Tailoring plant lipid composition: designer oilseeds come of age.

Plant neutral lipids such as seed oil triacylglycerols play a key role in many aspects of human life, ranging from providing essential nutrition to acting as biolubricants. There is also growing interest in using plant oils as a replacement for petrochemicals, either for fuel or as a chemical feedstock. Considerable effort has been focused on modifying the fatty acid composition of seed oils and/or increasing the levels of storage triacylglycerol. Certainly, it is now possible to successfully modify the profile of plant oils via transgenic metabolic engineering to generate something approaching a 'designer oil'. This is specifically true for the accumulation of omega-3 long chain polyunsaturated fatty acids that now stand at levels equivalent to those found in native marine organisms. However, it is equally clear that a holistic understanding of plant lipid metabolism is still lacking, mainly owing to the continually emerging complexity and interplay between pathways, recently exemplified by the identification of the ROD1 phosphatidylcholine:diacylglycerol cholinephosphotransferase involved in the channelling of unsaturated fatty acids into storage oil. The new approaches and outcomes described here will inform new paradigms and hasten the arrival of truly predictive biology in this vital field.