Metabolic Engineering for Synthesis of Omega-3 Long Chain Polyunsaturated Fatty Acids in Transgenic Plants and Algae
Conference Recording Dec 10, 2013
About the Speaker
Professor Johnathan A. Napier’s research on the biosynthesis of polyunsaturated fatty acids has delivered some of the key advances in the last 15 years, including the functional characterisation of the omega-3 long chain PUFA biosynthetic pathway and its heterologous reconstitution in transgenic plants. Johnathan obtained his BSc from the University of Nottingham, followed by a PhD in plant biochemistry from King’s College, London. He carried out post-doctoral research in the Department of Plant Sciences, University of Cambridge, then taking up a position at Long Ashton Research Station in Bristol. His research group relocated to Rothamsted Research in 2003 where he is currently Institute Assistant Director and Programme Leader. Johnathan is also an Affiliated Lecturer at the University of Cambridge and Visiting Professor at the University of Nottingham.AbstractWe have been evaluating the possibility of producing omega-3 LC-PUFAs in different transgenic hosts, to provide a sustainable source of these important nutrients. Attempts to metabolically engineer plants with the primary biosynthetic pathway for LC-PUFAs has been carried out in both model plants and crop species, allowing insights into factors constraining the accumulation of these fatty acids. Specifically, a generic bottleneck resides within the primary LC-PUFA biosynthetic pathway as a result of the “substrate dichotomy” between the lipid-dependent desaturases and the acyl-CoA-dependent elongases which catalyze the primary reactions. This bottleneck can be overcome through the use of acyl-CoA dependent desaturase, though not without impact on phospholipid composition. The use of lipidomic analyses have allowed us to identify further interventions in this pathway, ultimately leading to the production of a transgenic oilseed crop which contains up to 30% omega-3 LC-PUFAs in seed oil.
Analogous experiments have been carried out in transgenic microalgae, with the goal of enhancing and optimising the endogenous accumulation of EPA and DHA. Recent results from both systems will be presented.