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1.
Plant J ; 2019 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-31437323

RESUMO

As Oryza sativa (rice) seeds represent food for over three billion people worldwide, the identification of genes that enhance grain size and composition is much desired. Past reports have indicated that Arabidopsis thaliana acyl-CoA-binding proteins (ACBPs) are important in seed development but did not affect seed size. Herein, rice OsACBP2 was demonstrated not only to play a role in seed development and germination, but also to influence grain size. OsACBP2 mRNA accumulated in embryos and endosperm of germinating seeds in qRT-PCR analysis, while ß-glucuronidase (GUS) assays on OsACBP2pro::GUS rice transformants showed GUS expression in embryos, as well as the scutellum and aleurone layer of germinating seeds. Deletion analysis of the OsACBP2 5'-flanking region revealed five copies of the seed cis-element, Skn-I-like motif (-1486/-1482, -956/-952, -939/-935, -826/-822, and -766/-762), and the removal of any adversely affected expression in seeds, thereby providing a molecular basis for OsACBP2 expression in seeds. When OsACBP2 function was investigated using osacbp2 mutants and transgenic rice overexpressing OsACBP2 (OsACBP2-OE), osacbp2 was retarded in germination, while OsACBP2-OEs performed better than the wild-type and vector-transformed controls, in germination, seedling growth, grain size and grain weight. Transmission electron microscopy of OsACBP2-OE mature seeds revealed an accumulation of oil bodies in the scutellum cells, while confocal laser scanning microscopy indicated oil accumulation in OsACBP2-OE aleurone tissues. Correspondingly, OsACBP2-OE seeds showed gain in triacylglycerols and long-chain fatty acids over the vector-transformed control. As dietary rice bran contains beneficial bioactive components, OsACBP2 appears to be a promising candidate for enriching seed nutritional value.

2.
Sci Rep ; 9(1): 11444, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31391507

RESUMO

There is an urgent requirement for sustainable sources of food and feed due to world population growth. Aquaculture relies heavily on the fish meal and fish oils derived from capture fisheries, challenging sustainability of the production system. Furthermore, substitution of fish oil with vegetable oil and fish meal with plant seed meals in aquaculture feeds reduces the levels of valuable omega-3 long chain polyunsaturated fatty acids such as eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids, and lowers the nutritional value due to the presence of phytate. Addition of exogenous phytase to fish feed is beneficial for enhancing animal health and reducing phosphorus pollution. We have engineered the marine diatom Phaeodactylum tricornutum, accumulating high levels of EPA and DHA together with recombinant proteins: the fungal Aspergillus niger PhyA or the bacterial Escherichia coli AppA phytases. The removal of the N-terminal signal peptide further increased phytase activity. Strains engineered with fcpA and CIP1 promoters showed the highest level of phytase activity. The best engineered strain achieved up to 40,000 phytase activity units (FTU) per gram of soluble protein, thus demonstrating the feasibility of development of multifunctionalized microalgae to simultaneously produce industrially useful proteins and fatty acids to meet the demand of intensive fish farming activity.

3.
Nat Plants ; 5(6): 563-567, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31160704

RESUMO

The potential for using genetic modification (GM) to enhance the nutritional composition of crops (for either direct human consumption or as animal feed) has been recognized since the dawn of the GM era, with such 'output' traits being considered as distinct, if not potentially superior, to 'input' traits such as herbicide tolerance and insect resistance. However, while input traits have successfully been used and now form the basis of GM agriculture, output trait GM crops are still lagging behind after 20 years. This is despite the demonstrable benefits that some nutritionally enhanced crops would bring and the proven value of GM technologies. This Review considers the present state of nutritional enhancement through GM, highlighting two high-profile examples of nutritional enhancement-Golden Rice and omega-3 fish oil crops-systematically evaluating the progress, problems and pitfalls associated with the development of these traits. This includes not just the underlying metabolic engineering, but also the requirements to demonstrate efficacy and field performance of the crops and consideration of regulatory, intellectual property and consumer acceptance issues.


Assuntos
Produtos Agrícolas/genética , Alimentos Geneticamente Modificados , Valor Nutritivo , Plantas Geneticamente Modificadas , Animais , Ácidos Graxos Ômega-3/genética , Peixes/genética , Humanos , Nutrigenômica , Oryza/genética
4.
New Phytol ; 2019 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-31211869

RESUMO

Plants exist in an environment of changing abiotic and biotic stresses. They have developed a complex set of strategies to respond to these stresses and over recent years it has become clear that sphingolipids are a key player in these responses. Sphingolipids are not universally present in all three domains of life. Many bacteria and archaea do not produce sphingolipids but they are ubiquitous in eukaryotes and have been intensively studied in yeast and mammals. During the last decade there has been a steadily increasing interest in plant sphingolipids. Plant sphingolipids exhibit structural differences when compared with their mammalian counterparts and it is now clear that they perform some unique functions. Sphingolipids are recognised as critical components of the plant plasma membrane and endomembrane system. Besides being important structural elements of plant membranes, their particular structure contributes to the fluidity and biophysical order. Sphingolipids are also involved in multiple cellular and regulatory processes including vesicle trafficking, plant development and defence. This review will focus on our current knowledge as to the function of sphingolipids during plant stress responses, not only as structural components of biological membranes, but also as signalling mediators.

5.
Br J Nutr ; 121(11): 1235-1246, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30975228

RESUMO

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.

6.
Nutrients ; 11(1)2019 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-30621155

RESUMO

The omega-3 (n-3) long-chain polyunsaturated fatty acids (LC-PUFA), eicosapentaenoic (EPA, 20:5n-3) and docosahexaenoic (DHA, 22:6n-3) acids, are well accepted as being essential components of a healthy, balanced diet, having beneficial effects on development and in mitigating a range of pathological conditions. However, their global supply from all the traditional sources of these nutrients is insufficient to satisfy human nutritional requirements. For two decades there has been considerable research carried out into all possible alternatives to the main sources of n-3 LC-PUFA, marine fish oil and fishmeal, driven largely by the aquaculture sector, as both the major user and provider of EPA and DHA. In the last few years these efforts have focused increasingly on the development of entirely new supplies of n-3 LC-PUFA produced de novo. Recently, this has resulted in various new sources of EPA and/or DHA that are already available or likely to available in the near future. In this short review, we briefly summaries the current gap between supply and demand of EPA and DHA for human requirements, the role of aquaculture in providing n-3 LC-PUFA to human consumers, the range of potential novel sources, and suggest how these new products could be used effectively. We conclude that all the new sources have potentially important roles to play in increasing the supply of n-3 LC-PUFA so that they are available more widely and in higher concentrations providing more options and opportunities for human consumers to obtain sufficient EPA and DHA to support more healthy, balanced diets.


Assuntos
Ácidos Docosa-Hexaenoicos/provisão & distribução , Ácido Eicosapentaenoico/provisão & distribução , Necessidades Nutricionais , Animais , Aquicultura , Ácidos Docosa-Hexaenoicos/administração & dosagem , Ácido Eicosapentaenoico/administração & dosagem , Óleos de Peixe , Produtos Pesqueiros , Engenharia Genética , Dieta Saudável , Humanos
7.
Elife ; 72018 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-30558714

RESUMO

On 5 June this year the first field trial of a CRISPR-Cas-9 gene-edited crop began at Rothamsted Research in the UK, having been approved by the UK Department for Environment, Food & Rural Affairs. However, in late July 2018, after the trial had started, the European Court of Justice ruled that techniques such as gene editing fall within the European Union's 2001 GMO directive, meaning that our gene-edited Camelina plants should be considered as genetically modified (GM). Here we describe our experience of running this trial and the legal transformation of our plants. We also consider the future of European plant research using gene-editing techniques, which now fall under the burden of GM regulation, and how this will likely impede translation of publicly funded basic research.


Assuntos
Brassicaceae/crescimento & desenvolvimento , Brassicaceae/genética , Produtos Agrícolas/crescimento & desenvolvimento , Edição de Genes/legislação & jurisprudência , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/genética , Produtos Agrícolas/genética , União Europeia , Reino Unido
8.
Plant Biotechnol J ; 2018 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-30485634

RESUMO

There is considerable interest in new sources of omega-3 long-chain (here defined as fatty acids ≥C20) polyunsaturated fatty acids (LC-PUFA), specifically eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3), commonly known as omega-3 fish oils, to supplement the limited supplies of oceanic fish oil (Tocher, 2015). These alternative sources include extraction of other diverse marine organisms (e.g. krill, plankton etc.), algal fermentation, and the genetic engineering of microbes such as yeasts. Another approach is the synthesis of omega-3 fish oils in transgenic plants (reviewed in Napier et al., 2015), and this short article will discuss the recent results obtained by two major industry collaborations. This article is protected by copyright. All rights reserved.

9.
Br J Nutr ; 119(12): 1378-1392, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29845899

RESUMO

Facing a bottleneck in the growth of aquaculture, and a gap in the supply and demand of the highly beneficial n-3 long-chain PUFA (LC-PUFA), sustainable alternatives to traditional marine-based feeds are required. Therefore, in the present trial, a novel oil obtained from a genetically engineered oilseed crop, Camelina sativa, that supplied over 25 % n-3 LC-PUFA was tested as a sole dietary-added lipid source in Atlantic salmon (Salmo salar) feed. Three groups of fish were fed three experimental diets for 12 weeks with the same basal composition and containing 20 % added oil supplied by either a blend of fish oil and rapeseed oil (1:3) (COM) reflecting current commercial formulations, wild-type Camelina oil (WCO) or the novel transgenic Camelina oil (TCO). There were no negative effects on the growth, survival rate or health of the fish. The whole fish and flesh n-3 LC-PUFA levels were highest in fish fed TCO, with levels more than 2-fold higher compared with those of fish fed the COM and WCO diets, respectively. Diet TCO had no negative impacts on the evaluated immune and physiological parameters of head kidney monocytes. The transcriptomic responses of liver and mid-intestine showed only mild effects on metabolism genes. Overall, the results clearly indicated that the oil from transgenic Camelina was highly efficient in supplying n-3 LC-PUFA providing levels double that obtained with a current commercial standard, and similar to those a decade ago before substantial dietary fishmeal and oil replacement.

10.
Elife ; 62017 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-29132504

RESUMO

Advances in biological engineering are likely to have substantial impacts on global society. To explore these potential impacts we ran a horizon scanning exercise to capture a range of perspectives on the opportunities and risks presented by biological engineering. We first identified 70 potential issues, and then used an iterative process to prioritise 20 issues that we considered to be emerging, to have potential global impact, and to be relatively unknown outside the field of biological engineering. The issues identified may be of interest to researchers, businesses and policy makers in sectors such as health, energy, agriculture and the environment.


Assuntos
Bioengenharia/tendências , Pesquisa/tendências , Mudança Climática , Conservação dos Recursos Naturais , Humanos
11.
Sci Rep ; 7(1): 6570, 2017 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-28747792

RESUMO

There is considerable interest in the de novo production of omega-3 long chain polyunsaturated fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), not least of all given the importance of these fatty acids in both aquaculture and human nutrition. Previously we have demonstrated the feasibility of using metabolic engineering in transgenic plants (Camelina sativa) to modify the seed oil composition to now include EPA and/or DHA. In this study, we further tailored the seed oil profile to reduce the omega-6 content, and evaluated the performance of such GM plants under field conditions (i.e. environmental releases), in terms of agronomic performance and also the lipidomic profile of seed oil. We used MALDI- mass spectrometry imaging to identify discrete tissue-types in the seed in which these non-native fatty acids preferentially accumulated. Collectively, these data provide new insights into the complexity of plant lipid metabolism and the challenges associated with predictive manipulation of these pathways. However, this study identified the likely dispensable nature of a Δ12-desturase activity in our omega-3 metabolic engineering rationales for Camelina.

12.
Philos Trans R Soc Lond B Biol Sci ; 372(1728)2017 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-28717017

RESUMO

Diatoms are responsible for up to 40% of the carbon fixation in our oceans. The fixed carbon is moved through carbon metabolism towards the synthesis of organic molecules that are consumed through interlocking foodwebs, and this process is strongly impacted by the abiotic environment. However, it has become evident that diatoms can be used as 'platform' organisms for the production of high valuable bio-products such as lipids, pigments and carbohydrates where stress conditions can be used to direct carbon metabolism towards the commercial production of these compounds. In the first section of this review, some aspects of carbon metabolism in diatoms and how it is impacted by environmental factors are briefly described. The second section is focused on the biosynthesis of lipids and in particular omega-3 long-chain polyunsaturated fatty acids and how low temperature stress impacts on the production of these compounds. In a third section, we review the recent advances in bioengineering for lipid production. Finally, we discuss new perspectives for designing strains for the sustainable production of high-value lipids.This article is part of the themed issue 'The peculiar carbon metabolism in diatoms'.


Assuntos
Carbono/metabolismo , Temperatura Baixa , Diatomáceas/metabolismo , Lipídeos/biossíntese , Bioengenharia , Metabolismo dos Lipídeos , Estresse Fisiológico
13.
PLoS One ; 12(4): e0175415, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28403232

RESUMO

New de novo sources of omega 3 (n-3) long chain polyunsaturated fatty acids (LC-PUFA) are required as alternatives to fish oil in aquafeeds in order to maintain adequate levels of the beneficial fatty acids, eicosapentaenoic and docosahexaenoic (EPA and DHA, respectively). The present study investigated the use of an EPA+DHA oil derived from transgenic Camelina sativa in Atlantic salmon (Salmo salar) feeds containing low levels of fishmeal (35%) and fish oil (10%), reflecting current commercial formulations, to determine the impacts on tissue fatty acid profile, intestinal transcriptome, and health of farmed salmon. Post-smolt Atlantic salmon were fed for 12-weeks with one of three experimental diets containing either a blend of fish oil/rapeseed oil (FO), wild-type camelina oil (WCO) or transgenic camelina oil (DCO) as added lipid source. The DCO diet did not affect any of the fish performance or health parameters studied. Analyses of the mid and hindgut transcriptomes showed only mild effects on metabolism. Flesh of fish fed the DCO diet accumulated almost double the amount of n-3 LC-PUFA than fish fed the FO or WCO diets, indicating that these oils from transgenic oilseeds offer the opportunity to increase the n-3 LC-PUFA in farmed fish to levels comparable to those found a decade ago.


Assuntos
Ração Animal , Brassicaceae/química , Mucosa Intestinal/metabolismo , Óleos Vegetais/metabolismo , Plantas Geneticamente Modificadas/química , Salmo salar/crescimento & desenvolvimento , Transcriptoma , Animais , Brassicaceae/genética , Ácidos Docosa-Hexaenoicos/biossíntese , Ácido Eicosapentaenoico/biossíntese , Óleos de Peixe/química , Proteínas de Peixes/genética , Proteínas de Peixes/metabolismo , Pesqueiros , Células Caliciformes/citologia , Intestinos/citologia , Metabolismo dos Lipídeos , Plantas Geneticamente Modificadas/genética , Salmo salar/metabolismo
14.
Plant J ; 90(2): 358-371, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28142200

RESUMO

Peroxisomes are thought to have played a key role in the evolution of metabolic networks of photosynthetic organisms by connecting oxidative and biosynthetic routes operating in different compartments. While the various oxidative pathways operating in the peroxisomes of higher plants are fairly well characterized, the reactions present in the primitive peroxisomes (microbodies) of algae are poorly understood. Screening of a Chlamydomonas insertional mutant library identified a strain strongly impaired in oil remobilization and defective in Cre05.g232002 (CrACX2), a gene encoding a member of the acyl-CoA oxidase/dehydrogenase superfamily. The purified recombinant CrACX2 expressed in Escherichia coli catalyzed the oxidation of fatty acyl-CoAs into trans-2-enoyl-CoA and produced H2 O2 . This result demonstrated that CrACX2 is a genuine acyl-CoA oxidase, which is responsible for the first step of the peroxisomal fatty acid (FA) ß-oxidation spiral. A fluorescent protein-tagging study pointed to a peroxisomal location of CrACX2. The importance of peroxisomal FA ß-oxidation in algal physiology was shown by the impact of the mutation on FA turnover during day/night cycles. Moreover, under nitrogen depletion the mutant accumulated 20% more oil than the wild type, illustrating the potential of ß-oxidation mutants for algal biotechnology. This study provides experimental evidence that a plant-type FA ß-oxidation involving H2 O2 -producing acyl-CoA oxidation activity has already evolved in the microbodies of the unicellular green alga Chlamydomonas reinhardtii.


Assuntos
Acil-CoA Oxidase/metabolismo , Chlamydomonas/enzimologia , Chlamydomonas/metabolismo , Peroxissomos/metabolismo , Chlamydomonas/genética , Peróxido de Hidrogênio/metabolismo , Metabolismo dos Lipídeos/genética , Metabolismo dos Lipídeos/fisiologia , Nitrogênio/metabolismo , Oxirredução
15.
Plant Biotechnol J ; 15(2): 227-236, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27496594

RESUMO

Soya bean (Glycine max (L.) Merr.) is sought after for both its oil and protein components. Genetic approaches to add value to either component are ongoing efforts in soya bean breeding and molecular biology programmes. The former is the primary vegetable oil consumed in the world. Hence, its primary usage is in direct human consumption. As a means to increase its utility in feed applications, thereby expanding the market of soya bean coproducts, we investigated the simultaneous displacement of marine ingredients in aquafeeds with soya bean-based protein and a high Omega-3 fatty acid soya bean oil, enriched with alpha-linolenic and stearidonic acids, in both steelhead trout (Oncorhynchus mykiss) and Kampachi (Seriola rivoliana). Communicated herein are aquafeed formulations with major reduction in marine ingredients that translates to more total Omega-3 fatty acids in harvested flesh. Building off of these findings, subsequent efforts were directed towards a genetic strategy that would translate to a prototype design of an optimal identity-preserved soya bean-based feedstock for aquaculture, whereby a multigene stack approach for the targeted synthesis of two value-added output traits, eicosapentaenoic acid and the ketocarotenoid, astaxanthin, were introduced into the crop. To this end, the systematic introduction of seven transgenic cassettes into soya bean, and the molecular and phenotypic evaluation of the derived novel events are described.


Assuntos
Ração Animal , Aquicultura/métodos , Peixes/metabolismo , Soja/crescimento & desenvolvimento , Fenômenos Fisiológicos da Nutrição Animal , Animais , Ácido Eicosapentaenoico/metabolismo , Ácidos Graxos Ômega-3/administração & dosagem , Oncorhynchus mykiss/metabolismo , Óleos Vegetais , Plantas Geneticamente Modificadas , Óleo de Soja/administração & dosagem , Soja/genética , Xantofilas/metabolismo , Ácido alfa-Linoleico
16.
Plant Biotechnol J ; 15(7): 837-849, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27990737

RESUMO

The functional characterization of wax biosynthetic enzymes in transgenic plants has opened the possibility of producing tailored wax esters (WEs) in the seeds of a suitable host crop. In this study, in addition to systematically evaluating a panel of WE biosynthetic activities, we have also modulated the acyl-CoA substrate pool, through the co-expression of acyl-ACP thioesterases, to direct the accumulation of medium-chain fatty acids. Using this combinatorial approach, we determined the additive contribution of both the varied acyl-CoA pool and biosynthetic enzyme substrate specificity to the accumulation of non-native WEs in the seeds of transgenic Camelina plants. A total of fourteen constructs were prepared containing selected FAR and WS genes in combination with an acyl-ACP thioesterase. All enzyme combinations led to the successful production of wax esters, of differing compositions. The impact of acyl-CoA thioesterase expression on wax ester accumulation varied depending on the substrate specificity of the WS. Hence, co-expression of acyl-ACP thioesterases with Marinobacter hydrocarbonoclasticus WS and Marinobacter aquaeolei FAR resulted in the production of WEs with reduced chain lengths, whereas the co-expression of the same acyl-ACP thioesterases in combination with Mus musculus WS and M. aquaeolei FAR had little impact on the overall final wax composition. This was despite substantial remodelling of the acyl-CoA pool, suggesting that these substrates were not efficiently incorporated into WEs. These results indicate that modification of the substrate pool requires careful selection of the WS and FAR activities for the successful high accumulation of these novel wax ester species in Camelina seeds.


Assuntos
Camellia/metabolismo , Ésteres/metabolismo , Engenharia Metabólica/métodos , Plantas Geneticamente Modificadas/metabolismo , Sementes/metabolismo , Ceras/metabolismo , Camellia/genética , Plantas Geneticamente Modificadas/genética , Sementes/genética , Tioléster Hidrolases/genética , Tioléster Hidrolases/metabolismo , Ceras/química
17.
Plant Sci ; 252: 42-52, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27717477

RESUMO

In oil crops, triacylglycerol biosynthesis is an important metabolic pathway in which glycerol-3-phosphate acyltransferase (GPAT) performs the first acylation step. Mass spectrometry analysis of developing sunflower (Helianthus annuus) seed membrane fractions identified an abundant GPAT, HaGPAT9 isoform 1, with a N-terminal peptide that possessed two phosphorylated residues with possible regulatory function. HaGPAT9-1 belongs to a broad eukaryotic GPAT family, similar to mammalian GPAT3, and it represents one of the two sunflower GPAT9 isoforms, sharing 90% identity with HaGPAT9-2. Both sunflower genes are expressed during seed development and in vegetative tissues, with HaGPAT9-1 transcripts accumulating at relatively higher levels than those for HaGPAT9-2. Green fluorescent protein tagging of HaGPAT9-1 confirmed its subcellular accumulation in the endoplasmic reticulum. Despite their overall sequence similarities, the two sunflower isoforms displayed significant differences in their enzymatic activities. For instance, HaGPAT9-1 possesses in vivo GPAT activity that rescues the lethal phenotype of the cmy228 yeast strain, while in vitro assays revealed a preference of HaGPAT9-1 for palmitoyl-, oleoyl- and linoleoyl-CoAs of one order of magnitude, with the highest increase in yield for oleoyl- and linoleoyl-CoAs. By contrast, no enzymatic activity could be detected for HaGPAT9-2, even though its over-expression modified the TAG profile of yeast.


Assuntos
Glicerol-3-Fosfato O-Aciltransferase/fisiologia , Helianthus/enzimologia , Proteínas de Plantas/fisiologia , Clonagem Molecular , Retículo Endoplasmático/metabolismo , Glicerol-3-Fosfato O-Aciltransferase/análise , Glicerol-3-Fosfato O-Aciltransferase/metabolismo , Helianthus/genética , Helianthus/crescimento & desenvolvimento , Espectrometria de Massas , Filogenia , Proteínas de Plantas/análise , Proteínas de Plantas/metabolismo , RNA Mensageiro/metabolismo , Sementes/enzimologia , Sementes/genética , Sementes/crescimento & desenvolvimento
18.
Plant J ; 87(1): 76-86, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27483205

RESUMO

Plant seed lipid metabolism is an area of intensive research, including many examples of transgenic events in which oil composition has been modified. In the selected examples described in this review, progress towards the predictive manipulation of metabolism and the reconstitution of desired traits in a non-native host is considered. The advantages of a particular oilseed crop, Camelina sativa, as a flexible and utilitarian chassis for advanced metabolic engineering and applied synthetic biology are considered, as are the issues that still represent gaps in our ability to predictably alter plant lipid biosynthesis. Opportunities to deliver useful bio-based products via transgenic plants are described, some of which represent the most complex genetic engineering in plants to date. Future prospects are considered, with a focus on the desire to transition to more (computationally) directed manipulations of metabolism.


Assuntos
Biotecnologia/métodos , Engenharia Metabólica/métodos , Óleos Vegetais/metabolismo , Brassicaceae/metabolismo , Ácidos Graxos/metabolismo , Metabolismo dos Lipídeos/genética , Metabolismo dos Lipídeos/fisiologia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo
19.
PLoS One ; 11(7): e0159934, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27454884

RESUMO

Vegetable oils (VO) are possible substitutes for fish oil in aquafeeds but their use is limited by their lack of omega-3 (n-3) long-chain polyunsaturated fatty acids (LC-PUFA). However, oilseed crops can be modified to produce n-3 LC-PUFA such as eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids, representing a potential option to fill the gap between supply and demand of these important nutrients. Camelina sativa was metabolically engineered to produce a seed oil with around 15% total n-3 LC-PUFA to potentially substitute for fish oil in salmon feeds. Post-smolt Atlantic salmon (Salmo salar) were fed for 11-weeks with one of three experimental diets containing either fish oil (FO), wild-type Camelina oil (WCO) or transgenic Camelina oil (DCO) as added lipid source to evaluate fish performance, nutrient digestibility, tissue n-3 LC-PUFA, and metabolic impact determined by liver transcriptome analysis. The DCO diet did not affect any of the performance or health parameters studied and enhanced apparent digestibility of EPA and DHA compared to the WCO diet. The level of total n-3 LC-PUFA was higher in all the tissues of DCO-fed fish than in WCO-fed fish with levels in liver similar to those in fish fed FO. Endogenous LC-PUFA biosynthetic activity was observed in fish fed both the Camelina oil diets as indicated by the liver transcriptome and levels of intermediate metabolites such as docosapentaenoic acid, with data suggesting that the dietary combination of EPA and DHA inhibited desaturation and elongation activities. Expression of genes involved in phospholipid and triacylglycerol metabolism followed a similar pattern in fish fed DCO and WCO despite the difference in n-3 LC-PUFA contents.


Assuntos
Ração Animal , Brassicaceae/metabolismo , Ácidos Docosa-Hexaenoicos , Ácido Eicosapentaenoico , Óleos Vegetais , Salmo salar/metabolismo , Animais , Brassicaceae/química , Brassicaceae/genética , Ácidos Docosa-Hexaenoicos/química , Ácido Eicosapentaenoico/química , Ácidos Graxos/química , Ácidos Graxos Ômega-3/química , Perfilação da Expressão Gênica , Metabolismo dos Lipídeos , Lipídeos/química , Fígado/metabolismo , Lisossomos , Engenharia Metabólica , Avaliação Nutricional , Especificidade de Órgãos , Peroxidase , Extratos Vegetais/química , Óleos Vegetais/química , Plantas Geneticamente Modificadas , Salmo salar/genética , Salmo salar/crescimento & desenvolvimento , Sementes/química , Transcriptoma
20.
Biochim Biophys Acta ; 1861(9 Pt B): 1329-1335, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27086144

RESUMO

Sphingolipids and their phosphorylated derivatives are ubiquitous bio-active components of cells. They are structural elements in the lipid bilayer and contribute to the dynamic nature of the membrane. They have been implicated in many cellular processes in yeast and animal cells, including aspects of signaling, apoptosis, and senescence. Although sphingolipids have a better defined role in animal systems, they have been shown to be central to many essential processes in plants including but not limited to, pollen development, signal transduction and in the response to biotic and abiotic stress. A fuller understanding of the roles of sphingolipids within plants has been facilitated by classical biochemical studies and the identification of mutants of model species. Recently the development of powerful mass spectrometry techniques hailed the advent of the emerging field of lipidomics enabling more accurate sphingolipid detection and quantitation. This review will consider plant sphingolipid biosynthesis and function in the context of these new developments. This article is part of a Special Issue entitled: Plant Lipid Biology edited by Kent D. Chapman and Ivo Feussner.


Assuntos
Membrana Celular/genética , Bicamadas Lipídicas/metabolismo , Pólen/genética , Esfingolipídeos/genética , Aclimatação/genética , Membrana Celular/metabolismo , Fosforilação , Pólen/metabolismo , Transdução de Sinais/genética , Esfingolipídeos/isolamento & purificação , Esfingolipídeos/metabolismo , Estresse Fisiológico/genética
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