Transgenic Camelina Research Articles

Inclusion of oil from transgenic Camelina sativa in feed effectively supplies EPA and DHA to Atlantic salmon (Salmo salar) grown to market size in seawater pens

Atlantic salmon were fed either a diet reflecting current commercial feeds with added oil supplied by a blend of fish oil and rapeseed oil (COM), or a diet formulated with oil from transgenic Camelina sativa containing 20% EPA + DHA (TCO). Salmon were grown from smolt to market size (>3 kg) in sea pens under semi-commercial conditions. There were no differences in growth, feed efficiency or survival between fish fed the TCO or COM diets at the end of the trial. Levels of EPA + DHA in flesh of salmon fed TCO were significantly higher than in fish fed COM. A 140 g fillet from TCO-fed salmon delivered 2.3 g of EPA + DHA, 67% of the weekly requirement level recommended by many health agencies, and 1.5-fold more than the 1.5 g of EPA + DHA for COM-fed fish. Oil from transgenic Camelina supported growth and improved the nutritional quality of farmed salmon in terms of increased “omega-3” supply for human consumers.

Engineered Cleistogamy in Camelina sativa for bioconfinement.

Camelina sativa is a self-pollinating and facultative outcrossing oilseed crop. Genetic engineering has been used to improve camelina yield potential for altered fatty acid composition, modified protein profiles, improved seed and oil yield, and enhanced drought resistance. The deployment of transgenic camelina in the field posits high risks related to the introgression of transgenes into non-transgenic camelina and wild relatives. Thus, effective bioconfinement strategies need to be developed to prevent pollen-mediated gene flow (PMGF) from transgenic camelina. In the present study, we overexpressed the cleistogamy (i.e. floral petal non-openness)-inducing PpJAZ1 gene from peach in transgenic camelina. Transgenic camelina overexpressing PpJAZ1 showed three levels of cleistogamy, affected pollen germination rates after anthesis but not during anthesis, and caused a minor silicle abortion only on the main branches. We also conducted field trials to examine the effects of the overexpressed PpJAZ1 on PMGF in the field, and found that the overexpressed PpJAZ1 dramatically inhibited PMGF from transgenic camelina to non-transgenic camelina under the field conditions. Thus, the engineered cleistogamy using the overexpressed PpJAZ1 is a highly effective bioconfinement strategy to limit PMGF from transgenic camelina, and could be used for bioconfinement in other dicot species.

Agrobacterium-mediated transformation of spring camelina with yeast genes of trehalose biosynthesis

Aim. The aim of the study was the obtaining of Camelina sativa (L.) Crantz lines with yeast genes of trehalose synthesis TPS1 and TPS2 to increase their resistance to drought. Methods. Seeds of C. sativa genotype FEORZhYaF-1 were used for in vitro culture establishment. For this hypocotyl segments and shoot meristems of 5-days-old camelina seedlings were cultivated on three different nutrient media for regeneration supplemented with various hormone combinations. Vector constructions pGWB2-TPS1 and pGWB2-TPS2 with TPS1 and TPS2 genes have been used for genetic transformation. Results. The highest efficiency of plant regeneration from hypocotyl explants was found on medium supplemented with 1 mg/l BAP and 0.1 mg/l NAA, and from meristem explants – on medium with 1.5 mg/l BAP and 0.5 mg/l NAA. Agrobacterium-mediated transformation was conducted out, and camelina lines were picked up on corresponding medium with selective concentration of hygromycin. Transgenic nature of obtained plants was confirmed by PCR-analysis. Conclusions. The efficiency of in vitro plant regeneration of C. sativa genotype FEORZhYaF-1 has been investigated. Two types of explants and two vector constructions pGWB2-TPS1 and pGWB2-TPS2 with TPS1 and TPS2 yeast trehalose synthesis genes have been used for obtaining of transgenic camelina lines.

Enhancing the accumulation of eicosapentaenoic acid and docosahexaenoic acid in transgenic Camelina through the CRISPR-Cas9 inactivation of the competing FAE1 pathway.

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CsRCI2D enhances high-temperature stress tolerance in Camelina sativa L. through endo-membrane trafficking from the plasma membrane

Rare Cold Inducible 2s (RCI2s) are hydrophobic proteins in cell membranes that participate in abiotic stress tolerance mechanisms. Additionally, they are used as traceable membrane trafficking markers in endocytosis studies. Plants regulate cell homeostasis through endocytosis by limiting the activity of plasma membrane transporter proteins to adapt to stressful conditions. In this study, we found high temperature (HT) stress-induced membrane trafficking of RCI2D in Camelina sativa L. The gene expression and protein synthesis were increased by HT stress at 37 °C. Moreover, rapid membrane trafficking of CsRCI2D was traced by multiple-phase membrane fractionation using sucrose density gradients and compared with CsRCI2E/F/G from the same protein family subgroup. The distribution of CsRCI2s was shown to be similar to that of the clathrin heavy chain, which is known as a major endocytosis protein. Subcellular localization of CsRCI2D was observed in the plasma membrane and endo-membranes and overlapped with membrane lipids. CsRCI2D co-localized with lipids, and its overexpression increased the intracellular lipid content compared to that of wild-type camelina. Moreover, transgenic camelina lines showed enhanced HT stress tolerance during germination and hypocotyl elongation when compared to the wild type. These results suggest that HT-induced CsRCI2D membrane trafficking enhances HT stress tolerance in camelina.

Dietary Supplementation with Transgenic Camelina sativa Oil Containing 20:5n-3 and 22:6n-3 or Fish Oil Induces Differential Changes in the Transcriptome of CD3+ T Lymphocytes.

Eicosapentaenoic acid (20:5n-3) and docosahexaenoic acid (22:6n-3) are important for leukocyte function. This study investigated whether consuming transgenic Camelina sativa (tCSO) seed oil containing both 20:5n-3 and 22:6n-3 is as effective as fish oil (FO) for increasing the 20:5n-3 and 22:6n-3 content of leukocytes and altering mitogen-induced changes to the T cell transcriptome. Healthy adults (n = 31) consumed 450 mg/day of 20:5n-3 plus 22:6n-3 from either FO or tCSO for 8 weeks. Blood was collected before and after the intervention. 20:5n-3 and 22:6n-3 incorporation from tCSO into immune cell total lipids was comparable to FO. The relative expression of the transcriptomes of mitogen-stimulated versus unstimulated T lymphocytes in a subgroup of 16 women/test oil showed 4390 transcripts were differentially expressed at Baseline (59% up-regulated), 4769 (57% up-regulated) after FO and 3443 (38% up-regulated) after tCSO supplementation. The 20 most altered transcripts after supplementation differed between test oils. The most altered pathways were associated with cell proliferation and immune function. In conclusion, 20:5n-3 and 22:6n-3 incorporation into immune cells from tCSO was comparable to FO and can modify mitogen-induced changes in the T cell transcriptome, contingent on the lipid matrix of the oil.

Alterations of flower fertility, plant size, seed weight, and seed oil content in transgenic Camelina sativa plants overexpressing CYP78A

Camelina (Camelina sativa (L.) Crantz) is an orphan oil crop with high potential for yield improvement through breeding and biotechnological approaches. Seed size and oil content of camelina are particularly low compared with high-yielding oil crops such as rapeseed (Brassica napus L.). The CYP78A genes of the P450 monooxygenase family were previously demonstrated to be involved in regulating seed development in arabidopsis (Arabidopsis thaliana L.). Here, we show that expression of three arabidopsis genes, AtCYP78A5, AtCYP78A6 or AtCYP78A9 under control of the CaMV35S promoter caused enhanced growth of transgenic camelina plants with larger silicles and larger seeds. The phenotype of the camelina lines strongly depended on the expressed AtCYP78A paralog and on the level of transgene expression. Excess overexpression of AtCYP78A6 or AtCYP78A9 resulted in very large seeds, a decrease in total seed weight per plant and infertility of flowers at the lower sections of the stems. Plants with lower expression levels showed moderately increased seed weights, especially AtCYP78A5 lines, with elevated oil and protein contents per seed weight compared to the wild type. The increases in seed weight and plant height were correlated with higher expression levels of the transgenes. Slight but significant reductions in seed weight were observed for plants with downregulation of CsCYP78A9 expression by RNAi accompanied with an increase in the oil content per seed weight. These results show that CYP78A genes regulate the seed development in camelina, and that excess expression affects fertility, while moderate expression provides a powerful strategy for manipulating plant biomass and seed traits in camelina.

Increased Cuticle Waxes by Overexpression of WSD1 Improves Osmotic Stress Tolerance in Arabidopsis thaliana and Camelina sativa.

To ensure global food security under the changing climate, there is a strong need for developing ‘climate resilient crops’ that can thrive and produce better yields under extreme environmental conditions such as drought, salinity, and high temperature. To enhance plant productivity under the adverse conditions, we constitutively overexpressed a bifunctional wax synthase/acyl-CoA:diacylglycerol acyltransferase (WSD1) gene, which plays a critical role in wax ester synthesis in Arabidopsis stem and leaf tissues. The qRT-PCR analysis showed a strong upregulation of WSD1 transcripts by mannitol, NaCl, and abscisic acid (ABA) treatments, particularly in Arabidopsis thaliana shoots. Gas chromatography and electron microscopy analyses of Arabidopsis seedlings overexpressing WSD1 showed higher deposition of epicuticular wax crystals and increased leaf and stem wax loading in WSD1 transgenics compared to wildtype (WT) plants. WSD1 transgenics exhibited enhanced tolerance to ABA, mannitol, drought and salinity, which suggested new physiological roles for WSD1 in stress response aside from its wax synthase activity. Transgenic plants were able to recover from drought and salinity better than the WT plants. Furthermore, transgenics showed reduced cuticular transpirational rates and cuticle permeability, as well as less chlorophyll leaching than the WT. The knowledge from Arabidopsis was translated to the oilseed crop Camelina sativa (L.) Crantz. Similar to Arabidopsis, transgenic Camelina lines overexpressing WSD1 also showed enhanced tolerance to drought stress. Our results clearly show that the manipulation of cuticular waxes will be advantageous for enhancing plant productivity under a changing climate.

Transgenic camelina oil is an effective source of eicosapentaenoic acid and docosahexaenoic acid in diets for farmed rainbow trout, in terms of growth, tissue fatty acid content, and fillet sensory properties

AbstractThe oilseed Camelina sativa was genetically engineered to produce eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) at levels similar to fish oil (FO), which we tested as a lipid source in diets for rainbow trout. Three experimental diets were tested, a FO control, a low‐level transgenic camelina oil (LCO) diet (no FO with 12.5 g/kg camelina), and a high‐level transgenic camelina oil (HCO) diet (no FO with 130 g/kg transgenic camelina). Trout (initial weight 49.8 ± 11 g/fish) were fed for 12 weeks and were evaluated for growth performance, fatty acid content (muscle, liver, brain, and eye), and sensory properties of fillets. The final lengths and weights of fish fed LCO and HCO diets were higher compared to fish fed FO. There were no differences in weight gain, condition factor, specific growth rate, feed intake, and feed conversion ratio. EPA in muscle tissue was higher in fish fed HCO and FO diets compared to the LCO diet. Compound‐specific stable isotope analysis revealed that rainbow trout fed the FO diet stored isotopically enriched DHA compared to the lighter DHA in fish fed HCO. Trout fillets from the HCO treatment were firmer in texture and had a higher orange intensity compared to the FO group.

Genetically modified plants are an alternative to oily fish for providing n-3 polyunsaturated fatty acids in the human diet: A summary of the findings of a Biotechnology and Biological Sciences Research Council funded project.

The n‐3 polyunsaturated fatty acids (PUFA) present primarily in oily fish, namely eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are important components of cell membranes and that are needed for normal development and cell function. Humans have very limited capacity for EPA and DHA synthesis from α‐linolenic acid and so they must be obtained pre‐formed from the diet. However, perceived unpalatability of oily fish and fish oil concerns about contamination with environmental pollutants, dietary choices that exclude fish and animal products, and price limit the effectiveness of recommendations for EPA and DHA intakes. Moreover, marine sources of EPA and DHA are diminishing in the face of increasing demands. Therefore, an alternative source of EPA and DHA is needed that is broadly acceptable, can be upscaled and is sustainable. This review discusses these challenges and, using findings from recent nutritional trials, explains how they may be overcome by seed oils from transgenic plants engineered to produce EPA and DHA. Trials in healthy men and women assessed the acute uptake and appearance in blood over 8 hours of EPA and DHA from transgenic Camelina sativa compared to fish oil, and the incorporation of these PUFA into blood lipids after dietary supplementation. The findings showed that postprandial EPA and DHA incorporation into blood lipids and accumulation in plasma lipids after dietary supplementation was as good as that achieved with fish oil. The oil derived from this transgenic plant was well tolerated. This review also discusses the implications for human nutrition, marine ecology and agriculture.

Improving seed size, seed weight and seedling emergence in Camelina sativa by overexpressing the Atsob3-6 gene variant.

Seedling stand establishment is a critical factor affecting crop yield in low-precipitation agricultural regions. This is especially true for small seeded crops, such as Camelina (Camelina sativa) and canola (Brassica napus), that need to be planted shallow. Deeper planting would be desirable so that seeds can access soil moisture and bigger seeds could improve emergence and stand establishment by providing the energy necessary for seedling elongation. AHL (AT-Hook Containing, Nuclear Localized) genes play an important role in seedling growth and development. AHL proteins contain two structural units, the DNA-binding AT-hook motif and the Plant and Prokaryote Conserved (PPC) domain, required for protein-protein interactions. Our previous studies demonstrate that AtAHL29/SOB3 (Suppressor of phytochrome B-4 #3) regulates seedling development in Arabidopsis (Arabidopsis thaliana). Activation-tagged overexpression of AtSOB3 (Atsob3-D) represses the long-hypocotyl phenotype of an Arabidopsis phytochrome B mutant. In contrast, overexpression of the Atsob3-6 variant (Atsob3-6-OX), with a non-functional AT-hook, confers a long-hypocotyl phenotype. In this study, we demonstrate the role of Atsob3-D and Atsob3-6-OX in modulating seed size and hypocotyl length in the brassicas Arabidopsis and Camelina. In Arabidopsis, Atsob3-D reduces seed weight whereas Atsob3-6-OX increases seed weight and size when compared to the wild type. Similarly, Atsob3-6-OX transgenic Camelina seedlings are taller than the wild type, and produce larger and heavier seeds. These larger Atsob3-6-OX Camelina seeds also confer better emergence in deep-soil planting when compared to the wild type. Taken together, Atsob3-6-OX increases seed size, seed weight, seedling hypocotyl length and stand establishment in the oilseed crop Camelina.

Oil from transgenic Camelina sativa as a source of EPA and DHA in feed for European sea bass (Dicentrarchus labrax L.)

Aquaculture, the fastest growing food production sector cannot continue to rely on finite stocks of marine fish as the primary source of the omega-3 (n-3) long-chain polyunsaturated fatty acids (LC-PUFA), eicosapentaenoic acid (EPA; 20:5n3) and docosahexaenoic acid (DHA; 22:6n-3), for feeds. A four-month feeding trial was conducted to investigate the impact of a de novo oil, with high levels of EPA and DHA, obtained from transgenic Camelina sativa on growth performance, tissue fatty acid profiles, and expression of lipid metabolism genes when used as a replacement for fish oil in feed for European seabass (Dicentrachus labrax). Triplicate groups of 50 juvenile fish (initial weight 16.7 ± 0.92 g) per tank were fed for 4 months with one of three isolipidic and isoproteic experimental diets consisting of a standard diet containing a commercial blend of fish oil and rapeseed oil (CFO), a diet containing transgenic Camelina oil (TCO), or a blend of fish oil and rapeseed oil with enhanced levels of EPA and DHA (EFO) formulated to match the n-3 LC-PUFA profile of the TCO feed. Final weight of fish fed the GM-derived oil was not different to fish fed either CFO or EFO. Slight lower growth performance of fish fed TCO at the beginning of the trial was related to transient reduced feed intake, possibly caused by glucosinolates in the raw Camelina sativa oil. The GM-derived oil improved the nutritional quality of the fish fillet by enhancing total n-3 PUFA levels compared to the fish fed the other two feeds, and maintained flesh EPA and DHA at the same levels as in fish fed the diets containing fish oil. The metabolic response in liver and intestine was generally relatively mild although diets TCO and EFO seemed to trigger a metabolic response consisting of an up-regulation of both β-oxidation (cpt1a) and fatty acid transport (fabp1), possibly reflecting higher levels of LC-PUFA. Overall, the present study indicated that an oil of terrestrial origin, Camelina sativa, when engineered to contain high levels of EPA and DHA can replace fish oil in feeds for European seabass with no detrimental impact on growth or feed efficiency, while also maintaining or increasing tissue n-3 LC-PUFA contents.

Dietary supplementation with seed oil from transgenic Camelina sativa induces similar increments in plasma and erythrocyte DHA and EPA to fish oil in healthy humans.

EPA and DHA are required for normal cell function and can also induce health benefits. Oily fish are the main source of EPA and DHA for human consumption. However, food choices and concerns about the sustainability of marine fish stocks limit the effectiveness of dietary recommendations for EPA + DHA intakes. Seed oils from transgenic plants that contain EPA + DHA are a potential alternative source of EPA and DHA. The present study investigated whether dietary supplementation with transgenic Camelina sativa seed oil (CSO) that contained EPA and DHA was as effective as fish oil (FO) in increasing EPA and DHA concentrations when consumed as a dietary supplement in a blinded crossover study. Healthy men and women (n 31; age 53 (range 20-74) years) were randomised to consume 450 mg/d EPA + DHA provided either as either CSO or FO for 8 weeks, followed by 6 weeks washout and then switched to consuming the other test oil. Fasting venous blood samples were collected at the start and end of each supplementation period. Consuming the test oils significantly (P < 0·05) increased EPA and DHA concentrations in plasma TAG, phosphatidylcholine and cholesteryl esters. There were no significant differences between test oils in the increments of EPA and DHA. There was no significant difference between test oils in the increase in the proportion of erythrocyte EPA + DHA (CSO, 12 %; P < 0·0001 and FO, 8 %; P = 0·02). Together, these findings show that consuming CSO is as effective as FO for increasing EPA and DHA concentrations in humans.

High level accumulation of EPA and DHA in field-grown transgenic Camelina - a multi-territory evaluation of TAG accumulation and heterogeneity.

The transgene‐directed accumulation of non‐native omega‐3 long chain polyunsaturated fatty acids in the seed oil of Camelina sativa (Camelina) was evaluated in the field, in distinct geographical and regulatory locations. A construct, DHA2015.1, containing an optimal combination of biosynthetic genes, was selected for experimental field release in the UK, USA and Canada, and the accumulation of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) determined. The occurrence of these fatty acids in different triacylglycerol species was monitored and found to follow a broad trend irrespective of the agricultural environment. This is a clear demonstration of the stability and robust nature of the transgenic trait for omega‐3 long chain polyunsaturated fatty acids in Camelina. Examination of non‐seed tissues for the unintended accumulation of EPA and DHA failed to identify their presence in leaf, stem, flower, anther or capsule shell material, confirming the seed‐specific accumulation of these novel fatty acids. Collectively, these data confirm the promise of GM plant‐based sources of so‐called omega‐3 fish oils as a sustainable replacement for oceanically derived oils.

Differential postprandial incorporation of 20:5n-3 and 22:6n-3 into individual plasma triacylglycerol and phosphatidylcholine molecular species in humans

The mechanisms by which digested fat is absorbed and transported in the circulation are well documented. However, it is uncertain whether the molecular species composition of dietary fats influences the molecular species composition of meal-derived lipids in blood. This may be important because enzymes that remove meal-derived fatty acids from the circulation exhibit differential activities towards individual lipid molecular species. To determine the effect of consuming oils with different molecular compositions on the incorporation of 20:5n-3 and 22:6n-3 into plasma lipid molecular species. Men and women (18–30 years) consumed standardised meals containing 20:5n-5 and 22:6n-3 (total 450 mg) provided by an oil from transgenic Camelina sativa (CSO) or a blended fish oil (BFO) which differed in the composition of 20:5n-3 and 22:6n-3 – containing molecular species. Blood was collected during the subsequent 8 h. Samples were analysed by liquid chromatography-mass spectrometry. The molecular species composition of the test oils was distinct from the composition of plasma triacylglycerol (TG) or phosphatidylcholine (PC) molecular species at baseline and at 1.5 or 6 h after the meal. The rank order by concentration of both plasma PC and TG molecular species at baseline was maintained during the postprandial period. 20:5n-3 and 22:6n-3 were incorporated preferentially into plasma PC compared to plasma TG. Together these findings suggest that the composition of dietary lipids undergoes extensive rearrangement after absorption, such that plasma TG and PC maintain their molecular species composition, which may facilitate lipase activities in blood and/or influence lipoprotein structural stability and function.

Overexpression of CsRCI2H enhances salt tolerance in Camelina sativa (L.)

Although plant rare cold inducible 2 (RCI2), a homolog of yeast PMP3, has been considered to play important roles in responses to abiotic stress in plants, the functional role of RCI2 in salt-stress tolerance remains largely unknown for crop plants. In this study, we determined the function of CsRCI2H from Camelina under salt stress. Subcellular localization analysis of the yellow fluorescent protein (YFP)-CsRCI2H fusion protein revealed that CsRCI2H localizes to the plasma membrane in tobacco leaves. Expression of CsRCI2H was greatly increased in the presence of 150 mM NaCl. CsRCI2H compensated for the salt sensitivity of the yeast mutant ∆pmp3 lacking the PMP3 gene. CsRCI2H-overexpressing transgenic Camelina showed improved seed germination, root growth and fresh weight under high salt stress. CsRCI2H-overexpressing transgenic Camelina displayed lower accumulation of Na+ in the roots and shoots but higher K+ and Ca2+ accumulation in the shoots than wild type plants under salt stress. Furthermore, CsRCI2H-overexpressing Camelina displayed higher stomatal conductance and lower malondialdehyde under salt stress. Transcript levels of ion-homeostasis related genes, such as CsSOS1, CsSOS3, and CsHKT1, were significantly increased in the CsRCI2H-overexpressing transgenic plants upon salt treatment. These results suggest that Na+ and K+ homeostasis can be controlled by the Na+ and K+ transport systems throughout the CsRCI2H-overexpressing transgenic Camelina plant under salt-stress conditions. Collectively, these results indicate that CsRCI2H contributes to salt tolerance in Camelina during seed germination and seedling growth by reducing Na+ toxicity in the plant cells via regulation of ion homeostasis.

Obtainment and Analysis of Marker-Free Oil Plants Camelina sativa (L.) Expressing of Antimicrobial Peptide Cecropin P1 Gene

Marker-free transgenic Camelina sativa (L.) plants carrying a synthetic gene for cecropin P1, an antimicrobial peptide, under the control of the cauliflower mosaic virus 35S RNA promoter have been obtained and analyzed. The plants were transformed with an agrobacterial binary vector free of selective genes of antibiotic and herbicide resistance. The marker-free transformants were screened via measurement of the antibacterial activity of cecropin P1 and enzyme immunoassay. The obtained plants exhibited an increased resistance to infection with the bacteria Erwinia carotovora, the fungi Fusarium graminearum, and oxidative stress during infection. Analysis of the fatty acid composition of seed oil showed an increased amount of α-linolenic acid in the transgenic Camelina lines as compared to unmodified plants. The results indicate that the cecropin P1 gene can be included in an integral antistress plant-protective system.

Development of camelina enhanced with drought stress resistance and seed oil production by co-overexpression of MYB96A and DGAT1C

Camelina (Camelina sativa, Cs) is an emerging crop for the production of biodiesel and biofeedstock. This study aims to develop transgenic plants that have the advantage of two traits: improved drought resistance and oil content. Three genes, CsMYB96A, CsMYB96B, and CsMYB96C, were isolated from camelina stem. The deduced amino acid sequence of the three CsMYB96s showed at least 93% identity with Arabidopsis MYB96. CsMYB96A, B, and C transcripts were detected in various camelina tissues. Fluorescence signal from the fusion of CsMYB96A: enhanced yellow fluorescent protein was confined to the nucleus of tobacco epidermal cells. Transactivation analysis of tobacco protoplasts revealed that CsMYB96A was a transcription activator. Wax biosynthesis genes such as camelina β-ketoacyl-CoA synthase 2, β-ketoacyl-CoA synthase 6, β-ketoacyl-CoA reductase 1-1, β-ketoacyl-CoA reductase 1-2, enoyl-CoA reductase, ECERIFERUM 1 and ECERIFERUM 3 were upregulated approximately 2 to 120 times by CsMYB96A, indicating that CsMYB96A was involved in the activating of cuticular wax synthesis on plant epidemics. Camelina diacylglycerol acyltransferase 1C (CsDGAT1C) has been shown to increased oil synthesis genes in Arabidopsis. When CsDGAT1C and CsMYB96A were co-overexpressed in camelina, total fatty acid levels in transgenic seeds increased by approximately 21%. In addition, the transgenic camelina plants showed improved resistance to drought stress. This result suggests that the transgenic camelina can be grown to produce biodiesel and biofeedstock in arid or semi-arid lands.

Optical investigation of mixing-controlled combustion using a novel transgenic plant oil

Fuels derived from plant oils hold promise as alternatives to petroleum-derived fuels due to their renewable production strategies, and potential to reduce net carbon emissions. Due to their high viscosity and cloud point, and low volatility however, direct use of plant oils in engines, without transesterification, poses a challenge. Recently, genetic modification has been used to alter plant lipid biosynthesis, producing novel oils that may overcome some of these challenges. In this study, 3-acetyl-1, 2-diacyl-sn-glycerol (Ac-TAG), extracted from a strain of transgenic Camelina Sativa, was studied in an optically-accessible diesel engine. Simultaneous high-speed shadowgraphy and OH* chemiluminescence imaging data were collected to obtain measurements of jet development, liquid penetration, ignition location, and flame liftoff length. A conventional diesel fuel and untransformed neat camelina oil were run at the same conditions as the Ac-TAG fuel for comparison. Even though the Ac-TAG fuel had significantly lower viscosity than the neat camelina oil, no significant differences were observed between Ac-TAG and neat camelina oil in any of the quantities studied. Relative to diesel, the biofuels had greater liquid penetration, shorter liftoff lengths and ignition delay, and consistently ignited farther upstream.

Postprandial incorporation of EPA and DHA from transgenic Camelina sativa oil into blood lipids is equivalent to that from fish oil in healthy humans.

EPA and DHA are important components of cell membranes. Since humans have limited ability for EPA and DHA synthesis, these must be obtained from the diet, primarily from oily fish. Dietary EPA and DHA intakes are constrained by the size of fish stocks and by food choice. Seed oil from transgenic plants that synthesise EPA and DHA represents a potential alternative source of these fatty acids, but this has not been tested in humans. We hypothesised that incorporation of EPA and DHA into blood lipids from transgenic Camelina sativa seed oil (CSO) is equivalent to that from fish oil. Healthy men and women (18-30 years or 50-65 years) consumed 450 mg EPA + DHA from either CSO or commercial blended fish oil (BFO) in test meals in a double-blind, postprandial cross-over trial. There were no significant differences between test oils or sexes in EPA and DHA incorporation into plasma TAG, phosphatidylcholine or NEFA over 8 h. There were no significant differences between test oils, age groups or sexes in postprandial VLDL, LDL or HDL sizes or concentrations. There were no significant differences between test oils in postprandial plasma TNFα, IL 6 or 10, or soluble intercellular cell adhesion molecule-1 concentrations in younger participants. These findings show that incorporation into blood lipids of EPA and DHA consumed as CSO was equivalent to BFO and that such transgenic plant oils are a suitable dietary source of EPA and DHA in humans.