The synthesis and accumulation of stearidonic acid in transgenic plants: a novel source of 'heart-healthy' omega-3 fatty acids

Noemi Ruiz-Lopez, Richard P. Haslam, Monica Venegas-Caleron, Tony R. Larson, Ian A. Graham, Johnathan A. Napier, Olga Sayanova

Research output: Contribution to journalArticlepeer-review


P>Dietary omega-3 polyunsaturated fatty acids have a proven role in reducing the risk of cardiovascular disease and precursor disease states such as metabolic syndrome. Although most studies have focussed on the predominant omega-3 fatty acids found in fish oils (eicosapentaenoic acid and docosahexaenoic acid), recent evidence suggests similar health benefits from their common precursor, stearidonic acid. Stearidonic acid is a Delta 6-unsaturated C18 omega-3 fatty acid present in a few plant species (mainly the Boraginaceae and Primulaceae) reflecting the general absence of Delta 6-desaturation from higher plants. Using a Delta 6-desaturase from Primula vialii, we generated transgenic Arabidopsis and linseed lines accumulating stearidonic acid in their seed lipids. Significantly, the P. vialii Delta 6-desaturase specifically only utilises alpha-linolenic acid as a substrate, resulting in the accumulation of stearidonic acid but not omega-6 gamma-linolenic acid. Detailed lipid analysis revealed the accumulation of stearidonic acid in neutral lipids such as triacylglycerol but an absence from the acyl-CoA pool. In the case of linseed, the achieved levels of stearidonic acid (13.4% of triacylglycerols) are very similar to those found in the sole natural commercial plant source (Echium spp.) or transgenic soybean oil. However, both those latter oils contain gamma-linolenic acid, which is not normally present in fish oils and considered undesirable for heart-healthy applications. By contrast, the stearidonic acid-enriched linseed oil is essentially devoid of this fatty acid. Moreover, the overall omega-3/omega-6 ratio for this modified linseed oil is also significantly higher. Thus, this nutritionally enhanced linseed oil may have superior health-beneficial properties.

Original languageEnglish
Pages (from-to)704-716
Number of pages13
JournalPlant biotechnology journal
Issue number7
Publication statusPublished - Sept 2009


  • polyunsaturated fatty acids
  • desaturase
  • elongase
  • transgenic crop
  • omega-3
  • FISH
  • OIL
  • COA

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