Abstract

Metabolic Engineering for Synthesis of Omega-3 Long Chain Polyunsaturated Fatty Acids in Transgenic Plants and Algae

Johnathan Napier, Principal Investigator, Rothamsted Research

We 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.