Metabolic Engineering a Model Oilseed Camelina sativa for the Sustainable Production of High-Value Designed Oils

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.

[1]  Doug K. Allen,et al.  Phospholipase Dζ Enhances Diacylglycerol Flux into Triacylglycerol1[OPEN] , 2017, Plant Physiology.

[2]  Daniel F. Voytas,et al.  A CRISPR/Cas9 Toolbox for Multiplexed Plant Genome Editing and Transcriptional Regulation1[OPEN] , 2015, Plant Physiology.

[3]  Peter D. Nichols,et al.  Metabolic Engineering Camelina sativa with Fish Oil-Like Levels of DHA , 2014, PloS one.

[4]  Joshua K Young,et al.  Targeted Mutagenesis, Precise Gene Editing, and Site-Specific Gene Insertion in Maize Using Cas9 and Guide RNA[OPEN] , 2015, Plant Physiology.

[5]  Yanpeng Wang,et al.  CRISPR/Cas Genome Editing and Precision Plant Breeding in Agriculture. , 2019, Annual review of plant biology.

[6]  J. Napier,et al.  Tailoring seed oil composition in the real world: optimising omega-3 long chain polyunsaturated fatty acid accumulation in transgenic Camelina sativa , 2017, Scientific Reports.

[7]  R. Dahlstrom,et al.  Challenges and opportunities , 2021, Foundations of a Sustainable Economy.

[8]  S. Guy,et al.  Camelina: adaptation and performance of genotypes. , 2014 .

[9]  S. Bansal,et al.  Camelina sativa: An ideal platform for the metabolic engineering and field production of industrial lipids. , 2016, Biochimie.

[10]  J. Napier,et al.  Successful high-level accumulation of fish oil omega-3 long-chain polyunsaturated fatty acids in a transgenic oilseed crop , 2013, The Plant journal : for cell and molecular biology.

[11]  J. Ohlrogge,et al.  Isolation of a Gene Encoding a 1,2-Diacylglycerol-sn-acetyl-CoA Acetyltransferase from Developing Seeds of Euonymus alatus* , 2005, Journal of Biological Chemistry.

[12]  Jian‐Kang Zhu,et al.  The CRISPR/Cas9 system produces specific and homozygous targeted gene editing in rice in one generation. , 2014, Plant biotechnology journal.

[13]  N. Patron,et al.  Induction of targeted, heritable mutations in barley and Brassica oleracea using RNA-guided Cas9 nuclease , 2015, Genome Biology.

[14]  Anders S Carlsson,et al.  High-value oils from plants. , 2008, The Plant journal : for cell and molecular biology.

[15]  Andrew G. Sharpe,et al.  The emerging biofuel crop Camelina sativa retains a highly undifferentiated hexaploid genome structure , 2014, Nature Communications.

[16]  S. Filichkin,et al.  New FATB thioesterases from a high‐laurate Cuphea species: Functional and complementation analyses , 2006 .

[17]  F. Zanetti,et al.  Challenges and opportunities for new industrial oilseed crops in EU-27: A review , 2013 .

[18]  H. Puchta,et al.  Plant breeding at the speed of light: the power of CRISPR/Cas to generate directed genetic diversity at multiple sites , 2019, BMC Plant Biology.

[19]  Aaron Reba,et al.  Genome-Wide Association Study of Arabidopsis thaliana Identifies Determinants of Natural Variation in Seed Oil Composition. , 2016, The Journal of heredity.

[20]  J. Napier,et al.  Tailoring the composition of novel wax esters in the seeds of transgenic Camelina sativa through systematic metabolic engineering , 2017, Plant biotechnology journal.

[21]  Zhongsen Li,et al.  Cas9-Guide RNA Directed Genome Editing in Soybean[OPEN] , 2015, Plant Physiology.

[22]  Karen Bohmert-Tatarev,et al.  Camelina sativa, an oilseed at the nexus between model system and commercial crop , 2018, Plant Cell Reports.

[23]  J. Ohlrogge,et al.  Metabolic engineering of oilseed crops to produce high levels of novel acetyl glyceride oils with reduced viscosity, freezing point and calorific value. , 2015, Plant biotechnology journal.

[24]  Lixia Yuan,et al.  Characterisation of phospholipid: diacylglycerol acyltransferases (PDATs) from Camelina sativa and their roles in stress responses , 2017, Biology Open.

[25]  J. Browse,et al.  Castor Phospholipid:Diacylglycerol Acyltransferase Facilitates Efficient Metabolism of Hydroxy Fatty Acids in Transgenic Arabidopsis1[W][OA] , 2010, Plant Physiology.

[26]  E. Cahoon,et al.  Transgenic Production of Epoxy Fatty Acids by Expression of a Cytochrome P450 Enzyme from Euphorbia lagascaeSeed , 2002, Plant Physiology.

[27]  Runzhi Li,et al.  Biosynthesis and metabolic engineering of palmitoleate production, an important contributor to human health and sustainable industry. , 2012, Progress in lipid research.

[28]  Chaofu Lu,et al.  Towards the synthetic design of camelina oil enriched in tailored acetyl-triacylglycerols with medium-chain fatty acids , 2018, Journal of experimental botany.

[29]  E. Cahoon,et al.  Disruption of plastid acyl:acyl carrier protein synthetases increases medium chain fatty acid accumulation in seeds of transgenic Arabidopsis , 2013, FEBS letters.

[30]  J. Napier,et al.  Transgenic plants as a sustainable, terrestrial source of fish oils , 2015, European journal of lipid science and technology : EJLST.

[31]  Aldo R. Boccaccini,et al.  Engineering of Metabolic Pathways by Artificial Enzyme Channels , 2015, Front. Bioeng. Biotechnol..

[32]  Chaofu Lu,et al.  New frontiers in oilseed biotechnology: meeting the global demand for vegetable oils for food, feed, biofuel, and industrial applications. , 2011, Current opinion in biotechnology.

[33]  Runzhi Li,et al.  Vernonia DGATs increase accumulation of epoxy fatty acids in oil. , 2010, Plant biotechnology journal.

[34]  I. Hwang,et al.  Map-based cloning of a gene controlling omega-3 fatty acid desaturation in Arabidopsis. , 1992, Science.

[35]  J. Napier,et al.  An alternative pathway for the effective production of the omega‐3 long‐chain polyunsaturates EPA and ETA in transgenic oilseeds , 2015, Plant biotechnology journal.

[36]  Chaofu Lu,et al.  A Phospholipase C-Like Protein From Ricinus communis Increases Hydroxy Fatty Acids Accumulation in Transgenic Seeds of Camelina sativa , 2018, Front. Plant Sci..

[37]  K. Falk,et al.  Agronomic and seed quality evaluation of Camelina sativa in western Canada , 2006 .

[38]  Wei Liu,et al.  A Robust CRISPR/Cas9 System for Convenient, High-Efficiency Multiplex Genome Editing in Monocot and Dicot Plants. , 2015, Molecular plant.

[39]  E. Gontier,et al.  Identification of a potential bottleneck in branched chain fatty acid incorporation into triacylglycerol for lipid biosynthesis in agronomic plants. , 2009, Biochimie.

[40]  K. Mockaitis,et al.  Camelina seed transcriptome: a tool for meal and oil improvement and translational research. , 2013, Plant biotechnology journal.

[41]  O. Dhankher,et al.  Engineering Camelina sativa (L.) Crantz for enhanced oil and seed yields by combining diacylglycerol acyltransferase1 and glycerol‐3‐phosphate dehydrogenase expression , 2017, Plant biotechnology journal.

[42]  K. McVay,et al.  Camelina Yield Response to Different Plant Populations under Dryland Conditions , 2011 .

[43]  J. Schwender,et al.  Expression of a Lychee PHOSPHATIDYLCHOLINE:DIACYLGLYCEROL CHOLINEPHOSPHOTRANSFERASE with an Escherichia coli CYCLOPROPANE SYNTHASE Enhances Cyclopropane Fatty Acid Accumulation in Camelina Seeds. , 2019, Plant physiology.

[44]  J. Ohlrogge,et al.  Acyl-Lipid Metabolism , 2013, The arabidopsis book.

[45]  Josef Zubr,et al.  Oil-seed crop: Camelina sativa , 1997 .

[46]  Chaofu Lu,et al.  Metabolic engineering of hydroxy fatty acid production in plants: RcDGAT2 drives dramatic increases in ricinoleate levels in seed oil. , 2008, Plant biotechnology journal.

[47]  M. Suh,et al.  Overexpression of Arabidopsis MYB96 confers drought resistance in Camelina sativa via cuticular wax accumulation , 2014, Plant Cell Reports.

[48]  Chaofu Lu,et al.  Generation of transgenic plants of a potential oilseed crop Camelina sativa by Agrobacterium-mediated transformation , 2008, Plant Cell Reports.

[49]  Chaofu Lu,et al.  The Phosphatidylcholine Diacylglycerol Cholinephosphotransferase Is Required for Efficient Hydroxy Fatty Acid Accumulation in Transgenic Arabidopsis1[W][OA] , 2012, Plant Physiology.

[50]  Chaofu Lu,et al.  A fatty acid condensing enzyme from Physaria fendleri increases hydroxy fatty acid accumulation in transgenic oilseeds of Camelina sativa , 2014, Planta.

[51]  E. Cahoon,et al.  Production of high levels of poly-3-hydroxybutyrate in plastids of Camelina sativa seeds. , 2015, Plant biotechnology journal.

[52]  L. Gissot,et al.  Selective gene dosage by CRISPR‐Cas9 genome editing in hexaploid Camelina sativa , 2017, Plant biotechnology journal.

[53]  J. Napier,et al.  Synthetic redesign of plant lipid metabolism , 2016, The Plant journal : for cell and molecular biology.

[54]  Edgar B. Cahoon,et al.  Camelina: A designer biotech oilseed crop , 2011 .

[55]  J. Shanklin,et al.  Modulating seed β-ketoacyl-acyl carrier protein synthase II level converts the composition of a temperate seed oil to that of a palm-like tropical oil , 2007, Proceedings of the National Academy of Sciences.

[56]  Tim Iven,et al.  Synthesis of oleyl oleate wax esters in Arabidopsis thaliana and Camelina sativa seed oil. , 2016, Plant biotechnology journal.

[57]  E. Cahoon,et al.  Significant enhancement of fatty acid composition in seeds of the allohexaploid, Camelina sativa, using CRISPR/Cas9 gene editing , 2017, Plant biotechnology journal.

[58]  J. Napier,et al.  A nutritionally-enhanced oil from transgenic Camelina sativa effectively replaces fish oil as a source of eicosapentaenoic acid for fish , 2015, Scientific Reports.

[59]  Chaofu Lu,et al.  Seed-specific suppression of ADP-glucose pyrophosphorylase in Camelina sativa increases seed size and weight , 2018, Biotechnology for Biofuels.

[60]  H. Abdel-Haleem,et al.  Genome-wide association study (GWAS) of leaf cuticular wax components in Camelina sativa identifies genetic loci related to intracellular wax transport , 2019, BMC Plant Biology.

[61]  R. Garcés,et al.  Acyl-ACP thioesterases from Camelina sativa: cloning, enzymatic characterization and implication in seed oil fatty acid composition. , 2014, Phytochemistry.

[62]  Jian Zhang,et al.  LEAFY COTYLEDON1 Is a Key Regulator of Fatty Acid Biosynthesis in Arabidopsis1[C][W][OA] , 2008, Plant Physiology.

[63]  J. Ohlrogge,et al.  A distinct DGAT with sn-3 acetyltransferase activity that synthesizes unusual, reduced-viscosity oils in Euonymus and transgenic seeds , 2010, Proceedings of the National Academy of Sciences.

[64]  E. Farmer,et al.  Fatty acid signaling in Arabidopsis , 1998, Planta.

[65]  K. Athenstaedt,et al.  The life cycle of neutral lipids: synthesis, storage and degradation , 2006, Cellular and Molecular Life Sciences CMLS.

[66]  Yasuhiro Ito,et al.  Development and regulation of pedicel abscission in tomato , 2015, Front. Plant Sci..

[67]  Zhaohui Hu,et al.  Accumulation of medium-chain, saturated fatty acyl moieties in seed oils of transgenic Camelina sativa , 2017, PloS one.

[68]  Lixia Yuan,et al.  Spatio-temporal expression and stress responses of DGAT1, DGAT2 and PDAT responsible for TAG biosynthesis in Camelina sativa - , 2017 .

[69]  K. Mockaitis,et al.  Toward production of jet fuel functionality in oilseeds: identification of FatB acyl-acyl carrier protein thioesterases and evaluation of combinatorial expression strategies in Camelina seeds , 2015, Journal of experimental botany.

[70]  J. Ohlrogge,et al.  Field production, purification and analysis of high-oleic acetyl-triacylglycerols from transgenic Camelina sativa , 2015 .

[71]  J. Browse,et al.  The pathway of triacylglycerol synthesis through phosphatidylcholine in Arabidopsis produces a bottleneck for the accumulation of unusual fatty acids in transgenic seeds. , 2011, The Plant journal : for cell and molecular biology.

[72]  Zhukuan Cheng,et al.  Clonal seeds from hybrid rice by simultaneous genome engineering of meiosis and fertilization genes , 2019, Nature Biotechnology.

[73]  K. Chapman,et al.  Two Acyltransferases Contribute Differently to Linolenic Acid Levels in Seed Oil1[OPEN] , 2017, Plant Physiology.

[74]  Jun Li,et al.  Targeted genome modification of crop plants using a CRISPR-Cas system , 2013, Nature Biotechnology.

[75]  Patrik R. Jones,et al.  Renewable jet fuel. , 2014, Current opinion in biotechnology.

[76]  R. C. Badami,et al.  Structure and occurrence of unusual fatty acids in minor seed oils. , 1980, Progress in lipid research.

[77]  E. Cahoon,et al.  Engineering oilseeds for sustainable production of industrial and nutritional feedstocks: solving bottlenecks in fatty acid flux. , 2007, Current opinion in plant biology.

[78]  D. Voytas,et al.  Generation and Inheritance of Targeted Mutations in Potato (Solanum tuberosum L.) Using the CRISPR/Cas System , 2015, PloS one.

[79]  E. Cahoon,et al.  Combinatorial Effects of Fatty Acid Elongase Enzymes on Nervonic Acid Production in Camelina sativa , 2015, PloS one.

[80]  J. Forment,et al.  GoldenBraid 2.0: A Comprehensive DNA Assembly Framework for Plant Synthetic Biology1[C][W][OA] , 2013, Plant Physiology.

[81]  Chaofu Lu,et al.  Mutagenesis of the FAE1 genes significantly changes fatty acid composition in seeds of Camelina sativa. , 2018, Plant physiology and biochemistry : PPB.

[82]  T. Clemente,et al.  Redirection of metabolic flux for high levels of omega-7 monounsaturated fatty acid accumulation in camelina seeds. , 2015, Plant biotechnology journal.

[83]  C. Eynck,et al.  Camelina as a sustainable oilseed crop: Contributions of plant breeding and genetic engineering , 2015, Biotechnology journal.

[84]  V. Kruys,et al.  Guidelines for optimized gene knockout using CRISPR/Cas9. , 2019, BioTechniques.