Transgenic plants as a sustainable, terrestrial source of fish oils

An alternative, sustainable source of omega-3 long chain polyunsaturated fatty acids is widely recognized as desirable, helping to reduce pressure on current sources (wild capture fisheries) and providing a de novo source of these health beneficial fatty acids. This review will consider the efforts and progress to develop transgenic plants as terrestrial sources of omega-3 fish oils, focusing on recent developments and the possible explanations for advances in the field. We also consider the utility of such a source for use in aquaculture, since this industry is the major consumer of oceanic supplies of omega-3 fish oils. Given the importance of the aquaculture industry in meeting global requirements for healthy foodstuffs, an alternative source of omega-3 fish oils represents a potentially significant breakthrough for this production system. Transgenic Camelina seeds engineered to accumulate the omega-3 fatty acids EPA and DHA, represent a sustainable alternative to fish oils

Field trial evaluation of the accumulation of omega-3 long chain polyunsaturated fatty acids in transgenic Camelina sativa: making fish oil substitutes in plants

6 páginas, 2 figurasThe global consumption of fish oils currently exceeds one million tonnes, with the natural de novo source of these important fatty acids forming the base of marine foodwebs. Here we describe the first field-based evaluation of a terrestrial source of these essential nutrients, synthesised in the seeds of transgenic Camelina sativa plants via the heterologous reconstitution of the omega-3 long chain polyunsaturated fatty acid biosynthetic pathway. Our data demonstrate the robust nature of this novel trait, and the feasibility of making fish oils in genetically modified crops. Moreover, to our knowledge, this is the most complex example of plant genetic engineering to undergo environmental release and field evaluation.Rothamsted Research receives grand-aided support from the Biotechnology and Biological Sciences Research Council (BBSRC), UK. This study was supported via the Strategic Programme Grant BBS/E/C/00005207. We thank the staff of the Rothamsted Experimental Farm for their help in the management of this experimental trial. We acknowledge BASF Plant Sciences for generous provision of the vector system used in this study.Peer reviewe

Production Of Omega-3 Long Chain Polyunsaturated Fatty Acids (Patent US 2015/0216828 A1)

A recombinant camelina plant or cell comprising one or more polynucleotides encoding a Δ6-desaturase, a Δ6-elongase and a Δ5-desaturase operably linked with one or more regulatory sequences

The role of delta6-desaturase acyl-carrier specificity in the efficient synthesis of long-chain polyunsaturated fatty acids in transgenic plants

The role of acyl-CoA-dependent Delta 6-desaturation in the heterologous synthesis of omega-3 long-chain polyunsaturated fatty acids was systematically evaluated in transgenic yeast and Arabidopsis thaliana. The acyl-CoA Delta 6-desaturase from the picoalga Ostreococcus tauri and orthologous activities from mouse (Mus musculus) and salmon (Salmo salar) were shown to generate substantial levels of Delta 6-desaturated acyl-CoAs, in contrast to the phospholipid-dependent Delta 6-desaturases from higher plants that failed to modify this metabolic pool. Transgenic plants expressing the acyl-CoA Delta 6-desaturases from either O.tauri or salmon, in conjunction with the two additional activities required for the synthesis of C20 polyunsaturated fatty acids, contained higher levels of eicosapentaenoic acid compared with plants expressing the borage phospholipid-dependent Delta 6-desaturase. The use of acyl-CoA-dependent Delta 6-desaturases almost completely abolished the accumulation of unwanted biosynthetic intermediates such as gamma-linolenic acid in total seed lipids. Expression of acyl-CoA Delta 6-desaturases resulted in increased distribution of long-chain polyunsaturated fatty acids in the polar lipids of transgenic plants, reflecting the larger substrate pool available for acylation by enzymes of the Kennedy pathway. Expression of the O.tauri Delta 6-desaturase in transgenic Camelina sativa plants also resulted in the accumulation of high levels of Delta 6-desaturated fatty acids. This study provides evidence for the efficacy of using acyl-CoA-dependent Delta 6-desaturases in the efficient metabolic engineering of transgenic plants with high value traits such as the synthesis of omega-3 LC-PUFAs

Production Of Omega-3 Long Chain Polyunsaturated Fatty Acids (Patent WO 2013/153404 A1)

A recombinant camelina plant or cell comprising one or more polynucleotides encoding a Delta6-desaturase, a Delta6-elongase and a Delta5-desaturase operably linked with one or more regulatory sequences

Successful high-level accumulation of fish oil omega-3 long-chain polyunsaturated fatty acids in a transgenic oilseed crop

Omega-3 (also called n-3) long-chain polyunsaturated fatty acids (C20; LC-PUFAs) are of considerable interest, based on clear evidence of dietary health benefits and the concurrent decline of global sources (fish oils). Generating alternative transgenic plant sources of omega-3 LC-PUFAs, i.e. eicosapentaenoic acid (20:5 n-3, EPA) and docosahexaenoic acid (22:6 n-3, DHA) has previously proved problematic. Here we describe a set of heterologous genes capable of efficiently directing synthesis of these fatty acids in the seed oil of the crop Camelina sativa, while simultaneously avoiding accumulation of undesirable intermediate fatty acids. We describe two iterations: RRes_EPA in which seeds contain EPA levels of up to 31% (mean 24%), and RRes_DHA, in which seeds accumulate up to 12% EPA and 14% DHA (mean 11% EPA and 8% DHA). These omega-3 LC-PUFA levels are equivalent to those in fish oils, and represent a sustainable, terrestrial source of these fatty acids. We also describe the distribution of these non-native fatty acids within C.sativa seed lipids, and consider these data in the context of our current understanding of acyl exchange during seed oil synthesis

Effect of Nitrogen on Agronomic Yield, Spad Units and Nitrate Content in Roselle (Hibiscus Sabdariffal.) in Dry Weather

This study was conducted in polyethylene bags of 4 kg capacity with plants of Jamaica from seeds collected from an accession on the coast of Oaxaca, which were planted under the ecological conditions of Teotitlán de Flores Magón, and evaluated under completely randomized design, where treatments were four levels of nitrogen: 0, 50, 100 and 150 kg ha-1 and four repetitions (4x4) = 16 experimental units. The variables evaluated were: both agronomic yields: chalice and seed, harvest index, SPAD units and nitrate content in leaf. The results indicate that higher yields ofseed and chalice, biomass, nitrate content in leaf and SPAD units were achieved with the application of 100 kg ha-1 of nitrogen with 50.39, 196.80, 620.4 g plant-1, 85.00 mg kg-1 and 29.10 units, respectively. The content of nitrates and its relationship with SPAD units, adjusted to an increasing linear model for the four levels of nitrogen studied. From this study it can be concluded that the application of 100 kg N ha-1, positively affect the culture of Jamaica under dry weather conditions way