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Nam JW, Lee HG, Do H, Kim HU, Seo PJ. Transcriptional regulation of triacylglycerol accumulation in plants under environmental stress conditions. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:2905-2917. [PMID: 35560201 DOI: 10.1093/jxb/erab554] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 12/15/2021] [Indexed: 06/15/2023]
Abstract
Triacylglycerol (TAG), a major energy reserve in lipid form, accumulates mainly in seeds. Although TAG concentrations are usually low in vegetative tissues because of the repression of seed maturation programs, these programs are derepressed upon the exposure of vegetative tissues to environmental stresses. Metabolic reprogramming of TAG accumulation is driven primarily by transcriptional regulation. A substantial proportion of transcription factors regulating seed TAG biosynthesis also participates in stress-induced TAG accumulation in vegetative tissues. TAG accumulation leads to the formation of lipid droplets and plastoglobules, which play important roles in plant tolerance to environmental stresses. Toxic lipid intermediates generated from environmental-stress-induced lipid membrane degradation are captured by TAG-containing lipid droplets and plastoglobules. This review summarizes recent advances in the transcriptional control of metabolic reprogramming underlying stress-induced TAG accumulation, and provides biological insight into the plant adaptive strategy, linking TAG biosynthesis with plant survival.
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Affiliation(s)
- Jeong-Won Nam
- Department of Chemistry, Seoul National University, Seoul, South Korea
| | - Hong Gil Lee
- Plant Genomics and Breeding Institute, Seoul National University, Seoul, South Korea
| | - Hyungju Do
- Department of Bioindustry and Bioresource Engineering, Plant Engineering Research Institute, Sejong University, Seoul, South Korea
| | - Hyun Uk Kim
- Department of Bioindustry and Bioresource Engineering, Plant Engineering Research Institute, Sejong University, Seoul, South Korea
| | - Pil Joon Seo
- Department of Chemistry, Seoul National University, Seoul, South Korea
- Plant Genomics and Breeding Institute, Seoul National University, Seoul, South Korea
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2
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Perlikowski D, Lechowicz K, Skirycz A, Michaelis Ä, Pawłowicz I, Kosmala A. The Role of Triacylglycerol in the Protection of Cells against Lipotoxicity under Drought in Lolium multiflorum/Festucaarundinacea Introgression Forms. PLANT & CELL PHYSIOLOGY 2022; 63:353-368. [PMID: 34994787 DOI: 10.1093/pcp/pcac003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 12/08/2021] [Accepted: 01/05/2022] [Indexed: 06/14/2023]
Abstract
Triacylglycerol is a key lipid compound involved in maintaining homeostasis of both membrane lipids and free fatty acids (FFA) in plant cells under adverse environmental conditions. However, its role in the process of lipid remodeling has not been fully recognized, especially in monocots, including grass species. For our study, two closely related introgression forms of Lolium multiflorum (Italian ryegrass) and Festuca arundinacea (tall fescue), distinct in their level of drought tolerance, were selected as plant models to study rearrangements in plant lipidome under water deficit and further re-watering. The low drought tolerant (LDT) form revealed an elevated level of cellular membrane damage accompanied by an increased content of polyunsaturated FFA and triacylglycerol under water deficit, compared with the high drought tolerant (HDT) form. However, the LDT introgression form demonstrated also the ability to regenerate its membranes after stress cessation. The obtained results clearly indicated that accumulation of triacylglycerol under advanced drought in the LDT form could serve as a cellular protective mechanism against overaccumulation of toxic polyunsaturated FFA and other lipid intermediates. Furthermore, accumulation of triacylglycerol under drought conditions could serve also as storage of substrates required for further regeneration of membranes after stress cessation. The rearrangements in triacylglycerol metabolism were supported by the upregulation of several genes, involved in a biosynthesis of triacylglycerol. With respect to this process, diacylglycerol O-acyltransferase DGAT2 seems to play the most important role in the analyzed grasses.
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Affiliation(s)
- Dawid Perlikowski
- Department of Environmental Stress Biology, Institute of Plant Genetics, Polish Academy of Sciences, Strzeszyńska 34, Poznań 60-479, Poland
| | - Katarzyna Lechowicz
- Department of Environmental Stress Biology, Institute of Plant Genetics, Polish Academy of Sciences, Strzeszyńska 34, Poznań 60-479, Poland
| | - Aleksandra Skirycz
- Department of Molecular Physiology, Max-Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, Potsdam-Golm 14476, Germany
- Boyce Thompson Institute, 533 Tower Rd., Ithaca, NY 14853, USA
| | - Änna Michaelis
- Department of Molecular Physiology, Max-Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, Potsdam-Golm 14476, Germany
| | - Izabela Pawłowicz
- Department of Environmental Stress Biology, Institute of Plant Genetics, Polish Academy of Sciences, Strzeszyńska 34, Poznań 60-479, Poland
| | - Arkadiusz Kosmala
- Department of Environmental Stress Biology, Institute of Plant Genetics, Polish Academy of Sciences, Strzeszyńska 34, Poznań 60-479, Poland
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3
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Klińska S, Kędzierska S, Jasieniecka-Gazarkiewicz K, Banaś A. In Vitro Growth Conditions Boost Plant Lipid Remodelling and Influence Their Composition. Cells 2021; 10:2326. [PMID: 34571973 PMCID: PMC8472737 DOI: 10.3390/cells10092326] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 08/31/2021] [Accepted: 09/03/2021] [Indexed: 02/07/2023] Open
Abstract
Acyl-lipids are vital components for all life functions of plants. They are widely studied using often in vitro conditions to determine inter alia the impact of genetic modifications and the description of biochemical and physiological functions of enzymes responsible for acyl-lipid metabolism. What is currently lacking is knowledge of if these results also hold in real environments-in in vivo conditions. Our study focused on the comparative analysis of both in vitro and in vivo growth conditions and their impact on the acyl-lipid metabolism of Camelina sativa leaves. The results indicate that in vitro conditions significantly decreased the lipid contents and influenced their composition. In in vitro conditions, galactolipid and trienoic acid (16:3 and 18:3) contents significantly declined, indicating the impairment of the prokaryotic pathway. Discrepancies also exist in the case of acyl-CoA:lysophospholipid acyltransferases (LPLATs). Their activity increased about 2-7 times in in vitro conditions compared to in vivo. In vitro conditions also substantially changed LPLATs' preferences towards acyl-CoA. Additionally, the acyl editing process was three times more efficient in in vitro leaves. The provided evidence suggests that the results of acyl-lipid research from in vitro conditions may not completely reflect and be directly applicable in real growth environments.
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Affiliation(s)
- Sylwia Klińska
- Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, 80-307 Gdansk, Poland; (S.K.); (K.J.-G.); (A.B.)
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Billey E, Hafidh S, Cruz-Gallardo I, Litholdo CG, Jean V, Carpentier MC, Picart C, Kumar V, Kulichova K, Maréchal E, Honys D, Conte MR, Deragon JM, Bousquet-Antonelli C. LARP6C orchestrates posttranscriptional reprogramming of gene expression during hydration to promote pollen tube guidance. THE PLANT CELL 2021; 33:2637-2661. [PMID: 34124761 PMCID: PMC8408461 DOI: 10.1093/plcell/koab131] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 05/06/2021] [Indexed: 05/15/2023]
Abstract
Increasing evidence suggests that posttranscriptional regulation is a key player in the transition between mature pollen and the progamic phase (from pollination to fertilization). Nonetheless, the actors in this messenger RNA (mRNA)-based gene expression reprogramming are poorly understood. We demonstrate that the evolutionarily conserved RNA-binding protein LARP6C is necessary for the transition from dry pollen to pollen tubes and the guided growth of pollen tubes towards the ovule in Arabidopsis thaliana. In dry pollen, LARP6C binds to transcripts encoding proteins that function in lipid synthesis and homeostasis, vesicular trafficking, and polarized cell growth. LARP6C also forms cytoplasmic granules that contain the poly(A) binding protein and possibly represent storage sites for translationally silent mRNAs. In pollen tubes, the loss of LARP6C negatively affects the quantities and distribution of storage lipids, as well as vesicular trafficking. In Nicotiana benthamiana leaf cells and in planta, analysis of reporter mRNAs designed from the LARP6C target MGD2 provided evidence that LARP6C can shift from a repressor to an activator of translation when the pollen grain enters the progamic phase. We propose that LARP6C orchestrates the timely posttranscriptional regulation of a subset of mRNAs in pollen during the transition from the quiescent to active state and along the progamic phase to promote male fertilization in plants.
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Affiliation(s)
- Elodie Billey
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
| | - Said Hafidh
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, 16502 Prague 6, Czech Republic
| | - Isabel Cruz-Gallardo
- Randall Centre for Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK
| | - Celso G. Litholdo
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
| | - Viviane Jean
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
| | - Marie-Christine Carpentier
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
| | - Claire Picart
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
| | - Vinod Kumar
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, 16502 Prague 6, Czech Republic
| | - Katarina Kulichova
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, 16502 Prague 6, Czech Republic
| | - Eric Maréchal
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168 CNRS, CEA, INRAE, Université Grenoble Alpes, IRIG, CEA Grenoble, 38054 Grenoble, France
| | - David Honys
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, 16502 Prague 6, Czech Republic
| | - Maria R. Conte
- Randall Centre for Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK
| | - Jean-Marc Deragon
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
- Institut Universitaire de France, 75231 Paris Cedex 5, France
| | - Cécile Bousquet-Antonelli
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
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5
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Billey E, Hafidh S, Cruz-Gallardo I, Litholdo CG, Jean V, Carpentier MC, Picart C, Kumar V, Kulichova K, Maréchal E, Honys D, Conte MR, Deragon JM, Bousquet-Antonelli C. LARP6C orchestrates posttranscriptional reprogramming of gene expression during hydration to promote pollen tube guidance. THE PLANT CELL 2021; 33:2637-2661. [PMID: 34124761 DOI: 10.1101/2020.11.27.401307] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 05/06/2021] [Indexed: 05/19/2023]
Abstract
Increasing evidence suggests that posttranscriptional regulation is a key player in the transition between mature pollen and the progamic phase (from pollination to fertilization). Nonetheless, the actors in this messenger RNA (mRNA)-based gene expression reprogramming are poorly understood. We demonstrate that the evolutionarily conserved RNA-binding protein LARP6C is necessary for the transition from dry pollen to pollen tubes and the guided growth of pollen tubes towards the ovule in Arabidopsis thaliana. In dry pollen, LARP6C binds to transcripts encoding proteins that function in lipid synthesis and homeostasis, vesicular trafficking, and polarized cell growth. LARP6C also forms cytoplasmic granules that contain the poly(A) binding protein and possibly represent storage sites for translationally silent mRNAs. In pollen tubes, the loss of LARP6C negatively affects the quantities and distribution of storage lipids, as well as vesicular trafficking. In Nicotiana benthamiana leaf cells and in planta, analysis of reporter mRNAs designed from the LARP6C target MGD2 provided evidence that LARP6C can shift from a repressor to an activator of translation when the pollen grain enters the progamic phase. We propose that LARP6C orchestrates the timely posttranscriptional regulation of a subset of mRNAs in pollen during the transition from the quiescent to active state and along the progamic phase to promote male fertilization in plants.
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Affiliation(s)
- Elodie Billey
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
| | - Said Hafidh
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, 16502 Prague 6, Czech Republic
| | - Isabel Cruz-Gallardo
- Randall Centre for Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK
| | - Celso G Litholdo
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
| | - Viviane Jean
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
| | - Marie-Christine Carpentier
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
| | - Claire Picart
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
| | - Vinod Kumar
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, 16502 Prague 6, Czech Republic
| | - Katarina Kulichova
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, 16502 Prague 6, Czech Republic
| | - Eric Maréchal
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168 CNRS, CEA, INRAE, Université Grenoble Alpes, IRIG, CEA Grenoble, 38054 Grenoble, France
| | - David Honys
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, 16502 Prague 6, Czech Republic
| | - Maria R Conte
- Randall Centre for Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK
| | - Jean-Marc Deragon
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
- Institut Universitaire de France, 75231 Paris Cedex 5, France
| | - Cécile Bousquet-Antonelli
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
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Wayne LL, Gachotte DJ, Graupner PR, Adelfinskaya Y, McCaskill DG, Metz JG, Zirkle R, Walsh TA. Plant and algal lysophosphatidic acid acyltransferases increase docosahexaenoic acid accumulation at the sn-2 position of triacylglycerol in transgenic Arabidopsis seed oil. PLoS One 2021; 16:e0256625. [PMID: 34432852 PMCID: PMC8386867 DOI: 10.1371/journal.pone.0256625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 08/10/2021] [Indexed: 11/21/2022] Open
Abstract
Although docosahexaenoic acid (DHA), an important dietary omega-3 polyunsaturated fatty acid (PUFA), is at present primarily sourced from marine fish, bioengineered crops producing DHA may offer a more sustainable and cost-effective source. DHA has been produced in transgenic oilseed crops, however, DHA in seed oil primarily occupies the sn-1/3 positions of triacylglycerol (TAG) with relatively low amounts of DHA in the sn-2 position. To increase the amount of DHA in the sn-2 position of TAG and in seed oil, putative lysophosphatidic acid acyltransferases (LPAATs) were identified and characterized from the DHA-producing alga Schizochytrium sp. and from soybean (Glycine max). The affinity-purified proteins were confirmed to have LPAAT activity. Expression of the Schizochytrium or soybean LPAATs in DHA-producing Arabidopsis expressing the Schizochytrium PUFA synthase system significantly increased the total amount of DHA in seed oil. A novel sensitive band-selective heteronuclear single quantum coherence (HSQC) NMR method was developed to quantify DHA at the sn-2 position of glycerolipids. More than two-fold increases in sn-2 DHA were observed for Arabidopsis lines expressing Schizochytrium or soybean LPAATs, with one Schizochytrium LPAAT driving DHA accumulation in the sn-2 position to 61% of the total DHA. Furthermore, expression of a soybean LPAAT led to a redistribution of DHA-containing TAG species, with two new TAG species identified. Our results demonstrate that transgenic expression of Schizochytrium or soybean LPAATs can increase the proportion of DHA at the sn-2 position of TAG and the total amount of DHA in the seed oil of a DHA-accumulating oilseed plant. Additionally, the band-selective HSQC NMR method that we developed provides a sensitive and robust method for determining the regiochemistry of DHA in glycerolipids. These findings will benefit the advancement of sustainable sources of DHA via transgenic crops such as canola and soybean.
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Affiliation(s)
- Laura L. Wayne
- Corteva Agriscience, Johnston, Iowa, United States of America
- * E-mail:
| | | | - Paul R. Graupner
- Corteva Agriscience, Indianapolis, Indiana, United States of America
| | | | | | - James G. Metz
- DSM Nutritional Products, Columbia, Maryland, United States of America
| | - Ross Zirkle
- DSM Nutritional Products, Columbia, Maryland, United States of America
| | - Terence A. Walsh
- Corteva Agriscience, Indianapolis, Indiana, United States of America
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LPEATs Tailor Plant Phospholipid Composition through Adjusting Substrate Preferences to Temperature. Int J Mol Sci 2021; 22:ijms22158137. [PMID: 34360902 PMCID: PMC8348727 DOI: 10.3390/ijms22158137] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 07/27/2021] [Accepted: 07/27/2021] [Indexed: 01/10/2023] Open
Abstract
Acyl-CoA:lysophosphatidylethanolamine acyltransferases (LPEATs) are known as enzymes utilizing acyl-CoAs and lysophospholipids to produce phosphatidylethanolamine. Recently, it has been discovered that they are also involved in the growth regulation of Arabidopsis thaliana. In our study we investigated expression of each Camelina sativa LPEAT isoform and their behavior in response to temperature changes. In order to conduct a more extensive biochemical evaluation we focused both on LPEAT enzymes present in microsomal fractions from C. sativa plant tissues, and on cloned CsLPEAT isoforms expressed in yeast system. Phylogenetic analyses revealed that CsLPEAT1c and CsLPEAT2c originated from Camelina hispida, whereas other isoforms originated from Camelina neglecta. The expression ratio of all CsLPEAT1 isoforms to all CsLPEAT2 isoforms was higher in seeds than in other tissues. The isoforms also displayed divergent substrate specificities in utilization of LPE; CsLPEAT1 preferred 18:1-LPE, whereas CsLPEAT2 preferred 18:2-LPE. Unlike CsLPEAT1, CsLPEAT2 isoforms were specific towards very-long-chain fatty acids. Above all, we discovered that temperature strongly regulates LPEATs activity and substrate specificity towards different acyl donors, making LPEATs sort of a sensor of external thermal changes. We observed the presented findings not only for LPEAT activity in plant-derived microsomal fractions, but also for yeast-expressed individual CsLPEAT isoforms.
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Jasieniecka-Gazarkiewicz K, Demski K, Gidda SK, Klińska S, Niedojadło J, Lager I, Carlsson AS, Minina EA, Mullen RT, Bozhkov PV, Stymne S, Banaś A. Subcellular Localization of Acyl-CoA: Lysophosphatidylethanolamine Acyltransferases (LPEATs) and the Effects of Knocking-Out and Overexpression of Their Genes on Autophagy Markers Level and Life Span of A. thaliana. Int J Mol Sci 2021; 22:ijms22063006. [PMID: 33809440 PMCID: PMC8000221 DOI: 10.3390/ijms22063006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 03/10/2021] [Accepted: 03/12/2021] [Indexed: 12/14/2022] Open
Abstract
Arabidopsis thaliana possesses two acyl-CoA:lysophosphatidylethanolamine acyltransferases, LPEAT1 and LPEAT2, which are encoded by At1g80950 and At2g45670 genes, respectively. Both single lpeat2 mutant and double lpeat1 lpeat2 mutant plants exhibit a variety of conspicuous phenotypes, including dwarfed growth. Confocal microscopic analysis of tobacco suspension-cultured cells transiently transformed with green fluorescent protein-tagged versions of LPEAT1 or LPEAT2 revealed that LPEAT1 is localized to the endoplasmic reticulum (ER), whereas LPEAT2 is localized to both Golgi and late endosomes. Considering that the primary product of the reaction catalyzed by LPEATs is phosphatidylethanolamine, which is known to be covalently conjugated with autophagy-related protein ATG8 during a key step of the formation of autophagosomes, we investigated the requirements for LPEATs to engage in autophagic activity in Arabidopsis. Knocking out of either or both LPEAT genes led to enhanced accumulation of the autophagic adaptor protein NBR1 and decreased levels of both ATG8a mRNA and total ATG8 protein. Moreover, we detected significantly fewer membrane objects in the vacuoles of lpeat1 lpeat2 double mutant mesophyll cells than in vacuoles of control plants. However, contrary to what has been reported on autophagy deficient plants, the lpeat mutants displayed a prolonged life span compared to wild type, including delayed senescence.
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Affiliation(s)
- Katarzyna Jasieniecka-Gazarkiewicz
- Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, 80-307 Gdansk, Poland; (K.D.); (S.K.); (A.B.)
- Correspondence:
| | - Kamil Demski
- Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, 80-307 Gdansk, Poland; (K.D.); (S.K.); (A.B.)
| | - Satinder K. Gidda
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada; (S.K.G.); (R.T.M.)
| | - Sylwia Klińska
- Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, 80-307 Gdansk, Poland; (K.D.); (S.K.); (A.B.)
| | - Janusz Niedojadło
- Department of Cell Biology, Department of Cellular and Molecular Biology, Nicolaus Copernicus University, 87-100 Torun, Poland;
| | - Ida Lager
- Department of Plant Breeding, Swedish University of Agricultural Sciences, 230-53 Alnarp, Sweden; (I.L.); (A.S.C.); (S.S.)
| | - Anders S. Carlsson
- Department of Plant Breeding, Swedish University of Agricultural Sciences, 230-53 Alnarp, Sweden; (I.L.); (A.S.C.); (S.S.)
| | - Elena A. Minina
- Department of Molecular Sciences, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, 750-07 Uppsala, Sweden; (E.A.M.); (P.V.B.)
| | - Robert T. Mullen
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada; (S.K.G.); (R.T.M.)
| | - Peter V. Bozhkov
- Department of Molecular Sciences, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, 750-07 Uppsala, Sweden; (E.A.M.); (P.V.B.)
| | - Sten Stymne
- Department of Plant Breeding, Swedish University of Agricultural Sciences, 230-53 Alnarp, Sweden; (I.L.); (A.S.C.); (S.S.)
| | - Antoni Banaś
- Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, 80-307 Gdansk, Poland; (K.D.); (S.K.); (A.B.)
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9
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Klińska S, Jasieniecka-Gazarkiewicz K, Demski K, Banaś A. Editing of phosphatidic acid and phosphatidylethanolamine by acyl-CoA: lysophospholipid acyltransferases in developing Camelina sativa seeds. PLANTA 2020; 252:4. [PMID: 32524208 PMCID: PMC7286856 DOI: 10.1007/s00425-020-03408-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Accepted: 05/22/2020] [Indexed: 06/11/2023]
Abstract
The main source of polyunsaturated acyl-CoA in cytoplasmic acyl-CoA pool of Camelina sativa seeds are fatty acids derived from phosphatidylcholine followed by phosphatidic acid. Contribution of phosphatidylethanolamine is negligible. While phosphatidylethanolamine (PE) is the second most abundant phospholipid, phosphatidic acid (PA) only constitutes a small fraction of C. sativa seeds' polar lipids. In spite of this, the relative contribution of PA in providing fatty acids for the synthesis of acyl-CoA, supplying cytosolic acyl-CoA pool seems to be much higher than the contribution of PE. Our data indicate that up to 5% of fatty acids present in mature C. sativa seeds are first esterified with PA, in comparison to 2% first esterified with PE, before being transferred into acyl-CoA pool via backward reactions of either acyl-CoA:lysophosphatidic acid acyltransferases (CsLPAATs) or acyl-CoA:lysophoshatidylethanolamine acyltransferases (CsLPEATs). Those acyl-CoAs are later reused for lipid biosynthesis or remodelling. In the forward reactions both aforementioned acyltransferases display the highest activity at 30 °C. The spectrum of optimal pH differs for both enzymes with CsLPAATs most active between pH 7.5-9.0 and CsLPEATs between pH 9.0 to 10.0. Whereas addition of magnesium ions stimulates CsLPAATs, calcium and potassium ions inhibit them in concentrations of 0.05-2.0 mM. All three types of ions inhibit CsLPEATs activity. Both tested acyltransferases present the highest preferences towards 16:0-CoA and unsaturated 18-carbon acyl-CoAs in forward reactions. However, CsLPAATs preferentially utilise 18:1-CoA and CsLPEATs preferentially utilise 18:2-CoA while catalysing fatty acid remodelling of PA and PE, respectively.
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Affiliation(s)
- Sylwia Klińska
- Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Abrahama 58, 80-307, Gdansk, Poland
| | | | - Kamil Demski
- Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Abrahama 58, 80-307, Gdansk, Poland
| | - Antoni Banaś
- Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Abrahama 58, 80-307, Gdansk, Poland
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10
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LPIAT, a lyso-Phosphatidylinositol Acyltransferase, Modulates Seed Germination in Arabidopsis thaliana through PIP Signalling Pathways and is Involved in Hyperosmotic Response. Int J Mol Sci 2020; 21:ijms21051654. [PMID: 32121266 PMCID: PMC7084726 DOI: 10.3390/ijms21051654] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 02/17/2020] [Accepted: 02/26/2020] [Indexed: 11/17/2022] Open
Abstract
Lyso-lipid acyltransferases are enzymes involved in various processes such as lipid synthesis and remodelling. Here, we characterized the activity of an acyltransferase from Arabidopsis thaliana (LPIAT). In vitro, this protein, expressed in Escherichia coli membrane, displayed a 2-lyso-phosphatidylinositol acyltransferase activity with a specificity towards saturated long chain acyl CoAs (C16:0- and C18:0-CoAs), allowing the remodelling of phosphatidylinositol. In planta, LPIAT gene was expressed in mature seeds and very transiently during seed imbibition, mostly in aleurone-like layer cells. Whereas the disruption of this gene did not alter the lipid composition of seed, its overexpression in leaves promoted a strong increase in the phosphatidylinositol phosphates (PIP) level without affecting the PIP2 content. The spatial and temporal narrow expression of this gene as well as the modification of PIP metabolism led us to investigate its role in the control of seed germination. Seeds from the lpiat mutant germinated faster and were less sensitive to abscisic acid (ABA) than wild-type or overexpressing lines. We also showed that the protective effect of ABA on young seedlings against dryness was reduced for lpiat line. In addition, germination of lpiat mutant seeds was more sensitive to hyperosmotic stress. All these results suggest a link between phosphoinositides and ABA signalling in the control of seed germination.
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11
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Karki N, Johnson BS, Bates PD. Metabolically Distinct Pools of Phosphatidylcholine Are Involved in Trafficking of Fatty Acids out of and into the Chloroplast for Membrane Production. THE PLANT CELL 2019; 31:2768-2788. [PMID: 31511316 PMCID: PMC6881139 DOI: 10.1105/tpc.19.00121] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 08/12/2019] [Accepted: 09/11/2019] [Indexed: 05/18/2023]
Abstract
The eukaryotic pathway of galactolipid synthesis involves fatty acid synthesis in the chloroplast, followed by assembly of phosphatidylcholine (PC) in the endoplasmic reticulum (ER), and then turnover of PC to provide a substrate for chloroplast galactolipid synthesis. However, the mechanisms and classes of lipids transported between the chloroplast and the ER are unclear. PC, PC-derived diacylglycerol, phosphatidic acid, and lyso-phosphatidylcholine (LPC) have all been implicated in ER-to-chloroplast lipid transfer. LPC transport requires lysophosphatidylcholine acyltransferase (LPCAT) activity at the chloroplast to form PC before conversion to galactolipids. However, LPCAT has also been implicated in the opposite chloroplast-to-ER trafficking of newly synthesized fatty acids through PC acyl editing. To understand the role of LPC and LPCAT in acyl trafficking we produced and analyzed the Arabidopsis (Arabidopsis thaliana) act1 lpcat1 lpcat2 triple mutant. LPCAT1 and LPCAT2 encode the major lysophospholipid acyltransferase activity of the chloroplast, and it is predominantly for incorporation of nascent fatty acids exported form the chloroplast into PC by acyl editing. In vivo acyl flux analysis revealed eukaryotic galactolipid synthesis is not impaired in act1 lpcat1 lpcat2 and uses a PC pool distinct from that of PC acyl editing. We present a model for the eukaryotic pathway with metabolically distinct pools of PC, suggesting an underlying spatial organization of PC metabolism as part of the ER-chloroplast metabolic interactions.
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Affiliation(s)
- Nischal Karki
- Department of Chemistry and Biochemistry, University of Southern Mississippi, Hattiesburg, Mississippi 39406
| | - Brandon S Johnson
- Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164
| | - Philip D Bates
- Department of Chemistry and Biochemistry, University of Southern Mississippi, Hattiesburg, Mississippi 39406
- Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164
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12
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Guo X, Runavot JL, Bourot S, Meulewaeter F, Hernandez-Gomez M, Holland C, Harholt J, Willats WGT, Mravec J, Knox P, Ulvskov P. Metabolism of polysaccharides in dynamic middle lamellae during cotton fibre development. PLANTA 2019; 249:1565-1581. [PMID: 30737556 DOI: 10.1007/s00425-019-03107-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 02/04/2019] [Indexed: 06/09/2023]
Abstract
Evidence is presented that cotton fibre adhesion and middle lamella formation are preceded by cutin dilution and accompanied by rhamnogalacturonan-I metabolism. Cotton fibres are single cell structures that early in development adhere to one another via the cotton fibre middle lamella (CFML) to form a tissue-like structure. The CFML is disassembled around the time of initial secondary wall deposition, leading to fibre detachment. Observations of CFML in the light microscope have suggested that the development of the middle lamella is accompanied by substantial cell-wall metabolism, but it has remained an open question as to which processes mediate adherence and which lead to detachment. The mechanism of adherence and detachment were investigated here using glyco-microarrays probed with monoclonal antibodies, transcript profiling, and observations of fibre auto-digestion. The results suggest that adherence is brought about by cutin dilution, while the presence of relevant enzyme activities and the dynamics of rhamnogalacturonan-I side-chain accumulation and disappearance suggest that both attachment and detachment are accompanied by rhamnogalacturonan-I metabolism.
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Affiliation(s)
- Xiaoyuan Guo
- Department of Plant and Environmental Sciences, Copenhagen University, Frederiksberg, Denmark
| | - Jean-Luc Runavot
- Bayer CropScience NV, Innovation Center, Technologiepark 38, 9052, Ghent, Belgium
| | - Stéphane Bourot
- Bayer CropScience NV, Innovation Center, Technologiepark 38, 9052, Ghent, Belgium
| | - Frank Meulewaeter
- Bayer CropScience NV, Innovation Center, Technologiepark 38, 9052, Ghent, Belgium
| | - Mercedes Hernandez-Gomez
- Centre for Plant Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - Claire Holland
- Department of Plant and Environmental Sciences, Copenhagen University, Frederiksberg, Denmark
| | - Jesper Harholt
- Department of Plant and Environmental Sciences, Copenhagen University, Frederiksberg, Denmark
| | - William G T Willats
- School of Agriculture, Food and Rural Development, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
| | - Jozef Mravec
- Department of Plant and Environmental Sciences, Copenhagen University, Frederiksberg, Denmark
| | - Paul Knox
- Centre for Plant Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - Peter Ulvskov
- Department of Plant and Environmental Sciences, Copenhagen University, Frederiksberg, Denmark.
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13
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Jasieniecka-Gazarkiewicz K, Lager I, Carlsson AS, Gutbrod K, Peisker H, Dörmann P, Stymne S, Banaś A. Acyl-CoA:Lysophosphatidylethanolamine Acyltransferase Activity Regulates Growth of Arabidopsis. PLANT PHYSIOLOGY 2017; 174:986-998. [PMID: 28408542 PMCID: PMC5462050 DOI: 10.1104/pp.17.00391] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 04/12/2017] [Indexed: 05/05/2023]
Abstract
Arabidopsis (Arabidopsis thaliana) contains two enzymes (encoded by the At1g80950 and At2g45670 genes) preferentially acylating lysophosphatidylethanolamine (LPE) with acyl-coenzyme A (CoA), designated LYSOPHOSPHATIDYLETHANOLAMINE ACYLTRANSFERASE1 (LPEAT1) and LPEAT2. The transfer DNA insertion mutant lpeat2 and the double mutant lpeat1 lpeat2 showed impaired growth, smaller leaves, shorter roots, less seed setting, and reduced lipid content per fresh weight in roots and seeds and large increases in LPE and lysophosphatidylcholine (LPC) contents in leaves. Microsomal preparations from leaves of these mutants showed around 70% decrease in acylation activity of LPE with 16:0-CoA compared with wild-type membranes, whereas the acylation with 18:1-CoA was much less affected, demonstrating that other lysophospholipid acyltransferases than the two LPEATs could acylate LPE The above-mentioned effects were less pronounced in the single lpeat1 mutant. Overexpression of either LPEAT1 or LPEAT2 under the control of the 35S promotor led to morphological changes opposite to what was seen in the transfer DNA mutants. Acyl specificity studies showed that LPEAT1 utilized 16:0-CoA at the highest rate of 11 tested acyl-CoAs, whereas LPEAT2 utilized 20:0-CoA as the best acyl donor. Both LPEATs could acylate either sn position of ether analogs of LPC The data show that the activities of LPEAT1 and LPEAT2 are, in a complementary way, involved in growth regulation in Arabidopsis. It is shown that LPEAT activity (especially LPEAT2) is essential for maintaining adequate levels of phosphatidylethanolamine, LPE, and LPC in the cells.
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Affiliation(s)
- Katarzyna Jasieniecka-Gazarkiewicz
- Intercollegiate Faculty of Biotechnology, University of Gdańsk and Medical University of Gdańsk, 80-307 Gdansk, Poland (K.J.-G., A.B.)
- Department of Plant Breeding, Swedish University of Agricultural Sciences, 230 53 Alnarp, Sweden (I.L., A.S.C., S.S.); and
- Institute of Molecular Physiology and Biotechnology of Plants, University of Bonn, 53115 Bonn, Germany (K.G., H.P., P.D.)
| | - Ida Lager
- Intercollegiate Faculty of Biotechnology, University of Gdańsk and Medical University of Gdańsk, 80-307 Gdansk, Poland (K.J.-G., A.B.)
- Department of Plant Breeding, Swedish University of Agricultural Sciences, 230 53 Alnarp, Sweden (I.L., A.S.C., S.S.); and
- Institute of Molecular Physiology and Biotechnology of Plants, University of Bonn, 53115 Bonn, Germany (K.G., H.P., P.D.)
| | - Anders S Carlsson
- Intercollegiate Faculty of Biotechnology, University of Gdańsk and Medical University of Gdańsk, 80-307 Gdansk, Poland (K.J.-G., A.B.)
- Department of Plant Breeding, Swedish University of Agricultural Sciences, 230 53 Alnarp, Sweden (I.L., A.S.C., S.S.); and
- Institute of Molecular Physiology and Biotechnology of Plants, University of Bonn, 53115 Bonn, Germany (K.G., H.P., P.D.)
| | - Katharina Gutbrod
- Intercollegiate Faculty of Biotechnology, University of Gdańsk and Medical University of Gdańsk, 80-307 Gdansk, Poland (K.J.-G., A.B.)
- Department of Plant Breeding, Swedish University of Agricultural Sciences, 230 53 Alnarp, Sweden (I.L., A.S.C., S.S.); and
- Institute of Molecular Physiology and Biotechnology of Plants, University of Bonn, 53115 Bonn, Germany (K.G., H.P., P.D.)
| | - Helga Peisker
- Intercollegiate Faculty of Biotechnology, University of Gdańsk and Medical University of Gdańsk, 80-307 Gdansk, Poland (K.J.-G., A.B.)
- Department of Plant Breeding, Swedish University of Agricultural Sciences, 230 53 Alnarp, Sweden (I.L., A.S.C., S.S.); and
- Institute of Molecular Physiology and Biotechnology of Plants, University of Bonn, 53115 Bonn, Germany (K.G., H.P., P.D.)
| | - Peter Dörmann
- Intercollegiate Faculty of Biotechnology, University of Gdańsk and Medical University of Gdańsk, 80-307 Gdansk, Poland (K.J.-G., A.B.)
- Department of Plant Breeding, Swedish University of Agricultural Sciences, 230 53 Alnarp, Sweden (I.L., A.S.C., S.S.); and
- Institute of Molecular Physiology and Biotechnology of Plants, University of Bonn, 53115 Bonn, Germany (K.G., H.P., P.D.)
| | - Sten Stymne
- Intercollegiate Faculty of Biotechnology, University of Gdańsk and Medical University of Gdańsk, 80-307 Gdansk, Poland (K.J.-G., A.B.)
- Department of Plant Breeding, Swedish University of Agricultural Sciences, 230 53 Alnarp, Sweden (I.L., A.S.C., S.S.); and
- Institute of Molecular Physiology and Biotechnology of Plants, University of Bonn, 53115 Bonn, Germany (K.G., H.P., P.D.)
| | - Antoni Banaś
- Intercollegiate Faculty of Biotechnology, University of Gdańsk and Medical University of Gdańsk, 80-307 Gdansk, Poland (K.J.-G., A.B.);
- Department of Plant Breeding, Swedish University of Agricultural Sciences, 230 53 Alnarp, Sweden (I.L., A.S.C., S.S.); and
- Institute of Molecular Physiology and Biotechnology of Plants, University of Bonn, 53115 Bonn, Germany (K.G., H.P., P.D.)
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14
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Botella C, Jouhet J, Block MA. Importance of phosphatidylcholine on the chloroplast surface. Prog Lipid Res 2017; 65:12-23. [DOI: 10.1016/j.plipres.2016.11.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 11/04/2016] [Accepted: 11/06/2016] [Indexed: 12/11/2022]
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15
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Yamaoka Y, Achard D, Jang S, Legéret B, Kamisuki S, Ko D, Schulz-Raffelt M, Kim Y, Song WY, Nishida I, Li-Beisson Y, Lee Y. Identification of a Chlamydomonas plastidial 2-lysophosphatidic acid acyltransferase and its use to engineer microalgae with increased oil content. PLANT BIOTECHNOLOGY JOURNAL 2016; 14:2158-2167. [PMID: 27133096 PMCID: PMC5096022 DOI: 10.1111/pbi.12572] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2016] [Revised: 04/15/2016] [Accepted: 04/25/2016] [Indexed: 05/03/2023]
Abstract
Despite a strong interest in microalgal oil production, our understanding of the biosynthetic pathways that produce algal lipids and the genes involved in the biosynthetic processes remains incomplete. Here, we report that Chlamydomonas reinhardtii Cre09.g398289 encodes a plastid-targeted 2-lysophosphatidic acid acyltransferase (CrLPAAT1) that acylates the sn-2 position of a 2-lysophosphatidic acid to form phosphatidic acid, the first common precursor of membrane and storage lipids. In vitro enzyme assays showed that CrLPAAT1 prefers 16:0-CoA to 18:1-CoA as an acyl donor. Fluorescent protein-tagged CrLPAAT1 was localized to the plastid membrane in C. reinhardtii cells. Furthermore, expression of CrLPAAT1 in plastids led to a > 20% increase in oil content under nitrogen-deficient conditions. Taken together, these results demonstrate that CrLPAAT1 is an authentic plastid-targeted LPAAT in C. reinhardtii, and that it may be used as a molecular tool to genetically increase oil content in microalgae.
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Affiliation(s)
- Yasuyo Yamaoka
- Department of Life Science, Pohang University of Science and Technology, Pohang, Korea
| | - Dorine Achard
- Institut de Biosciences et Biotechnologies, CEA Cadarache, Saint-Paul-lez-Durance, France
| | - Sunghoon Jang
- Department of Life Science, Pohang University of Science and Technology, Pohang, Korea
| | - Bertrand Legéret
- Institut de Biosciences et Biotechnologies, CEA Cadarache, Saint-Paul-lez-Durance, France
| | - Shogo Kamisuki
- Division of Life Science, Graduate School of Science and Engineering, Saitama University, Sakura-Ku, Saitama, Japan
| | - Donghwi Ko
- Department of Life Science, Pohang University of Science and Technology, Pohang, Korea
| | - Miriam Schulz-Raffelt
- Institut de Biosciences et Biotechnologies, CEA Cadarache, Saint-Paul-lez-Durance, France
| | - Yeongho Kim
- Department of Life Science, Pohang University of Science and Technology, Pohang, Korea
| | - Won-Yong Song
- Department of Life Science, Pohang University of Science and Technology, Pohang, Korea
| | - Ikuo Nishida
- Division of Life Science, Graduate School of Science and Engineering, Saitama University, Sakura-Ku, Saitama, Japan
- JST, CREST, Chiyoda-ku, Tokyo, Japan
| | - Yonghua Li-Beisson
- Institut de Biosciences et Biotechnologies, CEA Cadarache, Saint-Paul-lez-Durance, France.
| | - Youngsook Lee
- Department of Life Science, Pohang University of Science and Technology, Pohang, Korea.
- Department of Integrative Bioscience & Biotechnology, Pohang University of Science and Technology, Pohang, Korea.
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16
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Allen DK. Assessing compartmentalized flux in lipid metabolism with isotopes. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:1226-1242. [PMID: 27003250 DOI: 10.1016/j.bbalip.2016.03.017] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2016] [Revised: 03/13/2016] [Accepted: 03/14/2016] [Indexed: 12/28/2022]
Abstract
Metabolism in plants takes place across multiple cell types and within distinct organelles. The distributions equate to spatial heterogeneity; though the limited means to experimentally assess metabolism frequently involve homogenizing tissues and mixing metabolites from different locations. Most current isotope investigations of metabolism therefore lack the ability to resolve spatially distinct events. Recognition of this limitation has resulted in inspired efforts to advance metabolic flux analysis and isotopic labeling techniques. Though a number of these efforts have been applied to studies in central metabolism; recent advances in instrumentation and techniques present an untapped opportunity to make similar progress in lipid metabolism where the use of stable isotopes has been more limited. These efforts will benefit from sophisticated radiolabeling reports that continue to enrich our knowledge on lipid biosynthetic pathways and provide some direction for stable isotope experimental design and extension of MFA. Evidence for this assertion is presented through the review of several elegant stable isotope studies and by taking stock of what has been learned from radioisotope investigations when spatial aspects of metabolism were considered. The studies emphasize that glycerolipid production occurs across several locations with assembly of lipids in the ER or plastid, fatty acid biosynthesis occurring in the plastid, and the generation of acetyl-CoA and glycerol-3-phosphate taking place at multiple sites. Considering metabolism in this context underscores the cellular and subcellular organization that is important to enhanced production of glycerolipids in plants. An attempt is made to unify salient features from a number of reports into a diagrammatic model of lipid metabolism and propose where stable isotope labeling experiments and further flux analysis may help address questions in the field. This article is part of a Special Issue entitled: Plant Lipid Biology edited by Kent D. Chapman and Ivo Feussner.
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Affiliation(s)
- Doug K Allen
- United States Department of Agriculture, Agricultural Research Service, 975 North Warson Road, St. Louis, MO 63132, United States; Donald Danforth Plant Science Center, 975 North Warson Road, St. Louis, MO 63132, United States.
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17
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Shockey J, Regmi A, Cotton K, Adhikari N, Browse J, Bates PD. Identification of Arabidopsis GPAT9 (At5g60620) as an Essential Gene Involved in Triacylglycerol Biosynthesis. PLANT PHYSIOLOGY 2016; 170:163-79. [PMID: 26586834 PMCID: PMC4704598 DOI: 10.1104/pp.15.01563] [Citation(s) in RCA: 109] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 11/19/2015] [Indexed: 05/20/2023]
Abstract
The first step in the biosynthesis of nearly all plant membrane phospholipids and storage triacylglycerols is catalyzed by a glycerol-3-phosphate acyltransferase (GPAT). The requirement for an endoplasmic reticulum (ER)-localized GPAT for both of these critical metabolic pathways was recognized more than 60 years ago. However, identification of the gene(s) encoding this GPAT activity has remained elusive. Here, we present the results of a series of in vivo, in vitro, and in silico experiments in Arabidopsis (Arabidopsis thaliana) designed to assign this essential function to AtGPAT9. This gene has been highly conserved throughout evolution and is largely present as a single copy in most plants, features consistent with essential housekeeping functions. A knockout mutant of AtGPAT9 demonstrates both male and female gametophytic lethality phenotypes, consistent with the role in essential membrane lipid synthesis. Significant expression of developing seed AtGPAT9 is required for wild-type levels of triacylglycerol accumulation, and the transcript level is directly correlated to the level of microsomal GPAT enzymatic activity in seeds. Finally, the AtGPAT9 protein interacts with other enzymes involved in ER glycerolipid biosynthesis, suggesting the possibility of ER-localized lipid biosynthetic complexes. Together, these results suggest that GPAT9 is the ER-localized GPAT enzyme responsible for plant membrane lipid and oil biosynthesis.
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Affiliation(s)
- Jay Shockey
- U.S. Department of Agriculture-Agricultural Research Service, Southern Regional Research Center, New Orleans, Louisiana 70124 (J.S.);Department of Chemistry and Biochemistry, University of Southern Mississippi, Hattiesburg, Mississippi 39406 (A.R., P.D.B.); andInstitute of Biological Chemistry, Washington State University, Pullman, Washington 99163 (K.C., N.A., J.B.)
| | - Anushobha Regmi
- U.S. Department of Agriculture-Agricultural Research Service, Southern Regional Research Center, New Orleans, Louisiana 70124 (J.S.);Department of Chemistry and Biochemistry, University of Southern Mississippi, Hattiesburg, Mississippi 39406 (A.R., P.D.B.); andInstitute of Biological Chemistry, Washington State University, Pullman, Washington 99163 (K.C., N.A., J.B.)
| | - Kimberly Cotton
- U.S. Department of Agriculture-Agricultural Research Service, Southern Regional Research Center, New Orleans, Louisiana 70124 (J.S.);Department of Chemistry and Biochemistry, University of Southern Mississippi, Hattiesburg, Mississippi 39406 (A.R., P.D.B.); andInstitute of Biological Chemistry, Washington State University, Pullman, Washington 99163 (K.C., N.A., J.B.)
| | - Neil Adhikari
- U.S. Department of Agriculture-Agricultural Research Service, Southern Regional Research Center, New Orleans, Louisiana 70124 (J.S.);Department of Chemistry and Biochemistry, University of Southern Mississippi, Hattiesburg, Mississippi 39406 (A.R., P.D.B.); andInstitute of Biological Chemistry, Washington State University, Pullman, Washington 99163 (K.C., N.A., J.B.)
| | - John Browse
- U.S. Department of Agriculture-Agricultural Research Service, Southern Regional Research Center, New Orleans, Louisiana 70124 (J.S.);Department of Chemistry and Biochemistry, University of Southern Mississippi, Hattiesburg, Mississippi 39406 (A.R., P.D.B.); andInstitute of Biological Chemistry, Washington State University, Pullman, Washington 99163 (K.C., N.A., J.B.)
| | - Philip D Bates
- U.S. Department of Agriculture-Agricultural Research Service, Southern Regional Research Center, New Orleans, Louisiana 70124 (J.S.);Department of Chemistry and Biochemistry, University of Southern Mississippi, Hattiesburg, Mississippi 39406 (A.R., P.D.B.); andInstitute of Biological Chemistry, Washington State University, Pullman, Washington 99163 (K.C., N.A., J.B.)
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18
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Jasieniecka-Gazarkiewicz K, Demski K, Lager I, Stymne S, Banaś A. Possible Role of Different Yeast and Plant Lysophospholipid:Acyl-CoA Acyltransferases (LPLATs) in Acyl Remodelling of Phospholipids. Lipids 2015; 51:15-23. [PMID: 26643989 PMCID: PMC4700060 DOI: 10.1007/s11745-015-4102-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 11/12/2015] [Indexed: 12/02/2022]
Abstract
Recent results have suggested that plant lysophosphatidylcholine:acyl-coenzyme A acyltransferases (LPCATs) can operate in reverse in vivo and thereby catalyse an acyl exchange between the acyl-coenzyme A (CoA) pool and the phosphatidylcholine. We have investigated the abilities of Arabidopsis AtLPCAT2, Arabidopsis lysophosphatidylethanolamine acyltransferase (LPEAT2), S. cerevisiae lysophospholipid acyltransferase (Ale1) and S. cerevisiae lysophosphatidic acid acyltransferase (SLC1) to acylate lysoPtdCho, lysoPtdEtn and lysoPtdOH and act reversibly on the products of the acylation; the PtdCho, PtdEtn and PtdOH. The tested LPLATs were expressed in an S. cervisiaeale1 strain and enzyme activities were assessed in assays using microsomal preparations of the different transformants. The results show that, despite high activity towards lysoPtdCho, lysoPtdEtn and lysoPtdOH by the ALE1, its capacities to operate reversibly on the products of the acylation were very low. Slc1 readily acylated lysoPtdOH, lysoPtdCho and lysoPtdEtn but showed no reversibility towards PtdCho, very little reversibility towards PtdEtn and very high reversibility towards PtdOH. LPEAT2 showed the highest levels of reversibility towards PtdCho and PtdEtn of all LPLATs tested but low ability to operate reversibly on PtdOH. AtLPCAT2 showed good reversible activity towards PtdCho and PtdEtn and very low reversibility towards PtdOH. Thus, it appears that some of the LPLATs have developed properties that, to a much higher degree than other LPLATs, promote the reverse reaction during the same assay conditions and with the same phospholipid. The results also show that the capacity of reversibility can be specific for a particular phospholipid, albeit the lysophospholipid derivatives of other phospholipids serve as good acyl acceptors for the forward reaction of the enzyme.
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Affiliation(s)
| | - Kamil Demski
- Intercollegiate Faculty of Biotechnology, University of Gdańsk and Medical University of Gdańsk, Kładki 24, 80-822, Gdańsk, Poland
| | - Ida Lager
- Department of Plant Breeding, Swedish University of Agricultural Sciences, 230 53, Alnarp, Sweden
| | - Sten Stymne
- Department of Plant Breeding, Swedish University of Agricultural Sciences, 230 53, Alnarp, Sweden
| | - Antoni Banaś
- Intercollegiate Faculty of Biotechnology, University of Gdańsk and Medical University of Gdańsk, Kładki 24, 80-822, Gdańsk, Poland.
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19
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Afitlhile M, Duffield-Duncan K, Fry M, Workman S, Hum-Musser S, Hildebrand D. The toc132toc120 heterozygote mutant of Arabidopsis thaliana accumulates reduced levels of hexadecatrienoic acid. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2015; 96:426-435. [PMID: 26381195 DOI: 10.1016/j.plaphy.2015.09.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Revised: 08/29/2015] [Accepted: 09/02/2015] [Indexed: 06/05/2023]
Abstract
A null and heterozygous mutant for the Arabidopsis thaliana TOC132 and TOC120 genes accumulates increased levels of 16:0 and decreased 16:3, suggesting altered homeostasis in fatty acid synthesis. The FAD5 gene encodes a plastid desaturase that catalyzes the first step in the synthesis of 16:3 in monogalactosyldiacylglycerol (MGDG). In non-acclimated toc132toc120+/- mutant plants, the FAD5 gene was repressed and this correlated with decreased levels of 16:3. In cold-acclimated mutant however, the FAD5 gene was upregulated and there was a small increase in 16:3 levels relative to the non-acclimated mutant plants. The MGD1 gene was expressed at control levels and the mutant accumulated levels of MGDG that were similar to the wild type. In the mutant however, MGDG had decreased 16:3 levels, suggesting that the activity of FAD5 desaturase was compromised. In the mutant, the FAD2 and FAD3 genes were downregulated but levels of 18:3-PC were increased, suggesting posttranscriptional regulation for the ER-localized fatty acid desaturases. The Toc120 or Toc159 receptor is likely to compensate for a defective Toc132 receptor. In the cold-acclimated mutant, the TOC159 gene was repressed ca. 300-fold, whereas the TOC120 gene was repressed 7-fold relative to the non-acclimated wild type. Thus, the TOC159 gene is more sensitive to cold-stress and might not compensate for defect in the TOC132 gene under these conditions. Overall, these data show that a mutation in the TOC132 gene results in decreased 16:3 levels, indicating the need for an intact Toc132/Toc120 receptor, presumably to facilitate the import of the FAD5 preprotein into chloroplasts.
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Affiliation(s)
- Meshack Afitlhile
- Western Illinois University, Department of Biological Sciences, 1 University Circle, Waggoner Hall 311, Macomb, IL 61455, USA.
| | - Kayla Duffield-Duncan
- Western Illinois University, Department of Biological Sciences, 1 University Circle, Waggoner Hall 311, Macomb, IL 61455, USA
| | - Morgan Fry
- Western Illinois University, Department of Biological Sciences, 1 University Circle, Waggoner Hall 311, Macomb, IL 61455, USA
| | - Samantha Workman
- Western Illinois University, Department of Biological Sciences, 1 University Circle, Waggoner Hall 311, Macomb, IL 61455, USA
| | - Sue Hum-Musser
- Western Illinois University, Department of Biological Sciences, 1 University Circle, Waggoner Hall 311, Macomb, IL 61455, USA
| | - David Hildebrand
- University of Kentucky, Department of Plant Sciences, 1405 Veterans Drive, Office 403 PSB, Lexington, KY 40546, USA
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20
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Lee KR, Chen GQ, Kim HU. Current progress towards the metabolic engineering of plant seed oil for hydroxy fatty acids production. PLANT CELL REPORTS 2015; 34:603-615. [PMID: 25577331 DOI: 10.1007/s00299-015-1736-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2014] [Accepted: 12/30/2014] [Indexed: 06/04/2023]
Abstract
Hydroxy fatty acids produced in plant seed oil are important industrial material. This review focuses on the use of metabolic engineering approaches for the production of hydroxy fatty acids in transgenic plants. Vegetable oil is not only edible but can also be used for industrial purposes. The industrial demand for vegetable oil will increase with the continued depletion of fossil fuels and ensuing environmental issues such as climate change, caused by increased carbon dioxide in the air. Some plants accumulate high levels of unusual fatty acids in their seeds, and these fatty acids (FAs) have properties that make them suitable for industrial applications. Hydroxy fatty acids (HFAs) are some of the most important of these industrial FAs. Castor oil is the conventional source of HFA. However, due to the presence of toxin ricin in its seeds, castor is not cultivated on a large scale. Lesquerella is another HFA accumulator and is currently being developed as a new crop for a safe source of HFAs. The mechanisms of HFA synthesis and accumulation have been extensively studied using castor genes and the model plant Arabidopsis. HFAs accumulated to 17% in the seed oil of Arabidopsis expressing a FA hydroxylase gene from castor (RcFAH12), but its seed oil content and plant growth decreased. When RcFAH12 gene was coexpressed with additional castor gene(s) in Arabidopsis, ~30% HFAs were accumulated and the seed oil content and plant growth was almost restored to the wild-type level. Further advancement of our understanding of pathways, genes and regulatory mechanisms underlying synthesis and accumulation of HFAs is essential to developing and implementing effective genetic approaches for enhancing HFA production in oilseeds.
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Affiliation(s)
- Kyeong-Ryeol Lee
- Department of Agricultural Biotechnology, National Academy of Agricultural Science, Rural Development Administration, Jeonju, 560-500, Republic of Korea
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21
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Allen DK, Bates PD, Tjellström H. Tracking the metabolic pulse of plant lipid production with isotopic labeling and flux analyses: Past, present and future. Prog Lipid Res 2015; 58:97-120. [PMID: 25773881 DOI: 10.1016/j.plipres.2015.02.002] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Revised: 01/30/2015] [Accepted: 02/11/2015] [Indexed: 11/25/2022]
Abstract
Metabolism is comprised of networks of chemical transformations, organized into integrated biochemical pathways that are the basis of cellular operation, and function to sustain life. Metabolism, and thus life, is not static. The rate of metabolites transitioning through biochemical pathways (i.e., flux) determines cellular phenotypes, and is constantly changing in response to genetic or environmental perturbations. Each change evokes a response in metabolic pathway flow, and the quantification of fluxes under varied conditions helps to elucidate major and minor routes, and regulatory aspects of metabolism. To measure fluxes requires experimental methods that assess the movements and transformations of metabolites without creating artifacts. Isotopic labeling fills this role and is a long-standing experimental approach to identify pathways and quantify their metabolic relevance in different tissues or under different conditions. The application of labeling techniques to plant science is however far from reaching it potential. In light of advances in genetics and molecular biology that provide a means to alter metabolism, and given recent improvements in instrumentation, computational tools and available isotopes, the use of isotopic labeling to probe metabolism is becoming more and more powerful. We review the principal analytical methods for isotopic labeling with a focus on seminal studies of pathways and fluxes in lipid metabolism and carbon partitioning through central metabolism. Central carbon metabolic steps are directly linked to lipid production by serving to generate the precursors for fatty acid biosynthesis and lipid assembly. Additionally some of the ideas for labeling techniques that may be most applicable for lipid metabolism in the future were originally developed to investigate other aspects of central metabolism. We conclude by describing recent advances that will play an important future role in quantifying flux and metabolic operation in plant tissues.
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Affiliation(s)
- Doug K Allen
- United States Department of Agriculture, Agricultural Research Service, 975 North Warson Road, St. Louis, MO 63132, United States; Donald Danforth Plant Science Center, 975 North Warson Road, St. Louis, MO 63132, United States.
| | - Philip D Bates
- Department of Chemistry and Biochemistry, University of Southern Mississippi, Hattiesburg, MS 39406, United States
| | - Henrik Tjellström
- Department of Plant Biology, Michigan State University, East Lansing, MI 48824, United States; Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI 48824, United States
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22
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Tjellström H, Strawsine M, Ohlrogge JB. Tracking synthesis and turnover of triacylglycerol in leaves. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:1453-61. [PMID: 25609824 PMCID: PMC4339603 DOI: 10.1093/jxb/eru500] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Triacylglycerol (TAG), typically represents <1% of leaf glycerolipids but can accumulate under stress and other conditions or if leaves are supplied with fatty acids, or in plants transformed with regulators or enzymes of lipid metabolism. To better understand the metabolism of TAG in leaves, pulse-chase radiolabelling experiments were designed to probe its synthesis and turnover. When Arabidopsis leaves were incubated with [(14)C]lauric acid (12:0), a major initial product was [(14)C]TAG. Thus, despite low steady-state levels, leaves possess substantial TAG biosynthetic capacity. The contributions of diacylglycerol acyltransferase1 and phospholipid:diacylglycerol acyltransferase1 to leaf TAG synthesis were examined by labelling of dgat1 and pdat1 mutants. The dgat1 mutant displayed a major (76%) reduction in [(14)C]TAG accumulation whereas pdat1 TAG labelling was only slightly reduced. Thus, DGAT1 has a principal role in TAG biosynthesis in young leaves. During a 4h chase period, radioactivity in TAG declined 70%, whereas the turnover of [(14)C]acyl chains of phosphatidylcholine (PC) and other polar lipids was much lower. Sixty percent of [(14)C]12:0 was directly incorporated into glycerolipids without modification, whereas 40% was elongated and desaturated to 16:0 and 18:1 by plastids. The unmodified [(14)C]12:0 and the plastid products of [(14)C]12:0 metabolism entered different pathways. Although plastid-modified (14)C-labelled products accumulated in monogalactosyldiacylglycerol, PC, phosphatidylethanolamine, and diacylglcerol (DAG), there was almost no accumulation of [(14)C]16:0 and [(14)C]18:1 in TAG. Because DAG and acyl-CoA are direct precursors of TAG, the differential labelling of polar glycerolipids and TAG by [(14)C]12:0 and its plastid-modified products provides evidence for multiple subcellular pools of both acyl-CoA and DAG.
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Affiliation(s)
- Henrik Tjellström
- Department of Plant Biology and Department of Energy, Great Lakes Bioenergy Research Center Michigan State University, East Lansing, MI 48824, USA
| | - Merissa Strawsine
- Department of Plant Biology and Department of Energy, Great Lakes Bioenergy Research Center Michigan State University, East Lansing, MI 48824, USA
| | - John B Ohlrogge
- Department of Plant Biology and Department of Energy, Great Lakes Bioenergy Research Center Michigan State University, East Lansing, MI 48824, USA
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23
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Wang P, Wang Z, Dou Y, Zhang X, Wang M, Tian X. Genome-wide identification and analysis of membrane-bound O-acyltransferase (MBOAT) gene family in plants. PLANTA 2013; 238:907-22. [PMID: 23928653 DOI: 10.1007/s00425-013-1939-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 07/23/2013] [Indexed: 05/05/2023]
Abstract
Membrane bound O-acyl transferase (MBOAT) family is composed of gene members encoding a variety of acyltransferase enzymes, which play important roles in plant acyl lipid metabolism. Here, we present the first genome-enabled identification and analysis of MBOAT gene models in plants. In total, we identified 136 plant MBOAT sequences from 14 plant species with complete genomes. Phylogenetic relationship analyses suggested the plant MBOAT gene models fell into four major groups, two of which likely encode enzymes of diacylglycerol acyltransferase 1 (DGAT1) and lysophospholipid acyltransferase (LPLAT), respectively, with one-three copies of paralogs present in each of the most plant species. A group of gene sequences, which are homologous to Saccharomyces cerevisiae glycerol uptake proteins (GUP), was identified in plants; copy numbers were conserved, with only one copy represented in each of the most plant species; analyses showed that residues essential for acyltransferases were more prone to be conserved than vertebrate orthologs. Among four groups, one was inferred to emerge in land plants and experience a rapid expansion in genomes of angiosperms, which suggested their important roles in adaptation of plants in lands. Sequence and phylogeny analyses indicated that genes in all four groups encode enzymes with acyltransferases. Comprehensive sequence identification of MBOAT family members and investigation into classification provide a complete picture of the MBOAT gene family in plants, and could shed light into enzymatic functions of different MBOAT genes in plants.
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Affiliation(s)
- Peng Wang
- Tropical Crops Genetic Resources Institute, Chinese Academy of Tropical Agricultural Sciences & Key Laboratory of Crop Gene Resources and Germplasm Enhancement in Southern China, Ministry of Agriculture, Danzhou, 571737, Hainan, China,
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24
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Arroyo-Caro JM, Chileh T, Alonso DL, García-Maroto F. Molecular characterization of a lysophosphatidylcholine acyltransferase gene belonging to the MBOAT family in Ricinus communis L. Lipids 2013; 48:663-74. [PMID: 23700249 DOI: 10.1007/s11745-013-3797-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Accepted: 05/07/2013] [Indexed: 11/27/2022]
Abstract
Acyl-CoA:lysophosphatidylcholine acyltransferase (LPCAT, EC 2.3.1.23) catalyzes acylation of lysophosphatidylcholine (lysoPtdCho) to produce phosphatidylcholine (PtdCho), the main phospholipid in cellular membranes. This reaction is a key component of the acyl-editing process, involving recycling of the fatty acids (FA) mainly at the sn-2 position of PtdCho. Growing evidences indicate that the LPCAT reaction controls the direct entry of newly synthesized FA into PtdCho and, at least in some plant species, it has an important impact on the synthesis and composition of triacylglycerols. Here we describe the molecular characterization of the single LPCAT gene found in the genome of Ricinus communis (RcLPCAT) that is homologous to LPCAT genes of the MBOAT family previously described in Arabidopsis and Brassica. RcLPCAT is ubiquitously expressed in all organs of the castor plant. Biochemical properties have been studied by heterologous expression of RcLPCAT in the ale1 yeast mutant, defective in lysophospholipid acyltransferase activity. RcLPCAT preferentially acylates lysoPtdCho against other lysophospholipids (lysoPL) and does not discriminates the acyl chain in the acceptor, displaying a strong activity with alkyl lysoPL. Regarding the acyl-CoA donor, RcLPCAT uses monounsaturated fatty acid thioesters, such as oleoyl-CoA (18:1-CoA), as preferred donors, while it has a low activity with saturated fatty acids and shows a poor utilization of ricinoleoyl-CoA (18:1-OH-CoA). These characteristics are discussed in terms of a possible role of RcLPCAT in regulating the entry of FA into PtdCho and the exclusion from the membranes of the hydroxylated FA.
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Affiliation(s)
- José María Arroyo-Caro
- Centro de Investigación en Biotecnología Agroalimentaria, Universidad de Almería, Campus de Excelencia Internacional Agroalimentario (CeiA3), CITE-II B, Almería, Spain
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25
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Ruiz-Lopez N, Haslam RP, Usher SL, Napier JA, Sayanova O. Reconstitution of EPA and DHA biosynthesis in arabidopsis: iterative metabolic engineering for the synthesis of n-3 LC-PUFAs in transgenic plants. Metab Eng 2013; 17:30-41. [PMID: 23500000 PMCID: PMC3650579 DOI: 10.1016/j.ymben.2013.03.001] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Revised: 01/21/2013] [Accepted: 03/01/2013] [Indexed: 11/19/2022]
Abstract
An iterative approach to optimising the accumulation of non-native long chain polyunsaturated fatty acids in transgenic plants was undertaken in Arabidopsis thaliana. The contribution of a number of different transgene enzyme activities was systematically determined, as was the contribution of endogenous fatty acid metabolism. Successive iterations were informed by lipidomic analysis of neutral, polar and acyl-CoA pools. This approach allowed for a four-fold improvement on levels previously reported for the accumulation of eicosapentaenoic acid in Arabidopsis seeds and also facilitated the successful engineering of the high value polyunsaturated fatty acid docosahexaenoic acid to 10-fold higher levels. Our studies identify the minimal gene set required to direct the efficient synthesis of these fatty acids in transgenic seed oil.
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Key Words
- ala, α-linolenic acid
- ara, arachidonic acid
- dag, diacylglycerol
- dha, docosahexaenoic acid
- dpa, docosapentaenoic acid
- epa, eicosapentaenoic acid
- gla, γ-linolenic acid
- la, linoleic acid
- lc-pufa, long chain polyunsaturated fatty acid
- pc, phosphatidylcholine
- pe, phosphatidylethanolamine
- pi, phosphatidylinositol
- ps, phosphatidylserine
- sda, stearidonic acid
- tag, triacylglycerol
- desaturase
- elongase
- nutritional enhancement
- omega-3 long chain polyunsaturated fatty acids
- transgenic plants
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Affiliation(s)
| | | | | | - Johnathan A. Napier
- Department of Biological Chemistry, Rothamsted Research, Harpenden, Herts AL5 2JQ, UK
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26
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Vanhercke T, Wood CC, Stymne S, Singh SP, Green AG. Metabolic engineering of plant oils and waxes for use as industrial feedstocks. PLANT BIOTECHNOLOGY JOURNAL 2013. [PMID: 23190163 DOI: 10.1111/pbi.12023] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Society has come to rely heavily on mineral oil for both energy and petrochemical needs. Plant lipids are uniquely suited to serve as a renewable source of high-value fatty acids for use as chemical feedstocks and as a substitute for current petrochemicals. Despite the broad variety of acyl structures encountered in nature and the cloning of many genes involved in their biosynthesis, attempts at engineering economic levels of specialty industrial fatty acids in major oilseed crops have so far met with only limited success. Much of the progress has been hampered by an incomplete knowledge of the fatty acid biosynthesis and accumulation pathways. This review covers new insights based on metabolic flux and reverse engineering studies that have changed our view of plant oil synthesis from a mostly linear process to instead an intricate network with acyl fluxes differing between plant species. These insights are leading to new strategies for high-level production of industrial fatty acids and waxes. Furthermore, progress in increasing the levels of oil and wax structures in storage and vegetative tissues has the potential to yield novel lipid production platforms. The challenge and opportunity for the next decade will be to marry these technologies when engineering current and new crops for the sustainable production of oil and wax feedstocks.
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27
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Arroyo-Caro JM, Chileh T, Kazachkov M, Zou J, Alonso DL, García-Maroto F. The multigene family of lysophosphatidate acyltransferase (LPAT)-related enzymes in Ricinus communis: cloning and molecular characterization of two LPAT genes that are expressed in castor seeds. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2013; 199-200:29-40. [PMID: 23265316 DOI: 10.1016/j.plantsci.2012.09.015] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Revised: 09/14/2012] [Accepted: 09/16/2012] [Indexed: 05/07/2023]
Abstract
The multigene family encoding proteins related to lysophosphatidyl-acyltransferases (LPATs) has been analyzed in the castor plant Ricinus communis. Among them, two genes designated RcLPAT2 and RcLPATB, encoding proteins with LPAT activity and expressed in the developing seed, have been cloned and characterized in some detail. RcLPAT2 groups with well characterized members of the so-called A-class LPATs and it shows a generalized expression pattern in the plant and along seed development. Enzymatic assays of RcLPAT2 indicate a preference for ricinoleoyl-CoA over other fatty acid thioesters when ricinoleoyl-LPA is used as the acyl acceptor, while oleoyl-CoA is the preferred substrate when oleoyl-LPA is employed. RcLPATB groups with B-class LPAT enzymes described as seed specific and selective for unusual fatty acids. However, RcLPATB exhibit a broad specificity on the acyl-CoAs, with saturated fatty acids (12:0-16:0) being the preferred substrates. RcLPATB is upregulated coinciding with seed triacylglycerol accumulation, but its expression is not restricted to the seed. These results are discussed in the light of a possible role for LPAT isoenzymes in the channelling of ricinoleic acid into castor bean triacylglycerol.
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Affiliation(s)
- José María Arroyo-Caro
- Grupo de Biotecnología de Productos Naturales (BIO-279), Centro de Investigación en Biotecnología Agroalimentaria, Campus de Excelencia Internacional Agroalimentario (CeiA3), Universidad de Almería, Almería, Spain
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28
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Li-Beisson Y, Shorrosh B, Beisson F, Andersson MX, Arondel V, Bates PD, Baud S, Bird D, DeBono A, Durrett TP, Franke RB, Graham IA, Katayama K, Kelly AA, Larson T, Markham JE, Miquel M, Molina I, Nishida I, Rowland O, Samuels L, Schmid KM, Wada H, Welti R, Xu C, Zallot R, Ohlrogge J. Acyl-lipid metabolism. THE ARABIDOPSIS BOOK 2013; 11:e0161. [PMID: 23505340 PMCID: PMC3563272 DOI: 10.1199/tab.0161] [Citation(s) in RCA: 707] [Impact Index Per Article: 64.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Acyl lipids in Arabidopsis and all other plants have a myriad of diverse functions. These include providing the core diffusion barrier of the membranes that separates cells and subcellular organelles. This function alone involves more than 10 membrane lipid classes, including the phospholipids, galactolipids, and sphingolipids, and within each class the variations in acyl chain composition expand the number of structures to several hundred possible molecular species. Acyl lipids in the form of triacylglycerol account for 35% of the weight of Arabidopsis seeds and represent their major form of carbon and energy storage. A layer of cutin and cuticular waxes that restricts the loss of water and provides protection from invasions by pathogens and other stresses covers the entire aerial surface of Arabidopsis. Similar functions are provided by suberin and its associated waxes that are localized in roots, seed coats, and abscission zones and are produced in response to wounding. This chapter focuses on the metabolic pathways that are associated with the biosynthesis and degradation of the acyl lipids mentioned above. These pathways, enzymes, and genes are also presented in detail in an associated website (ARALIP: http://aralip.plantbiology.msu.edu/). Protocols and methods used for analysis of Arabidopsis lipids are provided. Finally, a detailed summary of the composition of Arabidopsis lipids is provided in three figures and 15 tables.
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29
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Li-Beisson Y, Shorrosh B, Beisson F, Andersson MX, Arondel V, Bates PD, Baud S, Bird D, Debono A, Durrett TP, Franke RB, Graham IA, Katayama K, Kelly AA, Larson T, Markham JE, Miquel M, Molina I, Nishida I, Rowland O, Samuels L, Schmid KM, Wada H, Welti R, Xu C, Zallot R, Ohlrogge J. Acyl-lipid metabolism. THE ARABIDOPSIS BOOK 2013. [PMID: 23505340 DOI: 10.1199/tab.0161m] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Acyl lipids in Arabidopsis and all other plants have a myriad of diverse functions. These include providing the core diffusion barrier of the membranes that separates cells and subcellular organelles. This function alone involves more than 10 membrane lipid classes, including the phospholipids, galactolipids, and sphingolipids, and within each class the variations in acyl chain composition expand the number of structures to several hundred possible molecular species. Acyl lipids in the form of triacylglycerol account for 35% of the weight of Arabidopsis seeds and represent their major form of carbon and energy storage. A layer of cutin and cuticular waxes that restricts the loss of water and provides protection from invasions by pathogens and other stresses covers the entire aerial surface of Arabidopsis. Similar functions are provided by suberin and its associated waxes that are localized in roots, seed coats, and abscission zones and are produced in response to wounding. This chapter focuses on the metabolic pathways that are associated with the biosynthesis and degradation of the acyl lipids mentioned above. These pathways, enzymes, and genes are also presented in detail in an associated website (ARALIP: http://aralip.plantbiology.msu.edu/). Protocols and methods used for analysis of Arabidopsis lipids are provided. Finally, a detailed summary of the composition of Arabidopsis lipids is provided in three figures and 15 tables.
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30
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Bates PD, Fatihi A, Snapp AR, Carlsson AS, Browse J, Lu C. Acyl editing and headgroup exchange are the major mechanisms that direct polyunsaturated fatty acid flux into triacylglycerols. PLANT PHYSIOLOGY 2012; 160:1530-9. [PMID: 22932756 PMCID: PMC3490606 DOI: 10.1104/pp.112.204438] [Citation(s) in RCA: 163] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Accepted: 08/27/2012] [Indexed: 05/18/2023]
Abstract
Triacylglycerols (TAG) in seeds of Arabidopsis (Arabidopsis thaliana) and many plant species contain large amounts of polyunsaturated fatty acids (PUFA). These PUFA are synthesized on the membrane lipid phosphatidylcholine (PC). However, the exact mechanisms of how fatty acids enter PC and how they are removed from PC after being modified to participate in the TAG assembly are unclear, nor are the identities of the key enzymes/genes that control these fluxes known. By reverse genetics and metabolic labeling experiments, we demonstrate that two genes encoding the lysophosphatidylcholine acyltransferases LPCAT1 and LPCAT2 in Arabidopsis control the previously identified "acyl-editing" process, the main entry of fatty acids into PC. The lpcat1/lpcat2 mutant showed increased contents of very-long-chain fatty acids and decreased PUFA in TAG and the accumulation of small amounts of lysophosphatidylcholine in developing seeds revealed by [¹⁴C]acetate-labeling experiments. We also showed that mutations in LPCATs and the PC diacylglycerol cholinephosphotransferase in the reduced oleate desaturation1 (rod1)/lpcat1/lpcat2 mutant resulted in a drastic reduction of PUFA content in seed TAG, accumulating only one-third of the wild-type level. These results indicate that PC acyl editing and phosphocholine headgroup exchange between PC and diacylglycerols control the majority of acyl fluxes through PC to provide PUFA for TAG synthesis.
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31
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32
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Zheng Q, Li JQ, Kazachkov M, Liu K, Zou J. Identification of Brassica napus lysophosphatidylcholine acyltransferase genes through yeast functional screening. PHYTOCHEMISTRY 2012; 75:21-31. [PMID: 22212851 DOI: 10.1016/j.phytochem.2011.11.022] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2011] [Revised: 11/21/2011] [Accepted: 11/30/2011] [Indexed: 05/21/2023]
Abstract
Acyl-CoA:lysophosphatidylcholine acyltransferase (LPCAT), which acylates lysophosphatidylcholine (LPC) to produce phosphatidylcholine (PC), is a key enzyme in the Lands cycle. There is evidence that acyl exchange involving LPCAT is a prevailing metabolic process during triacylglycerol (TAG) synthesis in seeds. In this study, by complementing the yeast lca1Δ mutant deficient in LPCAT activity with an Arabidopsis seedling cDNA library, it was found that the previously reported lysophospholipid acyltransferases (LPLATs), At1g12640 and At1g63050, were the only two acyltransferase genes that restored hyposensitivity of the lca1Δ mutant to lyso-platelet-activating factor (lyso-PAF). A developing seed cDNA library from Brassica napus L. cv Hero was constructed to further explore the heterologous yeast complementation approach. Three B. napusLPCAT homologs were identified, of which BnLPCAT1-1 and BnLPCAT1-2 are orthologous to ArabidopsisAtLPLAT1 (At1g12640) while BnLPCAT2 is an ortholog of AtLPLAT2 (At1g63050). The proteins encoded by BnLPCAT1-1 and BnLPCAT2 were chosen for further study. Enzymatic assays demonstrated that both proteins exhibited a substrate preference for LPCs and unsaturated fatty acyl-CoAs. In addition to the enzymatic properties of plant lysophosphatidylcholine acyltransferases uncovered in this study, this report describes a useful technique that facilitates subsequent analyses into the role of LPCATs in PC turnover and seed oil biosynthesis.
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Affiliation(s)
- Qian Zheng
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, No. 1, Shizi Shan Street, Wuhan, Hubei 430070, China
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33
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Bulat E, Garrett TA. Putative N-acylphosphatidylethanolamine synthase from Arabidopsis thaliana is a lysoglycerophospholipid acyltransferase. J Biol Chem 2011; 286:33819-31. [PMID: 21803774 PMCID: PMC3190788 DOI: 10.1074/jbc.m111.269779] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Revised: 07/25/2011] [Indexed: 11/06/2022] Open
Abstract
AT1G78690, a gene found in Arabidopsis thaliana, has been reported to encode a N-acyltransferase that transfers an acyl chain from acyl-CoA to the headgroup of phosphatidylethanolamine (PE) to form N-acylphosphatidylethanolamine (N-acyl-PE). Our investigation suggests that At1g78690p is not a PE-dependent N-acyltransferase but is instead a lysoglycerophospholipid O-acyltransferase. We overexpressed AT1G78690 in Escherichia coli, extracted the cellular lipids, and identified the accumulating glycerophospholipid as acylphosphatidylglycerol (acyl-PG). Electrospray ionization quadrupole time-of-flight mass spectrometry (ESI-MS) analysis yielded [M - H](-) ions, corresponding by exact mass to acyl-PG rather than N-acyl-PE. Collision-induced dissociation mass spectrometry (MS/MS) yielded product ions consistent with acyl-PG. In addition, in vitro enzyme assays using both (32)P- and (14)C-radiolabeled substrates showed that AT1G78690 acylates 1-acyllysophosphatidylethanolamine (1-acyllyso-PE) and 1-acyllysophosphatidylglycerol (1-acyllyso-PG), but not PE or phosphatidylglycerol (PG), to form a diacylated product that co-migrates with PE and PG, respectively. We analyzed the diacylated product formed by AT1G78690 using a combination of base hydrolysis, phospholipase D treatment, ESI-MS, and MS/MS to show that AT1G78690 acylates the sn-2-position of 1-acyllyso-PE and 1-acyllyso-PG.
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Affiliation(s)
- Evgeny Bulat
- From the Department of Chemistry, Vassar College, Poughkeepsie, New York 12604
| | - Teresa A. Garrett
- From the Department of Chemistry, Vassar College, Poughkeepsie, New York 12604
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Carlsson AS, Yilmaz JL, Green AG, Stymne S, Hofvander P. Replacing fossil oil with fresh oil - with what and for what? EUR J LIPID SCI TECH 2011; 113:812-831. [PMID: 22102794 PMCID: PMC3210827 DOI: 10.1002/ejlt.201100032] [Citation(s) in RCA: 157] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2011] [Revised: 03/10/2011] [Accepted: 04/01/2011] [Indexed: 12/28/2022]
Abstract
Industrial chemicals and materials are currently derived mainly from fossil-based raw materials, which are declining in availability, increasing in price and are a major source of undesirable greenhouse gas emissions. Plant oils have the potential to provide functionally equivalent, renewable and environmentally friendly replacements for these finite fossil-based raw materials, provided that their composition can be matched to end-use requirements, and that they can be produced on sufficient scale to meet current and growing industrial demands. Replacement of 40% of the fossil oil used in the chemical industry with renewable plant oils, whilst ensuring that growing demand for food oils is also met, will require a trebling of global plant oil production from current levels of around 139 MT to over 400 MT annually. Realisation of this potential will rely on application of plant biotechnology to (i) tailor plant oils to have high purity (preferably >90%) of single desirable fatty acids, (ii) introduce unusual fatty acids that have specialty end-use functionalities and (iii) increase plant oil production capacity by increased oil content in current oil crops, and conversion of other high biomass crops into oil accumulating crops. This review outlines recent progress and future challenges in each of these areas. Practical applications: The research reviewed in this paper aims to develop metabolic engineering technologies to radically increase the yield and alter the fatty acid composition of plant oils and enable the development of new and more productive oil crops that can serve as renewable sources of industrial feedstocks currently provided by non-renewable and polluting fossil-based resources. As a result of recent and anticipated research developments we can expect to see significant enhancements in quality and productivity of oil crops over the coming decades. This should generate the technologies needed to support increasing plant oil production into the future, hopefully of sufficient magnitude to provide a major supply of renewable plant oils for the industrial economy without encroaching on the higher priority demand for food oils. Achievement of this goal will make a significant contribution to moving to a sustainable carbon-neutral industrial society with lower emissions of carbon dioxide to the atmosphere and reduced environmental impact as a result.
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Affiliation(s)
- Anders S Carlsson
- Department of Plant Breeding and Biotechnology, Swedish University of Agricultural Sciences Alnarp, Sweden
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Li-Beisson Y, Shorrosh B, Beisson F, Andersson MX, Arondel V, Bates PD, Baud S, Bird D, DeBono A, Durrett TP, Franke RB, Graham IA, Katayama K, Kelly AA, Larson T, Markham JE, Miquel M, Molina I, Nishida I, Rowland O, Samuels L, Schmid KM, Wada H, Welti R, Xu C, Zallot R, Ohlrogge J. Acyl-lipid metabolism. THE ARABIDOPSIS BOOK 2010; 8:e0133. [PMID: 22303259 PMCID: PMC3244904 DOI: 10.1199/tab.0133] [Citation(s) in RCA: 236] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Acyl lipids in Arabidopsis and all other plants have a myriad of diverse functions. These include providing the core diffusion barrier of the membranes that separates cells and subcellular organelles. This function alone involves more than 10 membrane lipid classes, including the phospholipids, galactolipids, and sphingolipids, and within each class the variations in acyl chain composition expand the number of structures to several hundred possible molecular species. Acyl lipids in the form of triacylglycerol account for 35% of the weight of Arabidopsis seeds and represent their major form of carbon and energy storage. A layer of cutin and cuticular waxes that restricts the loss of water and provides protection from invasions by pathogens and other stresses covers the entire aerial surface of Arabidopsis. Similar functions are provided by suberin and its associated waxes that are localized in roots, seed coats, and abscission zones and are produced in response to wounding. This chapter focuses on the metabolic pathways that are associated with the biosynthesis and degradation of the acyl lipids mentioned above. These pathways, enzymes, and genes are also presented in detail in an associated website (ARALIP: http://aralip.plantbiology.msu.edu/). Protocols and methods used for analysis of Arabidopsis lipids are provided. Finally, a detailed summary of the composition of Arabidopsis lipids is provided in three figures and 15 tables.
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Venegas-Calerón M, Sayanova O, Napier JA. An alternative to fish oils: Metabolic engineering of oil-seed crops to produce omega-3 long chain polyunsaturated fatty acids. Prog Lipid Res 2010; 49:108-19. [DOI: 10.1016/j.plipres.2009.10.001] [Citation(s) in RCA: 150] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2009] [Revised: 10/13/2009] [Accepted: 10/20/2009] [Indexed: 12/14/2022]
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Maisonneuve S, Bessoule JJ, Lessire R, Delseny M, Roscoe TJ. Expression of rapeseed microsomal lysophosphatidic acid acyltransferase isozymes enhances seed oil content in Arabidopsis. PLANT PHYSIOLOGY 2010; 152:670-84. [PMID: 19965969 PMCID: PMC2815856 DOI: 10.1104/pp.109.148247] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2009] [Accepted: 12/01/2009] [Indexed: 05/19/2023]
Abstract
In higher plants, lysophosphatidic acid acyltransferase (LPAAT), located in the cytoplasmic endomembrane compartment, plays an essential role in the synthesis of phosphatidic acid, a key intermediate in the biosynthesis of membrane phospholipids in all tissues and storage lipids in developing seeds. In order to assess the contribution of LPAATs to the synthesis of storage lipids, we have characterized two microsomal LPAAT isozymes, the products of homoeologous genes that are expressed in rapeseed (Brassica napus). DNA sequence homologies, complementation of a bacterial LPAAT-deficient mutant, and enzymatic properties confirmed that each of two cDNAs isolated from a Brassica napus immature embryo library encoded a functional LPAAT possessing the properties of a eukaryotic pathway enzyme. Analyses in planta revealed differences in the expression of the two genes, one of which was detected in all rapeseed tissues and during silique and seed development, whereas the expression of the second gene was restricted predominantly to siliques and developing seeds. Expression of each rapeseed LPAAT isozyme in Arabidopsis (Arabidopsis thaliana) resulted in the production of seeds characterized by a greater lipid content and seed mass. These results support the hypothesis that increasing the expression of glycerolipid acyltransferases in seeds leads to a greater flux of intermediates through the Kennedy pathway and results in enhanced triacylglycerol accumulation.
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