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Oil palm (Elaeis guineensis) produces two oils of major economic importance, commonly referred to as palm oil and palm kernel oil, extracted from the mesocarp and the endosperm, respectively. While lauric acid predominates in endosperm oil, the major fatty acids (FAs) of mesocarp oil are palmitic and oleic acids. The oil palm embryo also stores oil, which contains a significant proportion of linoleic acid. In addition, the three tissues display high variation for oil content at maturity. To gain insight into the mechanisms that govern such differences in oil content and FA composition, tissue transcriptome and lipid composition were compared during development. The contribution of the cytosolic and plastidial glycolytic routes differed markedly between the mesocarp and seed tissues, but transcriptional patterns of genes involved in the conversion of sucrose to pyruvate were not related to variations for oil content. Accumulation of lauric acid relied on the dramatic up-regulation of a specialized acyl-acyl carrier protein thioesterase paralog and the concerted recruitment of specific isoforms of triacylglycerol assembly enzymes. Three paralogs of the WRINKLED1 (WRI1) transcription factor were identified, of which EgWRI1-1 and EgWRI1-2 were massively transcribed during oil deposition in the mesocarp and the endosperm, respectively. None of the three WRI1 paralogs were detected in the embryo. The transcription level of FA synthesis genes correlated with the amount of WRI1 transcripts and oil content. Changes in triacylglycerol content and FA composition of Nicotiana benthamiana leaves infiltrated with various combinations of WRI1 and FatB paralogs from oil palm validated functions inferred from transcriptome analysis.

The current study evaluated the potential enhancement of lauric acid (LA) in black soldier fly, Hermetia illucens, (L.) (Diptera: Stratiomyidae) larvae (BSFL), a source of this short-chain fatty acid which has antimicrobial and immunostimulatory properties. Replicate groups of BSFL were reared on either the coconut or Gainesville diet for 7 days. After the rearing period, BSFL were harvested, purged, dried, and subjected to proximate, fatty acid and amino acid compositions, and pepsin digestibility analyses. Results demonstrate changes in proximate composition. BSFL reared on the coconut had significantly (P = 0.002) higher lipid content (47.3% vs. 25.2%) on a dry-matter basis. The LA concentration in BSFL produced on the coconut was 31% greater than those reared on Gainesville, resulting in almost 150% more LA. Furthermore, BSFL-fed coconut had reduced crude protein (29.7% of dry weight) and ash (3.7% of dry weight) relative to those fed Gainesville (43.4% and 7.5% for crude protein and ash, respectively) but higher pepsin digestibility (91.0% vs. 87.0%). The relative amounts of various amino acids in the 2 BSFL meals did not differ extensively, with statistically lower concentrations of only phenylalanine and tryptophan and higher concentrations of alanine, arginine, isoleucine, leucine, and serine in BSFL reared on coconut. Results demonstrate that the nutritional composition of BSFL can be manipulated, and an enhancement of LA concentrations of 150% was achieved with coconut, which has value for BSFL as a feed for various livestock, including aquaculture. Lower protein content is a tradeoff in terms of BSFL value as a feed additive.

We examined the long-term effect of feeding coconut oil (CO; rich in lauric acid, C12) on voluntary food intake and nutrient utilisation in rainbow trout (Oncorhynchus mykiss), with particular attention to the metabolic use (storage or oxidation) of ingested medium-chain TAG. Trout were fed for 15 weeks one of the four isoproteic diets containing fish oil (FO) or CO as fat source (FS), incorporated at 5 % (low fat, LF) or 15 % (high fat, HF). Fat level or FS did not modify food intake (g/kg0·8 per d), despite higher intestinal cholecystokinin-T mRNA in trout fed the HF-FO diet. The HF diets relative to the LF ones induced higher growth and adiposity, whereas the replacements of FO by CO resulted in similar growth and adiposity. This, together with the substantial retention of C12 (57 % of intake), suggests the relatively low oxidation of ingested C12. The down-regulation of carnitine palmitoyl-transferase-1 (CPT-1) confirms the minor dependency of medium-chain fatty acids (MCFA) on CPT-1 to enter the mitochondria. However, MCFA did not up-regulate mitochondrial oxidation evaluated using hepatic hydroxyacyl-CoA dehydrogenase as a marker, in line with their high retention in body lipids. At a low lipid level, MCFA increased mRNA levels of fatty acid synthase, elongase and stearoyl-CoA desaturase in liver, showing the hepatic activation of fatty acid synthesis pathways by MCFA, reflected by increased 16 : 0, 18 : 0, 16 : 1, 18 : 1 body levels. The high capacity of trout to incorporate and transform C12, rather than to readily oxidise C12, contrasts with data in mammals and may explain the absence of a satiating effect of CO in rainbow trout.

Trail pheromones deposited by ants lead nestmates to food sources. Based on previous evidence that the trail pheromone of the carpenter ant Camponotus modoc originates from the hindgut, our objective in this study was to identify the key component(s) of the pheromone. We collected C. modoc colonies from conifer forests and maintained them in an outdoor enclosure near our laboratory for chemical analyses and behavioral experiments. In gas chromatographic-electroantennographic detection and gas chromatography-mass spectrometric analyses of worker ant hindgut extracts, we identified five candidate components: 2,4-dimethylhexanoic acid, 2,4-dimethyl-5-hexanolide, pentadecane, dodecanoic acid and 3,4-dihydro-8-hydroxy-3,5,7-trimethylisocoumarin. In a series of trail-following experiments, ants followed trails of synthetic 2,4-dimethyl-5-hexanolide, a blend of the five compounds, and hindgut extract over similar distances, indicating that the hexanolide accounted for the entire behavioral activity of the hindgut extract. The hexanolide not only mediated orientation of C. modoc foragers on trails, it also attracted them over distance, indicating a dual function. Further analyses and bioassays with racemic and stereoselectively synthesized hexanolides revealed that the ants produce, and respond to, the (2S,4R,5S)-stereoisomer. The same stereoisomer is a trail pheromone component in several Camponotus congeners, indicating significant overlap in their respective trail pheromone communication systems.

Plant diseases reduce crop yield and quality, hampering the development of agriculture. Fungicides, which restrict chemical synthesis in fungi, are the strongest controls for plant diseases. However, the harmful effects on the environment due to continued and uncontrolled utilization of fungicides have become a major challenge in recent years. Plant-sourced fungicides are a class of plant antibacterial substances or compounds that induce plant defenses. They can kill or inhibit the growth of target pathogens efficiently with no or low toxicity, they degrade readily, and do not prompt development of resistance, which has led to their widespread use. In this study, the growth inhibition effect of 24 plant-sourced ethanol extracts on rice sprigs was studied. Ethanol extract of gallnuts and cloves inhibited the growth of bacteria by up to 100%. Indoor toxicity measurement results showed that the gallnut and glove constituents inhibition reached 39.23 μg/mL and 18.82 μg/mL, respectively. Extract treated rice sprigs were dry and wrinkled. Gallnut caused intracellular swelling and breakage of mitochondria, disintegration of nuclei, aggregation of protoplasts, and complete degradation of organelles in hyphae and aggregation of cellular contents. Protection of Rhizoctonia solani viability reached 46.8% for gallnut and 37.88% for clove in water emulsions of 1000 μg/mL gallnut and clove in the presence of 0.1% Tween 80. The protection by gallnut was significantly stronger than that of clove. The data could inform the choice of plant-sourced fungicides for the comprehensive treatment of rice sprig disease. The studied extract effectively protected rice sprigs and could be a suitable alternative to commercially available chemical fungicides. Further optimized field trials are needed to effectively sterilize rice paddies.

Perfluorododecanoic acid (PFDoA) is a ubiquitous environmental pollutant known to cause hepatocellular hypertrophy; however, the mechanisms of hepatotoxicity remain poorly understood. In this study, male rats were exposed to 0, 0.05, 0.2 and 0.5 mg/kg/day of PFDoA for 110 days. After two-dimensional differential gel electrophoresis and MALDI-TOF/TOF analysis, 73 differentially expressed proteins involved in lipid metabolism, inflammation, stress response and other functions were successfully identified. Among them, six significantly changed proteins (CTE1, MTE1, HADHA, ECH1, ALDH2 and CPS1) were found to be regulated by peroxisome proliferator-activated receptor alpha (PPARα). The anti-oxidant enzyme activity assays of superoxide dismutase and glutathione peroxidase and the content of thiobarbituric acid-reactive substances in the liver implied that PFDoA caused oxidative stress. The mRNA levels of PPARα in rat primary hepatocytes were knocked down by lentivirus-mediated RNAi. Furthermore, targeted protein levels of CTE1 and MTE1 were down-regulated, while those of HADHA, ALDH2 and CPS1 were up-regulated. After PFDoA exposure, however, the targeted protein levels of CTE1 and ALDH2 increased compared with those of the knockdown untreated group. The reactive oxygen species (ROS) content in rat hepatocytes assayed by flow cytometry significantly increased in the PPARα knockdown groups, consistent with the PPARα antagonist GW6471- and agonist WY14643-treated groups. These results strongly suggested that PPARα played an important role in suppressing ROS content in hepatocytes following PFDoA exposure.

Binary stable isotope labeling couple with LC-ESI-MS has been used as a powerful non-targeted approach for the relative quantification of lipids, amino acids, and many other important metabolite classes. A multiplexed approach using three or more isotopic labeling reagents greatly reduces analytical run-time while maintaining excellent sensitivity and reproducibility. Three isotopic cholamine labeling reagents have been developed to take advantage of the pre-ionized character of cholamine, for ESI, and the ease by which stable isotopes can be incorporated into the cholamine structure. These three cholamine labeling reagents have been used to relatively quantify three fatty acid samples simultaneously. The quantification resulted in the observation of 12 fatty acids that had an average absolute error of 0.9% and an average coefficient of variation of 6.1%. Caged versus cage-free isotope labeling experiments showed that cage-free eggs have an increased level of omega-3 fatty acids as compared to caged eggs. This multiplexed fatty acid analysis provides an inexpensive and expedited tool for broad-based lipid profiling that will further aid discoveries in the mechanisms of fatty acid action in cells.

Concentrations of 12 perfluorinated compounds (PFCs) were measured in 21 representive water, sediment and soil samples from Guanting Reservoir and vicinity. Perfluorooctanoic acid (PFOA) was the predominant PFCs with concentrations of 0.55–2.3 ng/L,

Journal Article

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