Metabolic engineering of Arabidopsis to produce nutritionally important DHA in seed oil
Stan S. Robert A B D , Surinder P. Singh A C D , Xue-Rong Zhou A C D , James R. Petrie A C , Susan I. Blackburn A B , Peter M. Mansour A B , Peter D. Nichols A B , Qing Liu A C and Allan G. Green A C EA Food Futures National Research Flagship.
B CSIRO Marine Research, GPO Box 1538, Hobart, Tas. 7001, Australia.
C CSIRO Plant Industry, PO Box 1600, Canberra, ACT 2601, Australia.
D These authors contributed equally.
E Corresponding author. Email: allan.green@csiro.au
Functional Plant Biology 32(6) 473-479 https://doi.org/10.1071/FP05084
Submitted: 14 April 2005 Accepted: 29 April 2005 Published: 18 May 2005
Abstract
Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are nutritionally important long-chain (≥ C20) omega-3 polyunsaturated fatty acids (ω3 LC-PUFA) currently obtained mainly from marine sources. A set of genes encoding the fatty acid chain elongation and desaturation enzymes required for the synthesis of LC-PUFA from their C18 PUFA precursors was expressed seed-specifically in Arabidopsis thaliana. This resulted in the synthesis of DHA, the most nutritionally important ω3 LC-PUFA, for the first time in seed oils, along with its precursor EPA and the ω6 LC-PUFA arachidonic acid (ARA). The assembled pathway utilised Δ5 and Δ6 desaturases that operate on acyl-CoA substrates and led to higher levels of synthesis of LC-PUFA than previously reported with acyl-PC desaturases. This demonstrates the potential for development of land plants as alternative sources of DHA and other LC-PUFA to meet the growing demand for these nutrients.
Keywords: desaturase, DHA, elongase, EPA, genetic engineering, omega-3 fatty acid, seed oil.
Acknowledgments
This research was conducted as part of the Food Futures Flagship, one of CSIRO’s National Research Flagships. We acknowledge the expert technical assistance provided by Mina Brock, Samantha Chhe, Dion Frampton, Diana Hall, Clive Hurlstone, Bronwyn Innes and Adam White.
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