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Production of very long chain polyunsaturated omega-3 and omega-6 fatty acids in plants


We report the production of two very long chain polyunsaturated fatty acids, arachidonic acid (AA) and eicosapentaenoic acid (EPA), in substantial quantities in a higher plant. This was achieved using genes encoding enzymes participating in the ω3/6 Δ8-desaturation biosynthetic pathways for the formation of C20 polyunsaturated fatty acids. Arabidopsis thaliana was transformed sequentially with genes encoding a Δ9-specific elongating activity from Isochrysis galbana, a Δ8-desaturase from Euglena gracilis and a Δ5-desaturase from Mortierella alpina. Instrumental in the successful reconstitution of these C20 polyunsaturated fatty acid biosynthetic pathways was the I. galbana C18-Δ9-elongating activity, which may bypass rate-limiting steps present in the conventional Δ6-desaturase/elongase pathways. The accumulation of EPA and AA in transgenic plants is a breakthrough in the search for alternative sustainable sources of fish oils.

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Figure 1: Conventional and alternative desaturation pathways for AA and EPA.
Figure 2: GC profiles of A. thaliana leaf fatty acid methyl esters.
Figure 3: Positional analysis (by GC-MS) of the carbon double bonds of the C20 PUFAs (as their DMOX derivatives) in triple transgenic A. thaliana leaf tissues.
Figure 4: Positional analysis (by GC-MS) of the carbon double bonds of the two nonmethylene-interrupted C20 PUFAs (as their DMOX derivatives) in triple transgenic A. thaliana leaf tissues.


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The authors gratefully acknowledge financial support from BASF Plant Sciences GmbH, Germany, and the Scottish Executive Environment and Rural Affairs Department. Long Ashton Research Station (1903–2003) and Rothamsted Research receive grant in aid from the Biotechnology and Biological Sciences Research Council (BBSRC) UK.

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Correspondence to Baoxiu Qi.

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The research reported here was funded in part by BASF BmbH, Ludwigshafen, Germany.

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Qi, B., Fraser, T., Mugford, S. et al. Production of very long chain polyunsaturated omega-3 and omega-6 fatty acids in plants. Nat Biotechnol 22, 739–745 (2004).

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