Nature’s Scientific Reports draws attention to genetically modified (GM) Camelina sativa and its role in producing the omega-3 long-chain polyunsaturated fatty acids, EPA (eicosapentaenoic acid) and the even longer chain DHA (docosahexaenoic acid).
The team from Rothamsted Research institution in the UK succeeded in growing this transgenic plant in the field on a commercial scale, identifying its potential for even greater oil storage within the plant’s seeds.
“Demonstrating that our GM camelina works in the field under real world conditions confirms the promise of our approach,” said professor Johnathan Napier, omega-3 Camelina programme leader at Rothamsted, who also led the research.
“Having a viable land-based source of omega-3 fish oils can really address the ever-increasing demand for these healthy fatty acids”
The latest research raises longstanding issues of fish oil quality and supply. EPA and DHA have long been associated in countering the global rise in cardiovascular disease and metabolic disorders.
However, concerns surrounding contamination of marine-derived fish oils such as that from heavy metals, dioxins and polychlorinated biphenyls (PCBs), have taken the shine off their health benefits.
In addition, growing demand for these fatty acids, especially from the aquaculture sector, has so pressurised supplies that farmed fish now contain less of these nutrients than a decade ago.
In camelina, one of Europe’s oldest oil seed crops, the team believe the cultivation technique is free from this contamination, representing a potentially more sustainable, less environmentally intrusive production route.
Providing the right nutrients
“Concerns are rising that food security is not just about providing enough calories for people, it’s also about providing the right nutrients,” added Dr Les Firbank, professor in sustainable agriculture at the University of Leeds-
“The news that we may be able to produce these compounds at a commercial scale from crops is therefore really exciting, and demonstrates the potential for modern biology to address the challenges of providing us with healthy nutrition.”
In collaboration with colleagues from the University of North Texas, the work details previous research on GM camelina in 2015 that confirmed older results in 2014.
It also shows how the team was able to reduce the level of unnecessary omega-6 fatty acids in the transgenic seeds to match more closely the mix in marine fish oils.
MALDI- mass spectrometry imaging was used to identify discrete tissue-types in the seed in which these non-native fatty acids preferentially accumulated.
Currently, valuable EPA & DHA accumulate in only the radicle of the transgenic seed leaving the majority of the seed’s cotyledon untapped and empty of LC-PUFAs.
The team also found the activity of the P. sojae Δ12-desturase enzyme was crucial in controlling the ratio of Oleic Acid (OA) and omega-6 linoleic acid (LA) in the seeds of the transgenic Camelina line.
By dispensing of the Δ12-desturase activity ratios of omega-3/omega-6, fatty acids could be tailored for the end-use of plant-derived fatty acids in aquaculture.
GM debate
“It is very significant that we can tailor camelina oil to accumulate omega-3 fish oils and that this trait is stable in field-grown plants,” said Dr Napier.
“Our insights into fatty acid accumulation across the seed points towards further opportunities to optimise this,” he added.
Along with fish oil quality and supply, the research also brings genetic modification as a tool in meeting escalating food production demands.
Dr Sarah Schmidt, research scientist and Marie Curie fellow at The Sainsbury Laboratory, questioned the need for GM crops to feed a growing population.
“GM plants are often debated in the context of food security,” she said. “This study shows that GM plants can also simply satisfy a specialized market need.
“In this case, the demand of the aquaculture sector to replace fish oil in aquafeed diets with an alternative source of omega-3 fatty acids.”
Whether the gains will allow them to see past a GM label is another thing said Dr Penny Hundleby, senior scientist from the John Innes Centre, who otherwise thought the findings, “demonstrated the science was there to better utilise crops to deliver products in a more sustainable and greener way”.
Source: Nature Scientific Reports
Published online ahead of print: doi:10.1038/s41598-017-06838-0
“Tailoring seed oil composition in the real world: optimising omega-3 long chain polyunsaturated fatty acid accumulation in transgenic Camelina sativa.”
Authors: Sarah Usher, Lihua Han, Richard Haslam, Louise Michaelson, Drew Sturtevant, Mina Aziz, Kent Chapman, Olga Sayanova & Johnathan Napier