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Parchuri P, Bhandari S, Azeez A, Chen G, Johnson K, Shockey J, Smertenko A, Bates PD. Identification of triacylglycerol remodeling mechanism to synthesize unusual fatty acid containing oils. Nat Commun 2024; 15:3547. [PMID: 38670976 PMCID: PMC11053099 DOI: 10.1038/s41467-024-47995-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 04/15/2024] [Indexed: 04/28/2024] Open
Abstract
Typical plant membranes and storage lipids are comprised of five common fatty acids yet over 450 unusual fatty acids accumulate in seed oils of various plant species. Plant oils are important human and animal nutrients, while some unusual fatty acids such as hydroxylated fatty acids (HFA) are used in the chemical industry (lubricants, paints, polymers, cosmetics, etc.). Most unusual fatty acids are extracted from non-agronomic crops leading to high production costs. Attempts to engineer HFA into crops are unsuccessful due to bottlenecks in the overlapping pathways of oil and membrane lipid synthesis where HFA are not compatible. Physaria fendleri naturally overcomes these bottlenecks through a triacylglycerol (TAG) remodeling mechanism where HFA are incorporated into TAG after initial synthesis. TAG remodeling involves a unique TAG lipase and two diacylglycerol acyltransferases (DGAT) that are selective for different stereochemical and acyl-containing species of diacylglycerol within a synthesis, partial degradation, and resynthesis cycle. The TAG lipase interacts with DGAT1, localizes to the endoplasmic reticulum (with the DGATs) and to puncta around the lipid droplet, likely forming a TAG remodeling metabolon near the lipid droplet-ER junction. Each characterized DGAT and TAG lipase can increase HFA accumulation in engineered seed oils.
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Affiliation(s)
- Prasad Parchuri
- Institute of Biological Chemistry, Washington State University, Pullman, WA, 99164, USA
| | - Sajina Bhandari
- Institute of Biological Chemistry, Washington State University, Pullman, WA, 99164, USA
| | - Abdul Azeez
- Institute of Biological Chemistry, Washington State University, Pullman, WA, 99164, USA
| | - Grace Chen
- United States Department of Agriculture, Agricultural Research Service, Western Regional Research Center, Albany, CA, 94710, USA
| | - Kumiko Johnson
- United States Department of Agriculture, Agricultural Research Service, Western Regional Research Center, Albany, CA, 94710, USA
| | - Jay Shockey
- United States Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, New Orleans, 70124, LA, USA
| | - Andrei Smertenko
- Institute of Biological Chemistry, Washington State University, Pullman, WA, 99164, USA
| | - Philip D Bates
- Institute of Biological Chemistry, Washington State University, Pullman, WA, 99164, USA.
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2
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Cocuron JC, Alonso AP. 13C-labeling reveals non-conventional pathways providing carbon for hydroxy fatty acid synthesis in Physaria fendleri. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:1754-1766. [PMID: 37668184 PMCID: PMC11275461 DOI: 10.1093/jxb/erad343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Accepted: 08/31/2023] [Indexed: 09/06/2023]
Abstract
Physaria fendleri is a member of the Brassicaceae that produces in its embryos hydroxy fatty acids, constituents of oils that are very valuable and widely used by industry for cosmetics, lubricants, biofuels, etc. Free of toxins and rich in hydroxy fatty acids, Physaria provides a promising alternative to imported castor oil and is on the verge of being commercialized. This study aims to identify important biochemical step(s) for oil synthesis in Physaria, which may serve as target(s) for future crop improvement. To advance towards this goal, the endosperm composition was analysed by LC-MS/MS to develop and validate culture conditions that mimic the development of the embryos in planta. Using developing Physaria embryos in culture and 13C-labeling, our studies revealed that: (i) Physaria embryos metabolize carbon into biomass with an efficiency significantly lower than other photosynthetic embryos; (ii) the plastidic malic enzyme provides 42% of the pyruvate used for de novo fatty acid synthesis, which is the highest measured so far in developing 'green' oilseed embryos; and (iii) Physaria uses non-conventional pathways to channel carbon into oil, namely the Rubisco shunt, which fixes CO2 released in the plastid, and the reversibility of isocitrate dehydrogenase, which provides additional carbon for fatty acid elongation.
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Affiliation(s)
| | - Ana Paula Alonso
- BioAnalytical Facility, University of North Texas, Denton, TX 76203, USA
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA
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3
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Park ME, Kim HU. PDAT1 genome editing reduces hydroxy fatty acid production in transgenic Arabidopsis. BMB Rep 2024; 57:86-91. [PMID: 38053289 PMCID: PMC10910088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 08/08/2023] [Accepted: 08/18/2023] [Indexed: 12/07/2023] Open
Abstract
The fatty acids content of castor (Ricinus communis L.) seed oil is 80-90% ricinoleic acid, which is a hydroxy fatty acid (HFA). The structures and functional groups of HFAs are different from those of common fatty acids and are useful for various industrial applications. However, castor seeds contain the toxin ricin and an allergenic protein, which limit their cultivation. Accordingly, many researchers are conducting studies to enhance the production of HFAs in Arabidopsis thaliana, a model plant for oil crops. Oleate 12-hydroxylase from castor (RcFAH12), which synthesizes HFA (18:1-OH), was transformed into an Arabidopsis fae1 mutant, resulting in the CL37 line producing a maximum of 17% HFA content. In addition, castor phospholipid:diacylglycerol acyltransferase 1-2 (RcPDAT1-2), which catalyzes the production of triacylglycerol by transferring HFA from phosphatidylcholine to diacylglycerol, was transformed into the CL37 line to develop a P327 line that produces 25% HFA. In this study, we investigated changes in HFA content when endogenous Arabidopsis PDAT1 (AtPDAT1) of the P327 line was edited using the CRISPR/Cas9 technique. The successful mutation resulted in three independent lines with different mutation patterns, which were transmitted until the T4 generation. Fatty acid analysis of the seeds showed that HFA content decreased in all three mutant lines. These findings indicate that AtPDAT1 as well as RcPDAT1-2 in the P327 line are involved in transferring and increasing HFAs to triacylglycerol. [BMB Reports 2024; 57(2): 86-91].
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Affiliation(s)
- Mid-Eum Park
- Department of Molecular Biology, Sejong University, Seoul 05006, Korea
| | - Hyun Uk Kim
- Department of Molecular Biology, Sejong University, Seoul 05006, Korea
- Department of Bioindustry and Bioresource Engineering, Sejong University, Seoul 05006, Korea
- Plant Engineering Research Institute, Sejong University, Seoul 05006, Korea
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4
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Shockey J, Parchuri P, Thyssen GN, Bates PD. Assessing the biotechnological potential of cotton type-1 and type-2 diacylglycerol acyltransferases in transgenic systems. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2023; 196:940-951. [PMID: 36889233 DOI: 10.1016/j.plaphy.2023.02.040] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 02/14/2023] [Accepted: 02/22/2023] [Indexed: 06/18/2023]
Abstract
The chemical and physical properties of vegetable oils are largely dictated by the ratios of 4-6 common fatty acids contained within each oil. However, examples of plant species that accumulate from trace amounts to >90% of certain unusual fatty acids in seed triacylglycerols have been reported. Many of the general enzymatic reactions that drive both common and unusual fatty acid biosynthesis and accumulation in stored lipids are known, but which isozymes have evolved to specifically fill this role and how they coordinate in vivo is still poorly understood. Cotton (Gossypium sp.) is the very rare example of a commodity oilseed that produces biologically relevant amounts of unusual fatty acids in its seeds and other organs. In this case, unusual cyclopropyl fatty acids (named after the cyclopropane and cyclopropene moieties within the fatty acids) are found in membrane and storage glycerolipids (e.g. seed oils). Such fatty acids are useful in the synthesis of lubricants, coatings, and other types of valuable industrial feedstocks. To characterize the role of cotton acyltransferases in cyclopropyl fatty acid accumulation for bioengineering applications, we cloned and characterized type-1 and type-2 diacylglycerol acyltransferases from cotton and compared their biochemical properties to that of litchi (Litchi chinensis), another cyclopropyl fatty acid-producing plant. The results presented from transgenic microbes and plants indicate both cotton DGAT1 and DGAT2 isozymes efficiently utilize cyclopropyl fatty acid-containing substrates, which helps to alleviate biosynthetic bottlenecks and enhances total cyclopropyl fatty acid accumulation in the seed oil.
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Affiliation(s)
- Jay Shockey
- United States Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, New Orleans, LA, USA, 70124.
| | - Prasad Parchuri
- Institute of Biological Chemistry, Washington State University, Pullman, WA, USA, 99164
| | - Gregory N Thyssen
- United States Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, New Orleans, LA, USA, 70124
| | - Philip D Bates
- Institute of Biological Chemistry, Washington State University, Pullman, WA, USA, 99164
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Cai Y, Yu XH, Shanklin J. A toolkit for plant lipid engineering: Surveying the efficacies of lipogenic factors for accumulating specialty lipids. FRONTIERS IN PLANT SCIENCE 2022; 13:1064176. [PMID: 36589075 PMCID: PMC9795026 DOI: 10.3389/fpls.2022.1064176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 11/28/2022] [Indexed: 06/17/2023]
Abstract
Plants produce energy-dense lipids from carbohydrates using energy acquired via photosynthesis, making plant oils an economically and sustainably attractive feedstock for conversion to biofuels and value-added bioproducts. A growing number of strategies have been developed and optimized in model plants, oilseed crops and high-biomass crops to enhance the accumulation of storage lipids (mostly triacylglycerols, TAGs) for bioenergy applications and to produce specialty lipids with increased uses and value for chemical feedstock and nutritional applications. Most successful metabolic engineering strategies involve heterologous expression of lipogenic factors that outperform those from other sources or exhibit specialized functionality. In this review, we summarize recent progress in engineering the accumulation of triacylglycerols containing - specialized fatty acids in various plant species and tissues. We also provide an inventory of specific lipogenic factors (including accession numbers) derived from a wide variety of organisms, along with their reported efficacy in supporting the accumulation of desired lipids. A review of previously obtained results serves as a foundation to guide future efforts to optimize combinations of factors to achieve further enhancements to the production and accumulation of desired lipids in a variety of plant tissues and species.
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Affiliation(s)
- Yingqi Cai
- Biology Department, Brookhaven National Laboratory, Upton, NY, United States
| | - Xiao-Hong Yu
- Biology Department, Brookhaven National Laboratory, Upton, NY, United States
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY, United States
| | - John Shanklin
- Biology Department, Brookhaven National Laboratory, Upton, NY, United States
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Trenz TS, Turchetto-Zolet AC, Margis R, Margis-Pinheiro M, Maraschin FDS. Functional analysis of alternative castor bean DGAT enzymes. Genet Mol Biol 2022; 46:e20220097. [PMID: 36512712 PMCID: PMC9747089 DOI: 10.1590/1678-4685-gmb-2022-0097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 10/30/2022] [Indexed: 12/14/2022] Open
Abstract
The diversity of diacylglycerol acyltransferases (DGATs) indicates alternative roles for these enzymes in plant metabolism besides triacylglycerol (TAG) biosynthesis. In this work, we functionally characterized castor bean (Ricinus communis L.) DGATs assessing their subcellular localization, expression in seeds, capacity to restore triacylglycerol (TAG) biosynthesis in mutant yeast and evaluating whether they provide tolerance over free fatty acids (FFA) in sensitive yeast. RcDGAT3 displayed a distinct subcellular localization, located in vesicles outside the endoplasmic reticulum (ER) in most leaf epidermal cells. This enzyme was unable to restore TAG biosynthesis in mutant yeast; however, it was able to outperform other DGATs providing higher tolerance over FFA. RcDAcTA subcellular localization was associated with the ER membranes, resembling RcDGAT1 and RcDGAT2, but it failed to rescue the long-chain TAG biosynthesis in mutant yeast, even with fatty acid supplementation. Besides TAG biosynthesis, our results suggest that RcDGAT3 might have alternative functions and roles in lipid metabolism.
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Affiliation(s)
- Thomaz Stumpf Trenz
- Universidade Federal do Rio Grande do Sul, Programa de Pós-graduação em Biologia Celular e Molecular, Centro de Biotecnologia, Porto Alegre, RS, Brazil
| | - Andreia Carina Turchetto-Zolet
- Universidade Federal do Rio Grande do Sul, Programa de Pós-graduação em Genética e Biologia Molecular, Porto Alegre, RS, Brazil.,Universidade Federal do Rio Grande do Sul, Instituto de Biociências, Departamento de Genética, Porto Alegre, RS, Brazil
| | - Rogério Margis
- Universidade Federal do Rio Grande do Sul, Programa de Pós-graduação em Biologia Celular e Molecular, Centro de Biotecnologia, Porto Alegre, RS, Brazil.,Universidade Federal do Rio Grande do Sul, Programa de Pós-graduação em Genética e Biologia Molecular, Porto Alegre, RS, Brazil.,Universidade Federal do Rio Grande do Sul, Instituto de Biociências, Departamento de Biofísica, Porto Alegre, RS, Brazil
| | - Marcia Margis-Pinheiro
- Universidade Federal do Rio Grande do Sul, Programa de Pós-graduação em Biologia Celular e Molecular, Centro de Biotecnologia, Porto Alegre, RS, Brazil.,Universidade Federal do Rio Grande do Sul, Programa de Pós-graduação em Genética e Biologia Molecular, Porto Alegre, RS, Brazil.,Universidade Federal do Rio Grande do Sul, Instituto de Biociências, Departamento de Genética, Porto Alegre, RS, Brazil
| | - Felipe dos Santos Maraschin
- Universidade Federal do Rio Grande do Sul, Programa de Pós-graduação em Genética e Biologia Molecular, Porto Alegre, RS, Brazil.,Universidade Federal do Rio Grande do Sul, Instituto de Biociências, Departamento de Botânica, Porto Alegre, RS, Brazil
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Chen G, Harwood JL, Lemieux MJ, Stone SJ, Weselake RJ. Acyl-CoA:diacylglycerol acyltransferase: Properties, physiological roles, metabolic engineering and intentional control. Prog Lipid Res 2022; 88:101181. [PMID: 35820474 DOI: 10.1016/j.plipres.2022.101181] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 05/31/2022] [Accepted: 07/04/2022] [Indexed: 12/15/2022]
Abstract
Acyl-CoA:diacylglycerol acyltransferase (DGAT, EC 2.3.1.20) catalyzes the last reaction in the acyl-CoA-dependent biosynthesis of triacylglycerol (TAG). DGAT activity resides mainly in membrane-bound DGAT1 and DGAT2 in eukaryotes and bifunctional wax ester synthase-diacylglycerol acyltransferase (WSD) in bacteria, which are all membrane-bound proteins but exhibit no sequence homology to each other. Recent studies also identified other DGAT enzymes such as the soluble DGAT3 and diacylglycerol acetyltransferase (EaDAcT), as well as enzymes with DGAT activities including defective in cuticular ridges (DCR) and steryl and phytyl ester synthases (PESs). This review comprehensively discusses research advances on DGATs in prokaryotes and eukaryotes with a focus on their biochemical properties, physiological roles, and biotechnological and therapeutic applications. The review begins with a discussion of DGAT assay methods, followed by a systematic discussion of TAG biosynthesis and the properties and physiological role of DGATs. Thereafter, the review discusses the three-dimensional structure and insights into mechanism of action of human DGAT1, and the modeled DGAT1 from Brassica napus. The review then examines metabolic engineering strategies involving manipulation of DGAT, followed by a discussion of its therapeutic applications. DGAT in relation to improvement of livestock traits is also discussed along with DGATs in various other eukaryotic organisms.
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Affiliation(s)
- Guanqun Chen
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta T6H 2P5, Canada.
| | - John L Harwood
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK
| | - M Joanne Lemieux
- Department of Biochemistry, University of Alberta, Membrane Protein Disease Research Group, Edmonton T6G 2H7, Canada
| | - Scot J Stone
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada.
| | - Randall J Weselake
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta T6H 2P5, Canada
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8
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Park ME, Lee KR, Chen GQ, Kim HU. Enhanced production of hydroxy fatty acids in Arabidopsis seed through modification of multiple gene expression. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2022; 15:66. [PMID: 35717237 PMCID: PMC9206371 DOI: 10.1186/s13068-022-02167-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Accepted: 06/09/2022] [Indexed: 02/07/2023]
Abstract
BACKGROUND Castor (Ricinus communis L.) seeds contain unusual fatty acid, hydroxy fatty acid (HFA) used as a chemical feedstock for numerous industrial products. Castor cultivation is limited by the potent toxin ricin in its seeds and other poor agronomic traits, so it is advantageous to develop a suitable HFA-producing crop. Significant research efforts have been made to produce HFA in model Arabidopsis, but the level of HFA produced in transgenic Arabidopsis is much less than the level found in castor seeds which produce 90% HFA in seed oil. RESULTS We designed a transformation construct that allowed co-expression of five essential castor genes (named pCam5) involved in HFA biosynthesis, including an oleate [Formula: see text] 12-hydroxylase (FAH12), diacylglycerol (DAG) acyltransferase 2 (DGAT2), phospholipid: DAG acyltransferase 1-2 (PDAT1-2), phosphatidylcholine (PC): DAG cholinephosphotransferase (PDCT) and Lyso-PC acyltransferase (LPCAT). Transgenic Arabidopsis pCam5 lines produced HFA counting for 25% in seed oil. By knocking out Arabidopsis Fatty acid elongase 1 (AtFAE1) in pCam5 using CRISPR/Cas9 technology, the resulted pCam5-atfae1 lines produced over 31% of HFA. Astonishingly, the pCam5-atfae1 line increased seed size, weight, and total oil per seed exceeding wild type by 40%. Seed germination, seedling growth and seed mucilage content of pCam5-atfae1 lines were not affected by the genetic modification. CONCLUSIONS Our results provide not only insights for future research uncovering mechanisms of HFA synthesis in seed, but also metabolic engineering strategies for generating safe HFA-producing crops.
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Affiliation(s)
- Mid-Eum Park
- grid.263333.40000 0001 0727 6358Department of Molecular Biology, Sejong University, Seoul, Republic of Korea
| | - Kyeong-Ryeol Lee
- grid.420186.90000 0004 0636 2782Department of Agricultural Biotechnology, Rural Development Administration, National Institute of Agricultural Sciences, Jeonju, Republic of Korea
| | - Grace Q. Chen
- grid.417548.b0000 0004 0478 6311Western Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, Albany, CA USA
| | - Hyun Uk Kim
- grid.263333.40000 0001 0727 6358Department of Molecular Biology, Sejong University, Seoul, Republic of Korea ,grid.263333.40000 0001 0727 6358Department of Bioindustry and Bioresource Engineering, Plant Engineering Research Institute, Sejong University, Seoul, 05006 Republic of Korea
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9
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Azeez A, Parchuri P, Bates PD. Suppression of Physaria fendleri SDP1 Increased Seed Oil and Hydroxy Fatty Acid Content While Maintaining Oil Biosynthesis Through Triacylglycerol Remodeling. FRONTIERS IN PLANT SCIENCE 2022; 13:931310. [PMID: 35720575 PMCID: PMC9204166 DOI: 10.3389/fpls.2022.931310] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 05/16/2022] [Indexed: 06/01/2023]
Abstract
Physaria fendleri is a burgeoning oilseed crop that accumulates the hydroxy fatty acid (HFA), lesquerolic acid, and can be a non-toxic alternative crop to castor for production of industrially valuable HFA. Recently, P. fendleri was proposed to utilize a unique seed oil biosynthetic pathway coined "triacylglycerol (TAG) remodeling" that utilizes a TAG lipase to remove common fatty acids from TAG allowing the subsequent incorporation of HFA after initial TAG synthesis, yet the lipase involved is unknown. SUGAR DEPENDENT 1 (SDP1) has been characterized as the dominant TAG lipase involved in TAG turnover during oilseed maturation and germination. Here, we characterized the role of a putative PfeSDP1 in both TAG turnover and TAG remodeling. In vitro assays confirmed that PfeSDP1 is a TAG lipase and demonstrated a preference for HFA-containing TAG species. Seed-specific RNAi knockdown of PfeSDP1 resulted in a 12%-16% increase in seed weight and 14%-19% increase in total seed oil content with no major effect on seedling establishment. The increase in total oil content was primarily due to ~4.7% to ~14.8% increase in TAG molecular species containing two HFA (2HFA-TAG), and when combined with a smaller decrease in 1HFA-TAG content the proportion of total HFA in seed lipids increased 4%-6%. The results are consistent with PfeSDP1 involved in TAG turnover but not TAG remodeling to produce 2HFA-TAG. Interestingly, the concomitant reduction of 1HFA-TAG in PfeSDP1 knockdown lines suggests PfeSDP1 may have a role in reverse TAG remodeling during seed maturation that produces 1HFA-TAG from 2HFA-TAG. Overall, our results provide a novel strategy to enhance the total amount of industrially valuable lesquerolic acid in P. fendleri seeds.
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Lunn D, Wallis JG, Browse J. A multigene approach secures hydroxy fatty acid production in Arabidopsis. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:2875-2888. [PMID: 35560203 DOI: 10.1093/jxb/erab533] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 12/02/2021] [Indexed: 06/15/2023]
Abstract
A central goal of green chemistry is to produce industrially useful fatty acids in oilseed crops. Although genes encoding suitable fatty acid-modifying enzymes are available from more than a dozen wild species, progress has been limited because expression of these enzymes in transgenic plants produces only low yields of the desired products. For example, fatty acid hydroxylase 12 (FAH12) from castor (Ricinus communis) produces only 17% hydroxy fatty acids (HFAs) when expressed in Arabidopsis (Arabidopsis thaliana), compared with 90% HFAs in castor seeds. The transgenic plants also have reduced oil content and seed vigor. Here, we review experiments that have provided for steady increased HFA accumulation and oil content. This research has led to exciting new discoveries of enzymes and regulatory processes in the pathways of both seed oil synthesis and lipid metabolism in other parts of the plant. Recent investigations have revealed that HFA-accumulating seeds are unable to rapidly mobilize HFA-containing triacylglycerol (TAG) storage lipid after germination to provide carbon and energy for seedling development, resulting in reduced seedling establishment. These findings present a new opportunity to investigate a different, key area of lipid metabolism-the pathways of TAG lipolysis and β-oxidation in germinating seedlings.
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Affiliation(s)
- Daniel Lunn
- Institute of Biology Chemistry, Washington State University, Pullman, WA 99164-6340, USA
| | - James G Wallis
- Institute of Biology Chemistry, Washington State University, Pullman, WA 99164-6340, USA
| | - John Browse
- Institute of Biology Chemistry, Washington State University, Pullman, WA 99164-6340, USA
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11
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Hatanaka T, Tomita Y, Matsuoka D, Sasayama D, Fukayama H, Azuma T, Soltani Gishini MF, Hildebrand D. Different acyl-CoA:diacylglycerol acyltransferases vary widely in function, and a targeted amino acid substitution enhances oil accumulation. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:3030-3043. [PMID: 35560190 DOI: 10.1093/jxb/erac084] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Accepted: 03/02/2022] [Indexed: 06/15/2023]
Abstract
Triacylglycerols (TAGs) are the major component of plant storage lipids such as oils. Acyl-CoA:diacylglycerol acyltransferase (DGAT) catalyzes the final step of the Kennedy pathway, and is mainly responsible for plant oil accumulation. We previously found that the activity of Vernonia DGAT1 was distinctively higher than that of Arabidopsis and soybean DGAT1 in a yeast microsome assay. In this study, the DGAT1 cDNAs of Arabidopsis, Vernonia, soybean, and castor bean were introduced into Arabidopsis. All Vernonia DGAT1-expressing lines showed a significantly higher oil content (49% mean increase compared with the wild-type) followed by soybean and castor bean. Most Arabidopsis DGAT1-overexpressing lines did not show a significant increase. In addition to these four DGAT1 genes, sunflower, Jatropha, and sesame DGAT1 genes were introduced into a TAG biosynthesis-defective yeast mutant. In the yeast expression culture, DGAT1s from Arabidopsis, castor bean, and soybean only slightly increased the TAG content; however, DGAT1s from Vernonia, sunflower, Jatropha, and sesame increased TAG content >10-fold more than the former three DGAT1s. Three amino acid residues were characteristically common in the latter four DGAT1s. Using soybean DGAT1, these amino acid substitutions were created by site-directed mutagenesis and substantially increased the TAG content.
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Affiliation(s)
- Tomoko Hatanaka
- Graduate School of Agricultural Science, Kobe University, Kobe, Hyogo, Japan
| | - Yoshiki Tomita
- Graduate School of Agricultural Science, Kobe University, Kobe, Hyogo, Japan
| | - Daisuke Matsuoka
- Graduate School of Agricultural Science, Kobe University, Kobe, Hyogo, Japan
| | - Daisuke Sasayama
- Graduate School of Agricultural Science, Kobe University, Kobe, Hyogo, Japan
| | - Hiroshi Fukayama
- Graduate School of Agricultural Science, Kobe University, Kobe, Hyogo, Japan
| | - Tetsushi Azuma
- Graduate School of Agricultural Science, Kobe University, Kobe, Hyogo, Japan
| | - Mohammad Fazel Soltani Gishini
- Department of Production Engineering and Plant Genetics, Faculty of Sciences and Agricultural Engineering, Campus of Agriculture and Natural Resources, Razi University, Kermanshah, Iran
| | - David Hildebrand
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY, USA
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12
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Song J, Pei W, Wang N, Ma J, Xin Y, Yang S, Wang W, Chen Q, Zhang J, Yu J, Wu M, Qu Y. Transcriptome analysis and identification of genes associated with oil accumulation in upland cotton. PHYSIOLOGIA PLANTARUM 2022; 174:e13701. [PMID: 35526222 DOI: 10.1111/ppl.13701] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 03/25/2022] [Accepted: 05/05/2022] [Indexed: 06/14/2023]
Abstract
Cotton is not only the most important fiber crop but also the fifth most important oilseed crop in the world because of its oil-rich seeds as a byproduct of fiber production. By comparative transcriptome analysis between two germplasms with diverse oil accumulation, we reveal pieces of the gene expression network involved in the process of oil synthesis in cottonseeds. Approximately, 197.16 Gb of raw data from 30 RNA sequencing samples with 3 biological replicates were generated. Comparison of the high-oil and low-oil transcriptomes enabled the identification of 7682 differentially expressed genes (DEGs). Based on gene expression profiles relevant to triacylglycerol (TAG) biosynthesis, we proposed that the Kennedy pathway (diacylglycerol acyltransferase-catalyzed diacylglycerol to TAG) is the main pathway for oil production, rather than the phospholipid diacylglycerol acyltransferase-mediated pathway. Using weighted gene co-expression network analysis, 5312 DEGs were obtained and classified into 14 co-expression modules, including the MEblack module containing 10 genes involved in lipid metabolism. Among the DEGs in the MEblack module, GhCYSD1 was identified as a potential key player in oil biosynthesis. The overexpression of GhCYSD1 in yeast resulted in increased oil content and altered fatty acid composition. This study may not only shed more light on the underlying molecular mechanism of oil accumulation in cottonseed oil, but also provide a set of new gene for potential enhancement of oil content in cottonseeds.
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Affiliation(s)
- Jikun Song
- Engineering Research Centre of Cotton, Ministry of Education/College of Agriculture, Xinjiang Agricultural University, Urumqi, China
- State Key Laboratory of Cotton Biology, Cotton Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Cotton Genetic Improvement, Ministry of Agriculture, Anyang, China
| | - Wenfeng Pei
- Engineering Research Centre of Cotton, Ministry of Education/College of Agriculture, Xinjiang Agricultural University, Urumqi, China
- State Key Laboratory of Cotton Biology, Cotton Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Cotton Genetic Improvement, Ministry of Agriculture, Anyang, China
| | - Nuohan Wang
- College of Biology and Food Engineering, Anyang Institute of Technology, Anyang, China
| | - Jianjiang Ma
- State Key Laboratory of Cotton Biology, Cotton Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Cotton Genetic Improvement, Ministry of Agriculture, Anyang, China
| | - Yue Xin
- State Key Laboratory of Cotton Biology, Cotton Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Cotton Genetic Improvement, Ministry of Agriculture, Anyang, China
| | - Shuxian Yang
- State Key Laboratory of Cotton Biology, Cotton Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Cotton Genetic Improvement, Ministry of Agriculture, Anyang, China
| | - Wei Wang
- Engineering Research Centre of Cotton, Ministry of Education/College of Agriculture, Xinjiang Agricultural University, Urumqi, China
| | - Quanjia Chen
- Engineering Research Centre of Cotton, Ministry of Education/College of Agriculture, Xinjiang Agricultural University, Urumqi, China
| | - Jinfa Zhang
- Department of Plant and Environmental Sciences, New Mexico State University, Las Cruces, New Mexico, USA
| | - Jiwen Yu
- Engineering Research Centre of Cotton, Ministry of Education/College of Agriculture, Xinjiang Agricultural University, Urumqi, China
- State Key Laboratory of Cotton Biology, Cotton Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Cotton Genetic Improvement, Ministry of Agriculture, Anyang, China
| | - Man Wu
- State Key Laboratory of Cotton Biology, Cotton Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Cotton Genetic Improvement, Ministry of Agriculture, Anyang, China
| | - Yanying Qu
- Engineering Research Centre of Cotton, Ministry of Education/College of Agriculture, Xinjiang Agricultural University, Urumqi, China
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13
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Busta L, Chapman KD, Cahoon EB. Better together: Protein partnerships for lineage-specific oil accumulation. CURRENT OPINION IN PLANT BIOLOGY 2022; 66:102191. [PMID: 35220088 DOI: 10.1016/j.pbi.2022.102191] [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: 12/03/2021] [Revised: 01/18/2022] [Accepted: 01/20/2022] [Indexed: 06/14/2023]
Abstract
Plant-derived oils are a major agricultural product that exist in both ubiquitous forms such as common vegetable oils and in specialized forms such as castor oil and coconut oil. These specialized oils are the result of lineage-specific metabolic pathways that create oils rich in unusual fatty acids. Considerable progress has been made toward understanding the enzymes that mediate fatty acid biosynthesis, triacylglycerol assembly, and oil storage. However, efforts to translate this knowledge into renewable bioproducts via engineered oil-producing plants and algae have had limited success. Here, we review recent evidence that protein-protein interactions in each of the three major phases of oil formation appear to have profound effects on specialized oil accumulation. We suggest that furthering our knowledge of the noncatalytic attributes of enzymes and other proteins involved in oil formation will be a critical step toward creating renewable bioproducts derived from high performing, engineered oilseeds.
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Affiliation(s)
- Lucas Busta
- Department of Chemistry and Biochemistry, University of Minnesota Duluth, Duluth, MN, 55812, USA.
| | - Kent D Chapman
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX, 76203, USA
| | - Edgar B Cahoon
- Department of Biochemistry and Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA.
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14
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Bhandari S, Bates PD. Triacylglycerol remodeling in Physaria fendleri indicates oil accumulation is dynamic and not a metabolic endpoint. PLANT PHYSIOLOGY 2021; 187:799-815. [PMID: 34608961 PMCID: PMC8491037 DOI: 10.1093/plphys/kiab294] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 06/05/2021] [Indexed: 05/26/2023]
Abstract
Oilseed plants accumulate triacylglycerol (TAG) up to 80% of seed weight with the TAG fatty acid composition determining its nutritional value or use in the biofuel or chemical industries. Two major pathways for production of diacylglycerol (DAG), the immediate precursor to TAG, have been identified in plants: de novo DAG synthesis and conversion of the membrane lipid phosphatidylcholine (PC) to DAG, with each pathway producing distinct TAG compositions. However, neither pathway fits with previous biochemical and transcriptomic results from developing Physaria fendleri seeds for accumulation of TAG containing >60% lesquerolic acid (an unusual 20 carbon hydroxylated fatty acid), which accumulates at only the sn-1 and sn-3 positions of TAG. Isotopic tracing of developing P. fendleri seed lipid metabolism identified that PC-derived DAG is utilized to initially produce TAG with only one lesquerolic acid. Subsequently a nonhydroxylated fatty acid is removed from TAG (transiently reproducing DAG) and a second lesquerolic acid is incorporated. Thus, a dynamic TAG remodeling process involving anabolic and catabolic reactions controls the final TAG fatty acid composition. Reinterpretation of P. fendleri transcriptomic data identified potential genes involved in TAG remodeling that could provide a new approach for oilseed engineering by altering oil fatty acid composition after initial TAG synthesis; and the comparison of current results to that of related Brassicaceae species in the literature suggests the possibility of TAG remodeling involved in incorporation of very long-chain fatty acids into the TAG sn-1 position in various plants.
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Affiliation(s)
- Sajina Bhandari
- Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164, USA
| | - Philip D. Bates
- Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164, USA
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15
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Chen GQ, Johnson K, Nazarenus TJ, Ponciano G, Morales E, Cahoon EB. Genetic Engineering of Lesquerella with Increased Ricinoleic Acid Content in Seed Oil. PLANTS 2021; 10:plants10061093. [PMID: 34072473 PMCID: PMC8230273 DOI: 10.3390/plants10061093] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 05/25/2021] [Accepted: 05/27/2021] [Indexed: 01/01/2023]
Abstract
Seeds of castor (Ricinus communis) are enriched in oil with high levels of the industrially valuable fatty acid ricinoleic acid (18:1OH), but production of this plant is limited because of the cooccurrence of the ricin toxin in its seeds. Lesquerella (Physaria fendleri) is being developed as an alternative industrial oilseed because its seeds accumulate lesquerolic acid (20:1OH), an elongated form of 18:1OH in seed oil which lacks toxins. Synthesis of 20:1OH is through elongation of 18:1OH by a lesquerella elongase, PfKCS18. Oleic acid (18:1) is the substrate for 18:1OH synthesis, but it is also used by fatty acid desaturase 2 (FAD2) and FAD3 to sequentially produce linoleic and linolenic acids. To develop lesquerella that produces 18:1OH-rich seed oils such as castor, RNA interference sequences targeting KCS18, FAD2 and FAD3 were introduced to lesquerella to suppress the elongation and desaturation steps. Seeds from transgenic lines had increased 18:1OH to 1.1-26.6% compared with that of 0.4-0.6% in wild-type (WT) seeds. Multiple lines had reduced 18:1OH levels in the T2 generation, including a top line with 18:1OH reduced from 26.7% to 19%. Transgenic lines also accumulated more 18:1 than that of WT, indicating that 18:1 is not efficiently used for 18:1OH synthesis and accumulation. Factors limiting 18:1OH accumulation and new targets for further increasing 18:1OH production are discussed. Our results provide insights into complex mechanisms of oil biosynthesis in lesquerella and show the biotechnological potential to tailor lesquerella seeds to produce castor-like industrial oil functionality.
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Affiliation(s)
- Grace Q. Chen
- Western Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, 800 Buchanan St., Albany, CA 94710, USA; (K.J.); (G.P.); (E.M.)
- Correspondence:
| | - Kumiko Johnson
- Western Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, 800 Buchanan St., Albany, CA 94710, USA; (K.J.); (G.P.); (E.M.)
| | - Tara J. Nazarenus
- Department of Biochemistry and Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE 68588, USA; (T.J.N.); (E.B.C.)
| | - Grisel Ponciano
- Western Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, 800 Buchanan St., Albany, CA 94710, USA; (K.J.); (G.P.); (E.M.)
| | - Eva Morales
- Western Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, 800 Buchanan St., Albany, CA 94710, USA; (K.J.); (G.P.); (E.M.)
| | - Edgar B. Cahoon
- Department of Biochemistry and Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE 68588, USA; (T.J.N.); (E.B.C.)
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16
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Meesapyodsuk D, Chen Y, Ye S, Chapman RG, Qiu X. Co-expressing Eranthis hyemalis lysophosphatidic acid acyltransferase 2 and elongase improves two very long chain polyunsaturated fatty acid production in Brassica carinata. Metab Eng Commun 2021; 12:e00171. [PMID: 34026531 PMCID: PMC8129929 DOI: 10.1016/j.mec.2021.e00171] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 04/01/2021] [Accepted: 04/02/2021] [Indexed: 12/12/2022] Open
Abstract
Docosadienoic acid (DDA, 22:2–13,16) and docosatrienoic acid (DTA, 22:3–13,16,19) are two very long chain polyunsaturated fatty acids (VLCPUFAs) that are recently shown to possess strong anti-inflammatory and antitumor properties. An ELO type elongase (EhELO1) from wild plant Eranthis hyemalis can synthesize the two fatty acids by sequential elongation of linoleic acid and alpha-linolenic acid, respectively. Seed-specific expression of this gene in oilseed crop Brassica carinata produced a considerable amount of DDA and DTA in transgenic seeds. However, these fatty acids were excluded from the sn-2 position of triacylglycerols (TAGs). To improve the production level and nutrition value of the VLCPUFAs in the transgenic oilseed crop, a cytoplasmic lysophosphatidic acid acyltransferase (EhLPAAT2) for the incorporation of the two fatty acids into the sn-2 position of triacylglycerols was identified from E. hyemalis. RT-PCR analysis showed that it was preferentially expressed in developing seeds where EhELO1 was exclusively expressed in E. hyemalis. Seed specific expression of EhLPAAT2 along with EhELO1 in B. carinata resulted in the effective incorporation of DDA and DTA at the sn-2 position of TAGs, thereby increasing the total amount of DDA and DTA in transgenic seeds. To our knowledge, this is the first plant LPAAT that can incorporate VLCPUFAs into TAGs. Improved production of DDA and DTA in the oilseed crop using EhLPAAT2 and EhELO1 provides a real commercial opportunity for high value agriculture products for nutraceutical uses. The first plant LPAAT able to acylate VLCPUFAs was identified from winter aconite. It could complement the defective phenotype of E. coli LPAAT mutant. It could improve the incorporation of two VLCPUFAs into TAGs in oilseeds. It could enhance the total production of two VLCPUFAs in oilseeds. Seed-specific expression of it could also increase seed oil and seed weight.
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Affiliation(s)
| | - Yi Chen
- Department of Food & Bioproduct Sciences, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Shengjian Ye
- Department of Food & Bioproduct Sciences, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | | | - Xiao Qiu
- National Research Council Canada, Saskatoon, Saskatchewan, Canada.,Department of Food & Bioproduct Sciences, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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17
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Chen GQ, Kim WN, Johnson K, Park ME, Lee KR, Kim HU. Transcriptome Analysis and Identification of Lipid Genes in Physaria lindheimeri, a Genetic Resource for Hydroxy Fatty Acids in Seed Oil. Int J Mol Sci 2021; 22:ijms22020514. [PMID: 33419225 PMCID: PMC7825617 DOI: 10.3390/ijms22020514] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 01/01/2021] [Accepted: 01/04/2021] [Indexed: 12/15/2022] Open
Abstract
Hydroxy fatty acids (HFAs) have numerous industrial applications but are absent in most vegetable oils. Physaria lindheimeri accumulating 85% HFA in its seed oil makes it a valuable resource for engineering oilseed crops for HFA production. To discover lipid genes involved in HFA synthesis in P. lindheimeri, transcripts from developing seeds at various stages, as well as leaf and flower buds, were sequenced. Ninety-seven percent clean reads from 552,614,582 raw reads were assembled to 129,633 contigs (or transcripts) which represented 85,948 unique genes. Gene Ontology analysis indicated that 60% of the contigs matched proteins involved in biological process, cellular component or molecular function, while the remaining matched unknown proteins. We identified 42 P. lindheimeri genes involved in fatty acid and seed oil biosynthesis, and 39 of them shared 78-100% nucleotide identity with Arabidopsis orthologs. We manually annotated 16 key genes and 14 of them contained full-length protein sequences, indicating high coverage of clean reads to the assembled contigs. A detailed profiling of the 16 genes revealed various spatial and temporal expression patterns. The further comparison of their protein sequences uncovered amino acids conserved among HFA-producing species, but these varied among non-HFA-producing species. Our findings provide essential information for basic and applied research on HFA biosynthesis.
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Affiliation(s)
- Grace Q. Chen
- Western Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, Albany, CA 94710, USA;
- Correspondence: (G.Q.C.); (H.U.K.)
| | - Won Nyeong Kim
- Department of Bioindustry and Bioresource Engineering, Sejong University, Seoul 05006, Korea;
| | - Kumiko Johnson
- Western Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, Albany, CA 94710, USA;
| | - Mid-Eum Park
- Department of Molecular Biology, Graduate School, Sejong University, Seoul 05006, Korea;
| | - Kyeong-Ryeol Lee
- Department of Agricultural Biotechnology, National Institute of Agricultural Sciences, Rural Development Administration, Jeonju 54974, Korea;
| | - Hyun Uk Kim
- Department of Bioindustry and Bioresource Engineering, Sejong University, Seoul 05006, Korea;
- Department of Molecular Biology, Graduate School, Sejong University, Seoul 05006, Korea;
- Correspondence: (G.Q.C.); (H.U.K.)
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18
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Xu Y, Caldo KMP, Singer SD, Mietkiewska E, Greer MS, Tian B, Dyer JM, Smith M, Zhou XR, Qiu X, Weselake RJ, Chen G. Physaria fendleri and Ricinus communis lecithin:cholesterol acyltransferase-like phospholipases selectively cleave hydroxy acyl chains from phosphatidylcholine. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 105:182-196. [PMID: 33107656 DOI: 10.1111/tpj.15050] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 10/12/2020] [Accepted: 10/21/2020] [Indexed: 06/11/2023]
Abstract
Production of hydroxy fatty acids (HFAs) in transgenic crops represents a promising strategy to meet our demands for specialized plant oils with industrial applications. The expression of Ricinus communis (castor) OLEATE 12-HYDROXYLASE (RcFAH12) in Arabidopsis has resulted in only limited accumulation of HFAs in seeds, which probably results from inefficient transfer of HFAs from their site of synthesis (phosphatidylcholine; PC) to triacylglycerol (TAG), especially at the sn-1/3 positions of TAG. Phospholipase As (PLAs) may be directly involved in the liberation of HFAs from PC, but the functions of their over-expression in HFA accumulation and distribution at TAG in transgenic plants have not been well studied. In this work, the functions of lecithin:cholesterol acyltransferase-like PLAs (LCAT-PLAs) in HFA biosynthesis were characterized. The LCAT-PLAs were shown to exhibit homology to LCAT and mammalian lysosomal PLA2 , and to contain a conserved and functional Ser/His/Asp catalytic triad. In vitro assays revealed that LCAT-PLAs from the HFA-accumulating plant species Physaria fendleri (PfLCAT-PLA) and castor (RcLCAT-PLA) could cleave acyl chains at both the sn-1 and sn-2 positions of PC, and displayed substrate selectivity towards sn-2-ricinoleoyl-PC over sn-2-oleoyl-PC. Furthermore, co-expression of RcFAH12 with PfLCAT-PLA or RcLCAT-PLA, but not Arabidopsis AtLCAT-PLA, resulted in increased occupation of HFA at the sn-1/3 positions of TAG as well as small but insignificant increases in HFA levels in Arabidopsis seeds compared with RcFAH12 expression alone. Therefore, PfLCAT-PLA and RcLCAT-PLA may contribute to HFA turnover on PC, and represent potential candidates for engineering the production of unusual fatty acids in crops.
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Affiliation(s)
- Yang Xu
- Department of Agricultural, Food and Nutritional Science, 410 Agriculture/Forestry Centre, University of Alberta, Edmonton, Alberta, T6G 2P5, Canada
| | - Kristian Mark P Caldo
- Department of Agricultural, Food and Nutritional Science, 410 Agriculture/Forestry Centre, University of Alberta, Edmonton, Alberta, T6G 2P5, Canada
| | - Stacy D Singer
- Department of Agricultural, Food and Nutritional Science, 410 Agriculture/Forestry Centre, University of Alberta, Edmonton, Alberta, T6G 2P5, Canada
- Agriculture and Agri-Food Canada, Lethbridge Research and Development Centre, Lethbridge, Alberta, T1J 4B1, Canada
| | - Elzbieta Mietkiewska
- Department of Agricultural, Food and Nutritional Science, 410 Agriculture/Forestry Centre, University of Alberta, Edmonton, Alberta, T6G 2P5, Canada
| | - Michael S Greer
- Department of Agricultural, Food and Nutritional Science, 410 Agriculture/Forestry Centre, University of Alberta, Edmonton, Alberta, T6G 2P5, Canada
| | - Bo Tian
- Department of Agricultural, Food and Nutritional Science, 410 Agriculture/Forestry Centre, University of Alberta, Edmonton, Alberta, T6G 2P5, Canada
- CAS Key Laboratory of Tropical Plant Resource and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, 650223, China
| | - John M Dyer
- U.S. Department of Agriculture-Agricultural Research Service, US Arid-Land Agricultural Research Center, Maricopa, AZ, 85138, USA
| | - Mark Smith
- Agriculture and Agri-Food Canada, 107 Science Place, Saskatoon, Saskatchewan, S7N 0X2, Canada
| | - Xue-Rong Zhou
- CSIRO Agriculture and Food, PO Box 1700, Canberra, ACT, 2601, Australia
| | - Xiao Qiu
- Department of Food and Bioproduct Sciences, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5A8, Canada
| | - Randall J Weselake
- Department of Agricultural, Food and Nutritional Science, 410 Agriculture/Forestry Centre, University of Alberta, Edmonton, Alberta, T6G 2P5, Canada
| | - Guanqun Chen
- Department of Agricultural, Food and Nutritional Science, 410 Agriculture/Forestry Centre, University of Alberta, Edmonton, Alberta, T6G 2P5, Canada
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19
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Correa SM, Fernie AR, Nikoloski Z, Brotman Y. Towards model-driven characterization and manipulation of plant lipid metabolism. Prog Lipid Res 2020; 80:101051. [PMID: 32640289 DOI: 10.1016/j.plipres.2020.101051] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 06/20/2020] [Accepted: 06/21/2020] [Indexed: 01/09/2023]
Abstract
Plant lipids have versatile applications and provide essential fatty acids in human diet. Therefore, there has been a growing interest to better characterize the genetic basis, regulatory networks, and metabolic pathways that shape lipid quantity and composition. Addressing these issues is challenging due to context-specificity of lipid metabolism integrating environmental, developmental, and tissue-specific cues. Here we systematically review the known metabolic pathways and regulatory interactions that modulate the levels of storage lipids in oilseeds. We argue that the current understanding of lipid metabolism provides the basis for its study in the context of genome-wide plant metabolic networks with the help of approaches from constraint-based modeling and metabolic flux analysis. The focus is on providing a comprehensive summary of the state-of-the-art of modeling plant lipid metabolic pathways, which we then contrast with the existing modeling efforts in yeast and microalgae. We then point out the gaps in knowledge of lipid metabolism, and enumerate the recent advances of using genome-wide association and quantitative trait loci mapping studies to unravel the genetic regulations of lipid metabolism. Finally, we offer a perspective on how advances in the constraint-based modeling framework can propel further characterization of plant lipid metabolism and its rational manipulation.
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Affiliation(s)
- Sandra M Correa
- Genetics of Metabolic Traits Group, Max Planck Institute for Molecular Plant Physiology, Potsdam 14476, Germany; Department of Life Sciences, Ben-Gurion University of the Negev, 8410501 Beer-Sheva, Israel; Departamento de Ciencias Exactas y Naturales, Universidad de Antioquia, Medellín 050010, Colombia.
| | - Alisdair R Fernie
- Central Metabolism Group, Max Planck Institute for Molecular Plant Physiology, Potsdam 14476, Germany; Center of Plant Systems Biology and Biotechnology, Plovdiv, Bulgaria
| | - Zoran Nikoloski
- Center of Plant Systems Biology and Biotechnology, Plovdiv, Bulgaria; Bioinformatics, Institute of Biochemistry and Biology, University of Potsdam, 14476 Potsdam, Germany; Systems Biology and Mathematical Modelling Group, Max Planck Institute for Molecular Plant Physiology, Potsdam-Golm 14476, Germany.
| | - Yariv Brotman
- Genetics of Metabolic Traits Group, Max Planck Institute for Molecular Plant Physiology, Potsdam 14476, Germany; Department of Life Sciences, Ben-Gurion University of the Negev, 8410501 Beer-Sheva, Israel
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20
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Cahoon EB, Li-Beisson Y. Plant unusual fatty acids: learning from the less common. CURRENT OPINION IN PLANT BIOLOGY 2020; 55:66-73. [PMID: 32304939 DOI: 10.1016/j.pbi.2020.03.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 02/17/2020] [Accepted: 03/09/2020] [Indexed: 06/11/2023]
Abstract
The plant kingdom contains an abundance of structurally diverse fatty acids referred to as unusual fatty acids. Unusual fatty acids on plant surfaces can form polyesters that contribute to the function of cutin as a barrier for water loss and pathogen protection. Unusual fatty acids are also found as abundant components of seed oils of selected species and often confer desirable properties for industrial and nutritional applications. Here, we review recent findings on the biosynthesis and metabolism of unusual fatty acids in cutin and seed oils and use of this information for enzyme structure-function studies and seed oil metabolic engineering. We also highlight the recent discovery of unusual fatty acids that are formed from a previously undescribed variation of fatty acid elongation.
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Affiliation(s)
- Edgar B Cahoon
- Center for Plant Science Innovation and Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Yonghua Li-Beisson
- Aix Marseille Univ, CEA, CNRS, BIAM, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache, 13108 Saint Paul-Lez-Durance, France.
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21
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Shockey J. Gene editing in plants: assessing the variables through a simplified case study. PLANT MOLECULAR BIOLOGY 2020; 103:75-89. [PMID: 32040758 PMCID: PMC7170989 DOI: 10.1007/s11103-020-00976-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 01/31/2020] [Indexed: 05/05/2023]
Abstract
Multiple variables that control the relative levels of successful heritable plant genome editing were addressed using simple case studies in Arabidopsis thaliana. The recent advent of genome editing technologies (especially CRISPR, Clustered Regularly Interspaced Short Palindromic Repeats) has revolutionized various fields of scientific research. The process is much more specific than previous mutagenic processes and allows for targeting of nearly any gene of interest for the creation of loss-of-function mutations and many other types of editing, including gene-replacement and gene activation. However, not all CRISPR construct designs are successful, due to several factors, including differences in the strength and cell- or tissue-type specificity of the regulatory elements used to express the Cas9 (CRISPR Associated protein 9) DNA nuclease and single guide RNA components, and differences in the relative editing efficiency at different target areas within a given gene. Here we compare the levels of editing created in Arabidopsis thaliana by CRISPR constructs containing either different promoters, or altered target sites with varied levels of guanine-cytosine base content. Additionally, nuclease activity at sites targeted by imperfectly matched single guide RNAs was observed, suggesting that while the primary goal of most CRISPR construct designs is to achieve rapid, robust, heritable gene editing, the formation of unintended mutations at other genomic loci must be carefully monitored.
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Affiliation(s)
- Jay Shockey
- Agricultural Research Service, Southern Regional Research Center, Commodity Utilization Research Unit, United States Department of Agriculture, 1100 Robert E. Lee Blvd., New Orleans, LA, 70124, USA.
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22
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Regiobiochemical analysis reveals the role of castor LPAT2 in the accumulation of hydroxy fatty acids in transgenic lesquerella seeds. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2020. [DOI: 10.1016/j.bcab.2020.101617] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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23
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Kotapati HK, Bates PD. Normal phase HPLC method for combined separation of both polar and neutral lipid classes with application to lipid metabolic flux. J Chromatogr B Analyt Technol Biomed Life Sci 2020; 1145:122099. [DOI: 10.1016/j.jchromb.2020.122099] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 03/08/2020] [Accepted: 03/31/2020] [Indexed: 12/11/2022]
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24
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Lager I, Jeppson S, Gippert AL, Feussner I, Stymne S, Marmon S. Acyltransferases Regulate Oil Quality in Camelina sativa Through Both Acyl Donor and Acyl Acceptor Specificities. FRONTIERS IN PLANT SCIENCE 2020; 11:1144. [PMID: 32922411 PMCID: PMC7456936 DOI: 10.3389/fpls.2020.01144] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 07/14/2020] [Indexed: 05/03/2023]
Abstract
Camelina sativa is an emerging biotechnology oil crop. However, more information is needed regarding its innate lipid enzyme specificities. We have therefore characterized several triacylglycerol (TAG) producing enzymes by measuring in vitro substrate specificities using different combinations of acyl-acceptors (diacylglycerol, DAG) and donors. Specifically, C. sativa acyl-CoA:diacylglycerol acyltransferase (DGAT) 1 and 2 (which both use acyl-CoA as acyl donor) and phospholipid:diacylglycerol acyltransferase (PDAT, with phosphatidylcoline as acyl donor) were studied. The results show that the DGAT1 and DGAT2 specificities are complementary, with DGAT2 exhibiting a high specificity for acyl acceptors containing only polyunsaturated fatty acids (FAs), whereas DGAT1 prefers acyl donors with saturated and monounsaturated FAs. Furthermore, the combination of substrates that resulted in the highest activity for DGAT2, but very low activity for DGAT1, corresponds to TAG species previously shown to increase in C. sativa seeds with downregulated DGAT1. Similarly, the combinations of substrates that gave the highest PDAT1 activity were also those that produce the two TAG species (54:7 and 54:8 TAG) with the highest increase in PDAT overexpressing C. sativa seeds. Thus, the in vitro data correlate well with the changes in the overall fatty acid profile and TAG species in C. sativa seeds with altered DGAT1 and PDAT activity. Additionally, in vitro studies of C. sativa phosphatidycholine:diacylglycerol cholinephosphotransferase (PDCT), another activity involved in TAG biosynthesis, revealed that PDCT accepts substrates with different desaturation levels. Furthermore, PDCT was unable to use DAG with ricineoleyl groups, and the presence of this substrate also inhibited PDCT from using other DAG-moieties. This gives insights relating to previous in vivo studies regarding this enzyme.
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Affiliation(s)
- Ida Lager
- Department of Plant Breeding, Swedish University of Agricultural Sciences, Alnarp, Sweden
| | - Simon Jeppson
- Department of Plant Breeding, Swedish University of Agricultural Sciences, Alnarp, Sweden
| | - Anna-Lena Gippert
- Department of Plant Biochemistry, Albrecht-von-Haller Institute for Plant Sciences, University of Goettingen, Goettingen, Germany
| | - Ivo Feussner
- Department of Plant Biochemistry, Albrecht-von-Haller Institute for Plant Sciences, University of Goettingen, Goettingen, Germany
- Göttingen Center for Molecular Biosciences (GZMB), University of Goettingen, Goettingen, Germany
| | - Sten Stymne
- Department of Plant Breeding, Swedish University of Agricultural Sciences, Alnarp, Sweden
| | - Sofia Marmon
- Department of Plant Breeding, Swedish University of Agricultural Sciences, Alnarp, Sweden
- Department of Plant Biochemistry, Albrecht-von-Haller Institute for Plant Sciences, University of Goettingen, Goettingen, Germany
- *Correspondence: Sofia Marmon,
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25
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Allen DK, Young JD. Tracing metabolic flux through time and space with isotope labeling experiments. Curr Opin Biotechnol 2019; 64:92-100. [PMID: 31864070 PMCID: PMC7302994 DOI: 10.1016/j.copbio.2019.11.003] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 11/02/2019] [Accepted: 11/04/2019] [Indexed: 12/11/2022]
Abstract
Metabolism is dynamic and must function in context-specific ways to adjust to changes in the surrounding cellular and ecological environment. When isotopic tracers are used, metabolite flow (i.e. metabolic flux) can be quantified through biochemical networks to assess metabolic pathway operation. The cellular activities considered across multiple tissues and organs result in the observed phenotype and can be analyzed to discover emergent, whole-system properties of biology and elucidate misconceptions about network operation. However, temporal and spatial challenges remain significant hurdles and require novel approaches and creative solutions. We survey current investigations in higher plant and animal systems focused on dynamic isotope labeling experiments, spatially resolved measurement strategies, and observations from re-analysis of our own studies that suggest prospects for future work. Related discoveries will be necessary to push the frontier of our understanding of metabolism to suggest novel solutions to cure disease and feed a growing future world population.
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Affiliation(s)
- Doug K Allen
- United States Department of Agriculture-Agricultural Research Service, Plant Genetics Research Unit, 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.
| | - Jamey D Young
- Department of Chemical & Biomolecular Engineering, Vanderbilt University, PMB 351604, 2301 Vanderbilt Place, Nashville, TN 37235, United States; Department of Molecular Physiology & Biophysics, Vanderbilt University, PMB 351604, 2301 Vanderbilt Place, Nashville, TN 37235, United States.
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26
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Lin Y, Chen G, Mietkiewska E, Song Z, Caldo KMP, Singer SD, Dyer J, Smith M, McKeon T, Weselake RJ. Castor patatin-like phospholipase A IIIβ facilitates removal of hydroxy fatty acids from phosphatidylcholine in transgenic Arabidopsis seeds. PLANT MOLECULAR BIOLOGY 2019; 101:521-536. [PMID: 31549344 DOI: 10.1007/s11103-019-00915-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 09/04/2019] [Indexed: 06/10/2023]
Abstract
Castor patatin-like phospholipase A IIIβ facilitates the exclusion of hydroxy fatty acids from phosphatidylcholine in developing transgenic Arabidopsis seeds. Hydroxy fatty acids (HFAs) are industrial useful, but their major natural source castor contains toxic components. Although expressing a castor OLEATE 12-HYDROXYLASE in Arabidopsis thaliana leads to the synthesis of HFAs in seeds, a high proportion of the HFAs are retained in phosphatidylcholine (PC). Thus, the liberation of HFA from PC seems to be critical for obtaining HFA-enriched seed oils. Plant phospholipase A (PLA) catalyzes the hydrolysis of PC to release fatty acyl chains that can be subsequently channeled into triacylglycerol (TAG) synthesis or other metabolic pathways. To further our knowledge regarding the function of PLAs from HFA-producing plant species, two class III patatin-like PLA cDNAs (pPLAIIIβ or pPLAIIIδ) from castor or Physaria fendleri were overexpressed in a transgenic line of A. thaliana producing C18-HFA, respectively. Only the overexpression of RcpPLAIIIβ resulted in a significant reduction in seed HFA content with concomitant changes in fatty acid composition. Reductions in HFA content occurred in both PC and TAG indicating that HFAs released from PC were not incorporated into TAG. These results suggest that RcpPLAIIIβ may catalyze the removal of HFAs from PC in the developing seeds synthesizing these unusual fatty acids.
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Affiliation(s)
- Yingyu Lin
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada
| | - Guanqun Chen
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada.
| | - Elzbieta Mietkiewska
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada
- Okanagan Specialty Fruits Inc. (OSF), 410 Downey Road, Saskatoon, SK, S7N 4N1, Canada
| | - Ziliang Song
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada
| | - Kristian Mark P Caldo
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada
| | - Stacy D Singer
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada
- Agriculture and Agri-Food Canada, Lethbridge Research and Development Centre, Lethbridge, AB, T1J 4B1, Canada
| | - John Dyer
- USDA-ARS, Arid-Land Agricultural Research Center, 21881 North Cardon Lane, Maricopa, AZ, 85138, USA
| | - Mark Smith
- Agriculture and Agri-Food Canada, Saskatoon Research Centre, 107 Science Place, Saskatoon, SK, S7N 0X2, Canada
| | - Thomas McKeon
- USDA-ARS, Western Regional Research Center, 800 Buchanan St, Albany, CA, 94710, USA
| | - Randall J Weselake
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada.
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27
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Jeppson S, Demski K, Carlsson AS, Zhu LH, Banaś A, Stymne S, Lager I. Crambe hispanica Subsp. abyssinica Diacylglycerol Acyltransferase Specificities Towards Diacylglycerols and Acyl-CoA Reveal Combinatorial Effects That Greatly Affect Enzymatic Activity and Specificity. FRONTIERS IN PLANT SCIENCE 2019; 10:1442. [PMID: 31798607 PMCID: PMC6863138 DOI: 10.3389/fpls.2019.01442] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 10/17/2019] [Indexed: 05/03/2023]
Abstract
Crambe is an oil crop suitable for industrial purposes due to the high content of erucic acid (22:1) in the seed oil. The final acylation of diacylglycerols (DAG) with acyl-CoA in the production of triacylglycerols (oil) is catalyzed by acyl-CoA:diacylglycerol acyltransferase (DGAT) enzymes. We identified eight forms of DGATs in crambe and characterized them in microsomal preparations of yeast expressing the enzymes using various acyl-CoAs and both di-6:0-DAG and long-chain DAG species as acyl acceptors. All DGATs accepted 22:1-CoA when using di-6:0-DAG as acyl acceptor. When di-22:1-DAG was the acyl acceptor, the DGAT1 type of enzyme utilized 22:1-CoA at a much-reduced rate compared to assays with sn-1-22:1-sn-2-18:1(oleoyl)-DAG, the most frequently available DAG precursor in crambe seeds. None of the DGAT2 enzymes was able to acylate di-22:1-DAG. Our results indicate that formation of trierucin by crambe DGATs is a limiting step for further increasing the levels of 22:1 in the previously developed transgenic crambe lines due to their poor abilities to acylate di-22:1-DAG. We also show that the acyl-CoA specificities and the enzymatic activities are highly influenced by the fatty acid composition of the DAG acyl acceptor. This finding implies that the use of artificial acyl acceptors (e.g. di-6:0-DAG) may not always reflect the actual acyl-CoA specificities of DGATs in planta. The relevance of the here reported pronounced specificities for specific DAG species exerted by DGAT enzymes is discussed in the context of the findings of DAG pools of distinct catalytic origin in triacylglycerol biosynthesis in the seed oil.
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Affiliation(s)
- Simon Jeppson
- Department of Plant Breeding, Swedish University of Agricultural Sciences, Alnarp, Sweden
- *Correspondence: Simon Jeppson,
| | - Kamil Demski
- Intercollegiate Faculty of Biotechnology of University of Gdańsk and Medical University of Gdańsk, Gdańsk, Poland
| | - Anders S. Carlsson
- Department of Plant Breeding, Swedish University of Agricultural Sciences, Alnarp, Sweden
| | - Li-Hua Zhu
- Department of Plant Breeding, Swedish University of Agricultural Sciences, Alnarp, Sweden
| | - Antoni Banaś
- Intercollegiate Faculty of Biotechnology of University of Gdańsk and Medical University of Gdańsk, Gdańsk, Poland
| | - Sten Stymne
- Department of Plant Breeding, Swedish University of Agricultural Sciences, Alnarp, Sweden
| | - Ida Lager
- Department of Plant Breeding, Swedish University of Agricultural Sciences, Alnarp, Sweden
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