In a nutshell: pistachio genome and kernel development

Phytochemical plant tannins are phenolic compounds that interfere with biohydrogenation (BH) of monounsaturated-(MUFA) and poly-unsaturated fatty acids(PUFA). The objective of the present animal study was to investigate the effects of three different levels of phytochemical tannin-containing ground pine bark diet on fatty acid profiles of goat meat, with particular reference to MUFA and PUFA. The saturated fatty acids (SFA), PUFA, and PUFA/SFA ratios in subcutaneous adipose tissue as well as MUFA and PUFA composition of mesenteric kidney fat were increased with increasing phytochemical tannin-containing ground pine bark supplementation. The study showed that phytochemical plant tannins could be a means to moderate the accumulation of unsaturated fatty acids with the aim of improving percentage of these PUFA/SFA ratios in goat meat. The effects would be useful to improve carcass fatty acids composition and human health.

Date palms are remarkably tolerant to environmental stresses, but the mechanisms involved remain poorly characterized. Leaf metabolome profiling was therefore performed on mature (ML) and young (YL) leaves of 2-year-old date palm seedlings that had been grown in climate chambers that simulate summer and winter conditions in eastern Saudi Arabia. Cultivation under high temperature (summer climate) resulted in higher YL H2O2 leaf levels despite increases in dehydroascorbate reductase (DHAR) activities. The levels of raffinose and galactinol, tricarboxylic acid cycle intermediates, and total amino acids were higher under these conditions, particularly in YL. The accumulation of unsaturated fatty acids, 9,12-octadecadienoic acid and 9,12,15-octadecatrienoic acid, was lower in ML. In contrast, the amounts of saturated tetradecanoic acid and heptadecanoic acid were increased in YL under summer climate conditions. The accumulation of phenolic compounds was favored under summer conditions, while flavonoids accumulated under lower temperature (winter climate) conditions. YL displayed stronger hydration, lower H2O2 levels, and more negative δ 13C values, indicating effective reactive oxygen species scavenging. These findings, which demonstrate the substantial metabolic adjustments that facilitate tolerance to the high temperatures in YL and ML, suggest that YL may be more responsive to climate change.

Metabolic effects of phospholipids extracted from capelin (Mallotus villosus) roe on HepG2 cells

Abstract:The mechanism by which phospholipase A2 (EC 3.1.1.4) inhibits the binding of 3H‐saxitoxin (STX) to membranes from lobster walking‐leg nerves was examined. It was concluded that this inhibition of the binding was due to the accumulation of unsaturated fatty acids and lysophosphatides, products of the lipase action, in the 3H‐STX binding site. The destruction of the lipids themselves did not appear to cause the loss of the binding. The following evidence was presented in support of these conclusions. (1) Among the phospholipases tested, phospholipase A2 was the most effective in inhibiting the binding. Phospholipase A2 is also the only lipase that produces fatty acids and lysophosphatides. (2) The addition of fatty acid‐free bovine serum albumin protected the 3H‐STX binding sites from the inhibitory action of phospholipase A2; fatty‐acid‐free bovine serum albumin is capable of binding free fatty acids and lysophosphatides, thus preventing these products from interacting with the STX binding sites. (3) The addition of exogenous unsaturated fatty acids or lysophosphatides to membrane material inhibited the binding. These findings show that the STX binding activity is sensitive to unsaturated fatty acids and to lysophosphatides.

Cancer cells undergo alterations in lipid metabolism to support their high energy needs, tumorigenesis and evade an anti-tumor immune response. Alterations in fatty acid production are controlled by multiple enzymes, chiefly Acetyl CoA Carboxylase, ATP-Citrate Lyase, Fatty Acid Synthase, and Stearoyl CoA Desaturase 1. Ovarian cancer (OC) is a common gynecological malignancy with a high rate of aggressive carcinoma progression and drug resistance. The accumulation of unsaturated fatty acids in ovarian cancer supports cell growth, increased cancer cell migration, and worse patient outcomes. Ovarian cancer cells also expand their lipid stores via increased uptake of lipids using fatty acid translocases, fatty acid-binding proteins, and low-density lipoprotein receptors. Furthermore, increased lipogenesis and lipid uptake promote chemotherapy resistance and dampen the adaptive immune response needed to eliminate tumors. In this review, we discuss the role of lipid synthesis and metabolism in driving tumorigenesis and drug resistance in ovarian cancer conferring poor prognosis and outcomes in patients. We also cover some aspects of how lipids fuel ovarian cancer stem cells, and how these metabolic alterations in intracellular lipid content could potentially serve as biomarkers of ovarian cancer.

Metabolomic analysis reveals the responses of docosahexaenoic-acid-producing Schizochytrium under hyposalinity conditions

Fatty acid accumulation and synthesis rates were measured in two species of daphniid Cladocera, Daphnia magna and D. pulex, to determine what fraction of deposited fatty acids accumulated by these zooplankton species are dietary and what fraction are synthesized de novo. Fatty acid accumulation rates were measured as the increment in lipid weight during the adult third instar. Lipids were extracted, separated on chromarods, and quantified by flame‐ionization detection. Fatty acid synthesis rates were measured by exposing adult third‐instar females to [3H]2O and [U‐14C]‐acetate. Synthetic rate estimates using [U‐14C]‐acetate were consistently less than estimates obtained by using [3H]2O. Lipid content (percent of dry weight) from D. magna cultures supplied with high algal food (100,000 cells/ml) increased from 16.6% at the beginning of the third instar (eggs removed from brood pouch) to 22% at the beginning of the fourth instar (with eggs). The increase in lipid of D. pulex under identical conditions ranged from 19.8% to 30.6% total lipid and under low food conditions (4,000 cells/ml) ranged from 37% to 40% lipid. Accumulated fatty acids were associated largely with triacylglycerol (60–80% of accumulated lipid) or phospholipid (10–20% of accumulated lipid). Fatty acid accumulation for high‐food animals was 1,043 ng/hr/individual and 364 ng/hr/individual for D. magna and D. pulex, respectively. The corresponding fatty acid synthesis rates were 17 ng/hr/individual and 6 ng/hr/individual, respectively. Low‐food adults of D. pulex accumulated fatty acids at a rate of 192 ng/hr/individual and only synthesized fatty acids at a rate of 0.3 ng/hr/individual. Incorporated label was present in a slow turnover pool of complex polar lipids. Fatty acid synthesis contributes less than 2% of the accumulated total fatty acids in these daphniids.

Genetic engineering to produce valuable lipids containing unsaturated fatty acids (UFAs) holds great promise for food and industrial applications. Efforts to genetically modify plants to produce desirable UFAs with single enzymes, however, have had modest success. The key enzymes fatty acid desaturase (FAD) and diacylglycerol acyltransferase (DGAT) are responsible for UFA biosynthesis (a push process) and assembling fatty acids into lipids (a pull process) in plants, respectively. To examine their roles in UFA accumulation, VfFAD2 and VfDGAT2 genes cloned from Vernicia fordii (tung tree) oilseeds were conjugated and transformed into Rhodotorula glutinis and Arabidopsis thaliana via Agrobacterium tumefaciens. Real-time quantitative PCR revealed variable gene expression levels in the transformants, with a much higher level of VfDGAT2 than VfFAD2. The relationship between VfFAD2 expression and linoleic acid (C18:2) increases in R. glutinis (R (2) = 0.98) and A. thaliana (R (2) = 0.857) transformants was statistically linear. The VfDGAT2 expression level was statistically correlated with increased total fatty acid content in R. glutinis (R (2) = 0.962) and A. thaliana (R (2) = 0.8157) transformants. With a similar expression level between single- and two-gene transformants, VfFAD2-VfDGAT2 co-transformants showed a higher linolenic acid (C18:3) yield in R. glutinis (174.36 % increase) and A. thaliana (14.61 % increase), and eicosatrienoic acid (C20:3) was enriched (17.10 % increase) in A. thaliana. Our data suggest that VfFAD2-VfDGAT2 had a synergistic effect on UFA metabolism in R. glutinis, and to a lesser extent, A. thaliana. These results show promise for further genetic engineering of plant lipids to produce desirable UFAs.

Photosynthetic apparatus in chilling-sensitive plants. VII. Comparison of the effect of galactolipase treatment of chloroplasts and cold-dark storage of leaves on photosynthetic electron flow

Chapter 22 - Cold pressed pistachio (Pistacia vera) oil

Fatty acid composition of oil during maize kernel development

Changes in fatty acid and tocopherol content during almond (Prunus dulcis, cv. Nonpareil) kernel development

Understanding the mechanisms of lipid accumulation in microorganisms is important for several reasons. In addition to providing insight into assembly of biological membranes, lipid accumulation has important applications in the production of renewable fuels and chemicals. The photosynthetic bacterium Rhodobacter sphaeroides is an attractive organism to study lipid accumulation, as it has the ability to increase membrane production at low O2 tensions. Under these conditions, R. sphaeroides develops invaginations of the cytoplasmic membrane to increase its membrane surface area for housing of the membrane-bound components of its photosynthetic apparatus. Here we use fatty acid levels as a reporter of membrane lipid content. We show that, under low-O2 and anaerobic conditions, the total fatty acid content per cell increases 3-fold. We also find that the increases in the amount of fatty acid and photosynthetic pigment per cell are correlated as O2 tensions or light intensity are changed. To ask if lipid and pigment accumulation were genetically separable, we analyzed strains with mutations in known photosynthetic regulatory pathways. While a strain lacking AppA failed to induce photosynthetic pigment-protein complex accumulation, it increased fatty acid content under low-O2 conditions. We also found that an intact PrrBA pathway is required for low-O2-induced fatty acid accumulation. Our findings suggest a previously unknown role of R. sphaeroides transcriptional regulators in increasing fatty acid and phospholipid accumulation in response to decreased O2 tension. Lipids serve important functions in living systems, either as structural components of membranes or as a form of carbon storage. Understanding the mechanisms of lipid accumulation in microorganisms is important for providing insight into the assembly of biological membranes and additionally has important applications in the production of renewable fuels and chemicals. In this study, we investigate the ability of Rhodobacter sphaeroides to increase membrane production at low O2 tensions in order to house its photosynthetic apparatus. We demonstrate that this bacterium has a mechanism to increase lipid content in response to decreased O2 tension and identify a transcription factor necessary for this response. This is significant because it identifies a transcriptional regulatory pathway that can increase microbial lipid content.

Abiotic stresses can increase the total fatty acid (TFA) and astaxanthin accumulation in microalgae. However, it remains unknown whether a unified signal transduction mechanism exists under different stresses. This study explored the link between nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-derived reactive oxygen species (ROS) and the accumulation of fatty acids and astaxanthin in Chromochloris zofingiensis under three abiotic stresses. Results showed significant increases in fatty acid, astaxanthin, and ROS levels under nitrogen deficiency, phosphorus deficiency, and high-salinity stress. The introduction of the NADPH oxidase inhibitor diphenyleneiodonium (DPI) decreased the content of these components. This underscores the pivotal role of NADPH oxidase-derived ROS in the accumulation of fatty acid and astaxanthin under abiotic stress. Analysis of transcriptomes across three conditions following DPI addition revealed 1,445 shared differentially expressed genes (DEGs). Enrichment analysis revealed that biotin, betalain, thiamine, and glucosinolate may be important in stress responses. The heatmap demonstrated that DPI notably suppressed gene expression in the fatty acid and carotenoid biosynthesis pathways. Our findings underscore the pivotal role of NADPH oxidase-derived ROS in the accumulation of fatty acid and astaxanthin under abiotic stresses.

Pistachio (Pistacia vera L.) is considered to be the most widely cultivated species in the genus Pistacia and regarded as the most probable ancestral species within the genus. As one of the oldest nut crops in human history, pistachio nuts have a high nutritional value and are commercially important. In the present study, the genetic variation of pistachio genotypes was investigated by nuclear SSR markers. The transferability of the SSR markers was high across genotypes, thus, flanking regions of the SSRs are conserved in the studied genotypes. High level of polymorphism was detected among the studied genotypes. The seven SSR primer pairs generated a total of 18 alleles that 13 of them were polymorphic among the genotypes. The range of the polymorphic alleles was 1 (for Ptms9, Ptms40, Ptms41, and Ptms42) to 5 (for Ptms7 locus) with an average of 2.57. The amplified allele sizes ranged from 120 to 250 bp. Pair-wise genetic similarity coefficients varied from 0.20 to 0.75. The UPGMA dendrogram differentiated the genotypes into two major clusters. The present results may be used for the conservation, core collection and future breeding of the pistachio.