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

Plant Biotechnol J. 2009 Sep;7(7):704-16. doi: 10.1111/j.1467-7652.2009.00436.x.


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 Delta6-unsaturated C18 omega-3 fatty acid present in a few plant species (mainly the Boraginaceae and Primulaceae) reflecting the general absence of Delta6-desaturation from higher plants. Using a Delta6-desaturase from Primula vialii, we generated transgenic Arabidopsis and linseed lines accumulating stearidonic acid in their seed lipids. Significantly, the P. vialiiDelta6-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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chromatography, Gas
  • Fatty Acid Desaturases / genetics
  • Fatty Acid Desaturases / physiology
  • Fatty Acids, Omega-3 / biosynthesis
  • Fatty Acids, Omega-3 / genetics
  • Fatty Acids, Omega-3 / metabolism*
  • Gas Chromatography-Mass Spectrometry
  • Linseed Oil / metabolism
  • Plants, Genetically Modified / genetics
  • Plants, Genetically Modified / metabolism*
  • Triglycerides / metabolism
  • alpha-Linolenic Acid / metabolism


  • Fatty Acids, Omega-3
  • Triglycerides
  • alpha-Linolenic Acid
  • Linseed Oil
  • Fatty Acid Desaturases
  • stearidonic acid