Desaturase Gene Expression Research Articles

Effects of temperature and salinity on the LC-PUFA biosynthesis and composition of the nereid polychaete Hediste diversicolor fed side streams

The rapid growth of aquaculture has prompted the exploration of alternative and sustainable feed ingredients. Polychaetes, such as Hediste diversicolor, offer promise in the circular economy due to their ability to recycle waste materials from bioindustries and convert low nutritional value fatty acids (FA) into eicosapentaenoic (EPA) and arachidonic (ARA) acids. This study explored the combined effect of temperature and salinity on growth and LC-PUFA biosynthesis in H. diversicolor fed on a side stream diet (33% sludge from salmon aquaculture (AS) and 66% solid-phase digestate from biogas production (SBD)). Polychaetes were cultured for 28 days along a 5-step temperature and salinity gradient ranging from 7.7 to 17.9 °C and 5 to 40 psu, respectively. Growth was highest at high temperatures (≥ 14.3 °C) and salinities (≥ 35 psu). The FA composition remained relatively stable across different culture temperatures, while salinity exhibited higher levels of n − 3 PUFA and n − 3 LC-PUFA at lower salinities (5 and 15 psu) compared to higher salinity (35 psu), mainly driven by EPA. This suggests that salinity may exert a more pronounced effect than temperature on the FA profiles of H. diversicolor. Despite low temperature and high salinity (40 psu) significantly upregulating the expression of elongase and desaturase genes, this was not translated into higher LC-PUFA. Remarkably, polychaetes exhibited high levels of n − 3 and n − 6 LC-PUFA, even when fed a diet deficient in such FA. These findings highlight the potential of H. diversicolor for LC-PUFA biosynthesis, positioning this species as a promising candidate for producing high-nutritional-value ingredients for aquafeeds.

Maize lipid droplet-associated protein 2 is recruited by a virus to enhance viral multiplication and infection through regulating cellular fatty acid metabolism.

Pathogen infection induces massive reprogramming of host primary metabolism. Lipid and fatty acid (FA) metabolism is generally disrupted by pathogens and co-opted for their proliferation. Lipid droplets (LDs) that play important roles in regulating cellular lipid metabolism are utilized by a variety of pathogens in mammalian cells. However, the function of LDs during pathogenic infection in plants remains unknown. We show here that infection by rice black streaked dwarf virus (RBSDV) affects the lipid metabolism of maize, which causes elevated accumulation of C18 polyunsaturated fatty acids (PUFAs) leading to viral proliferation and symptom development. The overexpression of one of the two novel LD-associated proteins (LDAPs) of maize (ZmLDAP1 and ZmLDAP2) induces LD clustering. The core capsid protein P8 of RBSDV interacts with ZmLDAP2 and prevents its degradation through the ubiquitin-proteasome system mediated by a UBX domain-containing protein, PUX10. In addition, silencing of ZmLDAP2 downregulates the expression of FA desaturase genes in maize, leading to a decrease in C18 PUFAs levels and suppression of RBSDV accumulation. Our findings reveal that plant virus may recruit LDAP to regulate cellular FA metabolism to promote viral multiplication and infection. These results expand the knowledge of LD functions and viral infection mechanisms in plants.

Effects of temperature up-shift and UV-A radiation on fatty acids content and expression of desaturase genes in cyanobacteria Microcystis aeruginosa: stress tolerance and acclimation responses.

Temperature up-shift and UV-A radiation effects on growth, lipid damage, fatty acid (FA) composition and expression of desaturase genes desA and desB were investigated in the cyanobacteria Microcystis aeruginosa. Although UV-A damaging effect has been well documented, reports on the interactive effects of UV radiation exposure and warming on cyanobacteria are scarce. Temperature and UV-A doses were selected based on the physiological responses previously obtained by studies with the same M. aeruginosa strain used in this study. Cells pre-grown at 26°C were incubated at the same temperature or 29°C and exposed to UV-A + PAR and only PAR for 9days. Growth rate was significantly affected by UV-A radiation independently of the temperature throughout the experiment. High temperature produced lipid damage significantly higher throughout the experiment, decreasing at day 9 as compared to 26°C. In addition, the cells grown at 29°C under UV-A displayed a decrease in polyunsaturated FA (PUFA) levels, with ω3 PUFA being mostly affected at the end of exposure. Previously, we reported that UV-A-induced lipid damage affects differentially ω3 and ω6 PUFAs. We report that UV-A radiation leads to an upregulation of desA, possibly due to lipid damage. In addition, the temperature up-shift upregulates desA and desB regardless of the radiation. The lack of lipid damage for UV-A on ω3 could explain the lack of transcription induction of desB. The significant ω6 decrease at 26°C in cells exposed to UV-A could be due to the lack of upregulation of desA.

Effect of Different Types of Organic Manure on Oil and Fatty Acid Accumulation and Desaturase Gene Expression of Oilseed Flax in the Dry Areas of the Loess Plateau of China

In order to understand the mechanism of action of oil and fatty acid accumulation and desaturase gene expression in how oilseed flax responds to different fertilization conditions, a three-factor split-plot experiment was conducted to investigate the accumulation trends of oil and fatty acids. The results revealed that soluble sugar (SS) and sucrose (SUC) contents decreased, and the starch (ST) content increased gradually with the grain development and maturity of oilseed flax. The application of sheep manure promoted the accumulation of nonstructural carbohydrates in the grains. Soluble sugar (SS) and sucrose (SUC) contents were negatively correlated with the oil content. Compared with chemical fertilizer, organic manure decreased the total saturated fatty acid but increased the unsaturated fatty acid. Organic manure significantly upregulated the expression of various genes, and fad2a gene expression was higher with the 5.8 t ha−1 chicken manure treatment. The 25 t ha−1 sheep manure treatment was more conducive to the expression of fad3a and fad3b genes and promoted the accumulation of linolenic acid (LIN), and the LIN content increased by 0.64–3.90% compared with other treatments. Consequently, an ongoing anthropogenic sheep manure input may impact the regulation of grain oil quality and yield per unit area.

Dietary omega-3 fatty acid deficiency from pre-pregnancy to lactation affects expression of genes involved in hippocampal neurogenesis of the offspring

Maternal n-3 PUFA (omega-3) deficiency can affect brain development in utero and postnatally. Despite the evidence, the impacts of n-3 PUFA deficiency on the expression of neurogenesis genes in the postnatal hippocampus remained elusive. Since postnatal brain development requires PUFAs via breast milk, we examined the fatty acid composition of breast milk and hippocampal expression of neurogenesis genes in n-3 PUFA deficient 21d mice. In addition, the expression of fatty acid desaturases, elongases, free fatty acids signaling receptors, insulin and leptin, and glucose transporters were measured. Among the genes involved in neurogenesis, the expression of brain-specific tenascin-R (TNR) was downregulated to a greater extent (∼31 fold), followed by adenosine A2A receptor (A2AAR), dopamine receptor D2 (DRD2), glial cell line-derived neurotrophic factor (GDNF) expression in the n-3 PUFA deficient hippocampus. Increasing dietary LA to ALA (50:1) elevated the ARA to DHA ratio by ∼8 fold in the n-3 PUFA deficient breast milk, with an overall increase of total n-6/n-3 PUFAs by ∼15:1 (p<0.05) compared to n-3 PUFA sufficient (LA to ALA: 2:1) diet. The n-3 PUFA deficient mice exhibited upregulation of FADS1, FADS2, ELOVL2, ELOVL5, ELOVL6, GPR40, GPR120, LEPR, IGF1 and downregulation of GLUT1, GLUT3, and GLUT4 mRNA expression in hippocampus (p<0.05). Maternal n-3 PUFA deficiency affects the hippocampal expression of key neurogenesis genes in the offspring with concomitant expression of desaturase and elongase genes, suggesting the importance of dietary n-3 PUFA for neurodevelopment.

Effects of Temperature and Salt Stress on the Expression of delta-12 Fatty Acid Desaturase Genes and Fatty Acid Compositions in Safflower.

The regulation of microsomal (e.g., FAD2) and plastidial (e.g., FAD6) oleate desaturases by cold, heat and salt stress were investigated. Gene expression levels and fatty acid compositions were determined in the roots, stems and leaves of safflower following stress treatments. A safflower plastidial oleate desaturase gene, CtFAD6, was cloned, and oleic acid desaturation was confirmed in Synechococcus sp. strain PCC7942. The results showed that temperature regulated oleate desaturation at the transcriptional level, and this regulation pattern was tissue-specific. CtFAD2-1, CtFAD2-2 and CtFAD6 were significantly induced under cold and heat stress in young leaves, and CtFAD2-2 and CtFAD6 were slightly induced in young stems. In contrast, CtFAD2-1, CtFAD2-11 and CtFAD2-10 were sensitive to salt stress in all safflower tissues (roots, stem and leaves). CtFAD6 was insensitive to salt and was slightly induced in leaves only.

How Temperatures May Affect the Synthesis of Fatty Acids during Olive Fruit Ripening: Genes at Work in the Field

A major concern for olive cultivation in many extra-Mediterranean regions is the adaptation of recently introduced cultivars to environmental conditions different from those prevailing in the original area, such as the Mediterranean basin. Some of these cultivars can easily adapt their physiological and biochemical parameters in new agro-environments, whereas others show unbalanced values of oleic acid content. The objective of this study was to evaluate the effects of the thermal regime during oil synthesis on the expression of fatty acid desaturase genes and on the unsaturated fatty acid contents at the field level. Two cultivars (Arbequina and Coratina) were included in the analysis over a wide latitudinal gradient in Argentina. The results suggest that the thermal regime exerts a regulatory effect at the transcriptional level on both OeSAD2 and OeFAD2-2 genes and that this regulation is cultivar-dependent. It was also observed that the accumulated thermal time affects gene expression and the contents of oleic and linoleic acids in cv. Arbequina more than in Coratina. The fatty acid composition of cv. Arbequina is more influenced by the temperature regime than Coratina, suggesting its greater plasticity. Overall, findings from this study may drive future strategies for olive spreading towards areas with different or extreme thermal regimes serve as guidance for the evaluation olive varietal patrimony.

Thiotemplated Biosynthesis of Bacterial Polyyne Fatty Acids by a Designated Desaturase Triad.

Various bacterial species are capable of producing highly modified fatty acid derivatives with conjugated triple bonds, which play important ecological roles as antifungals and toxins in mutualistic and pathogenic interactions. Furthermore, the terminal polyyne moiety is of interest as pharmacophore and as tag in bioorthogonal chemistry and live imaging. To gain insight into the assembly of these highly reactive natural products, we investigated tetrayne (caryoynencin and protegencin) biosynthesis genes (cay and pgn) from Trinickia caryophylli and Pseudomonas protegens. Pathway dissection and reconstitution in the heterologous host Burkholderia graminis revealed the genes minimally required for polyyne formation. Mutational analyses and biochemical assays demonstrated that polyyne biosynthesis is thiotemplated, involving a fatty acyl-AMP ligase, a designated acyl carrier protein, and a thioesterase. Heterologous expression of point-mutated desaturase genes showed that three desaturases work synergistically to introduce four triple bonds. These findings point to an intricate desaturase complex and provide important information for future bioengineering experiments.

Desaturases: Structural and mechanistic insights into the biosynthesis of unsaturated fatty acids.

This review highlights the key role of fatty acid desaturases in the synthesis of naturally occurring, more common and not unsaturated fatty acids. The three major classes of fatty acid desaturases, such as acyl-lipid, acyl-acyl carrier protein and acyl-coenzyme A, are described in detail, with particular attention to the cellular localisation, the structure, the substrate and product specificity and the expression and regulation of desaturase genes. The review also gives an insight into the biocatalytic reaction of fatty acid desaturation by covering the general and more class-specific mechanistic studies around the synthesis of unsaturated fatty acids Finally, we conclude the review by looking at the numerous novel applications for desaturases in order to meet the very high demand for polyunsaturated fatty acids, taking into account the opportunity for the development of new, more efficient, easily reproducible, sustainable bioengineering advances in the field.

A Novel Strategy for the Production of Edible Insects: Effect of Dietary Perilla Seed Supplementation on Nutritional Composition, Growth Performance, Lipid Metabolism, and Δ6 Desaturase Gene Expression of Sago Palm Weevil (Rhynchophorus ferrugineus) Larvae.

The nutritional value, growth performance, and lipid metabolism of sago palm weevil larvae (Rhynchophorus ferrugineus, SPWL) raised on plant-based diets (soybean, rice bran, and ground sago palm trunk (GSPT)), supplemented with various concentrations (0, 3, 7, 15, and 20%) of perilla seed (PS) were compared with traditional diets i.e., regular GSPT (control) and GSPT supplemented with pig feed. All supplemented diets rendered SPWL with higher lipid and protein contents (p < 0.05). Supplementing with 7–20% PS enhanced α-linoleic acid content in SPWL, resulting in a decrease in the n-6:n-3 ratio to a desirable level. Dietary PS supplementation increased Δ9 (18), total Δ9 and Δ5 + Δ6 desaturase indexes, fatty acid (FA) unsaturation, and the polyunsaturated FA:saturated FA ratio in SPWL, while lowering atherogenicity index, thrombogenicity index, and Δ6 desaturase (fads2) gene expression. Boosting with 7% PS improved the majority of growth parameters and enhanced essential amino acid and mineral contents (p < 0.05).

Iron and methyl jasmonate increase high-value PUFA production by elevating the expression of desaturase genes in marine microalga Isochrysis sp.

This study investigated the effect of several metabolic enhancers on the expression of fatty acid biosynthetic genes and their influence on the production of high-value PUFA in the marine microalgae Isochrysis sp., CASA CC 101. The effect of the presence of iron (Fe), nicotinic acid (NIC), methyl jasmonate (MJ) and thidiazuron (TDZ) on the expression of the fatty acid desaturase genes Δ6Des, Δ5Des and Δ4Des was studied in cultures of the marine microalga Isochrysis sp., CASA CC 101.The production of high-value PUFA like γ-linolenic acid (GLA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) was correlated with these gene expressions. The results showed that MJ, Fe and TDZ significantly increased the lipid content than the control. MJ specifically up-regulated ∆6Des gene expression and thereby increased GLA production. Whereas Fe specifically increased ∆5Des gene expression and thereby increased EPA production. However, Fe and TDZ-treated cells effectively upregulated the expression of ∆4Des and increased the production of DHA when compared with control cells. Our findings suggest that addition of Fe and MJ in the culture medium triggers the expression of PUFA biosynthetic genes, especially ∆6Des and ∆4Des, in marine microalga Isochrysis sp., CASA CC 101 their presence resulted in increased production of the PUFAs GLA, EPA and DHA. This study shows that the addition of Fe and MJ to the culture media ofIsochrysis sp., CASA CC 101results in up-regulation of its genes Δ4Des, Δ6Des and Δ5Des, and improves the production of PUFA. Therefore, the addition of Fe and MJ to the culture medium is useful to increase the production of high-value PUFA in Isochrysis sp., CASA CC 101 and also to the other micro algal species.

Molecular characterization of biosynthesis of polyunsaturated fatty acids during different developmental stages in the copepod Apocyclops royi

Copepod Apocyclops royi can biosynthesize long-chain polyunsaturated fatty acids (LC-PUFAs) when fed low-PUFA precursors. Previously, two elongases and two desaturases in the n-3 PUFA biosynthetic pathway were identified from A. royi. However, the complete PUFA biosynthesis pathway in this copepod species is poorly understood. Here, we report 13 genes, of which nine are novel genes, encoding PUFA biosynthesis-related enzymes belonging to the fatty acid desaturases (ArD6D, ArD5D, ArD4D, ArO3D-1, and ArO3D-2) and elongases (Elovl1, 2, 3, 4, 5, 6, 7, and 8) families identified from a Thai culture of A. royi (A. royi-TH). Identification of the fatty acid contents using gas chromatography/mass spectroscopy analysis indicated that the copepodid and adult stages were high in PUFAs, with omega-3 fatty acids, while the nauplius stage had the lowest level of PUFAs. Moreover, all copepod stages of A. royi-TH fed Tetraselmis suecica contained higher levels of LC-PUFAs, including docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), than the microalgae fatty acid content, which was deficient in omega-3 DHA. Changes in transcript expression levels were determined in three developmental stages of A. royi-TH. Interestingly, the increased gene expression of the fatty acid desaturases (ArD6D, ArD5D, ArD4D, ArO3D-1, and ArO3D-2) and elongases (ArElovl3, 4, 5, 6, and 7) in the adult stages was reflected in the increased fatty acid concentration of DHA and EPA in the adult stages compared with the other developmental stages, suggesting the possible function of these genes for LC-PUFA synthesis in the different copepod developmental stages. These results indicate that the nauplius, copepodid, and adult stages are capable of synthesizing DHA from low PUFA through a LC-PUFA biosynthesis pathway.

Response of Transgenic Potato Plants Expressing Heterologous Genes of ∆9- or ∆12-Acyl-lipid Desaturases to Phytophthora infestans Infection.

Late blight is one of the most economically important diseases affecting potato and causing a significant loss in yield. The development of transgenic potato plants with enhanced resistance to infection by Phytophthora infestans may represent a possible approach to solving this issue. A comparative study of the leaf response in control potato plants (S.tuberosum L. cultivar Skoroplodnyi), control transgenic plants expressing the reporter gene of thermostable lichenase (transgenic licBM3 line) and transgenic plants expressing cyanobacterial hybrid genes ∆9-acyl-lipid desaturase (transgenic desC lines) and ∆12-acyl-lipid desaturase (transgenic desA lines) to infection with P. infestans has been performed. The expression of desaturase genes in potato plants enhanced their tolerance to potato late blight agents as compared with the control. The lipid peroxidation level raised in the leaves of the control and transgenic desA plants on third day after inoculation with P. infestans zoospores and remained the same in the transgenic desC plants. The number of total phenolic compounds was increased as early as on the second day after infection in all studied variants and continued to remain the same, except for transgenic desC plants. Accumulation of flavonoids, the main components of the potato leaf phenolic complex, raised on the second day in all studied variants, remained unchanged on the third day in the control plants and decreased in most transgenic plants expressing desaturase genes. The results obtained in our study demonstrate that the expression of genes of Δ9- and Δ12-acyl-lipid desaturases in potato plants enhanced their resistance to P. infestans as compared with the control non-transgenic plants due to concomitant accumulation of phenolic compounds, including flavonoids, in the leaves. All these changes were more pronounced in transgenic desC plants, which indicates that the Δ9-acyllipid desaturase gene appears to be a potential inducer of the production of biological antioxidants in plant cells.

Association between FADS Gene Expression and Polyunsaturated Fatty Acids in Breast Milk.

Polyunsaturated fatty acid (PUFA) in breast milk provides physiological benefits for offspring and is closely related to endogenous biosynthesis in lactating women. Few studies have addressed the association between fatty acid desaturase (FADS) gene expression patterns and fatty acids in breast milk. This research aimed to explore the differences in PUFA levels among breast milk groups with different levels of FADS gene expression and provide a scientific basis for precision nutrition strategies. A total of 50 healthy women 42–45 days postpartum were included in this study. A basic information questionnaire and breast milk samples were collected. Eight types of PUFA were detected, and RNA was extracted from breast milk. The transcription level of the FADS gene was detected using real-time quantitative PCR. Significant differences in the content of gamma-linolenic acid and eicosatrienoic acid (C20:3n6) were found in breast milk among FADS1 gene transcription groups (p = 0.009, p = 0.042, respectively). No significant differences in PUFA were found among the FADS2 and FADS3 gene expression groups. The results demonstrated that n-6 PUFA was associated with the mRNA expression levels of the FADS1 gene. They are of great significance in developing new methods and diets to optimize infant feeding using breast milk.

Stearoyl-CoA Desaturase Activity and Gene Expression in the Adipose Tissue of Buffalo Bulls Was Unaffected by Diets with Different Fat Content and Fatty Acid Profile

Research on diet effects on buffalo meat quality may be critical to assess its possible consumption benefits in human nutrition. This study investigated, in growing buffalo bulls, the effects of two diets differing in total fat content and fatty acid profile on the activity and gene expression of Stearoyl-CoA Desaturase (SCD) in the adipose tissue and on meat quality. Twenty buffalo bulls, 6 months old, were randomly assigned to the two dietary treatments until slaughtering (about 400 kg body weight). No significant difference between the groups was observed for chemical composition, fatty acid profile and CLAs content of Longissimus thoracis as well as for the SCD gene expression. Such results seem to be in contrast with similar studies performed on other ruminant species, but confirm that important differences occur between buffalo and bovine species, such as the lower content in fat of buffalo meat. Our results also confirm that specific studies should be performed on buffalo, also in terms of the metabolic pathways activated by different diets.

Gibberellic acid-induced fatty acid metabolism and ABC transporters promote astaxanthin production in Phaffia rhodozyma.

Astaxanthin is an important natural antioxidant with various biological functions; however, the production of astaxanthin does not meet the requirements for industrialization. The aim of the present study was to identify an inducer that increases astaxanthin yield and to evaluate the regulatory mechanism of the induction of astaxanthin synthesis in Phaffia rhodozyma. The effects of indole-3-acetic acid (IAA), jasmonic acid (JA) and gibberellic acid (GA) on astaxanthin synthesis were studied by fermentation kinetics analysis. Then, combined transcriptomics and metabolomics approaches were used to analyse differential metabolites and expressed genes involved in astaxanthin synthesis induced by GA. The results indicated that GA significantly increased astaxanthin production; however, IAA and JA had no significant effect on astaxanthin synthesis. The induction by GA significantly enhanced fatty acid metabolism and ABC transporters, increased the expression of fatty acid desaturase and ABC transporter genes, and elevated the contents of unsaturated fatty acids. These results suggested that fatty acid saturation plays an important role in astaxanthin accumulation and that ABC transporters may be the efflux pumps for astaxanthin. The present study reveals metabolic mechanism of GA-induced astaxanthin synthesis and proposes a new strategy of transporter engineering to improve astaxanthin production.

Fatty acid modulation and desaturase gene expression are differentially triggered in grapevine incompatible interaction with biotrophs and necrotrophs

Grapevine (Vitis vinifera L.) is prone to fungal and oomycete diseases. Downy and powdery mildews and grey mold, are caused by Plasmopara viticola, Erisiphe necator and Botrytis cinerea, respectively. P. viticola and E. necator are obligatory biotrophs whereas B. cinerea is a necrotroph. In tolerant grapevine cultivars, plant-pathogen interaction induces defence responses, including metabolite and protein accumulation and hypersensitive reaction. Lipid and lipid-derived molecules may have a key role in the activation of defence mechanisms. Previous results suggest that V. vinifera cv Regent tolerance to P. viticola may be mediated in the first hours post inoculation by fatty acid (FA) associated signalling. In the present study we characterized FA modulation in V. vinifera cv Regent leaves upon inoculation with P. viticola, E. necator and B. cinerea and correlated FA modulation with the expression profiles of genes encoding the FA desaturases FAD6 and FAD8. In all the interactions, a progressive desaturation of stearic acid to α-linolenic acid, precursor of jasmonic acid, occurred, which was observed for a longer period against B. cinerea. Our results provide evidence of a distinct FA meditated signalling pattern in grapevine interaction with biotrophs and necrotrophs. While the interaction with the biotrophs may trigger a higher synthesis of polyunsaturated FA (PUFA) at early time-points with a tendency to return to basal levels, the interaction with B. cinerea may trigger a later and more durable induction of PUFA synthesis. In all interactions, membrane fluidity modulation occurred, which may be crucial to maintain cellular function during infection.

The Oleic/Linoleic Acid Ratio in Olive (Olea europaea L.) Fruit Mesocarp Is Mainly Controlled by OeFAD2-2 and OeFAD2-5 Genes Together With the Different Specificity of Extraplastidial Acyltransferase Enzymes.

Fatty acid composition of olive oil has an important effect on the oil quality to such an extent that oils with a high oleic and low linoleic acid contents are preferable from a nutritional and technological point of view. In the present work, we have first studied the diversity of the fatty acid composition in a set of eighty-nine olive cultivars from the Worldwide Olive Germplasm Bank of IFAPA Cordoba (WOGBC-IFAPA), and in a core collection (Core-36), which includes 28 olive cultivars from the previously mentioned set. Our results indicate that oleic and linoleic acid contents displayed the highest degree of variability of the different fatty acids present in the olive oil of the 89 cultivars under study. In addition, the independent study of the Core-36 revealed two olive cultivars, Klon-14 and Abou Kanani, with extremely low and high linoleic acid contents, respectively. Subsequently, these two cultivars were used to investigate the specific contribution of different fatty acid desaturases to the linoleic acid content of mesocarp tissue during olive fruit development and ripening. Fatty acid desaturase gene expression levels, together with lipid analysis, suggest that not only OeFAD2-2 and OeFAD2-5 but also the different specificities of extraplastidial acyltransferase enzymes are responsible for the variability of the oleic/linoleic acid ratio in olive cultivars. All this information allows for an advancement in the knowledge of the linoleic acid biosynthesis in different olive cultivars, which can impact olive breeding programs to improve olive oil quality.

Effects of Salicylic Acid on Fatty Acid Gene Expression in Carthamus tinctorious L. cv. Dinçer under Pendimethalin Stress

Pendimethalin is a member of the dinitroaniline class herbicide. It used to control most annual grasses and many annual broad-leaved weeds. Salicylic acid acts as an endogenous signal molecule in charge of inducing environmental stress tolerance in plants. Omega-3 fatty acid desaturase is a key enzyme for α-linolenic acid biosynthesis. Here, we searched to understand the beneficial impacts of salicylic acid on fatty acid desaturase gene (FAD3 and FAD7) expression during pendimethalin stress in safflower (Carthamus tinctorious cv. “Dinçer). In this study, 0.004 and 0.01 M pendimethalin was applied to safflower plants grown under controlled climatic conditions in 36 pots. 0.05 mM salicylic acid was applied to the samples where pendimethalin was applied. After application, gene expression analyze were performed using quantitative polymerase chain reaction. The floor change between the test and control groups was calculated with the formula 2 ^ (delta delta CT). The change between gene expression levels was evaluated by t test (p &amp;lt;0.05). FAD3 and FAD7 expression levels decreased at low pendimethalin concentration. A down-regulation in FAD3 expression was observed in high pendimethalin stress, while an up-regulation in FAD7 expression was detected. Salicylic acid had a ameliorative effect on the negative effect of pendimethalin stress on FAD3 and FAD7 gene expression.

Maternal high-fat diet in mice alters immune regulation and lung function in the offspring.

PUFA modulate immune function and have been associated with the risk of childhood atopy and asthma. We investigated the effect of maternal fat intake in mice on PUFA status, elongase and desaturase gene expression, inflammatory markers and lung function in the offspring. C57BL/6J mice (n 32) were fed either standard chow (C, 20·4 % energy as fat) or a high-fat diet (HFD, 39·9 % energy as fat) for 4 weeks prior to conception and during gestation and lactation. At 21 d of age, offspring were weaned onto either the HFD or C, generating four experimental groups: C/C, C/HF, HF/C and HF/HF. Plasma and liver fatty acid composition were measured by GC and gene expression by quantitative PCR. Lung resistance to methacholine was assessed. Arachidonic acid concentrations in offspring plasma and liver phospholipids were increased by HFD; this effect was greater in the post-natal HFD group. DHA concentration in offspring liver phospholipids was increased in response to HFD and was higher in the post-natal HFD group. Post-natal HFD increased hepatic fatty acid desaturase (FADS) 2 and elongation of very long-chain fatty acid 5 expression in male offspring, whereas maternal HFD elevated expression of FADS1 and FADS2 in female offspring compared with males. Post-natal HFD increased expression of IL-6 and C-C motif chemokine ligand 2 (CCL2) in perivascular adipose tissue. The HFD lowered lung resistance to methacholine. Excessive maternal fat intake during development modifies hepatic PUFA status in offspring through regulation of gene expression of enzymes that are involved in PUFA biosynthesis and modifies the development of the offspring lungs leading to respiratory dysfunction.