1
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Wang J, Singer SD, Chen G. Biotechnological advances in the production of unusual fatty acids in transgenic plants and recombinant microorganisms. Biotechnol Adv 2024; 76:108435. [PMID: 39214484 DOI: 10.1016/j.biotechadv.2024.108435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2024] [Revised: 07/28/2024] [Accepted: 08/25/2024] [Indexed: 09/04/2024]
Abstract
Certain plants and microorganisms can produce high amounts of unusual fatty acids (UFAs) such as hydroxy, conjugated, cyclic, and very long-chain polyunsaturated fatty acids, which have distinct physicochemical properties and significant applications in the food, feed, and oleochemical industries. Since many natural sources of UFAs are not ideal for large-scale agricultural production or fermentation, it is attractive to produce them through synthetic biology. Although several UFAs have been commercially or pre-commercially produced in transgenic plants and microorganisms, their contents in transgenic hosts are generally much lower than in natural sources. Moreover, reproducing this success for a wider spectrum of UFAs has remained challenging. This review discusses recent advancements in our understanding of the biosynthesis, accumulation, and heterologous production of UFAs, and addresses the challenges and potential strategies for achieving high UFA content in engineered plants and microorganisms.
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Affiliation(s)
- Juli Wang
- Department of Agricultural, Food and Nutritional Science, University of Alberta, 116 St and 85 Ave, Edmonton, Alberta T6G 2P5, Canada
| | - Stacy D Singer
- Agriculture and Agri-Food Canada, Lethbridge Research and Development Centre, Lethbridge, Alberta T1J 4B1, Canada
| | - Guanqun Chen
- Department of Agricultural, Food and Nutritional Science, University of Alberta, 116 St and 85 Ave, Edmonton, Alberta T6G 2P5, Canada.
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2
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Sah SK, Fan J, Blanford J, Shanklin J, Xu C. Physiological Functions of Phospholipid:Diacylglycerol Acyltransferases. PLANT & CELL PHYSIOLOGY 2024; 65:863-871. [PMID: 37702708 DOI: 10.1093/pcp/pcad106] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 08/01/2023] [Accepted: 09/08/2023] [Indexed: 09/14/2023]
Abstract
Triacylglycerol (TAG) is among the most energy dense storage forms of reduced carbon in living systems. TAG metabolism plays critical roles in cellular energy balance, lipid homeostasis, cell growth and stress responses. In higher plants, microalgae and fungi, TAG is assembled by acyl-CoA-dependent and acyl-CoA-independent pathways catalyzed by diacylglycerol (DAG) acyltransferase and phospholipid:DAG acyltransferase (PDAT), respectively. This review contains a summary of the current understanding of the physiological functions of PDATs. Emphasis is placed on their role in lipid remodeling and lipid homeostasis in response to abiotic stress or perturbations in lipid metabolism.
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Affiliation(s)
- Saroj Kumar Sah
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Jilian Fan
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Jantana Blanford
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA
| | | | - Changcheng Xu
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA
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3
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Yang W, Xin Z, Zhang Q, Zhang Y, Niu L. The tree peony DREB transcription factor PrDREB2D regulates seed α-linolenic acid accumulation. PLANT PHYSIOLOGY 2024; 195:745-761. [PMID: 38365221 DOI: 10.1093/plphys/kiae082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 01/11/2024] [Accepted: 01/17/2024] [Indexed: 02/18/2024]
Abstract
α-Linolenic acid (ALA), an essential fatty acid (FA) for human health, serves as the precursor of 2 nutritional benefits, docosahexaenoic acid and eicosapentaenoic acid, and can only be obtained from plant foods. We previously found that phospholipid:diacylglycerol acyltransferase 2 (PrPDAT2) derived from ALA-rich tree peony (Paeonia rockii) can promote seed ALA accumulation. However, the regulatory mechanism underlying its promoting effect on ALA accumulation remains unknown. Here, we revealed a tree peony dehydration-responsive element binding transcription factor, PrDREB2D, as an upstream regulator of PrPDAT2, which is involved in regulating seed ALA accumulation. Our findings demonstrated that PrDREB2D serves as a nucleus-localized transcriptional activator that directly activates PrPDAT2 expression. PrDREB2D altered the FA composition in transient overexpression Nicotiana benthamiana leaves and stable transgenic Arabidopsis (Arabidopsis thaliana) seeds. Repressing PrDREB2D expression in P. rockii resulted in decreased PrPDAT2 expression and ALA accumulation. In addition, PrDREB2D strengthened its regulation of ALA accumulation by recruiting the cofactor ABA-response element binding factor PrABF2b. Collectively, the study findings provide insights into the mechanism of seed ALA accumulation and avenues for enhancing ALA yield via biotechnological manipulation.
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Affiliation(s)
- Weizong Yang
- College of Landscape Architecture and Arts, Northwest A&F University, Yangling 712100, China
- Oil Peony Engineering Technology Research Center of National Forestry Administration, Yangling 712100, China
| | - Ziwei Xin
- College of Landscape Architecture and Arts, Northwest A&F University, Yangling 712100, China
- Oil Peony Engineering Technology Research Center of National Forestry Administration, Yangling 712100, China
| | - Qingyu Zhang
- College of Landscape Architecture and Arts, Northwest A&F University, Yangling 712100, China
- Oil Peony Engineering Technology Research Center of National Forestry Administration, Yangling 712100, China
| | - Yanlong Zhang
- College of Landscape Architecture and Arts, Northwest A&F University, Yangling 712100, China
- Oil Peony Engineering Technology Research Center of National Forestry Administration, Yangling 712100, China
| | - Lixin Niu
- College of Landscape Architecture and Arts, Northwest A&F University, Yangling 712100, China
- Oil Peony Engineering Technology Research Center of National Forestry Administration, Yangling 712100, China
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4
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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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5
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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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6
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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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7
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Pan Y, Zhang W, Wang X, Jouhet J, Maréchal E, Liu J, Xia XQ, Hu H. Allele-dependent expression and functionality of lipid enzyme phospholipid:diacylglycerol acyltransferase affect diatom carbon storage and growth. PLANT PHYSIOLOGY 2024; 194:1024-1040. [PMID: 37930282 DOI: 10.1093/plphys/kiad581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 09/06/2023] [Accepted: 10/11/2023] [Indexed: 11/07/2023]
Abstract
In the acyl-CoA-independent pathway of triacylglycerol (TAG) synthesis unique to plants, fungi, and algae, TAG formation is catalyzed by the enzyme phospholipid:diacylglycerol acyltransferase (PDAT). The unique PDAT gene of the model diatom Phaeodactylum tricornutum strain CCMP2561 boasts 47 single nucleotide variants within protein coding regions of the alleles. To deepen our understanding of TAG synthesis, we observed the allele-specific expression of PDAT by the analysis of 87 published RNA-sequencing (RNA-seq) data and experimental validation. The transcription of one of the two PDAT alleles, Allele 2, could be specifically induced by decreasing nitrogen concentrations. Overexpression of Allele 2 in P. tricornutum substantially enhanced the accumulation of TAG by 44% to 74% under nutrient stress; however, overexpression of Allele 1 resulted in little increase of TAG accumulation. Interestingly, a more serious growth inhibition was observed in the PDAT Allele 1 overexpression strains compared with Allele 2 counterparts. Heterologous expression in yeast (Saccharomyces cerevisiae) showed that enzymes encoded by PDAT Allele 2 but not Allele 1 had TAG biosynthetic activity, and 7 N-terminal and 3 C-terminal amino acid variants between the 2 allele-encoded proteins substantially affected enzymatic activity. P. tricornutum PDAT, localized in the innermost chloroplast membrane, used monogalactosyldiacylglycerol and phosphatidylcholine as acyl donors as demonstrated by the increase of the 2 lipids in PDAT knockout lines, which indicated a common origin in evolution with green algal PDATs. Our study reveals unequal roles among allele-encoded PDATs in mediating carbon storage and growth in response to nitrogen stress and suggests an unsuspected strategy toward lipid and biomass improvement for biotechnological purposes.
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Affiliation(s)
- Yufang Pan
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Wanting Zhang
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Xiaofei Wang
- Laboratory for Algae Biotechnology and Innovation, College of Engineering, Peking University, Beijing 100871, China
| | - Juliette Jouhet
- Laboratoire de Physiologie Cellulaire Végétale, Université Grenoble Alpes, CEA, CNRS, INRA, IRIG-LPCV, Grenoble Cedex 9 38054, France
| | - Eric Maréchal
- Laboratoire de Physiologie Cellulaire Végétale, Université Grenoble Alpes, CEA, CNRS, INRA, IRIG-LPCV, Grenoble Cedex 9 38054, France
| | - Jin Liu
- Laboratory for Algae Biotechnology and Innovation, College of Engineering, Peking University, Beijing 100871, China
| | - Xiao-Qin Xia
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hanhua Hu
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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8
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Yu A, Zhou Z, Chen Y, Sun J, Li P, Gu X, Liu A. Functional Genome Analyses Reveal the Molecular Basis of Oil Accumulation in Developing Seeds of Castor Beans. Int J Mol Sci 2023; 25:92. [PMID: 38203263 PMCID: PMC10778879 DOI: 10.3390/ijms25010092] [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: 11/22/2023] [Revised: 12/18/2023] [Accepted: 12/19/2023] [Indexed: 01/12/2024] Open
Abstract
Castor (Ricinus communis L.) seeds produce abundant ricinoleic acid during seed maturation, which is important for plant development and human demands. Ricinoleic acid, as a unique hydroxy fatty acid (HFA), possesses a distinct bond structure that could be used as a substitute for fossil fuels. Here, we identified all homologous genes related to glycolysis, hydroxy fatty acid biosynthesis, and triacylglycerol (TAG) accumulation in castor seeds. Furthermore, we investigated their expression patterns globally during five seed development stages. We characterized a total of 66 genes involved in the glycolysis pathway, with the majority exhibiting higher expression levels during the early stage of castor bean seed development. This metabolic process provided abundant acetyl-CoA for fatty acid (FA) biosynthesis. Subsequently, we identified 82 genes involved in the processes of de novo FA biosynthesis and TAG assembly, with the majority exhibiting high expression levels during the middle or late stages. In addition, we examined the expression patterns of the transcription factors involved in carbohydrate and oil metabolism. For instance, RcMYB73 and RcERF72 exhibited high expression levels during the early stage, whereas RcWRI1, RcABI3, and RcbZIP67 showed relatively higher expression levels during the middle and late stages, indicating their crucial roles in seed development and oil accumulation. Our study suggests that the high HFA production in castor seeds is attributed to the interaction of multiple genes from sugar transportation to lipid droplet packaging. Therefore, this research comprehensively characterizes all the genes related to glycolysis, fatty acid biosynthesis, and triacylglycerol (TAG) accumulation in the castor and provides novel insight into exploring the genetic mechanisms underlying seed oil accumulation in the endosperm of castor beans.
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Affiliation(s)
| | | | | | | | | | | | - Aizhong Liu
- Key Laboratory for Forest Resources Conservation and Utilization in the Southwest Mountains of China, Ministry of Education, Southwest Forestry University, Kunming 650224, China; (A.Y.); (Z.Z.); (Y.C.); (J.S.); (P.L.); (X.G.)
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9
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Zhou Y, Huang X, Hu T, Chen S, Wang Y, Shi X, Yin M, Li R, Wang J, Jia X. Genome-Wide Analysis of Glycerol-3-Phosphate Acyltransferase (GPAT) Family in Perilla frutescens and Functional Characterization of PfGPAT9 Crucial for Biosynthesis of Storage Oils Rich in High-Value Lipids. Int J Mol Sci 2023; 24:15106. [PMID: 37894786 PMCID: PMC10606570 DOI: 10.3390/ijms242015106] [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: 09/06/2023] [Revised: 10/02/2023] [Accepted: 10/05/2023] [Indexed: 10/29/2023] Open
Abstract
Glycerol-3-phosphate acyltransferase (GPAT) catalyzes the first step in triacylglycerol (TAG) biosynthesis. However, GPAT members and their functions remain poorly understood in Perilla frutescens, a special edible-medicinal plant with its seed oil rich in polyunsaturated fatty acids (mostly α-linolenic acid, ALA). Here, 14 PfGPATs were identified from the P. frutescens genome and classified into three distinct groups according to their phylogenetic relationships. These 14 PfGPAT genes were distributed unevenly across 11 chromosomes. PfGPAT members within the same subfamily had highly conserved gene structures and four signature functional domains, despite considerable variations detected in these conserved motifs between groups. RNA-seq and RT-qPCR combined with dynamic analysis of oil and FA profiles during seed development indicated that PfGPAT9 may play a crucial role in the biosynthesis and accumulation of seed oil and PUFAs. Ex vivo enzymatic assay using the yeast expression system evidenced that PfGPAT9 had a strong GPAT enzyme activity crucial for TAG assembly and also a high substrate preference for oleic acid (OA, C18:1) and ALA (C18:3). Heterogeneous expression of PfGPAT9 significantly increased total oil and UFA (mostly C18:1 and C18:3) levels in both the seeds and leaves of the transgenic tobacco plants. Moreover, these transgenic tobacco lines exhibited no significant negative effect on other agronomic traits, including plant growth and seed germination rate, as well as other morphological and developmental properties. Collectively, our findings provide important insights into understanding PfGPAT functions, demonstrating that PfGPAT9 is the desirable target in metabolic engineering for increasing storage oil enriched with valuable FA profiles in oilseed crops.
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Affiliation(s)
- Yali Zhou
- College of Agronomy/Institute of Molecular Agriculture & Bioenergy, Shanxi Agricultural University, Jinzhong 030801, China; (Y.Z.); (Y.W.); (X.J.)
| | - Xusheng Huang
- College of Agronomy/Institute of Molecular Agriculture & Bioenergy, Shanxi Agricultural University, Jinzhong 030801, China; (Y.Z.); (Y.W.); (X.J.)
| | - Ting Hu
- College of Agronomy/Institute of Molecular Agriculture & Bioenergy, Shanxi Agricultural University, Jinzhong 030801, China; (Y.Z.); (Y.W.); (X.J.)
| | - Shuwei Chen
- College of Agronomy/Institute of Molecular Agriculture & Bioenergy, Shanxi Agricultural University, Jinzhong 030801, China; (Y.Z.); (Y.W.); (X.J.)
| | - Yao Wang
- College of Agronomy/Institute of Molecular Agriculture & Bioenergy, Shanxi Agricultural University, Jinzhong 030801, China; (Y.Z.); (Y.W.); (X.J.)
| | - Xianfei Shi
- College of Agronomy/Institute of Molecular Agriculture & Bioenergy, Shanxi Agricultural University, Jinzhong 030801, China; (Y.Z.); (Y.W.); (X.J.)
| | - Miao Yin
- College of Agronomy/Institute of Molecular Agriculture & Bioenergy, Shanxi Agricultural University, Jinzhong 030801, China; (Y.Z.); (Y.W.); (X.J.)
| | - Runzhi Li
- College of Agronomy/Institute of Molecular Agriculture & Bioenergy, Shanxi Agricultural University, Jinzhong 030801, China; (Y.Z.); (Y.W.); (X.J.)
| | - Jiping Wang
- College of Agronomy/Institute of Molecular Agriculture & Bioenergy, Shanxi Agricultural University, Jinzhong 030801, China; (Y.Z.); (Y.W.); (X.J.)
| | - Xiaoyun Jia
- College of Agronomy/Institute of Molecular Agriculture & Bioenergy, Shanxi Agricultural University, Jinzhong 030801, China; (Y.Z.); (Y.W.); (X.J.)
- College of Life Sciences, Shanxi Agricultural University, Jinzhong 030801, China
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10
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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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11
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Sagun JV, Yadav UP, Alonso AP. Progress in understanding and improving oil content and quality in seeds. FRONTIERS IN PLANT SCIENCE 2023; 14:1116894. [PMID: 36778708 PMCID: PMC9909563 DOI: 10.3389/fpls.2023.1116894] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 01/09/2023] [Indexed: 06/18/2023]
Abstract
The world's population is projected to increase by two billion by 2050, resulting in food and energy insecurity. Oilseed crops have been identified as key to address these challenges: they produce and store lipids in the seeds as triacylglycerols that can serve as a source of food/feed, renewable fuels, and other industrially-relevant chemicals. Therefore, improving seed oil content and composition has generated immense interest. Research efforts aiming to unravel the regulatory pathways involved in fatty acid synthesis and to identify targets for metabolic engineering have made tremendous progress. This review provides a summary of the current knowledge of oil metabolism and discusses how photochemical activity and unconventional pathways can contribute to high carbon conversion efficiency in seeds. It also highlights the importance of 13C-metabolic flux analysis as a tool to gain insights on the pathways that regulate oil biosynthesis in seeds. Finally, a list of key genes and regulators that have been recently targeted to enhance seed oil production are reviewed and additional possible targets in the metabolic pathways are proposed to achieve desirable oil content and quality.
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Affiliation(s)
| | | | - Ana Paula Alonso
- Department of Biological Sciences, BioDiscovery Institute, University of North Texas, Denton, TX, United States
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12
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Behera J, Rahman MM, Shockey J, Kilaru A. Acyl-CoA-dependent and acyl-CoA-independent avocado acyltransferases positively influence oleic acid content in nonseed triacylglycerols. FRONTIERS IN PLANT SCIENCE 2023; 13:1056582. [PMID: 36714784 PMCID: PMC9874167 DOI: 10.3389/fpls.2022.1056582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 12/15/2022] [Indexed: 06/18/2023]
Abstract
In higher plants, acyl-CoA:diacylglycerol acyltransferase (DGAT) and phospholipid:diacylglycerol acyltransferase (PDAT) catalyze the terminal step of triacylglycerol (TAG) synthesis in acyl-CoA-dependent and -independent pathways, respectively. Avocado (Persea americana) mesocarp, a nonseed tissue, accumulates significant amounts of TAG (~70% by dry weight) that is rich in heart-healthy oleic acid (18:1). The oil accumulation stages of avocado mesocarp development coincide with high expression levels for type-1 DGAT (DGAT1) and PDAT1, although type-2 DGAT (DGAT2) expression remains low. The strong preference for oleic acid demonstrated by the avocado mesocarp TAG biosynthetic machinery represents lucrative biotechnological opportunities, yet functional characterization of these three acyltransferases has not been explored to date. We expressed avocado PaDGAT1, PaDGAT2, and PaPDAT1 in bakers' yeast and leaves of Nicotiana benthamiana. PaDGAT1 complemented the TAG biosynthesis deficiency in the quadruple mutant yeast strain H1246, and substantially elevated total cellular lipid content. In vitro enzyme assays showed that PaDGAT1 prefers oleic acid compared to palmitic acid (16:0). Both PaDGAT1 and PaPDAT1 increased the lipid content and elevated oleic acid levels when expressed independently or together, transiently in N. benthamiana leaves. These results indicate that PaDGAT1 and PaPDAT1 prefer oleate-containing substrates, and their coordinated expression likely contributes to sustained TAG synthesis that is enriched in oleic acid. This study establishes a knowledge base for future metabolic engineering studies focused on exploitation of the biochemical properties of PaDGAT1 and PaPDAT1.
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Affiliation(s)
- Jyoti Behera
- Department of Biological Sciences, East Tennessee State University, Johnson City, TN, United States
| | - Md Mahbubur Rahman
- Department of Biological Sciences, East Tennessee State University, Johnson City, TN, United States
- dNTP Laboratory, Teaneck, NJ, United States
| | - Jay Shockey
- U.S. Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, Commodity Utilization Research Unit, New Orleans, LA, United States
| | - Aruna Kilaru
- Department of Biological Sciences, East Tennessee State University, Johnson City, TN, United States
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13
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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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14
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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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15
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Parchuri P, Pappanoor A, Naeem A, Durrett TP, Welti R, R V S. Lipidome analysis and characterization of Buglossoides arvensis acyltransferases that incorporate polyunsaturated fatty acids into triacylglycerols. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2022; 324:111445. [PMID: 36037983 DOI: 10.1016/j.plantsci.2022.111445] [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: 06/28/2022] [Revised: 07/26/2022] [Accepted: 08/24/2022] [Indexed: 06/15/2023]
Abstract
Buglossoides arvensis is a burgeoning oilseed crop that contains an unique combination of ω-3 and ω-6 polyunsaturated fatty acids (PUFA), constituting ~80-85% of seed triacylglycerols (TAGs). To uncover the critical TAG biosynthetic pathways contributing for high PUFA accumulation, we performed lipidome of developing seeds and characterized acyltransferases involved in the final step of TAG biosynthesis. During seed development, distribution of lipid molecular species in individual lipid classes showed distinct patterns from an early-stage (6 days after flowering (DAF)) to the middle-stage (12 and 18 DAF) of oil biosynthesis. PUFA-containing TAG species drastically increased from 6 to 12 DAF. The expression profiles of key triacylglycerol biosynthesis genes and patterns of phosphatidylcholine, diacylglycerol and triacylglycerol molecular species during seed development were used to predict the contribution of diacylglycerol acyltransferases (DGAT1 and DGAT2) and phospholipid: diacylglycerol acyltransferases (PDAT1 and PDAT2) to PUFA-rich TAG biosynthesis. Our analysis suggests that DGATs play a crucial role in enriching TAGs with PUFA compared to PDATs. This was further confirmed by fatty acid feeding studies in yeast expressing acyltransferases. BaDGAT2 preferentially incorporated high amounts of PUFAs into TAG, compared to BaDGAT1. Our results provide insight into the molecular mechanisms of TAG accumulation in this plant and identify target genes for transgenic production of SDA in traditional oilseed crops.
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Affiliation(s)
- Prasad Parchuri
- Plant Cell Biotechnology Department, CSIR-Central Food Technological Research Institute (CSIR-CFTRI), Mysuru, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India; Kansas Lipidomics Research Center, Division of Biology, Kansas State University, Manhattan, KS 66506, USA.
| | - Anjali Pappanoor
- Plant Cell Biotechnology Department, CSIR-Central Food Technological Research Institute (CSIR-CFTRI), Mysuru, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India.
| | - Abdulrahman Naeem
- Kansas Lipidomics Research Center, Division of Biology, Kansas State University, Manhattan, KS 66506, USA.
| | - Timothy P Durrett
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS 66506, USA.
| | - Ruth Welti
- Kansas Lipidomics Research Center, Division of Biology, Kansas State University, Manhattan, KS 66506, USA.
| | - Sreedhar R V
- Plant Cell Biotechnology Department, CSIR-Central Food Technological Research Institute (CSIR-CFTRI), Mysuru, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India.
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16
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Demski K, Jeppson S, Stymne S, Lager I. Phosphatidylcholine:diacylglycerol cholinephosphotransferase's unique regulation of castor bean oil quality. PLANT PHYSIOLOGY 2022; 189:2001-2014. [PMID: 35522031 PMCID: PMC9342994 DOI: 10.1093/plphys/kiac209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 04/09/2022] [Indexed: 05/10/2023]
Abstract
Castor bean (Ricinus communis) seed oil (triacylglycerol [TAG]) is composed of ∼90% of the industrially important ricinoleoyl (12-hydroxy-9-octadecenoyl) groups. Here, phosphatidylcholine (PC):diacylglycerol (DAG) cholinephosphotransferase (PDCT) from castor bean was biochemically characterized and compared with camelina (Camelina sativa) PDCT. DAGs with ricinoleoyl groups were poorly used by Camelina PDCT, and their presence inhibited the utilization of DAG with "common" acyl groups. In contrast, castor PDCT utilized DAG with ricinoleoyl groups similarly to DAG with common acyl groups and showed a 10-fold selectivity for DAG with one ricinoleoyl group over DAG with two ricinoleoyl groups. Castor DAG acyltransferase2 specificities and selectivities toward different DAG and acyl-CoA species were assessed and shown to not acylate DAG without ricinoleoyl groups in the presence of ricinoleoyl-containing DAG. Eighty-five percent of the DAG species in microsomal membranes prepared from developing castor endosperm lacked ricinoleoyl groups. Most of these species were predicted to be derived from PC, which had been formed by PDCT in exchange with DAG with one ricinoleoyl group. A scheme of the function of PDCT in castor endosperm is proposed where one ricinoleoyl group from de novo-synthesized DAG is selectivity transferred to PC. Nonricinoleate DAG is formed and ricinoleoyl groups entering PC are re-used either in de novo synthesis of DAG with two ricinoleoyl groups or in direct synthesis of triricinoleoyl TAG by PDAT. The PC-derived DAG is not used in TAG synthesis but is proposed to serve as a substrate in membrane lipid biosynthesis during oil deposition.
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Affiliation(s)
- Kamil Demski
- Department of Plant Breeding, Swedish University of Agricultural Sciences, S-230 53 Alnarp, Sweden
| | - Simon Jeppson
- Department of Plant Breeding, Swedish University of Agricultural Sciences, S-230 53 Alnarp, Sweden
| | - Sten Stymne
- Department of Plant Breeding, Swedish University of Agricultural Sciences, S-230 53 Alnarp, Sweden
| | - Ida Lager
- Department of Plant Breeding, Swedish University of Agricultural Sciences, S-230 53 Alnarp, Sweden
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17
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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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18
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Bengtsson JD, Wallis JG, Browse J. Expression of Physaria longchain acyl-CoA synthetases and hydroxy fatty acid accumulation in transgenic Arabidopsis. JOURNAL OF PLANT PHYSIOLOGY 2022; 274:153717. [PMID: 35584570 PMCID: PMC9494924 DOI: 10.1016/j.jplph.2022.153717] [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: 04/07/2022] [Revised: 05/04/2022] [Accepted: 05/06/2022] [Indexed: 06/15/2023]
Abstract
Hydroxy fatty acids (HFA) are industrially useful chemical feedstocks that accumulate in seed-storage triacylglycerols (TAG) of several plant species, including castor (Ricinus communis) and Physaria (Physaria fendleri). For researchers, HFA also offer a unique opportunity to trace fatty acid metabolism and modification. Past work producing HFA in Arabidopsis (Arabidopsis thaliana) has demonstrated the importance of isozymes of TAG synthesis from plants that evolved to store HFA and as a result have a high degree of specificity towards HFA substrates. Castor phospholipase A2α (RcPLA2) has specificity for HFA-containing phosphatidylcholine. However, expression of RcPLA2 in HFA-accumulating Arabidopsis line CL37-PLA2 reduced HFA content of TAG. This loss was interpreted as being due to poor ability of Arabidopsis longchain acyl-CoA synthetases (LACSs) to utilize HFAs substrates. LACS enzymes are essential to activate HFA to HFA-CoA for TAG synthesis. Physaria is a close relative of Arabidopsis in the Brassicaceae family. To test the hypothesis that this close relatedness would allow Physaria LACSs to interface successfully with Arabidopsis enzymes of seed lipid metabolism and thereby restore HFA accumulation, we transformed PfLACS4 and PfLACS8 constructs into the CL37-PLA2 line. However, HFA content was not recovered, and biochemical characterization of recombinant PfLACS4 and PfLACS8 indicated that these isozymes have substrate specificities and selectivities that are similar to their Arabidopsis orthologues. These and other results pose an important question about how HFA synthesized on phosphatidylcholine can be transferred into the acyl-CoA pool for TAG synthesis.
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Affiliation(s)
- Jesse D Bengtsson
- Institute of Biological Chemistry, Washington State University, Pullman, WA, USA
| | - James G Wallis
- Institute of Biological Chemistry, Washington State University, Pullman, WA, USA
| | - John Browse
- Institute of Biological Chemistry, Washington State University, Pullman, WA, USA.
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19
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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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20
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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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21
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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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22
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Overexpression of phospholipid: diacylglycerol acyltransferase in Brassica napus results in changes in lipid metabolism and oil accumulation. Biochem J 2022; 479:805-823. [PMID: 35298586 PMCID: PMC9022997 DOI: 10.1042/bcj20220003] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 03/05/2022] [Accepted: 03/17/2022] [Indexed: 11/17/2022]
Abstract
The regulation of lipid metabolism in oil seeds is still not fully understood and increasing our knowledge in this regard is of great economic, as well as intellectual, importance. Oilseed rape (Brassica napus) is a major global oil crop where increases in triacylglycerol (TAG) accumulation have been achieved by overexpression of relevant biosynthetic enzymes. In this study, we expressed Arabidopsis phospholipid: diacylglycerol acyltransferase (PDAT1), one of the two major TAG-forming plant enzymes in B. napus DH12075 to evaluate its effect on lipid metabolism in developing seeds and to estimate its flux control coefficient. Despite several-fold increase in PDAT activity, seeds of three independently generated PDAT transgenic events showed a small but consistent decrease in seed oil content and had altered fatty acid composition of phosphoglycerides and TAG, towards less unsaturation. Mass spectrometry imaging of seed sections confirmed the shift in lipid compositions and indicated that PDAT overexpression altered the distinct heterogeneous distributions of phosphatidylcholine (PC) molecular species. Similar, but less pronounced, changes in TAG molecular species distributions were observed. Our data indicate that PDAT exerts a small, negative, flux control on TAG biosynthesis and could have under-appreciated effects in fine-tuning of B. napus seed lipid composition in a tissue-specific manner. This has important implications for efforts to increase oil accumulation in similar crops.
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23
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Chellamuthu M, Kumaresan K, Subramanian S. Increase in alpha-linolenic acid content by simultaneous expression of fatty acid metabolism genes in Sesame ( Sesamum indicum L.). PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2022; 28:559-572. [PMID: 35465201 PMCID: PMC8986930 DOI: 10.1007/s12298-022-01152-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 02/12/2022] [Accepted: 02/17/2022] [Indexed: 06/14/2023]
Abstract
UNLABELLED Sesame is considered one of India's important sources of edible oil and an excellent dietary source for its nutritional and medicinal value. Sesame DGAT1 and PDAT1 genes were co-expressed with omega 3 FAD genes. Systemic isolation of sesame DGAT1, PDAT1, ER type FAD3, and chloroplast type FAD7/8 genes were performed. Their sequence was analyzed for genomic organization, amino acid characterization, organ specificity, and phylogenetic relationships. The insilico analysis revealed the unique features of DGAT1, PDAT1, and FAD3 gene sequences, whereas FAD7 and FAD8 sequences had the same protein characters and were grouped in phylogeny analysis, only variation was found in their mRNA UTR regions. Functional expression of sesame TAG synthesis genes and omega-3 FAD genes was studied in yeast mutant H1246 deficient for TAG synthesis. Functional analyses in yeast with the presence of ALA confirmed the identity of sesame FAD3, FAD7 and FAD8 genes. Recombinant expression of pESC + DGAT1 + FAD3 vector in yeast mutant resulted in lipid accumulation with 10% higher ALA content. Thus this gene combination can be co-expressed in sesame and other plant systems to increase the lipid accumulation with high omega-3 fatty acid (ALA) content. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s12298-022-01152-0.
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Affiliation(s)
| | - Kanimozhi Kumaresan
- Department of Biotechnology, PSG College of Technology, 641004 Coimbatore, Tamil Nadu India
| | - Selvi Subramanian
- Department of Biotechnology, PSG College of Technology, 641004 Coimbatore, Tamil Nadu India
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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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Production of the infant formula ingredient 1,3-olein-2-palmitin in Arabidopsis thaliana seeds. Metab Eng 2021; 67:67-74. [PMID: 34091040 DOI: 10.1016/j.ymben.2021.05.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 05/07/2021] [Accepted: 05/29/2021] [Indexed: 11/24/2022]
Abstract
In human milk fat, palmitic acid (16:0) is esterified to the middle (sn-2 or β) position on the glycerol backbone and oleic acid (18:1) predominantly to the outer positions, giving the triacylglycerol (TG) a distinctive stereoisomeric structure that is believed to assist nutrient absorption in the infant gut. However, the fat used in most infant formulas is derived from plants, which preferentially esterify 16:0 to the outer positions. We have previously showed that the metabolism of the model oilseed Arabidopsis thaliana can be engineered to incorporate 16:0 into the middle position of TG. However, the fatty acyl composition of Arabidopsis seed TG does not mimic human milk, which is rich in both 16:0 and 18:1 and is defined by the high abundance of the TG molecular species 1,3-olein-2-palmitin (OPO). Here we have constructed an Arabidopsis fatty acid biosynthesis 1-1 fatty acid desaturase 2 fatty acid elongase 1 mutant with around 20% 16:0 and 70% 18:1 in its seeds and we have engineered it to esterify more than 80% of the 16:0 to the middle position of TG, using heterologous expression of the human lysophosphatidic acid acyltransferase isoform AGPAT1, combined with suppression of LYSOPHOSPHATIDIC ACID ACYLTRANSFERASE 2 and PHOSPHATIDYLCHOLINE:DIACYLGLYCEROL CHOLINEPHOSPHOTRANSFERASE. Our data show that oilseeds can be engineered to produce TG that is rich in OPO, which is a structured fat ingredient used in infant formulas.
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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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Yu XH, Cai Y, Keereetaweep J, Wei K, Chai J, Deng E, Liu H, Shanklin J. Biotin attachment domain-containing proteins mediate hydroxy fatty acid-dependent inhibition of acetyl CoA carboxylase. PLANT PHYSIOLOGY 2021; 185:892-901. [PMID: 33793910 PMCID: PMC8133645 DOI: 10.1093/plphys/kiaa109] [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: 11/13/2020] [Accepted: 11/13/2020] [Indexed: 05/02/2023]
Abstract
Hundreds of naturally occurring specialized fatty acids (FAs) have potential as desirable chemical feedstocks if they could be produced at large scale by crop plants; however, transgenic expression of their biosynthetic genes has generally been accompanied by dramatic reductions in oil yield. For example, expression of castor (Ricinus communis) FA hydroxylase (FAH) in the Arabidopsis thaliana FA elongation mutant fae1 resulted in a 50% reduction of FA synthesis rate that was attributed to inhibition of acetyl-CoA carboxylase (ACCase) by an undefined mechanism. Here, we tested the hypothesis that the ricinoleic acid-dependent decrease in ACCase activity is mediated by biotin attachment domain-containing (BADC) proteins. BADCs are inactive homologs of biotin carboxy carrier protein that lack a biotin cofactor and can inhibit ACCase. Arabidopsis contains three BADC genes. To reduce expression levels of BADC1 and BADC3 in fae1/FAH plants, a homozygous badc1,3/fae1/FAH line was created. The rate of FA synthesis in badc1,3/fae1/FAH seeds doubled relative to fae1/FAH, restoring it to fae1 levels, increasing both native FA and HFA accumulation. Total FA per seed, seed oil content, and seed yield per plant all increased in badc1,3/fae1/FAH, to 5.8 µg, 37%, and 162 mg, respectively, relative to 4.9 µg, 33%, and 126 mg, respectively, for fae1/FAH. Transcript levels of FA synthesis-related genes, including those encoding ACCase subunits, did not significantly differ between badc1,3/fae1/FAH and fae1/FAH. These results demonstrate that BADC1 and BADC3 mediate ricinoleic acid-dependent inhibition of FA synthesis. We propose that BADC-mediated FAS inhibition as a general mechanism that limits FA accumulation in specialized FA-accumulating seeds.
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Affiliation(s)
- Xiao-Hong Yu
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Yuanheng Cai
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794, USA
| | | | - Kenneth Wei
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Jin Chai
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Elen Deng
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Hui Liu
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - John Shanklin
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA
- Author for communication:
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Gao H, Gao Y, Zhang F, Liu B, Ji C, Xue J, Yuan L, Li R. Functional characterization of an novel acyl-CoA:diacylglycerol acyltransferase 3-3 (CsDGAT3-3) gene from Camelina sativa. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2021; 303:110752. [PMID: 33487340 DOI: 10.1016/j.plantsci.2020.110752] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 10/06/2020] [Accepted: 11/06/2020] [Indexed: 06/12/2023]
Abstract
Diacylglycerol acyltransferases (DGAT) catalyze the final committed step of de novo biosynthesis of triacylglycerol (TAG) in plant seeds. This study was to functionally characterize DGAT3 genes in Camelina sativa, an important oil crops accumulating high levels of unsaturated fatty acids (UFAs) in seeds. Three camelina DGAT3 genes (CsDGAT3-1, CsDGAT3-2 and CsDGAT3-3) were identified, and the encoded proteins were predicted to be cytosolic-soluble proteins present as a homodimer containing the 2Fe-2S domain. They had divergent expression patterns in various tissues, suggesting that they may function in tissue-specific manner with CsDGAT3-1 in roots, CsDGAT3-2 in flowers and young seedlings, and CsDGAT3-3 in developing seeds. Functional complementation assay in yeast demonstrated that CsDGAT3-3 restored TAG synthesis. TAG content and UFAs, particularly eicosenoic acid (EA, 20:1n-9) were largely increased by adding exogenous UFAs in the yeast medium. Further heterogeneously transient expression in N. benthamiana leaves and seed-specific expression in tobacco seeds indicated that CsDGAT3-3 significantly enhanced oil and UFA accumulation with much higher level of EA. Overall, CsDGAT3-3 exhibited a strong abilty catalyzing TAG synthesis and high substrate preference for UFAs, especially for 20:1n-9. The present data provide new insights for further understanding oil biosynthesis mechanism in camelina seeds, indicating that CsDGAT3-3 may have practical applications for increasing both oil yield and quality.
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Affiliation(s)
- Huiling Gao
- Institute of Molecular Agriculture and Bioenergy, Shanxi Agricultural University, Taigu, Shanxi, China
| | - Yu Gao
- Institute of Molecular Agriculture and Bioenergy, Shanxi Agricultural University, Taigu, Shanxi, China
| | - Fei Zhang
- Institute of Molecular Agriculture and Bioenergy, Shanxi Agricultural University, Taigu, Shanxi, China
| | - Baoling Liu
- Institute of Molecular Agriculture and Bioenergy, Shanxi Agricultural University, Taigu, Shanxi, China
| | - Chunli Ji
- Institute of Molecular Agriculture and Bioenergy, Shanxi Agricultural University, Taigu, Shanxi, China
| | - Jinai Xue
- Institute of Molecular Agriculture and Bioenergy, Shanxi Agricultural University, Taigu, Shanxi, China.
| | - Lixia Yuan
- College of Biological Science and Technology, Jinzhong University, Jinzhong, Shanxi, China.
| | - Runzhi Li
- Institute of Molecular Agriculture and Bioenergy, Shanxi Agricultural University, Taigu, Shanxi, China.
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29
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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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30
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Hernández ML, Moretti S, Sicardo MD, García Ú, Pérez A, Sebastiani L, Martínez-Rivas JM. Distinct Physiological Roles of Three Phospholipid:Diacylglycerol Acyltransferase Genes in Olive Fruit with Respect to Oil Accumulation and the Response to Abiotic Stress. FRONTIERS IN PLANT SCIENCE 2021; 12:751959. [PMID: 34868139 PMCID: PMC8632719 DOI: 10.3389/fpls.2021.751959] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 10/21/2021] [Indexed: 05/13/2023]
Abstract
Three different cDNA sequences, designated OepPDAT1-1, OepPDAT1-2, and OepPDAT2, encoding three phospholipid:diacylglycerol acyltransferases (PDAT) have been isolated from olive (Olea europaea cv. Picual). Sequence analysis showed the distinctive features typical of the PDAT family and together with phylogenetic analysis indicated that they encode PDAT. Gene expression analysis in different olive tissues showed that transcript levels of these three PDAT genes are spatially and temporally regulated and suggested that, in addition to acyl-CoA:diacylglycerol acyltransferase, OePDAT1-1 may contribute to the biosynthesis of triacylglycerols in the seed, whereas OePDAT1-2 could be involved in the triacylglycerols content in the mesocarp and, therefore, in the olive oil. The relative contribution of PDAT and acyl-CoA:diacylglycerol acyltransferase enzymes to the triacylglycerols content in olive appears to be tissue-dependent. Furthermore, water regime, temperature, light, and wounding regulate PDAT genes at transcriptional level in the olive fruit mesocarp, indicating that PDAT could be involved in the response to abiotic stresses. Altogether, this study represents an advance in our knowledge on the regulation of oil accumulation in oil fruit.
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Affiliation(s)
- M. Luisa Hernández
- Department of Biochemistry and Molecular Biology of Plant Products, Instituto de la Grasa (IG-CSIC), Campus Universidad Pablo de Olavide, Seville, Spain
| | - Samuele Moretti
- Department of Biochemistry and Molecular Biology of Plant Products, Instituto de la Grasa (IG-CSIC), Campus Universidad Pablo de Olavide, Seville, Spain
- BioLabs, Institute of Life Sciences, Scuola Superiore Sant’Anna, Pisa, Italy
| | - M. Dolores Sicardo
- Department of Biochemistry and Molecular Biology of Plant Products, Instituto de la Grasa (IG-CSIC), Campus Universidad Pablo de Olavide, Seville, Spain
| | - Úrsula García
- Department of Biochemistry and Molecular Biology of Plant Products, Instituto de la Grasa (IG-CSIC), Campus Universidad Pablo de Olavide, Seville, Spain
| | - Ana Pérez
- Department of Biochemistry and Molecular Biology of Plant Products, Instituto de la Grasa (IG-CSIC), Campus Universidad Pablo de Olavide, Seville, Spain
| | - Luca Sebastiani
- BioLabs, Institute of Life Sciences, Scuola Superiore Sant’Anna, Pisa, Italy
| | - José M. Martínez-Rivas
- Department of Biochemistry and Molecular Biology of Plant Products, Instituto de la Grasa (IG-CSIC), Campus Universidad Pablo de Olavide, Seville, Spain
- *Correspondence: José M. Martínez-Rivas,
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31
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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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32
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Lunn D, Le A, Wallis JG, Browse J. Castor LPCAT and PDAT1A Act in Concert to Promote Transacylation of Hydroxy-Fatty Acid onto Triacylglycerol. PLANT PHYSIOLOGY 2020; 184:709-719. [PMID: 32737074 PMCID: PMC7536696 DOI: 10.1104/pp.20.00691] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 07/23/2020] [Indexed: 05/27/2023]
Abstract
Oilseeds produce abundant triacylglycerol (TAG) during seed maturation to fuel the establishment of photoautotrophism in the subsequent generation. Commonly, TAG contains 18-carbon polyunsaturated fatty acids (FA), but plants also produce oils with unique chemical properties highly desirable for industrial processes. Unfortunately, plants that produce such oils are poorly suited to agronomic exploitation, leading to a desire to reconstitute novel oil biosynthesis in crop plants. Here, we studied the production and incorporation of hydroxy-fatty acids (HFA) onto TAG in Arabidopsis (Arabidopsis thaliana) plants expressing the castor (Ricinus communis) FAH12 hydroxylase. One factor limiting HFA accumulation in these plants is the inefficient removal of HFA from the site of synthesis on phosphatidylcholine (PC). In Arabidopsis, lysophosphatidic acid acyltransferase (LPCAT) cycles FA to and from PC for modification. We reasoned that the castor LPCAT (RcLPCAT) would preferentially remove HFA from PC, resulting in greater incorporation onto TAG. However, expressing RcLPCAT in Arabidopsis expressing FAH12 alone (line CL37) or together with castor acyl:coenzyme A:diacylglycerol acyltransferase2 reduced HFA and total oil yield. Detailed analysis indicated that RcLPCAT reduced the removal of HFA from PC, possibly by competing with the endogenous LPCAT isozymes. Significantly, coexpressing RcLPCAT with castor phospholipid:diacylglycerol acyltransferase increased novel FA and total oil contents by transferring HFA from PC to diacylglycerol. Our results demonstrate that a detailed understanding is required to engineer modified FA production in oilseeds and suggest that phospholipase A2 enzymes rather than LPCAT mediate the highly efficient removal of HFA from PC in castor seeds.
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Affiliation(s)
- Daniel Lunn
- Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164-6340
| | - Anh Le
- Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164-6340
| | - James G Wallis
- Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164-6340
| | - John Browse
- Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164-6340
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33
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Regmi A, Shockey J, Kotapati HK, Bates PD. Oil-Producing Metabolons Containing DGAT1 Use Separate Substrate Pools from those Containing DGAT2 or PDAT. PLANT PHYSIOLOGY 2020; 184:720-737. [PMID: 32732347 PMCID: PMC7536707 DOI: 10.1104/pp.20.00461] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 07/23/2020] [Indexed: 05/03/2023]
Abstract
Seed triacylglycerol (TAG) biosynthesis involves a metabolic network containing multiple different diacylglycerol (DAG) and acyl donor substrate pools. This network of pathways overlaps with those for essential membrane lipid synthesis and utilizes multiple different classes of TAG biosynthetic enzymes. Acyl flux through this network ultimately dictates the final oil fatty acid composition. Most strategies to alter seed oil composition involve the overexpression of lipid biosynthetic enzymes, but how these enzymes are assembled into metabolons and which substrate pools are used by each is still not well understood. To understand the roles of different classes of TAG biosynthetic acyltransferases in seed oil biosynthesis, we utilized the Arabidopsis (Arabidopsis thaliana) diacylglycerol acyltransferase mutant dgat1-1 (in which phosphatidylcholine:diacylglycerol acyltransferase (AtPDAT1) is the major TAG biosynthetic enzyme), and enhanced TAG biosynthesis by expression of Arabidopsis acyltransferases AtDGAT1 and AtDGAT2, as well as the DGAT2 enzymes from soybean (Glycine max), and castor (Ricinus communis), followed by isotopic tracing of glycerol flux through the lipid metabolic network in developing seeds. The results indicate each acyltransferase has a unique effect on seed oil composition. AtDGAT1 produces TAG from a rapidly produced phosphatidylcholine-derived DAG pool. However, AtPDAT1 and plant DGAT2 enzymes utilize a different and larger bulk phosphatidylcholine-derived DAG pool that is more slowly turned over for TAG biosynthesis. Based on metabolic fluxes and protein:protein interactions, our model of TAG synthesis suggests that substrate channeling to select enzymes and spatial separation of different acyltransferases into separate metabolons affect efficient TAG production and oil fatty acid composition.
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Affiliation(s)
- Anushobha Regmi
- Department of Chemistry and Biochemistry, University of Southern Mississippi, Hattiesburg, Mississippi 39406
| | - Jay Shockey
- United States Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, New Orleans, Louisiana 70124
| | - Hari Kiran Kotapati
- Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164
| | - Philip D Bates
- Department of Chemistry and Biochemistry, University of Southern Mississippi, Hattiesburg, Mississippi 39406
- Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164
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Yin Y, Guo Z, Chen K, Tian T, Tan J, Chen X, Chen J, Yang B, Tang S, Peng K, Liu S, Liang Y, Zhang K, Yu L, Li M. Ultra-high α-linolenic acid accumulating developmental defective embryo was rescued by lysophosphatidic acid acyltransferase 2. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 103:2151-2167. [PMID: 32573846 DOI: 10.1111/tpj.14889] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 06/01/2020] [Accepted: 06/05/2020] [Indexed: 05/20/2023]
Abstract
For decades, genetic engineering approaches to produce unusual fatty acids (UFAs) in crops has reached a bottleneck, including reduced seed oil production and seed vigor. Currently, plant models in the field of research are primarily used to investigate defects in oil production and seedling development, while the role of UFAs in embryonic developmental defects remains unknown. In this study, we developed a transgenic Arabidopsis plant model, in which the embryo exhibits severely wrinkled appearance owing to α-linolenic acid (ALA) accumulation. RNA-sequencing analysis in the defective embryo suggested that brassinosteroid synthesis, FA synthesis and photosynthesis were inhibited, while FA degradation, endoplasmic reticulum stress and oxidative stress were activated. Lipidomics analysis showed that ultra-accumulated ALA is released from phosphatidylcholine as a free FA in cells, inducing severe endoplasmic reticulum and oxidative stress. Furthermore, we identified that overexpression of lysophosphatidic acid acyltransferase 2 rescued the defective phenotype. In the rescue line, the pool capacity of the Kennedy pathway was increased, and the esterification of ALA indirectly to triacylglycerol was enhanced to avoid stress. This study provides a plant model that aids in understanding the molecular mechanism of embryonic developmental defects and generates strategies to produce higher levels of UFAs.
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Affiliation(s)
- Yongtai Yin
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
- Hubei Key Laboratory of Economic Forest Germplasm Improvement and Resource Comprehensive Utilization, Hubei Collaborative Innovation Center for the Characteristic Resources Exploitation of Dabie Mountains, Huanggang Normal University, Huanggang, 438000, China
| | - Zhenyi Guo
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Kang Chen
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Tian Tian
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Jiajun Tan
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Xinfeng Chen
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Jing Chen
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Bing Yang
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Shuyan Tang
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Kangfu Peng
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Si Liu
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Yu Liang
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Kai Zhang
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Longjiang Yu
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Maoteng Li
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
- Hubei Key Laboratory of Economic Forest Germplasm Improvement and Resource Comprehensive Utilization, Hubei Collaborative Innovation Center for the Characteristic Resources Exploitation of Dabie Mountains, Huanggang Normal University, Huanggang, 438000, China
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Zhou B, Fei W, Yang S, Yang F, Qu G, Tang W, Ou J, Peng D. Alteration of the fatty acid composition of Brassica napus L. via overexpression of phospholipid: Diacylglycerol acyltransferase 1 from Sapium sebiferum (L.) Roxb. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2020; 298:110562. [PMID: 32771163 DOI: 10.1016/j.plantsci.2020.110562] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 06/03/2020] [Accepted: 06/08/2020] [Indexed: 06/11/2023]
Abstract
Sapium sebiferum (L.) Roxb. plays an important role in traditional Chinese medicine and is one of major woody oil tree in China. Phospholipid: diacylglycerol acyltransferase 1 (PDAT1), as an important catalytic enzyme for the formation of triacylglycerol (TAG), is mainly responsible for the transfer of an acyl group from the sn-2 position of phospholipids to the sn-3 position of sn-1, 2-diacylglycerol (DAG) to produce TAG and sn-1 lysophospholipids. The importance of PDAT1 in triacylglycerol biosynthesis has been illustrated in previous research, and at least 67 PDAT1 sequences have been identified from 31 organisms. However, little is known about the gene encoding PDAT1 in S. sebiferum (SsPDAT1), which is involved in seed oil biosynthesis. To explore the functional characteristics of SsPDAT1, we cloned and analyzed the full-length cDNA in the coding region of SsPDAT1, which consists of 2040 bp and encodes a putative protein of 680 amino acid (aa) residues. Thin-layer chromatography (TLC) analysis showed that recombinant SsPDAT1 could restore TAG accumulation in TAG-deficient mutant yeast (Saccharomyces cerevisiae) H1246, which revealed the enzyme activity of SsPDAT1. Moreover, transgenic Brassica napus L. W10 plants overexpressing SsPDAT1 showed significant increases of 19.6-28.9 % in linoleic acid levels but decreases of 27.3-37.1 % in linolenic acid. Furthermore, the total oil content increased by 8.1 %-10.8 % in SsPDAT1 transgenic seeds. These results confirmed the role of SsPDAT1 in stabilizing oil biosynthesis and suggested that SsPDAT1 could be exploitable to specifically regulate the oil composition of plants. These experimental results provide a new concept that may enable the industrial development of plants with high-linoleic-acid oil through overexpression of SsPDAT1 in S. sebiferum L.
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Affiliation(s)
- Bo Zhou
- Faculty of Bioscience and Biotechnology of Central South University of Forestry and Technology, 410004, Changsha, China; Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees, Ministry of Education, Central South University of Forestry and Technology, 410018, Changsha, China; Forestry Biotechnology Hunan Key Laboratories, Hunan, Changsha, 410004, China; National Engineering Laboratory of Applied Technology for Forestry and Ecology in Southern China, Changsha, 410004, Hunan, China; Huitong National Field Station for Scientific Observation and Research of Chinese Fir Plantation Ecosystem in Hunan Province, Huitong, 438107, China.
| | - Wenjie Fei
- Faculty of Bioscience and Biotechnology of Central South University of Forestry and Technology, 410004, Changsha, China
| | - Shiquan Yang
- Faculty of Bioscience and Biotechnology of Central South University of Forestry and Technology, 410004, Changsha, China
| | - Feng Yang
- Faculty of Bioscience and Biotechnology of Central South University of Forestry and Technology, 410004, Changsha, China
| | - Gaoyi Qu
- Faculty of Bioscience and Biotechnology of Central South University of Forestry and Technology, 410004, Changsha, China
| | - Weiwei Tang
- Faculty of Bioscience and Biotechnology of Central South University of Forestry and Technology, 410004, Changsha, China
| | - Jianping Ou
- Faculty of Bioscience and Biotechnology of Central South University of Forestry and Technology, 410004, Changsha, China
| | - Dan Peng
- Faculty of Bioscience and Biotechnology of Central South University of Forestry and Technology, 410004, Changsha, China; Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees, Ministry of Education, Central South University of Forestry and Technology, 410018, Changsha, China.
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Falarz LJ, Xu Y, Caldo KMP, Garroway CJ, Singer SD, Chen G. Characterization of the diversification of phospholipid:diacylglycerol acyltransferases in the green lineage. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 103:2025-2038. [PMID: 32538516 DOI: 10.1111/tpj.14880] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 05/28/2020] [Accepted: 06/02/2020] [Indexed: 05/03/2023]
Abstract
Triacylglycerols have important physiological roles in photosynthetic organisms, and are widely used as food, feed and industrial materials in our daily life. Phospholipid:diacylglycerol acyltransferase (PDAT) is the pivotal enzyme catalyzing the acyl-CoA-independent biosynthesis of triacylglycerols, which is unique in plants, algae and fungi, but not in animals, and has essential functions in plant and algal growth, development and stress responses. Currently, this enzyme has yet to be examined in an evolutionary context at the level of the green lineage. Some fundamental questions remain unanswered, such as how PDATs evolved in photosynthetic organisms and whether the evolution of terrestrial plant PDATs from a lineage of charophyte green algae diverges in enzyme function. As such, we used molecular evolutionary analysis and biochemical assays to address these questions. Our results indicated that PDAT underwent divergent evolution in the green lineage: PDATs exist in a wide range of plants and algae, but not in cyanobacteria. Although PDATs exhibit the conservation of several features, phylogenetic and selection-pressure analyses revealed that overall they evolved to be highly divergent, driven by different selection constraints. Positive selection, as one major driving force, may have resulted in enzymes with a higher functional importance in land plants than green algae. Further structural and mutagenesis analyses demonstrated that some amino acid sites under positive selection are critically important to PDAT structure and function, and may be central in lecithin:cholesterol acyltransferase family enzymes in general.
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Affiliation(s)
- Lucas J Falarz
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada
| | - Yang Xu
- 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
| | - Colin J Garroway
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada
| | - Stacy D Singer
- Agriculture and Agri-Food Canada, Lethbridge Research and Development Centre, Lethbridge, AB, T1J 4B1, Canada
| | - Guanqun Chen
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada
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Correa SM, Alseekh S, Atehortúa L, Brotman Y, Ríos-Estepa R, Fernie AR, Nikoloski Z. Model-assisted identification of metabolic engineering strategies for Jatropha curcas lipid pathways. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 104:76-95. [PMID: 33001507 DOI: 10.1111/tpj.14906] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 06/03/2020] [Accepted: 06/12/2020] [Indexed: 06/11/2023]
Abstract
Efficient approaches to increase plant lipid production are necessary to meet current industrial demands for this important resource. While Jatropha curcas cell culture can be used for in vitro lipid production, scaling up the system for industrial applications requires an understanding of how growth conditions affect lipid metabolism and yield. Here we present a bottom-up metabolic reconstruction of J. curcas supported with labeling experiments and biomass characterization under three growth conditions. We show that the metabolic model can accurately predict growth and distribution of fluxes in cell cultures and use these findings to pinpoint energy expenditures that affect lipid biosynthesis and metabolism. In addition, by using constraint-based modeling approaches we identify network reactions whose joint manipulation optimizes lipid production. The proposed model and computational analyses provide a stepping stone for future rational optimization of other agronomically relevant traits in J. curcas.
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Affiliation(s)
- Sandra M Correa
- Genetics of Metabolic Traits Group, Max Planck Institute of Molecular Plant Physiology, Potsdam, 14476, Germany
- Grupo de Biotecnología, Departamento de Ciencias Exactas y Naturales, Universidad de Antioquia, Medellín, 050010, Colombia
| | - Saleh Alseekh
- Central Metabolism Group, Max Planck Institute of Molecular Plant Physiology, Potsdam, 14476, Germany
- Centre for Plant Systems Biology and Biotechnology, Plovdiv, 4000, Bulgaria
| | - Lucía Atehortúa
- Grupo de Biotecnología, Departamento de Ciencias Exactas y Naturales, Universidad de Antioquia, Medellín, 050010, Colombia
| | - Yariv Brotman
- Genetics of Metabolic Traits Group, Max Planck Institute of Molecular Plant Physiology, Potsdam, 14476, Germany
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel
| | - Rigoberto Ríos-Estepa
- Grupo de Bioprocesos, Departamento de Ingeniería Química, Universidad de Antioquia, Medellín, 050010, Colombia
| | - Alisdair R Fernie
- Central Metabolism Group, Max Planck Institute of Molecular Plant Physiology, Potsdam, 14476, Germany
- Centre for Plant Systems Biology and Biotechnology, Plovdiv, 4000, Bulgaria
| | - Zoran Nikoloski
- Centre for Plant Systems Biology and Biotechnology, Plovdiv, 4000, Bulgaria
- Bioinformatics, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, 14476, Germany
- Systems Biology and Mathematical Modelling Group, Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, 14476, Germany
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38
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Tian B, Sun M, Jayawardana K, Wu D, Chen G. Characterization of a PLDζ2 Homology Gene from Developing Castor Bean Endosperm. Lipids 2020; 55:537-548. [PMID: 32115716 DOI: 10.1002/lipd.12231] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 02/18/2020] [Accepted: 02/18/2020] [Indexed: 12/18/2022]
Abstract
Castor oil contains approximately 90% ricinoleic acid (RA) which is stored mainly in the form of tri-ricinoleic acid containing triacylglycerols (TAG). Ricinoleate is synthesized from oleate (18:1n-9) esterified to the sn-2 position of phosphatidylcholine (PtdCho) catalyzed by oleoyl-12-hydroxylase. PtdCho-derived diacylglycerol (DAG) is an important substrate pool for TAG synthesis, and the interconversion between PtdCho and DAG has been shown to play a critical role in channeling hydroxy fatty acids (HFA) to TAG. Although phospholipase D (PLD) has been reported to catalyze the hydrolysis of PtdCho to produce phosphatidic acid which can then be converted to DAG, its potential functions in the channeling of RA from PtdCho to DAG and the assembly of RA on TAG is largely unknown. In the present study, 11 PLD genes were identified from the Castor Bean Genome Database. Gene expression analysis indicated that RcPLD9 is expressed at relatively high levels in developing seeds compared to other plant tissues. Sequence and phylogenetic analyses revealed that RcPLD9 is a homolog of Arabidopsis PLDζ2. Overexpression of RcPLD9 in the Arabidopsis CL7 line producing C18-HFA resulted in RA content reductions in the polar lipid fraction (mainly PtdCho) and mono-HFA-TAG, but increased RA content in di-HFA-TAG. Since part of RA in di-HFA-TAG is derived from HFA-DAG, the results indicated that RcPLD9 facilitates the channeling of RA from PtdCho to DAG for its assembly on TAG in developing seeds.
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Affiliation(s)
- Bo Tian
- CAS Key Laboratory of Tropical Plant Resource and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan, 666303, China
- Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Menglun, Mengla, Yunnan, 666303, China
| | - Meijuan Sun
- CAS Key Laboratory of Tropical Plant Resource and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan, 666303, China
| | - Kethmi Jayawardana
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada
| | - Ding Wu
- Jingdezhen University, Jingdezhen, 333000, China
| | - Guanqun Chen
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada
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Xu Y, Mietkiewska E, Shah S, Weselake RJ, Chen G. Punicic acid production in Brassica napus. Metab Eng 2020; 62:20-29. [PMID: 32841680 DOI: 10.1016/j.ymben.2020.08.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 07/03/2020] [Accepted: 08/20/2020] [Indexed: 11/17/2022]
Abstract
Punicic acid (PuA; 18:3Δ9cis,11trans,13cis), a conjugated linolenic acid isomer bearing three conjugated double bonds, is associated with various health benefits and has potential for industrial use. The major nature source of this unusual fatty acid is pomegranate (Punica granatum) seed oil, which contains up to 80% (w/w) of its fatty acids as PuA. Pomegranate seed oil, however, is low yielding with unstable production and thus limits the supply of PuA. Metabolic engineering of established temperate oil crops for PuA production, therefore, has the potential to be a feasible strategy to overcome the limitations associated with sourcing PuA from pomegranate. In this study, the cDNAs encoding a pomegranate fatty acid conjugase and a pomegranate oleate desaturase were co-expressed in canola-type Brassica napus. Transgenic B. napus lines accumulated up to 11% (w/w) of the total fatty acids as PuA in the seed oil, which is the highest level of PuA reported in metabolically engineered oilseed crops so far. Levels of seed oil PuA were stable over two generations and had no negative effects on seed germination. The transgenic B. napus lines with the highest PuA levels contained multiple transgene insertions and the PuA content of B. napus seed oil was correlated with efficiency of oleic acid desaturation and linoleic acid conjugation. In addition, PuA accumulated at lower levels in polar lipids (5.0-6.9%) than triacylglycerol (7.5-10.6%), and more than 60% of triacylglycerol-associated PuA was present at the sn-2 position. This study provides the basis for the commercial production of PuA in transgenic oilseed crops and thus would open new prospects for the application of this unusual fatty acid in health and industry.
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Affiliation(s)
- Yang Xu
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, T6G 2P5, Canada
| | - Elzbieta Mietkiewska
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, T6G 2P5, Canada
| | - Saleh Shah
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, T6G 2P5, Canada
| | - Randall J Weselake
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, T6G 2P5, Canada
| | - Guanqun Chen
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, T6G 2P5, Canada.
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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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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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Kaur H, Wang L, Stawniak N, Sloan R, van Erp H, Eastmond P, Bancroft I. The impact of reducing fatty acid desaturation on the composition and thermal stability of rapeseed oil. PLANT BIOTECHNOLOGY JOURNAL 2020; 18:983-991. [PMID: 31553825 PMCID: PMC7061866 DOI: 10.1111/pbi.13263] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 09/11/2019] [Accepted: 09/17/2019] [Indexed: 05/20/2023]
Abstract
Oilseed rape (Brassica napus) is the third largest source of vegetable oil globally. In addition to food uses, there are industrial applications that exploit the ability of the species to accumulate the very-long-chain fatty acid (VLCFA) erucic acid in its seed oil, controlled by orthologues of FATTY ACID ELONGASE 1 (Bna.FAE1.A8 and Bna.FAE1.C3). The proportion of polyunsaturated fatty acids (PUFAs) in rapeseed oil is predicted to affect its thermal stability and is controlled by orthologues of FATTY ACID DESATURASE 2, particularly Bna.FAD2.C5. Our aim was to develop rapeseed lines combining high erucic and low PUFA characters and to assess the impact on thermal stability of the oil they produce. The new type of rapeseed oil (high erucic low polyunsaturate; HELP) contained a substantially greater proportion of erucic acid (54%) compared with high erucic rapeseed oil (46%). Although the total VLCFA content was greater in oil from HELP lines (64%) than from high erucic rapeseed (57%), analysis of triacylglycerol composition showed negligible incorporation of VLCFAs into the sn-2 position. Rancimat analysis showed that the thermal stability of rapeseed oil was improved greatly as a consequence of reduction of PUFA content, from 3.8 and 4.2 h in conventional low erucic and high erucic rapeseed oils, respectively, to 11.3 and 16.4 h in high oleic low PUFA (HOLP) and HELP oils, respectively. Our results demonstrate that engineering of the lipid biosynthetic pathway of rapeseed, using traditional approaches, enables the production of renewable industrial oils with novel composition and properties.
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Affiliation(s)
- Harjeevan Kaur
- University of YorkHeslingtonYorkUK
- Present address:
Punjab Agricultural UniversityLudhianaIndia
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Okada S, Taylor M, Zhou XR, Naim F, Marshall D, Blanksby SJ, Singh SP, Wood CC. Producing Cyclopropane Fatty Acid in Plant Leafy Biomass via Expression of Bacterial and Plant Cyclopropane Fatty Acid Synthases. FRONTIERS IN PLANT SCIENCE 2020; 11:30. [PMID: 32117373 PMCID: PMC7020751 DOI: 10.3389/fpls.2020.00030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 01/13/2020] [Indexed: 05/14/2023]
Abstract
Saturated mid-chain branched fatty acids (SMCBFAs) are widely used in the petrochemical industry for their high oxidative stability and low melting temperature. Dihydrosterculic acid (DHSA) is a cyclopropane fatty acid (CPA) that can be converted to SMCBFA via hydrogenation, and therefore oils rich in DHSA are a potential feedstock for SMCBFA. Recent attempts to produce DHSA in seed oil by recombinant expression of cyclopropane fatty acid synthases (CPFASes) resulted in decreased oil content and poor germination or low DHSA accumulation. Here we explored the potential for plant vegetative tissue to produce DHSA by transiently expressing CPFAS enzymes in leaf. When CPFASes from plant and bacterial origin were transiently expressed in Nicotiana benthamiana leaf, it accumulated up to 1 and 3.7% DHSA in total fatty acid methyl ester (FAME), respectively, which increased up to 4.8 and 11.8%, respectively, when the N. benthamiana endogenous oleoyl desaturase was silenced using RNA interference (RNAi). Bacterial CPFAS expression produced a novel fatty acid with a cyclopropane ring and two carbon-carbon double bonds, which was not seen with plant CPFAS expression. We also observed a small but significant additive effect on DHSA accumulation when both plant and bacterial CPFASes were co-expressed, possibly due to activity upon different oleoyl substrates within the plant cell. Lipidomics analyses found that CPFAS expression increased triacylglycerol (TAG) accumulation relative to controls and that DHSA was distributed across a range of lipid species, including diacylglycerol and galactolipids. DHSA and the novel CPA were present in phosphatidylethanolamine when bacterial CPFAS was expressed in leaf. Finally, when plant diacylglycerol acyltransferase was coexpressed with the CPFASes DHSA accumulated up to 15% in TAG. This study shows that leaves can readily produce and accumulate DHSA in leaf oil. Our findings are discussed in line with current knowledge in leaf oil production for a possible route to DHSA production in vegetative tissue.
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Affiliation(s)
- Shoko Okada
- CSIRO Land and Water, Canberra, ACT, Australia
| | | | - Xue-Rong Zhou
- CSIRO Agriculture and Food, Canberra, ACT, Australia
| | - Fatima Naim
- Center for Crop Disease Management, Faculty of Science and Engineering, School of Molecular and Life Sciences, Curtin University, Perth, WA, Australia
| | - David Marshall
- Central Analytical Research Facility, Institute for Future Environments, Queensland University of Technology, Brisbane, QLD, Australia
| | - Stephen J. Blanksby
- Central Analytical Research Facility, Institute for Future Environments, Queensland University of Technology, Brisbane, QLD, Australia
| | | | - Craig C. Wood
- CSIRO Agriculture and Food, Canberra, ACT, Australia
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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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Yuan L, Li R. Metabolic Engineering a Model Oilseed Camelina sativa for the Sustainable Production of High-Value Designed Oils. FRONTIERS IN PLANT SCIENCE 2020; 11:11. [PMID: 32117362 PMCID: PMC7028685 DOI: 10.3389/fpls.2020.00011] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 01/08/2020] [Indexed: 05/06/2023]
Abstract
Camelina sativa (L.) Crantz is an important Brassicaceae oil crop with a number of excellent agronomic traits including low water and fertilizer input, strong adaptation and resistance. Furthermore, its short life cycle and easy genetic transformation, combined with available data of genome and other "-omics" have enabled camelina as a model oil plant to study lipid metabolism regulation and genetic improvement. Particularly, camelina is capable of rapid metabolic engineering to synthesize and accumulate high levels of unusual fatty acids and modified oils in seeds, which are more stable and environmentally friendly. Such engineered camelina oils have been increasingly used as the super resource for edible oil, health-promoting food and medicine, biofuel oil and high-valued chemical production. In this review, we mainly highlight the latest advance in metabolic engineering towards the predictive manipulation of metabolism for commercial production of desirable bio-based products using camelina as an ideal platform. Moreover, we deeply analysis camelina seed metabolic engineering strategy and its promising achievements by describing the metabolic assembly of biosynthesis pathways for acetyl glycerides, hydroxylated fatty acids, medium-chain fatty acids, ω-3 long-chain polyunsaturated fatty acids, palmitoleic acid (ω-7) and other high-value oils. Future prospects are discussed, with a focus on the cutting-edge techniques in camelina such as genome editing application, fine directed manipulation of metabolism and future outlook for camelina industry development.
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Affiliation(s)
- Lixia Yuan
- College of Biological Science and Technology, Jinzhong University, Jinzhong, China
| | - Runzhi Li
- Institute of Molecular Agriculture and Bioenergy, Shanxi Agricultural University, Taigu, China
- *Correspondence: Runzhi Li,
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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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Sánchez-Álvarez A, Ruíz-López N, Moreno-Pérez AJ, Martínez-Force E, Garcés R, Salas JJ. Agrobacterium-Mediated Transient Gene Expression in Developing Ricinus communis Seeds: A First Step in Making the Castor Oil Plant a Chemical Biofactory. FRONTIERS IN PLANT SCIENCE 2019; 10:1410. [PMID: 31737023 PMCID: PMC6831639 DOI: 10.3389/fpls.2019.01410] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 10/11/2019] [Indexed: 06/10/2023]
Abstract
The castor oil plant represents a promising platform to produce oils with industrial applications. However, its use in biotechnology is limited by the absence of a well-established procedure to transform it, and a poor understanding of gene regulation and promoter use in this species. As such, a method has been developed to express proteins or hairpin-RNA in this plant, a method based on the direct injection of Agrobacterium into the developing endosperm of castor oil fruit, enabling different constructs and promoters to be tested. This method produces a high rate of transformation and a good proportion of viable seeds that express reporter genes for up to 20 days after infiltration (DAI). Gene expression under the control of different promoters was tested by quantitative real-time polymerase chain reaction and by directly assaying the activity of the galactouronidase reporter gene, which proved to be strongest when driven by the glycinin promoter. Constructs expressing a fatty acid elongase from Lesquerella fendleri were tested, the expression of which provoked an important increase in the lesquerolic acid in the castor oil endosperm at 5 and 10 DAI, although this fatty acid did not accumulate significantly in the final mature seeds. The nature of this response could reflect the poor availability of substrates for this enzyme. In the light of this data, the potential of this technique to test promoters and different constructs in castor oil plants and other oilseeds is discussed.
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Affiliation(s)
- Alfonso Sánchez-Álvarez
- Department of Biochemistry and Molecular Biology of Plant Products, Instituto de la Grasa (CSIC), Sevilla, Spain
| | | | - Antonio Javier Moreno-Pérez
- Department of Biochemistry and Molecular Biology of Plant Products, Instituto de la Grasa (CSIC), Sevilla, Spain
| | - Enrique Martínez-Force
- Department of Biochemistry and Molecular Biology of Plant Products, Instituto de la Grasa (CSIC), Sevilla, Spain
| | - Rafael Garcés
- Department of Biochemistry and Molecular Biology of Plant Products, Instituto de la Grasa (CSIC), Sevilla, Spain
| | - Joaquín J. Salas
- Department of Biochemistry and Molecular Biology of Plant Products, Instituto de la Grasa (CSIC), Sevilla, Spain
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Abstract
Human milk fat substitute (HMFS) is a class of structured lipid that is widely used as an ingredient in infant formulas. Like human milk fat, HMFS is characterized by enrichment of palmitoyl (C16:0) groups specifically at the middle (sn-2 or β) position on the glycerol backbone, and there is evidence that triacylglycerol (TAG) with this unusual stereoisomeric structure provides nutritional benefits. HMFS is currently made by in vitro enzyme-based catalysis because there is no appropriate biological alternative to human milk fat. Most of the fat currently used in infant formulas is obtained from plants, which exclude C16:0 from the middle position. In this study, we have modified the metabolic pathway for TAG biosynthesis in the model oilseed Arabidopsis thaliana to increase the percentage of C16:0 at the middle (vs. outer) positions by more than 20-fold (i.e., from ∼3% in wild type to >70% in our final iteration). This level of C16:0 enrichment is comparable to human milk fat. We achieved this by relocating the C16:0-specific chloroplast isoform of the enzyme lysophosphatidic acid acyltransferase (LPAT) to the endoplasmic reticulum so that it functions within the cytosolic glycerolipid biosynthetic pathway to esterify C16:0 to the middle position. We then suppressed endogenous LPAT activity to relieve competition and knocked out phosphatidylcholine:diacylglycerol cholinephosphotransferase activity to promote the flux of newly made diacylglycerol directly into TAG. Applying this technology to oilseed crops might provide a source of HMFS for infant formula.
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Falarz L, Xu Y, Singer SD, Chen G. A Fluorescence-Based Assay for Quantitative Analysis of Phospholipid:Diacylglycerol Acyltransferase Activity. Lipids 2019; 54:571-579. [PMID: 31478204 DOI: 10.1002/lipd.12190] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 08/14/2019] [Accepted: 08/15/2019] [Indexed: 12/23/2022]
Abstract
Phospholipid:diacylglycerol acyltransferase (PDAT) catalyzes the acyl-CoA-independent triacylglycerol (TAG) biosynthesis in plants and oleaginous microorganisms and thus is a key target in lipid research. The conventional in vitro PDAT activity assay involves the use of radiolabeled substrates, which, however, are expensive and demand strict regulation. In this study, a reliable fluorescence-based method using nitrobenzoxadiazole-labeled diacylglycerol (NBD-DAG) as an alternative substrate was established and subsequently used to characterize the enzyme activity and kinetics of a recombinant Arabidopsis thaliana PDAT1 (AtPDAT1). We also demonstrate that the highly toxic benzene used in typical PDAT assays can be substituted with diethyl ether without affecting the formation rate of NBD-TAG. Overall, this method works well with a broad range of PDAT protein content and shows linear correlation with the conventional method with radiolabeled substrates, and thus may be applicable to PDAT from various plant and microorganism species.
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Affiliation(s)
- Lucas Falarz
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada, T6G 2P5.,Department of Biological Sciences, University of Manitoba, Winnipeg, MB, Canada, R3T 2N2
| | - Yang Xu
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada, T6G 2P5
| | - Stacy D Singer
- Agriculture and Agri-Food Canada, Lethbridge Research and Development Centre, Lethbridge, AB, Canada, T1J 4B1
| | - Guanqun Chen
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada, T6G 2P5.,Department of Biological Sciences, University of Manitoba, Winnipeg, MB, Canada, R3T 2N2
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50
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Yue XH, Chen WC, Wang ZM, Liu PY, Li XY, Lin CB, Lu SH, Huang FH, Wan X. Lipid Distribution Pattern and Transcriptomic Insights Revealed the Potential Mechanism of Docosahexaenoic Acid Traffics in Schizochytrium sp. A-2. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:9683-9693. [PMID: 31379160 DOI: 10.1021/acs.jafc.9b03536] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Schizochytrium sp. A-2 is a heterotrophic marine fungus used for the commercial production of docosahexaenoic acid (DHA). However, the pattern of the distribution of DHA and how DHA is channeled into phospholipid (PL) and triacylglycerol (TAG) are unknown. In this study, we systematically analyzed the distribution of DHA in TAG and PL during the growth of the cell. The migration of DHA from PL to TAG was presumed during the fermentation cycle. DHA and docosapentaenoic acid were accumulated in both TAG and phosphatidylcholine (PC), whereas eicosapentaenoic acid was mainly deposited in PC. RNA seq revealed that malic enzyme may provide lipogenic NADPH. In addition, long-chain acyl-CoA synthase and acyl-CoA:lysophosphatidylcholine acyltransferase may participate in the accumulation of DHA in PL. No phosphatidylcholine:diacylglycerol cholinephosphotransferase was identified from the genome sequence. In contrast, phospholipid:diacylglycerol acyltransferase-mediated acyl-CoA-independent TAG synthesis pathway and phospholipase C may contribute to the channeling of DHA from PC to TAG.
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Affiliation(s)
- Xiu-Hong Yue
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences , Wuhan 430062 , P. R. China
| | - Wen-Chao Chen
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences , Wuhan 430062 , P. R. China
- Key Laboratory of Biology and Genetic Improvement of Oil Crops , Ministry of Agriculture , Wuhan 430062 , P. R. China
- Oil Crops and Lipids Process Technology National & Local Joint Engineering Laboratory , Wuhan 430062 , P. R. China
- Hubei Key Laboratory of Lipid Chemistry and Nutrition , Wuhan 430062 , P. R. China
| | - Zhi-Ming Wang
- CABIO Biotech (Wuhan) Co., Ltd , Wuhan 430223 , P. R. China
| | - Peng-Yang Liu
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences , Wuhan 430062 , P. R. China
| | - Xiang-Yu Li
- CABIO Biotech (Wuhan) Co., Ltd , Wuhan 430223 , P. R. China
| | - Chu-Bin Lin
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences , Wuhan 430062 , P. R. China
| | - Shu-Huan Lu
- CABIO Biotech (Wuhan) Co., Ltd , Wuhan 430223 , P. R. China
| | - Feng-Hong Huang
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences , Wuhan 430062 , P. R. China
- Key Laboratory of Biology and Genetic Improvement of Oil Crops , Ministry of Agriculture , Wuhan 430062 , P. R. China
- Oil Crops and Lipids Process Technology National & Local Joint Engineering Laboratory , Wuhan 430062 , P. R. China
- Hubei Key Laboratory of Lipid Chemistry and Nutrition , Wuhan 430062 , P. R. China
| | - Xia Wan
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences , Wuhan 430062 , P. R. China
- Key Laboratory of Biology and Genetic Improvement of Oil Crops , Ministry of Agriculture , Wuhan 430062 , P. R. China
- Oil Crops and Lipids Process Technology National & Local Joint Engineering Laboratory , Wuhan 430062 , P. R. China
- Hubei Key Laboratory of Lipid Chemistry and Nutrition , Wuhan 430062 , P. R. China
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