Plant Cuttings

Something fishy in the veggie patch…

Omega FA-enriched fish in GM-enhanced camelina oil could be a new non-marine source of fatty acids.
Image: Nada Meeks, www.fineartamerica.com.
Image: Nada Meeks, www.fineartamerica.com.

The ‘alpha’ category is widely regarded as the best of its kind; think of alpha (males) in the context of animal behaviour and Aldous Huxley’s Brave New World, an α+ grade on your exams or the sports cars from Alfa Romeo. But omega – right at the other end of the Greek alphabet – is also merit-worthy, especially when it’s omega fatty acids (FAs), which are polyunsaturated FAs needed for human metabolism. However, since they cannot be made de novo by the human body – and are therefore considered ‘essential’ – it is necessary to acquire them in the diet.

Two of the three essential omega FAs needed for human metabolism – Eicosapentaenoic acid (EPA) and Docosahexaenoic acid (DHA) – are derived from marine sources, such as fish. The third – alpha-Linolenic acid (ALA – which, despite its name, is still an omega fatty acid!) comes from plant products and is used in the body to produce EPA, which in turn is used to generate DHA. One way of getting your essential omegas is to consume milk produced by cows that have grazed on fresh grass/red clover, whose milk has been shown to increase in ALA as a result. But if you are milk-averse or lactose intolerant this won’t work for you. Another dietary strategy is to eat fish. However, with concerns about dwindling fish stocks, and recognising that fish themselves actually get their omegas from the algae that they have ingested, a more imaginative – and plant-based – avenue is being promoted.

Using a GMO (genetically modified organism) Noemi Ruiz-Lopez et al. have successfully demonstrated high-level accumulation of fish-oil omega-3 long-chain polyunsaturated fatty acids in a transgenic (which includes at least one gene from an alga…) oilseed crop plant. Using heterologous genes (i.e. genes from organisms different to the host crop species) the Rothamsted Research (Harpenden, UK) -based team have developed Camelina sativa (like arabidopsis, a member of the Brassicaceae) whose seeds accumulate up to 12 % EPA and 14 % DHA (which levels are equivalent to those in fish oils). On the back of expectations that this could represent a sustainable, terrestrial source of these fatty acids, Rothamsted Research has applied to Defra (the UK government’s Department for Environment, Food and Rural Affairs) ‘to conduct a field trial of Camelina plants that have been genetically modified to produce omega-3 oils that may provide health, environmental and societal benefits’. Interestingly, one of the enzymes in the 5-gene cassette used to genetically manipulate EPA levels in the plant is derived from Phytophthora infestans – the potato blight-causing oomycete (definitely NOT a fungus) which infamously caused so much devastation to the potato crop of Europe in the 19th century.  Maybe this is an opportunity for that notorious plant pest to do some good for a change! And something to ponder as you fry your naturally omega FA-enriched fish in GM-enhanced camelina oil…? Regardless, let us hope that false flax (an alternative common name for the plant) does not give false hope but, rather, provides ‘gold-of-pleasure’ (another of its common names). And that this 21st century fish oil project has more to offer than the 19th century’s over-promising, under-delivering pedlars of ‘snake oil’! Here’s a video showcasing the work at the 2014 UKPSF meeting.

[For more on the proposed GM trials, there is a dedicated Questions and Answers Section on the Rothamsted Research website. But what we really want to know is whether there is a hidden agenda to use the GM-crop to produce jet fuel for the F-22 raptor supersonic fighter aircraft, which apparently can fly very well using biofuel produced from Camelina… In which case, maybe GM stands for Go Mach – Ed.]

[Update – since this piece was originally penned, not only has the GM trial been approved but it has taken place and the crop harvested. It is anticipated that the results will be published in an open access journal later this year – Ed.]