Metabolic Engineering Camelina sativa with Fish Oil-Like Levels of DHA

Petrie, James R.; Shrestha, Pushkar; Belide, Srinivas; Kennedy, Yoko; Lester, Geraldine; Liu, Qing; Divi, Uday K.; Mulder, Roger J.; Mansour, Maged P.; Nichols, Peter D.; Singh, Surinder P.

doi:10.1371/journal.pone.0085061

Cited by 154 publications

(153 citation statements)

References 20 publications

Supporting

Mentioning

147

Contrasting

Order By: Relevance

“…Therefore, the only currently viable approach to developing a novel, renewable supply of EPA and DHA is the metabolic engineering of oilseed crops with the capacity to synthesise n-3 LC-PUFA in seeds . Production of n-3 LC-PUFA in terrestrial plant seeds was demonstrated in the model plant Arabidopsis (Petrie et al, 2012;RuizLopez et al, 2013), and very recently reported in an oilseed crop, Camelina sativa (Petrie et al, 2014;Ruiz-Lopez et al, 2014). C. sativa or false flax, is a member of the Brassicaceae family and an ancient crop that, in the wild-type, produces an oil with LNA at up to 45 % of total fatty acids (Gunstone and Harwood, 2007).…”

Section: Transgenicsmentioning

confidence: 98%

Omega-3 long-chain polyunsaturated fatty acids and aquaculture in perspective

2015

View full text Add to dashboard Cite

Abbreviations: ARA, arachidonic acid (20:4n-6); CVD, cardiovascular disease; DHA, docosahexaenoic acid (22:6n-3); DPA, docosapentaenoic acid (22:5n-3); EFA, essential fatty acid; Elovl, fatty acid elongase; EPA, eicosapentaenoic acid (20:5n-3); Fads, fatty acyl desaturase; FM, fishmeal; FO, fish oil; LC-PUFA, long-chain polyunsaturated fatty acids (≥ C20 ≥ 3 double bonds); LOA, linoleic acid (18:2n-6); LNA, linolenic acid (18:3n-3); PUFA, polyunsaturated fatty acid; TAG, triacylglycerol; VO, vegetable oil. ABSTRACTIn the 40 years since the essentiality of polyunsaturated fatty acids (PUFA) in fish was first established by determining quantitative requirements for 18:3n-3 and 18:2n-6 in rainbow trout, essential fatty acid (EFA) research has gone through distinct phases. For 20 years the focus was primarily on determining qualitative and quantitative EFA requirements of fish species. Nutritional and biochemical studies showed major differences between fish species based on whether C 18 PUFA or long-chain (LC)-PUFA were required to satisfy requirements. In contrast, in the last 20 years, research emphasis shifted to determining "optimal" levels of EFA to support growth of fish fed diets with increased lipid content and where growth expectations were much higher. This required greater knowledge of the roles and functions of EFA in metabolism and physiology, and how these impacted on fish health and disease. Requirement studies were more focused on early life stages, in particular larval marine fish, defining not only levels, but also balances between different EFA. Finally, a major driver in the last 10-15 years has been the unavoidable replacement of fish oil and fishmeal in feeds and the impacts that this can have on n-3 LC-PUFA contents of diets and farmed fish, and the human consumer. Thus, dietary n-3 in fish feeds can be defined by three levels.Firstly, the minimum level required to satisfy EFA requirements and thus prevent nutritional pathologies. This level is relatively small and easy to supply even with today's current high demand for fish oil. The second level is that required to sustain maximum growth and optimum health in fish being fed modern high-energy diets. The balance between different PUFA and LC-PUFA is important and defining them is more challenging, and so ideal levels and balances are still not well understood, particularly in relation to fish health. The third level is currently driving much research; how can we supply sufficient n-3 LC-PUFA to maintain the nutritional quality of farmed fish at the same level as 20 years ago, and similar or better than in wild fish? This level far exceeds the biological requirements of the fish itself and to satisfy it we require entirely new sources of n-3 LC-PUFA. We cannot rely on the finite and limited marine resources that we can sustainably harvest or 3 efficiently recycle. We need to produce n-3 LC-PUFA de novo and all possible options should be considered.Keywords: Fish oil; essential fatty acids; nutrition; health; metabolism; sustainability 4 Highl...

show abstract

Section: Transgenicsmentioning

confidence: 98%

Omega-3 long-chain polyunsaturated fatty acids and aquaculture in perspective

2015

View full text Add to dashboard Cite

show abstract

“…Moreover, the seed yield is adequate to facilitate the rapid production of oil in quantities large enough for small-scale testing and product development. In recent years, several different oil traits have been developed in C. sativa seeds, such as high 18:1n-9 (Kang et al, 2011;, high 16:0 , and high v-7 fatty acids (Nguyen et al, 2015), as well as the production of diverse extrinsic lipid compounds, such as wax esters (Iven et al, 2016), fish oils (Petrie et al, 2014;Ruiz-Lopez et al, 2014), nervonic acid (Huai et al, 2015), and acetyl glyceride oils (Liu et al, 2015).…”

mentioning

confidence: 99%

Two Acyltransferases Contribute Differently to Linolenic Acid Levels in Seed Oil

et al. 2017

View full text Add to dashboard Cite

ORCID IDs: 0000-0001-6929-7859 (S.M.); 0000-0003-3152-0394 (D.S.); 0000-0001-8255-3255 (C.H.); 0000-0003-0489-3072 (K.C.); 0000-0002-9888-7003 (I.F.).Acyltransferases are key contributors to triacylglycerol (TAG) synthesis and, thus, are of great importance for seed oil quality. The effects of increased or decreased expression of ACYL-COENZYME A:DIACYLGLYCEROL ACYLTRANSFERASE1 (DGAT1) or PHOSPHOLIPID:DIACYLGLYCEROL ACYLTRANSFERASE (PDAT) on seed lipid composition were assessed in several Camelina sativa lines. Furthermore, in vitro assays of acyltransferases in microsomal fractions prepared from developing seeds of some of these lines were performed. Decreased expression of DGAT1 led to an increased percentage of 18:3n-3 without any change in total lipid content of the seed. The tri-18:3 TAG increase occurred predominantly in the cotyledon, as determined with matrix-assisted laser desorption/ionization-mass spectrometry, whereas species with two 18:3n-3 acyl groups were elevated in both cotyledon and embryonal axis. PDAT overexpression led to a relative increase of 18:2n-6 at the expense of 18:3n-3, also without affecting the total lipid content. Differential distributions of TAG species also were observed in different parts of the seed. The microsomal assays revealed that C. sativa seeds have very high activity of diacylglycerol-phosphatidylcholine interconversion. The combination of analytical and biochemical data suggests that the higher 18:2n-6 content in the seed oil of the PDAT overexpressors is due to the channeling of fatty acids from phosphatidylcholine into TAG before being desaturated to 18:3n-3, caused by the high activity of PDAT in general and by PDAT specificity for 18:2n-6. The higher levels of 18:3n-3 in DGAT1-silencing lines are likely due to the compensatory activity of a TAG-synthesizing enzyme with specificity for this acyl group and more desaturation of acyl groups occurring on phosphatidylcholine.

show abstract

“…Camelina was chosen for obvious advantages-it can be floral-dip transformed (Lu et al, 2011); it has a short lifecycle; and it has oil-rich seeds (30% to 40% of seed weight) that contain high levels of PUFAs (.50%), especially a-linolenic acid (18:3, .30% of total fatty acids; Campbell et al, 2013;Iskandarov et al, 2013). Recently phospholipase A overexpression in Camelina resulted in an increase in total oil (Li et al, 2015a), and other transgenics have resulted in TAG containing nonnative FAs (Lu and Kang, 2008;Petrie et al, 2014;Ruiz-Lopez et al, 2014;Liu et al, 2015;Nguyen et al, 2015). However, mechanisms that control acyl flux through PC into TAG have not been studied as extensively in Camelina as in other species.…”

mentioning

confidence: 99%

Phospholipase Dζ Enhances Diacylglycerol Flux into Triacylglycerol

Yang

Wang

et al. 2017

Plant Physiol.

View full text Add to dashboard Cite

Plant seeds are the primary source of triacylglycerols (TAG) for food, feed, fuel, and industrial applications. As TAG is produced from diacylglycerol (DAG), successful engineering strategies to enhance TAG levels have focused on the conversion of DAG to TAG. However, the production of TAG can be limited by flux through the enzymatic reactions that supply DAG. In this study, two Arabidopsis phospholipase D z genes (AtPLD z1 and AtPLD z2 ) were coexpressed in Camelina sativa to test whether the conversion of phosphatidylcholine to DAG impacts TAG levels in seeds. The resulting transgenic plants produced 2% to 3% more TAG as a component of total seed biomass and had increased 18:3 and 20:1 fatty acid levels relative to wild type. Increased DAG and decreased PC levels were examined through the kinetics of lipid assembly by [ 14 C]acetate and [ 14 C]glycerol incorporation into glycerolipids. [ 14 C]acetate was rapidly incorporated into TAG in both wild-type and overexpression lines, indicating a significant flux of nascent and elongated acyl-CoAs into the sn-3 position of TAG. Stereochemical analysis revealed that newly synthesized fatty acids were preferentially incorporated into the sn-2 position of PC, but the sn-1 position of de novo DAG and indicated similar rates of nascent acyl groups into the Kennedy pathway and acyl editing. [ 14 C]glycerol studies demonstrated PC-derived DAG is the major source of DAG for TAG synthesis in both tissues. The results emphasize that the interconversions of DAG and PC pools can impact oil production and composition.

show abstract

Metabolic Engineering Camelina sativa with Fish Oil-Like Levels of DHA

Cited by 154 publications

References 20 publications

Omega-3 long-chain polyunsaturated fatty acids and aquaculture in perspective

Omega-3 long-chain polyunsaturated fatty acids and aquaculture in perspective

Two Acyltransferases Contribute Differently to Linolenic Acid Levels in Seed Oil

Phospholipase Dζ Enhances Diacylglycerol Flux into Triacylglycerol

Contact Info

Product

Resources

About