning and leaf senescence, although its molecular mechanism remains to be established.
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Affiliation(s)
- Yanjun Yang
- Institute of Genetics, College of Life Sciences, Zhejiang University, Zijingang Campus, Hangzhou 310058, China
| | - Haiyan Jin
- Institute of Genetics, College of Life Sciences, Zhejiang University, Zijingang Campus, Hangzhou 310058, China
| | - Yong Chen
- Institute of Genetics, College of Life Sciences, Zhejiang University, Zijingang Campus, Hangzhou 310058, China
| | - Weiqiang Lin
- Institute of Genetics, College of Life Sciences, Zhejiang University, Zijingang Campus, Hangzhou 310058, China
| | - Chaoqun Wang
- Institute of Genetics, College of Life Sciences, Zhejiang University, Zijingang Campus, Hangzhou 310058, China
| | - Zhehao Chen
- Institute of Genetics, College of Life Sciences, Zhejiang University, Zijingang Campus, Hangzhou 310058, China
| | - Ning Han
- Institute of Genetics, College of Life Sciences, Zhejiang University, Zijingang Campus, Hangzhou 310058, China
| | - Hongwu Bian
- Institute of Genetics, College of Life Sciences, Zhejiang University, Zijingang Campus, Hangzhou 310058, China
| | - Muyuan Zhu
- Institute of Genetics, College of Life Sciences, Zhejiang University, Zijingang Campus, Hangzhou 310058, China
| | - Junhui Wang
- Institute of Genetics, College of Life Sciences, Zhejiang University, Zijingang Campus, Hangzhou 310058, China
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34
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Irigoyen S, Karlsson PM, Kuruvilla J, Spetea C, Versaw WK. The sink-specific plastidic phosphate transporter PHT4;2 influences starch accumulation and leaf size in Arabidopsis. PLANT PHYSIOLOGY 2011; 157:1765-77. [PMID: 21960139 PMCID: PMC3327177 DOI: 10.1104/pp.111.181925] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Accepted: 09/29/2011] [Indexed: 05/03/2023]
Abstract
Nonphotosynthetic plastids are important sites for the biosynthesis of starch, fatty acids, and amino acids. The uptake and subsequent use of cytosolic ATP to fuel these and other anabolic processes would lead to the accumulation of inorganic phosphate (Pi) if not balanced by a Pi export activity. However, the identity of the transporter(s) responsible for Pi export is unclear. The plastid-localized Pi transporter PHT4;2 of Arabidopsis (Arabidopsis thaliana) is expressed in multiple sink organs but is nearly restricted to roots during vegetative growth. We identified and used pht4;2 null mutants to confirm that PHT4;2 contributes to Pi transport in isolated root plastids. Starch accumulation was limited in pht4;2 roots, which is consistent with the inhibition of starch synthesis by excess Pi as a result of a defect in Pi export. Reduced starch accumulation in leaves and altered expression patterns for starch synthesis genes and other plastid transporter genes suggest metabolic adaptation to the defect in roots. Moreover, pht4;2 rosettes, but not roots, were significantly larger than those of the wild type, with 40% greater leaf area and twice the biomass when plants were grown with a short (8-h) photoperiod. Increased cell proliferation accounted for the larger leaf size and biomass, as no changes were detected in mature cell size, specific leaf area, or relative photosynthetic electron transport activity. These data suggest novel signaling between roots and leaves that contributes to the regulation of leaf size.
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Affiliation(s)
| | | | | | | | - Wayne K. Versaw
- Department of Biology and Interdepartmental Program in Molecular and Environmental Plant Sciences, Texas A&M University, College Station, Texas 77843 (S.I., W.K.V.); Division of Molecular Genetics, Department of Physics, Chemistry, and Biology, Linköping University, 581 83 Linkoeping, Sweden (P.M.K., J.K., C.S.); Department of Plant and Environmental Sciences, University of Gothenburg, 405 30 Gothenburg, Sweden (P.M.K., C.S.)
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35
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Gilliham M, Athman A, Tyerman SD, Conn SJ. Cell-specific compartmentation of mineral nutrients is an essential mechanism for optimal plant productivity--another role for TPC1? PLANT SIGNALING & BEHAVIOR 2011; 6:1656-61. [PMID: 22067997 PMCID: PMC3329329 DOI: 10.4161/psb.6.11.17797] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Vacuoles of different leaf cell-types vary in their capacity to store specific mineral elements. In Arabidopsis thaliana potassium (K) accumulates preferentially in epidermal and bundle sheath cells whereas calcium (Ca) and magnesium (Mg) are stored at high concentrations only in mesophyll cells. Accumulation of these elements in a particular vacuole can be reciprocal, i.e. as [K]vac increases [Ca]vac decreases. Mesophyll-specific Ca-storage involves CAX1 (a Ca2+/H+ antiporter) and Mg-storage involves MRS2-1/MGT2 and MRS2-5/MGT3 (both Mg2+-transporters), all of which are preferentially expressed in the mesophyll and encode tonoplast-localised proteins. However, what controls leaf-cell [K]vac is less well understood. TPC1 encodes the two-pore Ca2+ channel protein responsible for the tonoplast-localised SV cation conductance, and is highly expressed in cell-types that not preferentially accumulate Ca. Here, we evaluate evidence that TPC1 has a role in maintaining differential K and Ca storage across the leaf, and propose a function for TPC1 in releasing Ca2+ from epidermal and bundle sheath cell vacuoles to maintain low [Ca]vac. Mesophyll-specific Ca storage is essential to maintain apoplastic free Ca concentration at a level that does not perturb a range of physiological parameters including leaf gas exchange, cell wall extensibility and growth. When plants are grown under serpentine conditions (high Mg/Ca ratio), MGT2/MRS2-1 and MGT3/MRS2-5 are required to sequester additional Mg2+ in vacuoles to replace Ca2+ as an osmoticum to maintain growth. An updated model of Ca2+ and Mg2+ transport in leaves is presented as a reference for future interrogation of nutritional flows and elemental storage in plant leaves.
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Affiliation(s)
- Matthew Gilliham
- School of Agriculture, Food, and Wine & Waite Research Institute, University of Adelaide, Glen Osmond, South Australia, Australia.
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36
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Inoue K. Emerging roles of the chloroplast outer envelope membrane. TRENDS IN PLANT SCIENCE 2011; 16:550-7. [PMID: 21775189 DOI: 10.1016/j.tplants.2011.06.005] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Revised: 06/11/2011] [Accepted: 06/15/2011] [Indexed: 05/25/2023]
Abstract
The chloroplast is essential for the viability of plants. It is enclosed by a double-membrane envelope that originated from the outer and plasma membranes of a cyanobacterial endosymbiont. Chloroplast biogenesis depends on binary fission and import of nuclear-encoded proteins. Our understanding of the mechanisms and evolutionary origins of these processes has been greatly advanced by recent genetic and biochemical studies on envelope-localized multiprotein machines. Furthermore, the latest studies on outer envelope proteins have provided molecular insights into organelle movement and membrane lipid remodeling, activities that are vital for plant survival under diverse environmental conditions. Ongoing and future research on the chloroplast outer envelope should add to our knowledge of organelle biology and the evolution of eukaryotic cells.
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Affiliation(s)
- Kentaro Inoue
- Department of Plant Sciences, University of California, Davis, CA 95616, USA.
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37
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Agrawal GK, Bourguignon J, Rolland N, Ephritikhine G, Ferro M, Jaquinod M, Alexiou KG, Chardot T, Chakraborty N, Jolivet P, Doonan JH, Rakwal R. Plant organelle proteomics: collaborating for optimal cell function. MASS SPECTROMETRY REVIEWS 2011; 30:772-853. [PMID: 21038434 DOI: 10.1002/mas.20301] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2009] [Revised: 02/02/2010] [Accepted: 02/02/2010] [Indexed: 05/10/2023]
Abstract
Organelle proteomics describes the study of proteins present in organelle at a particular instance during the whole period of their life cycle in a cell. Organelles are specialized membrane bound structures within a cell that function by interacting with cytosolic and luminal soluble proteins making the protein composition of each organelle dynamic. Depending on organism, the total number of organelles within a cell varies, indicating their evolution with respect to protein number and function. For example, one of the striking differences between plant and animal cells is the plastids in plants. Organelles have their own proteins, and few organelles like mitochondria and chloroplast have their own genome to synthesize proteins for specific function and also require nuclear-encoded proteins. Enormous work has been performed on animal organelle proteomics. However, plant organelle proteomics has seen limited work mainly due to: (i) inter-plant and inter-tissue complexity, (ii) difficulties in isolation of subcellular compartments, and (iii) their enrichment and purity. Despite these concerns, the field of organelle proteomics is growing in plants, such as Arabidopsis, rice and maize. The available data are beginning to help better understand organelles and their distinct and/or overlapping functions in different plant tissues, organs or cell types, and more importantly, how protein components of organelles behave during development and with surrounding environments. Studies on organelles have provided a few good reviews, but none of them are comprehensive. Here, we present a comprehensive review on plant organelle proteomics starting from the significance of organelle in cells, to organelle isolation, to protein identification and to biology and beyond. To put together such a systematic, in-depth review and to translate acquired knowledge in a proper and adequate form, we join minds to provide discussion and viewpoints on the collaborative nature of organelles in cell, their proper function and evolution.
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Affiliation(s)
- Ganesh Kumar Agrawal
- Research Laboratory for Biotechnology and Biochemistry (RLABB), P.O. Box 13265, Sanepa, Kathmandu, Nepal.
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Tarantino D, Morandini P, Ramirez L, Soave C, Murgia I. Identification of an Arabidopsis mitoferrinlike carrier protein involved in Fe metabolism. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2011; 49:520-9. [PMID: 21371898 DOI: 10.1016/j.plaphy.2011.02.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Accepted: 02/03/2011] [Indexed: 05/22/2023]
Abstract
Iron has a major role in mitochondrial as well as in chloroplast metabolism, however the processes involved in organelle iron transport in plants are only partially understood. To identify mitochondrial iron transporters in Arabidopsis, we searched for proteins homologous to the Danio rerio (zebrafish) Mitoferrin2 MFRN2, a mitochondrial iron importer in non-erythroid cells. Among the identified putative Arabidopsis mitoferrinlike proteins, we focused on that one encoded by At5g42130, which we named AtMfl1 (MitoFerrinLike1). AtMfl1 expression strongly correlates with genes coding for proteins involved in chloroplast metabolism. Such an unexpected result is supported by the identification by different research groups, of the protein encoded by At5g42130 and of its homologs from various plant species in the inner chloroplastic envelope membrane proteome. Notably, neither the protein encoded by At5g42130 nor its homologs from other plant species have been identified in the mitochondrial proteome. AtMfl1 gene expression is dependent on Fe supply: AtMfl1 transcript strongly accumulates under Fe excess, moderately under Fe sufficiency and weakly under Fe deficiency. In order to understand the physiological role of AtMfl1, we isolated and characterized two independent AtMfl1 KO mutants, atmfl1-1 and atmfl1-2: both show reduced vegetative growth. When grown under conditions of Fe excess, atmfl1-1 and atmfl1-2 mutants (seedlings, rosette leaves) contain less total Fe than wt and also reduced expression of the iron storage ferritin AtFer1. Taken together, these results suggest that Arabidopsis mitoferrinlike gene AtMfl1 is involved in Fe transport into chloroplasts, under different conditions of Fe supply and that suppression of its expression alters plant Fe accumulation in various developmental stages.
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Affiliation(s)
- Delia Tarantino
- Sezione di Fisiologia e Biochimica delle Piante, Dipartimento di Biologia, Università degli Studi di Milano, via Celoria 26, 20133 Italy
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Fischer K. The import and export business in plastids: transport processes across the inner envelope membrane. PLANT PHYSIOLOGY 2011; 155:1511-9. [PMID: 21263040 PMCID: PMC3091126 DOI: 10.1104/pp.110.170241] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Accepted: 01/20/2011] [Indexed: 05/17/2023]
Affiliation(s)
- Karsten Fischer
- Institute for Arctic and Marine Biology, University of Tromsø, 9037 Tromsø, Norway.
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Infanger S, Bischof S, Hiltbrunner A, Agne B, Baginsky S, Kessler F. The chloroplast import receptor Toc90 partially restores the accumulation of Toc159 client proteins in the Arabidopsis thaliana ppi2 mutant. MOLECULAR PLANT 2011; 4:252-63. [PMID: 21220583 DOI: 10.1093/mp/ssq071] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Successful import of hundreds of nucleus-encoded proteins is essential for chloroplast biogenesis. The import of cytosolic precursor proteins relies on the Toc- (translocon at the outer chloroplast membrane) and Tic- (translocon at the inner chloroplast membrane) complexes. In Arabidopsis thaliana, precursor recognition is mainly mediated by outer membrane receptors belonging to two gene families: Toc34/33 and Toc159/132/120/90. The role in import and precursor selectivity of these receptors has been intensively studied, but the function of Toc90 still remains unclear. Here, we report the ability of Toc90 to support the import of Toc159 client proteins. We show that the overexpression of Toc90 partially complements the albino knockout of Toc159 and restores photoautotrophic growth. Several lines of evidence including proteome profiling demonstrate the import and accumulation of proteins essential for chloroplast biogenesis and functionality.
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Affiliation(s)
- Sibylle Infanger
- Laboratoire de physiologie végétale, Université de Neuchâtel, Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland
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Breuers FKH, Bräutigam A, Weber APM. The Plastid Outer Envelope - A Highly Dynamic Interface between Plastid and Cytoplasm. FRONTIERS IN PLANT SCIENCE 2011; 2:97. [PMID: 22629266 PMCID: PMC3355566 DOI: 10.3389/fpls.2011.00097] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Accepted: 11/29/2011] [Indexed: 05/09/2023]
Abstract
Plastids are the defining organelles of all photosynthetic eukaryotes. They are the site of photosynthesis and of a large number of other essential metabolic pathways, such as fatty acid and amino acid biosyntheses, sulfur and nitrogen assimilation, and aromatic and terpenoid compound production, to mention only a few examples. The metabolism of plastids is heavily intertwined and connected with that of the surrounding cytosol, thus causing massive traffic of metabolic precursors, intermediates, and products. Two layers of biological membranes that are called the inner (IE) and the outer (OE) plastid envelope membranes bound the plastids of Archaeplastida. While the IE is generally accepted as the osmo-regulatory barrier between cytosol and stroma, the OE was considered to represent an unspecific molecular sieve, permeable for molecules of up to 10 kDa. However, after the discovery of small substrate specific pores in the OE, this view has come under scrutiny. In addition to controlling metabolic fluxes between plastid and cytosol, the OE is also crucial for protein import into the chloroplast. It contains the receptors and translocation channel of the TOC complex that is required for the canonical post-translational import of nuclear-encoded, plastid-targeted proteins. Further, the OE is a metabolically active compartment of the chloroplast, being involved in, e.g., fatty acid metabolism and membrane lipid production. Also, recent findings hint on the OE as a defense platform against several biotic and abiotic stress conditions, such as cold acclimation, freezing tolerance, and phosphate deprivation. Moreover, dynamic non-covalent interactions between the OE and the endomembrane system are thought to play important roles in lipid and non-canonical protein trafficking between plastid and endoplasmic reticulum. While proteomics and bioinformatics has provided us with comprehensive but still incomplete information on proteins localized in the plastid IE, the stroma, and the thylakoids, our knowledge of the protein composition of the plastid OE is far from complete. In this article, we report on the recent progress in discovering novel OE proteins to draw a conclusive picture of the OE. A "parts list" of the plastid OE will be presented, using data generated by proteomics of plastids isolated from various plant sources.
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Affiliation(s)
| | - Andrea Bräutigam
- Institut für Biochemie der Pflanzen, Heinrich-Heine Universität DüsseldorfDüsseldorf, Germany
| | - Andreas P. M. Weber
- Institut für Biochemie der Pflanzen, Heinrich-Heine Universität DüsseldorfDüsseldorf, Germany
- *Correspondence: Andreas P. M. Weber, Institut für Biochemie der Pflanzen, Heinrich-Heine Universität Düsseldorf, Universitätstrasse 1, D-40225 Düsseldorf, Germany. e-mail:
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Armbruster U, Pesaresi P, Pribil M, Hertle A, Leister D. Update on chloroplast research: new tools, new topics, and new trends. MOLECULAR PLANT 2011; 4:1-16. [PMID: 20924030 DOI: 10.1093/mp/ssq060] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Chloroplasts, the green differentiation form of plastids, are the sites of photosynthesis and other important plant functions. Genetic and genomic technologies have greatly boosted the rate of discovery and functional characterization of chloroplast proteins during the past decade. Indeed, data obtained using high-throughput methodologies, in particular proteomics and transcriptomics, are now routinely used to assign functions to chloroplast proteins. Our knowledge of many chloroplast processes, notably photosynthesis and photorespiration, has reached such an advanced state that biotechnological approaches to crop improvement now seem feasible. Meanwhile, efforts to identify the entire complement of chloroplast proteins and their interactions are progressing rapidly, making the organelle a prime target for systems biology research in plants.
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Affiliation(s)
- Ute Armbruster
- Lehrstuhl für Molekularbiologie der Pflanzen (Botanik), Department Biologie I, Ludwig-Maximilians-Universität München, Großhaderner Str. 2, D-82152 Planegg-Martinsried, Germany
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Weber APM, Linka N. Connecting the plastid: transporters of the plastid envelope and their role in linking plastidial with cytosolic metabolism. ANNUAL REVIEW OF PLANT BIOLOGY 2011; 62:53-77. [PMID: 21526967 DOI: 10.1146/annurev-arplant-042110-103903] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Plastids have a multitude of functions in eukaryotic cells, ranging from photosynthesis to storage, and a role in essential biosynthetic pathways. All plastids are of either primary or higher-order endosymbiotic origin. That is, either a photosynthetic cyanobacterium was integrated into a mitochondriate eukaryotic host cell (primary endosymbiosis) or a plastid-bearing eukaryotic cell merged with another eukaryotic cell (secondary or higher-order endosymbioses), thereby passing on the plastid between various eukaryotic lineages. For all of these endosymbioses to become functional, it was essential to establish metabolic connections between organelle and host cell. Here, we review the present understanding of metabolite exchange between plastids and the surrounding cytosol in the context of the endosymbiotic origin of plastids in various eukaryotic lineages. We show that only a small number of transporters that can be traced down to the primary endosymbiotic event are conserved between plastids of diverse origins.
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Affiliation(s)
- Andreas P M Weber
- Institute of Plant Biochemistry, Heinrich-Heine Universität Düsseldorf, 40225 Düsseldorf, Germany.
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Pudelski B, Kraus S, Soll J, Philippar K. The plant PRAT proteins - preprotein and amino acid transport in mitochondria and chloroplasts. PLANT BIOLOGY (STUTTGART, GERMANY) 2010; 12 Suppl 1:42-55. [PMID: 20712620 DOI: 10.1111/j.1438-8677.2010.00357.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The membrane proteins of the plant preprotein and amino acid transporter (PRAT) superfamily all share common structural elements, such as four membrane-spanning alpha-helices. Interestingly they display diverse localisation to outer and inner membranes of chloroplasts and mitochondria. Furthermore, they fulfil different functions in preprotein translocation as well as amino acid transport across these membranes. This review summarises current knowledge on precursor protein import and amino acid transport in plastids and mitochondria and provides an overview of the distinct tasks and features of members of the PRAT superfamily in the model plant Arabidopsis thaliana.
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Affiliation(s)
- B Pudelski
- Biochemie und Physiologie der Pflanzen, Department Biologie I, Botanik, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
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Andrès C, Agne B, Kessler F. The TOC complex: preprotein gateway to the chloroplast. BIOCHIMICA ET BIOPHYSICA ACTA 2010; 1803:715-23. [PMID: 20226817 DOI: 10.1016/j.bbamcr.2010.03.004] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2009] [Revised: 02/26/2010] [Accepted: 03/03/2010] [Indexed: 01/22/2023]
Abstract
Photosynthetic eukaryotes strongly depend on chloroplast metabolic pathways. Most if not all involve nuclear encoded proteins. These are synthesized as cytosolic preproteins with N-terminal, cleavable targeting sequences (transit peptide). Preproteins are imported by a major pathway composed of two proteins complexes: TOC and TIC (Translocon of the Outer and Inner membranes of the Chloroplasts, respectively). These selectively recognize the preproteins and facilitate their transport across the chloroplast envelope. The TOC core complex consists of three types of components, each belonging to a small family: Toc34, Toc75 and Toc159. Toc34 and Toc159 isoforms represent a subfamily of the GTPase superfamily. The members of the Toc34 and Toc159 subfamily act as GTP-dependent receptors at the chloroplast surface and distinct members of each occur in defined, substrate-specific TOC complexes. Toc75, a member of the Omp85 family, is conserved from prokaryotes and functions as the unique protein-conducting channel at the outer membrane. In this review we will describe the current state of knowledge regarding the composition and function of the TOC complex.
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Affiliation(s)
- Charles Andrès
- Institut de Biologie, Université de Neuchâtel, CH-2009 Neuchâtel, Switzerland
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Chen M, Thelen JJ. The plastid isoform of triose phosphate isomerase is required for the postgerminative transition from heterotrophic to autotrophic growth in Arabidopsis. THE PLANT CELL 2010; 22:77-90. [PMID: 20097871 PMCID: PMC2828694 DOI: 10.1105/tpc.109.071837] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
During postgerminative seedling establishment, reserves stored during seed filling are mobilized to provide energy and carbon for the growing seedling until autotrophic growth is possible. A plastid isoform of triose phosphate isomerase (pdTPI) plays a crucial role in this transition from heterotrophic to autotrophic growth. A T-DNA insertion in Arabidopsis thaliana pdTPI resulted in a fivefold reduction in transcript, reduced TPI activity, and a severely stunted and chlorotic seedling that accumulated dihydroxyacetone phosphate (DHAP), glycerol, and glycerol-3-phosphate. Methylglyoxal (MG), a by-product of DHAP, also accumulated in the pdtpi mutant. Wild-type seed sown in the presence of any of these four metabolites resulted in a phenocopy of this pdtpi mutant, although MG and DHAP were the most effective based upon dosage. These metabolites (except MG) are by-products of triacylglycerol mobilization and precursors for glycerolipid synthesis, suggesting that lipid metabolism may also be affected. Lipid profiling revealed lower monogalactosyl but higher digalactosyl lipids. It is unclear whether the change in lipid composition is a direct or indirect consequence of the pdtpi mutation, as ribulose-1,5-bis-phosphate carboxylase/oxygenase expression, chloroplast morphology, and starch synthesis are also defective in this mutant. We propose that DHAP and MG accumulation in developing plastids delays the transition from heterotrophic to autotrophic growth, possibly due to MG toxicity.
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Abstract
Due to the presence of plastids, eukaryotic photosynthetic cells represent the most highly compartmentalized eukaryotic cells. This high degree of compartmentation requires the transport of solutes across intracellular membrane systems by specific membrane transporters. In this review, we summarize the recent progress on functionally characterized intracellular plant membrane transporters and we link transporter functions to Arabidopsis gene identifiers and to the transporter classification system. In addition, we outline challenges in further elucidating the plant membrane permeome and we provide an outline of novel approaches for the functional characterization of membrane transporters.
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Affiliation(s)
- Nicole Linka
- Institute of Plant Biochemistry, Heinrich-Heine Universität Düsseldorf, Geb. 26.03.01, Universitätsstrasse 1, Düsseldorf, Germany
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