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Bates PD. Understanding the control of acyl flux through the lipid metabolic network of plant oil biosynthesis. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:1214-1225. [PMID: 27003249 DOI: 10.1016/j.bbalip.2016.03.021] [Citation(s) in RCA: 119] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 03/10/2016] [Accepted: 03/11/2016] [Indexed: 10/22/2022]
Abstract
Plant oil biosynthesis involves a complex metabolic network with multiple subcellular compartments, parallel pathways, cycles, and pathways that have a dual function to produce essential membrane lipids and triacylglycerol. Modern molecular biology techniques provide tools to alter plant oil compositions through bioengineering, however with few exceptions the final composition of triacylglycerol cannot be predicted. One reason for limited success in oilseed bioengineering is the inadequate understanding of how to control the flux of fatty acids through various fatty acid modification, and triacylglycerol assembly pathways of the lipid metabolic network. This review focuses on the mechanisms of acyl flux through the lipid metabolic network, and highlights where uncertainty resides in our understanding of seed oil biosynthesis. 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)
- Philip D Bates
- Department of Chemistry and Biochemistry, The University of Southern Mississippi, 118 College Dr. #5043, Hattiesburg, MS 39406-0001, United States.
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52
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Tejera N, Vauzour D, Betancor MB, Sayanova O, Usher S, Cochard M, Rigby N, Ruiz-Lopez N, Menoyo D, Tocher DR, Napier JA, Minihane AM. A Transgenic Camelina sativa Seed Oil Effectively Replaces Fish Oil as a Dietary Source of Eicosapentaenoic Acid in Mice. J Nutr 2016; 146:227-35. [PMID: 26791554 PMCID: PMC4725436 DOI: 10.3945/jn.115.223941] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 12/08/2015] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND Fish currently supplies only 40% of the eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) required to allow all individuals globally to meet the minimum intake recommendation of 500 mg/d. Therefore, alternative sustainable sources are needed. OBJECTIVE The main objective was to investigate the ability of genetically engineered Camelina sativa (20% EPA) oil (CO) to enrich tissue EPA and DHA relative to an EPA-rich fish oil (FO) in mammals. METHODS Six-week-old male C57BL/6J mice were fed for 10 wk either a palm oil-containing control (C) diet or diets supplemented with EPA-CO or FO, with the C, low-EPA CO (COL), high-EPA CO (COH), low-EPA FO (FOL), and high-EPA FO (FOH) diets providing 0, 0.4, 3.4, 0.3, and 2.9 g EPA/kg diet, respectively. Liver, muscle, and brain were collected for fatty acid analysis, and blood glucose and serum lipids were quantified. The expression of selected hepatic genes involved in EPA and DHA biosynthesis and in modulating their cellular impact was determined. RESULTS The oils were well tolerated, with significantly greater weight gain in the COH and FOH groups relative to the C group (P < 0.001). Significantly lower (36-38%) blood glucose concentrations were evident in the FOH and COH mice relative to C mice (P < 0.01). Hepatic EPA concentrations were higher in all EPA groups relative to the C group (P < 0.001), with concentrations of 0.0, 0.4, 2.9, 0.2, and 3.6 g/100 g liver total lipids in the C, COL, COH, FOL, and FOH groups, respectively. Comparable dose-independent enrichments of liver DHA were observed in mice fed CO and FO diets (P < 0.001). Relative to the C group, lower fatty acid desaturase 1 (Fads1) expression (P < 0.005) was observed in the COH and FOH groups. Higher fatty acid desaturase 2 (Fads2), peroxisome proliferator-activated receptor α (Ppara), and peroxisome proliferator-activated receptor γ (Pparg) (P < 0.005) expressions were induced by CO. No impact of treatment on liver X receptor α (Lxra) or sterol regulatory element-binding protein 1c (Srebp1c) was evident. CONCLUSIONS Oil from transgenic Camelina is a bioavailable source of EPA in mice. These data provide support for the future assessment of this oil in a human feeding trial.
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Affiliation(s)
- Noemi Tejera
- Department of Nutrition, Norwich Medical School, Faculty of Medicine and Health Sciences, University of East Anglia, Norwich, United Kingdom;
| | - David Vauzour
- Department of Nutrition, Norwich Medical School, Faculty of Medicine and Health Sciences, University of East Anglia, Norwich, United Kingdom;,Institute of Food Research, Norwich Research Park, Norwich, United Kingdom
| | - Monica B Betancor
- Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling, United Kingdom
| | - Olga Sayanova
- Department of Biological Chemistry and Crop Protection, Rothamsted Research, Harpenden, United Kingdom; and
| | - Sarah Usher
- Department of Biological Chemistry and Crop Protection, Rothamsted Research, Harpenden, United Kingdom; and
| | - Marianne Cochard
- Department of Nutrition, Norwich Medical School, Faculty of Medicine and Health Sciences, University of East Anglia, Norwich, United Kingdom
| | - Neil Rigby
- Institute of Food Research, Norwich Research Park, Norwich, United Kingdom
| | - Noemi Ruiz-Lopez
- Department of Agricultural Production, School of Agricultural Engineering, Technical University of Madrid, Madrid, Spain
| | - David Menoyo
- Department of Agricultural Production, School of Agricultural Engineering, Technical University of Madrid, Madrid, Spain
| | - Douglas R Tocher
- Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling, United Kingdom
| | - Johnathan A Napier
- Department of Biological Chemistry and Crop Protection, Rothamsted Research, Harpenden, United Kingdom; and
| | - Anne Marie Minihane
- Department of Nutrition, Norwich Medical School, Faculty of Medicine and Health Sciences, University of East Anglia, Norwich, United Kingdom
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Li N, Xu C, Li-Beisson Y, Philippar K. Fatty Acid and Lipid Transport in Plant Cells. TRENDS IN PLANT SCIENCE 2016; 21:145-158. [PMID: 26616197 DOI: 10.1016/j.tplants.2015.10.011] [Citation(s) in RCA: 150] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 09/29/2015] [Accepted: 10/15/2015] [Indexed: 05/18/2023]
Abstract
Fatty acids (FAs) and lipids are essential - not only as membrane constituents but also for growth and development. In plants and algae, FAs are synthesized in plastids and to a large extent transported to the endoplasmic reticulum for modification and lipid assembly. Subsequently, lipophilic compounds are distributed within the cell, and thus are transported across most membrane systems. Membrane-intrinsic transporters and proteins for cellular FA/lipid transfer therefore represent key components for delivery and dissemination. In addition to highlighting their role in lipid homeostasis and plant performance, different transport mechanisms for land plants and green algae - in the model systems Arabidopsis thaliana, Chlamydomonas reinhardtii - are compared, thereby providing a current perspective on protein-mediated FA and lipid trafficking in photosynthetic cells.
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Affiliation(s)
- Nannan Li
- Research Center of Bioenergy and Bioremediation (RCBB), College of Resources and Environment, Southwest University, Beibei District, Chongqing, 400715, P.R. China
| | - Changcheng Xu
- Biology Department, Brookhaven National Laboratory, 50 Bell Avenue, Upton, NY 11973-5000, USA
| | - Yonghua Li-Beisson
- Institute of Environmental Biology and Biotechnology, The French Atomic and Alternative Energy Commission, Unité Mixte de Recherche 7265, Commissariat à l'Energie Atomique (CEA) Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - Katrin Philippar
- Department of Biology I, Ludwig-Maximilians-University München, 82152 Planegg-Martinsried, Germany.
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Iven T, Hornung E, Heilmann M, Feussner I. Synthesis of oleyl oleate wax esters in Arabidopsis thaliana and Camelina sativa seed oil. PLANT BIOTECHNOLOGY JOURNAL 2016; 14:252-9. [PMID: 25912558 DOI: 10.1111/pbi.12379] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 03/15/2015] [Accepted: 03/18/2015] [Indexed: 05/20/2023]
Abstract
Seed oil composed of wax esters with long-chain monoenoic acyl moieties represents a high-value commodity for industry. Such plant-derived sperm oil-like liquid wax esters are biodegradable and can have excellent properties for lubrication. In addition, wax ester oil may represent a superior substrate for biodiesel production. In this study, we demonstrate that the low-input oil seed crop Camelina sativa can serve as a biotechnological platform for environmentally benign wax ester production. Two biosynthetic steps catalysed by a fatty alcohol-forming acyl-CoA reductase (FAR) and a wax ester synthase (WS) are sufficient to achieve wax ester accumulation from acyl-CoA substrates. To produce plant-derived sperm oil-like liquid wax esters, the WS from Mus musculus (MmWS) or Simmondsia chinensis (ScWS) were expressed in combination with the FAR from Mus musculus (MmFAR1) or Marinobacter aquaeolei (MaFAR) in seeds of Arabidopsis thaliana and Camelina sativa. The three analysed enzyme combinations Oleo3:mCherry:MmFAR1∆c/Oleo3:EYFP:MmWS, Oleo3:mCherry:MmFAR1∆c/ScWS and MaFAR/ScWS showed differences in the wax ester molecular species profiles and overall biosynthetic performance. By expressing MaFAR/ScWS in Arabidopsis or Camelina up to 59% or 21% of the seed oil TAGs were replaced by wax esters, respectively. This combination also yielded wax ester molecular species with highest content of monounsaturated acyl moieties. Expression of the enzyme combinations in the Arabidopsis fae1 fad2 mutant background high in oleic acid resulted in wax ester accumulation enriched in oleyl oleate (18:1/18:1 > 60%), suggesting that similar values may be obtained with a Camelina high oleic acid line.
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Affiliation(s)
- Tim Iven
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, Georg-August-University, Göttingen, Germany
| | - Ellen Hornung
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, Georg-August-University, Göttingen, Germany
| | - Mareike Heilmann
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, Georg-August-University, Göttingen, Germany
| | - Ivo Feussner
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, Georg-August-University, Göttingen, Germany
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Maravi DK, Kumar S, Sharma PK, Kobayashi Y, Goud VV, Sakurai N, Koyama H, Sahoo L. Ectopic expression of AtDGAT1, encoding diacylglycerol O-acyltransferase exclusively committed to TAG biosynthesis, enhances oil accumulation in seeds and leaves of Jatropha. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:226. [PMID: 27790288 PMCID: PMC5073959 DOI: 10.1186/s13068-016-0642-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 10/11/2016] [Indexed: 05/18/2023]
Abstract
BACKGROUND Jatropha curcas is an important biofuel crop due to the presence of high amount of oil in its seeds suitable for biodiesel production. Triacylglycerols (TAGs) are the most abundant form of storage oil in plants. Diacylglycerol O-acyltransferase (DGAT1) enzyme is responsible for the last and only committed step in seed TAG biosynthesis. Direct upregulation of TAG biosynthesis in seeds and vegetative tissues through overexpression of the DGAT1 could enhance the energy density of the biomass, making significant impact on biofuel production. RESULTS The enzyme diacylglycerol O-acyltransferase is the rate-limiting enzyme responsible for the TAG biosynthesis in seeds. We generated transgenic Jatropha ectopically expressing an Arabidopsis DGAT1 gene through Agrobacterium-mediated transformation. The resulting AtDGAT1 transgenic plants showed a dramatic increase in lipid content by 1.5- to 2 fold in leaves and 20-30 % in seeds, and an overall increase in TAG and DAG, and lower free fatty acid (FFA) levels compared to the wild-type plants. The increase in oil content in transgenic plants is accompanied with increase in average plant height, seeds per tree, average 100-seed weight, and seed length and breadth. The enhanced TAG accumulation in transgenic plants had no penalty on the growth rates, growth patterns, leaf number, and leaf size of plants. CONCLUSIONS In this study, we produced transgenic Jatropha ectopically expressing AtDGAT1. We successfully increased the oil content by 20-30 % in seeds and 1.5- to 2.0-fold in leaves of Jatropha through genetic engineering. Transgenic plants had reduced FFA content compared with control plants. Our strategy of increasing energy density by enhancing oil accumulation in both seeds and leaves in Jatropha would make it economically more sustainable for biofuel production.
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Affiliation(s)
| | - Sanjeev Kumar
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781039 India
| | - Prabin Kumar Sharma
- Center for Energy, Indian Institute of Technology Guwahati, Guwahati, 781039 India
| | - Yasufumi Kobayashi
- Center for Energy, Indian Institute of Technology Guwahati, Guwahati, 781039 India
- Applied Biological Sciences, Gifu University, 1-1, Yanagido, Gifu, 501-1193 Japan
| | - Vaibhav V. Goud
- Center for Energy, Indian Institute of Technology Guwahati, Guwahati, 781039 India
- Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati, 781039 India
| | - Nozomu Sakurai
- Department of Technology Development, Kazusa DNA Research Institute, 2-6-7 Kazusa-Kamatari, Kisarazu, Chiba 292-0818 Japan
| | - Hiroyuki Koyama
- Applied Biological Sciences, Gifu University, 1-1, Yanagido, Gifu, 501-1193 Japan
| | - Lingaraj Sahoo
- Center for Energy, Indian Institute of Technology Guwahati, Guwahati, 781039 India
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781039 India
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Mihálik D, Klčová L, Ondreičková K, Hudcovicová M, Gubišová M, Klempová T, Čertík M, Pauk J, Kraic J. Biosynthesis of Essential Polyunsaturated Fatty Acids in Wheat Triggered by Expression of Artificial Gene. Int J Mol Sci 2015; 16:30046-60. [PMID: 26694368 PMCID: PMC4691084 DOI: 10.3390/ijms161226137] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 11/16/2015] [Accepted: 11/19/2015] [Indexed: 12/03/2022] Open
Abstract
The artificial gene D6D encoding the enzyme ∆⁶desaturase was designed and synthesized using the sequence of the same gene from the fungus Thamnidium elegans. The original start codon was replaced by the signal sequence derived from the wheat gene for high-molecular-weight glutenin subunit and the codon usage was completely changed for optimal expression in wheat. Synthesized artificial D6D gene was delivered into plants of the spring wheat line CY-45 and the gene itself, as well as transcribed D6D mRNA were confirmed in plants of T₀ and T₁ generations. The desired product of the wheat genetic modification by artificial D6D gene was the γ-linolenic acid. Its presence was confirmed in mature grains of transgenic wheat plants in the amount 0.04%-0.32% (v/v) of the total amount of fatty acids. Both newly synthesized γ-linolenic acid and stearidonic acid have been detected also in leaves, stems, roots, awns, paleas, rachillas, and immature grains of the T₁ generation as well as in immature and mature grains of the T₂ generation. Contents of γ-linolenic acid and stearidonic acid varied in range 0%-1.40% (v/v) and 0%-1.53% (v/v) from the total amount of fatty acids, respectively. This approach has opened the pathway of desaturation of fatty acids and production of essential polyunsaturated fatty acids in wheat.
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Affiliation(s)
- Daniel Mihálik
- Research Institute of Plant Production, National Agricultural and Food Center, 921 68 Piešťany, Slovakia.
- Department of Biotechnology, Faculty of Natural Sciences, University of SS, Cyril and Methodius in Trnava, 917 01 Trnava, Slovakia.
| | - Lenka Klčová
- Research Institute of Plant Production, National Agricultural and Food Center, 921 68 Piešťany, Slovakia.
- Department of Botany and Genetics, Faculty of Natural Sciences, Constantine the Philosopher University in Nitra, 949 74 Nitra, Slovakia.
| | - Katarína Ondreičková
- Research Institute of Plant Production, National Agricultural and Food Center, 921 68 Piešťany, Slovakia.
| | - Martina Hudcovicová
- Research Institute of Plant Production, National Agricultural and Food Center, 921 68 Piešťany, Slovakia.
| | - Marcela Gubišová
- Research Institute of Plant Production, National Agricultural and Food Center, 921 68 Piešťany, Slovakia.
| | - Tatiana Klempová
- Faculty of Chemical and Food Technology, Slovak University of Technology, 812 37 Bratislava, Slovakia.
| | - Milan Čertík
- Faculty of Chemical and Food Technology, Slovak University of Technology, 812 37 Bratislava, Slovakia.
| | - János Pauk
- Cereal Research Non-profit Ltd., Szeged, Alsó kikötö sor 9, H-6726 Szeged, Hungary.
| | - Ján Kraic
- Research Institute of Plant Production, National Agricultural and Food Center, 921 68 Piešťany, Slovakia.
- Department of Biotechnology, Faculty of Natural Sciences, University of SS, Cyril and Methodius in Trnava, 917 01 Trnava, Slovakia.
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Pollard M, Martin TM, Shachar-Hill Y. Lipid analysis of developing Camelina sativa seeds and cultured embryos. PHYTOCHEMISTRY 2015; 118:23-32. [PMID: 26262674 DOI: 10.1016/j.phytochem.2015.07.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Revised: 07/17/2015] [Accepted: 07/27/2015] [Indexed: 05/20/2023]
Abstract
Camelina sativa is a cultivated oilseed rich in triacylglycerols containing oleic, linoleic, α-linolenic and eicosenoic acids. As it holds promise as a model species, its lipid synthesis was characterized in vivo and in culture. Lipid accumulates at a maximum rate of about 26 μg/day/seed (11.5 mg lipid/day/g fresh seed weight), a rate comparable with other oilseeds. Noteworthy is a late stage surge in α-linolenic acid accumulation. Small amounts of unusual epoxy and hydroxy fatty acids are also present in the triacylglycerols. These include 15,16-epoxy- and 15-hydroxy-octadecadienoic acids and homologous series of ω7-hydroxy-alk-ω9-enoic and ω9/10-hydroxy-alkanoic acids. Mid-maturation embryos cultured in vitro have growth and lipid deposition rates and fatty acid compositions that closely match that of seeds, but extended culture periods allow these rates to rise and surpass those observed in planta. Optimized thin layer chromatography systems for characterization of labeled products from acetate or glycerol labeling are described. Glycerol label is only found in acylglycerols, largely as the intact glyceryl backbone, but acetate can label acyl groups and sterols, the latter to a much higher relative specific activity. This presumably occurs because mevalonic acid precursor is derived from the non-plastid pool of acetyl-CoA that is also the source for malonyl-CoA to drive FAE1-dependent chain elongation. Particular attention has been paid to the separation of sterols and diacylglycerols, and to hydrogenation of triacylglycerols to simplify their analysis. These improved methods will allow more accurate analyses of the fluxes of lipid metabolism in cultured plant embryos.
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Affiliation(s)
- Mike Pollard
- Department of Plant Biology, Michigan State University, 612 Wilson Rd., East Lansing, MI 48824, United States.
| | - Tina M Martin
- Department of Plant Biology, Michigan State University, 612 Wilson Rd., East Lansing, MI 48824, United States
| | - Yair Shachar-Hill
- Department of Plant Biology, Michigan State University, 612 Wilson Rd., East Lansing, MI 48824, United States
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58
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Willers C, Jansen van Rensburg P, Claassens S. Phospholipid fatty acid profiling of microbial communities-a review of interpretations and recent applications. J Appl Microbiol 2015; 119:1207-18. [PMID: 26184497 DOI: 10.1111/jam.12902] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Revised: 07/02/2015] [Accepted: 07/03/2015] [Indexed: 11/29/2022]
Affiliation(s)
- C. Willers
- Unit for Environmental Sciences and Management; North-West University; Potchefstroom South Africa
| | | | - S. Claassens
- Unit for Environmental Sciences and Management; North-West University; Potchefstroom South Africa
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Napier JA, Usher S, Haslam RP, Ruiz-Lopez N, Sayanova O. Transgenic plants as a sustainable, terrestrial source of fish oils. EUR J LIPID SCI TECH 2015; 117:1317-1324. [PMID: 26900346 PMCID: PMC4744972 DOI: 10.1002/ejlt.201400452] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Revised: 04/21/2015] [Accepted: 04/23/2015] [Indexed: 11/21/2022]
Abstract
An alternative, sustainable source of omega‐3 long chain polyunsaturated fatty acids is widely recognized as desirable, helping to reduce pressure on current sources (wild capture fisheries) and providing a de novo source of these health beneficial fatty acids. This review will consider the efforts and progress to develop transgenic plants as terrestrial sources of omega‐3 fish oils, focusing on recent developments and the possible explanations for advances in the field. We also consider the utility of such a source for use in aquaculture, since this industry is the major consumer of oceanic supplies of omega‐3 fish oils. Given the importance of the aquaculture industry in meeting global requirements for healthy foodstuffs, an alternative source of omega‐3 fish oils represents a potentially significant breakthrough for this production system.
Transgenic Camelina seeds engineered to accumulate the omega‐3 fatty acids EPA and DHA, represent a sustainable alternative to fish oils.
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Affiliation(s)
- Johnathan A Napier
- Department of Biological Chemistry and Crop Protection Rothamsted Research Harpenden UK
| | - Sarah Usher
- Department of Biological Chemistry and Crop Protection Rothamsted Research Harpenden UK
| | - Richard P Haslam
- Department of Biological Chemistry and Crop Protection Rothamsted Research Harpenden UK
| | | | - Olga Sayanova
- Department of Biological Chemistry and Crop Protection Rothamsted Research Harpenden UK
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Yu M, Liu F, Zhu W, Sun M, Liu J, Li X. New features of triacylglycerol biosynthetic pathways of peanut seeds in early developmental stages. Funct Integr Genomics 2015; 15:707-16. [PMID: 26071211 DOI: 10.1007/s10142-015-0447-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Revised: 05/25/2015] [Accepted: 06/01/2015] [Indexed: 02/04/2023]
Abstract
The peanut (Arachis hypogaea L.) is one of the three most important oil crops in the world due to its high average oil content (50 %). To reveal the biosynthetic pathways of seed oil in the early developmental stages of peanut pods with the goal of improving the oil quality, we presented a method combining deep sequencing analysis of the peanut pod transcriptome and quantitative real-time PCR (RT-PCR) verification of seed oil-related genes. From the sequencing data, approximately 1500 lipid metabolism-associated Unigenes were identified. The RT-PCR results quantified the different expression patterns of these triacylglycerol (TAG) synthesis-related genes in the early developmental stages of peanut pods. Based on these results and analysis, we proposed a novel construct of the metabolic pathways involved in the biosynthesis of TAG, including the Kennedy pathway, acyl-CoA-independent pathway and proposed monoacylglycerol pathway. It showed that the biosynthetic pathways of TAG in the early developmental stages of peanut pods were much more complicated than a simple, unidirectional, linear pathway.
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Affiliation(s)
- Mingli Yu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Daizong Road No.61, Tai'an, Shandong, 271000, China.
| | - Fengzhen Liu
- State Key Laboratory of Crop Biology, College of Agronomic Sciences, Shandong Agricultural University, Tai'an, Shandong, 271000, China.
| | - Weiwei Zhu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Daizong Road No.61, Tai'an, Shandong, 271000, China.
| | - Meihong Sun
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Daizong Road No.61, Tai'an, Shandong, 271000, China.
| | - Jiang Liu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Daizong Road No.61, Tai'an, Shandong, 271000, China.
| | - Xinzheng Li
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Daizong Road No.61, Tai'an, Shandong, 271000, China.
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Tan H, Xie Q, Xiang X, Li J, Zheng S, Xu X, Guo H, Ye W. Dynamic Metabolic Profiles and Tissue-Specific Source Effects on the Metabolome of Developing Seeds of Brassica napus. PLoS One 2015; 10:e0124794. [PMID: 25919591 PMCID: PMC4412398 DOI: 10.1371/journal.pone.0124794] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 03/06/2015] [Indexed: 11/25/2022] Open
Abstract
Canola (Brassica napus) is one of several important oil-producing crops, and the physiological processes, enzymes, and genes involved in oil synthesis in canola seeds have been well characterized. However, relatively little is known about the dynamic metabolic changes that occur during oil accumulation in seeds, as well as the mechanistic origins of metabolic changes. To explore the metabolic changes that occur during oil accumulation, we isolated metabolites from both seed and silique wall and identified and characterized them by using gas chromatography coupled with mass spectrometry (GC-MS). The results showed that a total of 443 metabolites were identified from four developmental stages. Dozens of these metabolites were differentially expressed during seed ripening, including 20 known to be involved in seed development. To investigate the contribution of tissue-specific carbon sources to the biosynthesis of these metabolites, we examined the metabolic changes of silique walls and seeds under three treatments: leaf-detachment (Ld), phloem-peeling (Pe), and selective silique darkening (Sd). Our study demonstrated that the oil content was independent of leaf photosynthesis and phloem transport during oil accumulation, but required the metabolic influx from the silique wall. Notably, Sd treatment resulted in seed senescence, which eventually led to a severe reduction of the oil content. Sd treatment also caused a significant accumulation of fatty acids (FA), organic acids and amino acids. Furthermore, an unexpected accumulation of sugar derivatives and organic acid was observed in the Pe- and Sd-treated seeds. Consistent with this, the expression of a subset of genes involved in FA metabolism, sugar and oil storage was significantly altered in Pe and Sd treated seeds. Taken together, our studies suggest the metabolite profiles of canola seeds dynamically varied during the course of oil accumulation, which may provide a new insight into the mechanisms of the oil accumulation at the metabolite level.
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Affiliation(s)
- Helin Tan
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, China
- * E-mail:
| | - Qingjun Xie
- State Key Laboratory for Conservation and Utilization of Subtropical Agrobioresources, South China Agricultural University, Guangzhou, 510642, China
| | - Xiaoe Xiang
- Animal Sciences National Teaching Demonstration Center, Nanjing Agricultural University, Nanjing, 210095, China
| | - Jianqiao Li
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, China
| | - Suning Zheng
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Supervision and Testing Center for Vegetable Quality, Ministry of Agriculture, Beijing, 100081, China
| | - Xinying Xu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, China
| | - Haolun Guo
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, China
| | - Wenxue Ye
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, China
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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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Ruiz-Lopez N, Usher S, Sayanova OV, Napier JA, Haslam RP. Modifying the lipid content and composition of plant seeds: engineering the production of LC-PUFA. Appl Microbiol Biotechnol 2015; 99:143-54. [PMID: 25417743 PMCID: PMC4286622 DOI: 10.1007/s00253-014-6217-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Revised: 11/05/2014] [Accepted: 11/05/2014] [Indexed: 01/05/2023]
Abstract
Omega-3 fatty acids are characterized by a double bond at the third carbon atom from the end of the carbon chain. Latterly, long chain polyunsaturated omega-3 fatty acids such as eicosapentaenoic acid (EPA; 20:5Δ5,8,11,14,17) and docosahexanoic acid (DHA; 22:6 Δ4,7,10,13,16,19), which typically only enter the human diet via the consumption of oily fish, have attracted much attention. The health benefits of the omega-3 LC-PUFAs EPA and DHA are now well established. Given the desire for a sustainable supply of omega-LC-PUFA, efforts have focused on enhancing the composition of vegetable oils to include these important fatty acids. Specifically, EPA and DHA have been the focus of much study, with the ultimate goal of producing a terrestrial plant-based source of these so-called fish oils. Over the last decade, many genes encoding the primary LC-PUFA biosynthetic activities have been identified and characterized. This has allowed the reconstitution of the LC-PUFA biosynthetic pathway in oilseed crops, producing transgenic plants engineered to accumulate omega-3 LC-PUFA to levels similar to that found in fish oil. In this review, we will describe the most recent developments in this field and the challenges of overwriting endogenous seed lipid metabolism to maximize the accumulation of these important fatty acids.
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Affiliation(s)
- Noemi Ruiz-Lopez
- Department of Biological Chemistry, Rothamsted Research, Harpenden, Herts AL5 2JQ UK
| | - Sarah Usher
- Department of Biological Chemistry, Rothamsted Research, Harpenden, Herts AL5 2JQ UK
| | - Olga V. Sayanova
- Department of Biological Chemistry, Rothamsted Research, Harpenden, Herts AL5 2JQ UK
| | - Johnathan A. Napier
- Department of Biological Chemistry, Rothamsted Research, Harpenden, Herts AL5 2JQ UK
| | - Richard P. Haslam
- Department of Biological Chemistry, Rothamsted Research, Harpenden, Herts AL5 2JQ UK
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