Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

Discontinuous fatty acid elongation yields hydroxylated seed oil with improved function

Abstract

The biosynthesis of ‘unusual’ fatty acids with structures that deviate from the common C16 and C18 fatty acids has evolved numerous times in the plant kingdom. Characterization of unusual fatty acid biosynthesis has enabled increased understanding of enzyme substrate properties, metabolic plasticity and oil functionality. Here, we report the identification of a novel pathway for hydroxy fatty acid biosynthesis based on the serendipitous discovery of two C24 fatty acids containing hydroxyl groups at the 7 and 18 carbon atoms as major components of the seed oil of Orychophragmus violaceus, a China-native Brassicaceae. Biochemical and genetic evidence are presented for premature or ‘discontinuous’ elongation of a 3-OH intermediate by a divergent 3-ketoacyl-CoA (coenzyme A) synthase during a chain extension cycle as the origin of the 7-OH group of the dihydroxy fatty acids. Tribology studies revealed superior high-temperature lubricant properties for O. violaceus seed oil compared to castor oil, a high-performance vegetable oil lubricant. These findings provide a direct pathway for designing a new class of environmentally friendly lubricants and unveil the potential of O. violaceus as a new industrial oilseed crop.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: O. violaceus flowers, seeds and seed oil analyses.
Fig. 2: GC-MS analysis of unusual fatty acids in O. violaceus seeds.
Fig. 3: Elucidation of the structures of the very-long-chain dihydroxy fatty acids from O. violaceus seed oil.
Fig. 4: Analysis of FAMEs of Arabidopsis seeds engineered to express OvFAD2-2 alone or in combination with OvFAE1-1 and/or OvFAE1-2.
Fig. 5: Comparison of lubricative properties of cold-pressed O. violaceus (Ov oil) and castor oil (Castor oil).
Fig. 6: Proposed biosynthetic pathway for nebraskanic acid.

Similar content being viewed by others

References

  1. Badami, R. C. & Patil, K. B. Structure and occurrence of unusual fatty acids in minor seed oils. Prog. Lipid Res. 19, 119–153 (1980).

    Article  PubMed  CAS  Google Scholar 

  2. Smith, C. R. Occurrence of unusual fatty acids in plants. Prog. Chem. Fats Other Lipids 11, 137–177 (1971).

    Article  Google Scholar 

  3. Broun, P., Shanklin, J., Whittle, E. & Somerville, C. Catalytic plasticity of fatty acid modification enzymes underlying chemical diversity of plant lipids. Science 282, 1315–1317 (1998).

    Article  PubMed  CAS  Google Scholar 

  4. Cahoon, E. B., Lindqvist, Y., Schneider, G. & Shanklin, J. Redesign of soluble fatty acid desaturases from plants for altered substrate specificity and double bond position. Proc. Natl Acad. Sci. USA 94, 4872–4877 (1997).

  5. Cahoon, E. B. & Kinney, A. J. The production of vegetable oils with novel properties: Using genomic tools to probe and manipulate plant fatty acid metabolism. Eur. J. Lipid Sci. Technol. 107, 239–243 (2005).

    Article  CAS  Google Scholar 

  6. Dyer, J. M., Stymne, S., Green, A. G. & Carlsson, A. S. High-value oils from plants. Plant J. 54, 640–655 (2008).

    Article  PubMed  CAS  Google Scholar 

  7. Appelqvist, L.-A. Lipids in CruciferaeI. I. Fatty acid composition in seeds of some Svalöf varieties and strains of rape, turnip rape, white mustard and false flax. Acta Agric. Scand. 18, 3–21 (1968).

    Article  Google Scholar 

  8. Miller, R. W., Earle, F. R., Wolff, I. A. & Jones, Q. Search for new industrial oils. XIII. Oils from 102 species of Cruciferae. J. Amer. Oil Chem. Soc. 42, 817–821 (1965).

    Article  CAS  Google Scholar 

  9. Miwa, T. K. & Wolff, I. A. Fatty acids, fatty alcohols, wax esters, and methyl esters from Crambe abyssinica and Lunaria annua seed oils. J. Amer. Oil Chem. Soc. 40, 742–744 (1963).

    Article  CAS  Google Scholar 

  10. Jart, A. The fatty acid composition of various cruciferous seeds. J. Amer. Oil Chem. Soc. 55, 873–875 (1978).

    Article  CAS  Google Scholar 

  11. Mikolajczak, K. L., Earle, F. R. & Wolff, I. A. Search for new industrial oils. VI. Seed oils of the genus Lesquerella. J. Amer. Oil Chem. Soc. 39, 78–80 (1962).

    Article  Google Scholar 

  12. Salywon, A. M., Dierig, D. A., Rebman, J. P. & de Rodriguez, D. J. Evaluation of new Lesquerella and Physaria (Brassicaceae) oilseed germplasm. Am. J. Bot. 92, 53–62 (2005).

    Article  PubMed  Google Scholar 

  13. Luo, P., Lan, Z. Q. & Li, Z. Y. Orychophragmus violaceus, a potential edible-oil crop. Plant Breeding 113, 83–85 (1994).

    Article  Google Scholar 

  14. Zhou, L., Wu, J. & Wang, S. Orychophragmus in Wild Crop Relatives: Genomic and Breeding Resources (ed. C., Kole) 199–225 (Springer, Berlin, 2011).

  15. Li, Z.-y & Ge, X.-h Unique chromosome behavior and genetic control in Brassica × Orychophragmus wide hybrids: a review. Plant Cell Rep. 26, 701–710 (2007).

    Article  PubMed  CAS  Google Scholar 

  16. Zhao, Z.-g et al. Production and characterization of intergeneric somatic hybrids between Brassica napus and Orychophragmus violaceus and their backcrossing progenies. Plant Cell Rep. 27, 1611–1621 (2008).

    Article  PubMed  CAS  Google Scholar 

  17. Xu, C. & Li, Z. Seed quality and genetic analysis of F12 progenies from intergeneric hybrids between Brassica napus and Orychophragmus violaceus. Chinese. J. Oil Crop Sci. 33, 20–24 (2011).

    Google Scholar 

  18. Wang, R. et al. Orychophragmus violaceus L., a marginal land-based plant for biodiesel feedstock: heterogeneous catalysis, fuel properties, and potential. Energy Convers. Manag. 84, 497–502 (2014).

    Article  CAS  Google Scholar 

  19. Kwon, Y., Lee, S., Oh, D.-C. & Kim, S. Simple determination of double-bond positions in long-chain olefins by cross-metathesis. Angew Chem., Int. Ed. Engl. 50, 8275–8278 (2011).

    Article  CAS  Google Scholar 

  20. Hoye, T. R., Jeffrey, C. S. & Shao, F. Mosher ester analysis for the determination of absolute configuration of stereogenic (chiral) carbinol carbons. Nat. Protoc. 2, 2451–2458 (2007).

    Article  PubMed  CAS  Google Scholar 

  21. Wakil, S. & Bressler, R. Studies on the mechanism of fatty acid synthesis. X. Reduced triphosphopyridine nucleotide-acetoacetyl coenzyme A reductase. J. Biol. Chem. 237, 687–93 (1962).

    PubMed  CAS  Google Scholar 

  22. Dugan, R. E., Slakey, L. L. & Porter, J. W. Stereospecificity of the transfer of hydrogen from reduced nicotinamide adenine dinucleotide phosphate to the acyl chain in the dehydrogenase-catalyzed reactions of fatty acid synthesis. J. Biol. Chem. 245, 6312–6316 (1970).

    PubMed  CAS  Google Scholar 

  23. Blacklock, B. J. & Jaworski, J. G. Studies into factors contributing to substrate specificity of membrane-bound 3-ketoacyl-CoA synthases. Eur. J. Biochem. 269, 4789–4798 (2002).

    Article  PubMed  CAS  Google Scholar 

  24. Broun, P., Boddupalli, S. & Somerville, C. A bifunctional oleate 12-hydroxylase: desaturase from Lesquerella fendleri. Plant J. 13, 201–210 (1998).

    Article  PubMed  CAS  Google Scholar 

  25. Smith, M. A., Moon, H., Chowrira, G. & Kunst, L. Heterologous expression of a fatty acid hydroxylase gene in developing seeds of Arabidopsis thaliana. Planta 217, 507–516 (2003).

    Article  PubMed  CAS  Google Scholar 

  26. Cermak, S. C. et al. New crop oils—properties as potential lubricants. Ind. Crops Prod. 44, 232–239 (2013).

    Article  CAS  Google Scholar 

  27. Asadauskas, S., Perez, J. H. & Duda, J. L. Lubrication properties of castor oil–potential basestock for biodegradable lubricants. Tribol. Lubric. Technol. 53, 35 (1997).

    CAS  Google Scholar 

  28. Mobarak, H. M. et al. The prospects of biolubricants as alternatives in automotive applications. Renew. Sustain. Energy Rev. 33, 34–43 (2014).

    Article  CAS  Google Scholar 

  29. Quinchia, L. A., Delgado, M. A., Reddyhoff, T., Gallegos, C. & Spikes, H. A. Tribological studies of potential vegetable oil-based lubricants containing environmentally friendly viscosity modifiers. Tribol. Int. 69, 110–117 (2014).

    Article  CAS  Google Scholar 

  30. Loewenthal, S. H. & Moyer, D. W. Filtration effects on ball bearing life and condition in a contaminated lubricant. J. Lubric. Technol. 101, 171–176 (1979).

    Article  Google Scholar 

  31. Bach, L. et al. The very-long-chain hydroxy fatty acyl-CoA dehydratase PASTICCINO2 is essential and limiting for plant development. Proc. Natl Acad. Sci. USA 105, 14727–14731 (2008).

  32. Gmeiner, J. & Martin, H. H. Phospholipid and lipopolysaccharide in Proteus mirabilis and its stable protoplast L-form. Difference in content and fatty acid composition. Eur. J .Biochem. 67, 487–494 (1976).

    Article  PubMed  CAS  Google Scholar 

  33. Yano, I., Ohno, Y., Masui, M., Kato, K. & Yabuuchi, E. Occurrence of 2- and 3-hydroxy fatty acids in high concentrations in the extractable and bound lipids of Flavobacterium meningosepticum and Flavobacterium IIb. Lipids 11, 685–688 (1976).

    Article  PubMed  CAS  Google Scholar 

  34. Venter, P. et al. Production of 3R-hydroxy-polyenoic fatty acids by the yeast Dipodascopsis uninucleata. Lipids 32, 1277–1283 (1997).

    Article  PubMed  CAS  Google Scholar 

  35. Jin, S. J., Hoppel, C. L. & Tserng, K. Y. Incomplete fatty acid oxidation. The production and epimerization of 3-hydroxy fatty acids. J. Biol. Chem. 267, 119–125 (1992).

    PubMed  CAS  Google Scholar 

  36. Busta, L. & Jetter, R. Moving beyond the ubiquitous: the diversity and biosynthesis of specialty compounds in plant cuticular waxes. Phytochem. Rev. https://doi.org/10.1007/s11101-017-9542-0 (2017).

  37. Moon, H., Smith, M. A. & Kunst, L. A condensing enzyme from the seeds of Lesquerella fendleri that specifically elongates hydroxy fatty acids. Plant Physiol. 127, 1635–1643 (2001).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  38. Cronan, J. E. & Thomas, J. Bacterial fatty acid synthesis and its relationships with polyketide synthetic pathways. Methods Enzymol. 459, 395–433 (2009).

  39. Kass, L. R. & Bloch, K. On the enzymatic synthesis of unsaturated fatty acids in Escherichia coli. Proc. Natl Acad. Sci. USA 58, 1168–1173 (1967).

  40. D’Agnolo, G., Rosenfeld, I. S. & Vagelos, P. R. Multiple forms of β-ketoacyl-acyl carrier protein synthetase in Escherichia coli. J. Biol. Chem. 250, 5289–5294 (1975).

    PubMed  Google Scholar 

  41. Cermak, S. C. & Isbell, T. A. Improved oxidative stability of estolide esters. Ind. Crops Prod. 18, 223–230 (2003).

    Article  CAS  Google Scholar 

  42. Isbell, T. A., Edgcomb, M. R. & Lowery, B. A. Physical properties of estolides and their ester derivatives. Ind. Crops Prod. 13, 11–20 (2001).

    Article  CAS  Google Scholar 

  43. Soni, S. & Agarwal, M. Lubricants from renewable energy sources – a review. Green Chem. Lett. Rev. 7, 359–382 (2014).

    Article  CAS  Google Scholar 

  44. Bligh, E. G. & Dyer, W. J. A rapid method of total lipid extraction and purification. Can. J. Biochem. Physiol. 37, 911–917 (1959).

    Article  PubMed  CAS  Google Scholar 

  45. Cahoon, E. B. et al. Conjugated fatty acids accumulate to high levels in phospholipids of metabolically engineered soybean and Arabidopsis seeds. Phytochemistry 67, 1166–1176 (2006).

    Article  PubMed  CAS  Google Scholar 

  46. von Rudloff, E. Periodate-permanganate oxidations. IV. Determination of the position of double bonds in unsaturated fatty acids and esters. J. Amer. Oil .Chem. Soc. 33, 126–128 (1956).

    Article  Google Scholar 

  47. Boeckman, R. K., Shao, P., Mullins, J. J., Minbiole, K. P. & Smith, A. B. The Dess–Martin periodinane: 1,1,1-triacetoxy-1,1- dihydro-1,2-benziodoxol-3(1H)-one. Organic Syntheses 77, 141 (2000).

    Article  CAS  Google Scholar 

  48. Brown, H. C. & Bhat, K. S. Hydroboration. 77. Hydroboration of cyclic dienes with representative hydroborating agents. J. Organic Chem. 51, 445–449 (1986).

    Article  CAS  Google Scholar 

  49. Donohoe, T. J. et al. Scope of the directed dihydroxylation: application to cyclic homoallylic alcohols and trihaloacetamides. Organic Biomolec. Chem. 1, 2173–2186 (2003).

    Article  CAS  Google Scholar 

  50. Kim, J. et al. Arabidopsis 3-ketoacyl-coenzyme Asynthase9 is involved in the synthesis of tetracosanoic acids as precursors of cuticular waxes, suberins, sphingolipids, and phospholipids. Plant Physiol. 162, 567–580 (2013).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  51. Kim, H. J. 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. J. Expt Bot. 66, 4251–4265 (2015).

    Article  CAS  Google Scholar 

  52. Li, X. et al. A large insertion in bHLH transcription factor BrTT8 resulting in yellow seed coat in Brassica rapa. PLoS ONE 7, e44145 (2012).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  53. Edgar, R. C. MUSCLE: multiple sequence alignment with high accuracy and high throughput. Nucleic Acids Res. 32, 1792–1797 (2004).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  54. Castresana, J. Selection of conserved blocks from multiple alignments for their use in phylogenetic analysis. Mol. Biol. Evol. 17, 540–52 (2000).

    Article  PubMed  CAS  Google Scholar 

  55. Schliep, K. P. Phangorn: phylogenetic analysis in R. Bioinformatics 27, 592–3 (2011).

    Article  PubMed  CAS  Google Scholar 

  56. Cahoon, E. B. & Kinney, A. J. Dimorphecolic acid is synthesized by the coordinate activities of two divergent Δ12-oleic acid desaturases. J. Biol. Chem. 279, 12495–12502 (2004).

    Article  PubMed  CAS  Google Scholar 

  57. Nguyen, H. T. et al. Camelina seed transcriptome: a tool for meal and oil improvement and translational research. Plant Biotechnol. J. 11, 759–769 (2013).

    Article  PubMed  CAS  Google Scholar 

  58. Clough, S. J. & Bent, A. F. Floral dip: a simplified method for Agrobacterium-mediated transformation of Arabidopsis thaliana. Plant J. 16, 735–743 (1998).

    Article  PubMed  CAS  Google Scholar 

Download references

Acknowledgements

We thank the National Natural Science Foundation of China (grant number 31370286) and Fundamental Research Funds for the Central Universities (programme number 2662015PY12) for support to C.Z. and the National Science Foundation (Plant Genome IOS-13-39385) and Huazhong Agricultural University Scientific and Technological Self-Innovation Foundation (programme number 2015RC010) for support to E.B.C. NMR and LC/MS instrumentation at IUPUI were acquired with funding from the NSF (grant numbers CHE-0619254 and DBI-0821661, R.E.M.). A.M.T. appreciates support of the NSF (MCB-0919938, R.E.M.) and the Department of Chemistry and Chemical Biology, IUPUI. We thank M.Morton (University of Nebraska-Lincoln) for assistance with preliminary NMR studies, S.Stymne and J.Lindberg Yilmaz (ScanBiRes) for conducting fatty acid elongation assays, and E.Moriyama and A.Voshall (University of Nebraska-Lincoln) for transcriptome assembly and mining.

Author information

Authors and Affiliations

Authors

Contributions

X.L., A.M.T., K.D.C., D.B., C.Z., R.E.M. and E.B.C. designed the research. X.L., A.M.T., A.S., J.L., R.E.C., W.Z., L.B., C.Z., R.E.M. and E.B.C. performed the research. Z.L. provided novel research materials and contributed to the research conception. X.L., A.M.T., J.L., R.E.C., K.D.C., D.B., C.Z., R.E.M. and E.B.C. analysed the data. X.L., A.M.T., J.L., K.D.C, D.B., C.Z., R.E.M. and E.B.C. wrote the manuscript.

Corresponding authors

Correspondence to Chunyu Zhang, Robert E. Minto or Edgar B. Cahoon.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary Tables 1 and 2, Supplementary Figures 1–11, and Supplementary Notes 1 and 2.

Reporting Summary

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Li, X., Teitgen, A.M., Shirani, A. et al. Discontinuous fatty acid elongation yields hydroxylated seed oil with improved function. Nature Plants 4, 711–720 (2018). https://doi.org/10.1038/s41477-018-0225-7

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41477-018-0225-7

This article is cited by

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing