The role of neutral lipids in the physiology and ecology of subarctic Dicranum elongatum

1981 ◽  
Vol 59 (10) ◽  
pp. 1902-1909 ◽  
Author(s):  
Pirjo Karunen

Temperature (1–23 °C) had little effect on the percentage composition of fatty acids in the common and acetylenic triglycerides of Dicranum elongatum Schleich., though the triglyceride contents in both green and senescent parts were highly dependent on temperature. Field material collected in October from low temperature and dim light plus dark conditions, when exposed to light (140 μE m−2 s−1) in growth chambers, showed increased amounts of acetylenic triglycerides most prominently at low temperature, and decreased amounts of the common triglycerides most prominently at the highest temperature. An overall increase of triglycerides (common plus acetylenic) was found only at low temperature (1 and 6 °C).In contrast to the triglycerides, the fatty acid content of the combined steryl plus wax esters increased only slightly (9%) at low temperature (1 °C). At elevated temperature (17 and 23 °C) the content in both green and senescent parts decreased in conjunction with growth. Temperature (1–17 °C) had no great effect on the proportions of the alkyl or acyl moieties of the esters. At 23 °C, however, a clear decrease was found in the proportions of 20:4 ω6 and 18:3 ω3, along with an increase in the proportion of saturated fatty acids. This was most pronounced in the green segment, where the proportion of the steryl esters was lowest.

2002 ◽  
Vol 22 (23) ◽  
pp. 8204-8214 ◽  
Author(s):  
Linda E. Hammond ◽  
Patricia A. Gallagher ◽  
Shuli Wang ◽  
Sylvia Hiller ◽  
Kimberly D. Kluckman ◽  
...  

ABSTRACT Microsomal and mitochondrial isoforms of glycerol-3-phosphate acyltransferase (GPAT; E.C. 2.3.1.15) catalyze the committed step in glycerolipid synthesis. The mitochondrial isoform, mtGPAT, was believed to control the positioning of saturated fatty acids at the sn-1 position of phospholipids, and nutritional, hormonal, and overexpression studies suggested that mtGPAT activity is important for the synthesis of triacylglycerol. To determine whether these purported functions were true, we constructed mice deficient in mtGPAT. mtGPAT−/− mice weighed less than controls and had reduced gonadal fat pad weights and lower hepatic triacylglycerol content, plasma triacylglycerol, and very low density lipoprotein triacylglycerol secretion. As predicted, in mtGPAT−/− liver, the palmitate content was lower in triacylglycerol, phosphatidylcholine, and phosphatidylethanolamine. Positional analysis revealed that mtGPAT−/− liver phosphatidylethanolamine and phosphatidylcholine had about 21% less palmitate in the sn-1 position and 36 and 40%, respectively, more arachidonate in the sn-2 position. These data confirm the important role of mtGPAT in the synthesis of triacylglycerol, in the fatty acid content of triacylglycerol and cholesterol esters, and in the positioning of specific fatty acids, particularly palmitate and arachidonate, in phospholipids. The increase in arachidonate may be functionally significant in terms of eicosanoid production.


2014 ◽  
Vol 521 ◽  
pp. 81-87 ◽  
Author(s):  
Min Chen ◽  
Yan Liu ◽  
Na Sui ◽  
Fang Yuan ◽  
Bao Shan Wang

Hybrid Pennisetum (Pennisetum americanum×P. purpureum) is a widely used bioenergy grass that could also serve as forage for livestock production. In a pot experiment, breed No.1 and breed No. 2 of hybrid Pennisetum were treated with 15°C /10°C day/night temperature for 10 days. Results showed that yield and photosynthesis of breed No. 1 were higher than those of breed No. 2 under low temperature. The unsaturated fatty acid content and the DBI (double bond index) of the major membrane lipid of MGDG (monogalactosyldiacylglycerols), DGDG (digalactosyldiacylglycerols), PG (phosphatidylglycerols), PC (phosphatidylcholines) and PE (phosphatidylethanolamine) of breed No. 1 were significantly increased, while significantly decreased for breed No. 2. We also observed an increase in the proportion of unsaturated fatty acids and a decrease in the proportion of saturated fatty acids under low temperature for breed No. 1, while it was reverse for breed No. 2. Thes results inducate that chilling resistance of breed No. 1 was improved by enhancing the unsaturation of membrane lipid under low temperature. These findings would be useful for understanding mechanism of chilling resistance and the production of hybrid Pennisetum as a biofuel on saline land in the Northern of the China.


2021 ◽  
Vol 22 (4) ◽  
pp. 1554
Author(s):  
Tawhidur Rahman ◽  
Mingxuan Shao ◽  
Shankar Pahari ◽  
Prakash Venglat ◽  
Raju Soolanayakanahally ◽  
...  

Cuticular waxes are a mixture of hydrophobic very-long-chain fatty acids and their derivatives accumulated in the plant cuticle. Most studies define the role of cuticular wax largely based on reducing nonstomatal water loss. The present study investigated the role of cuticular wax in reducing both low-temperature and dehydration stress in plants using Arabidopsis thaliana mutants and transgenic genotypes altered in the formation of cuticular wax. cer3-6, a known Arabidopsis wax-deficient mutant (with distinct reduction in aldehydes, n-alkanes, secondary n-alcohols, and ketones compared to wild type (WT)), was most sensitive to water loss, while dewax, a known wax overproducer (greater alkanes and ketones compared to WT), was more resistant to dehydration compared to WT. Furthermore, cold-acclimated cer3-6 froze at warmer temperatures, while cold-acclimated dewax displayed freezing exotherms at colder temperatures compared to WT. Gas Chromatography-Mass Spectroscopy (GC-MS) analysis identified a characteristic decrease in the accumulation of certain waxes (e.g., alkanes, alcohols) in Arabidopsis cuticles under cold acclimation, which was additionally reduced in cer3-6. Conversely, the dewax mutant showed a greater ability to accumulate waxes under cold acclimation. Fourier Transform Infrared Spectroscopy (FTIR) also supported observations in cuticular wax deposition under cold acclimation. Our data indicate cuticular alkane waxes along with alcohols and fatty acids can facilitate avoidance of both ice formation and leaf water loss under dehydration stress and are promising genetic targets of interest.


Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1133
Author(s):  
Atique Ahmed Behan ◽  
Muhammad Tayyab Akhtar ◽  
Teck Chwen Loh ◽  
Sharida Fakurazi ◽  
Ubedullah Kaka ◽  
...  

The supplementation of rumen bypass fat (RBF) has remained one of the preferred approaches used to decrease undesirable saturated fatty acids (FA) and increase beneficial unsaturated FA in the meat. This study was planned to evaluate the influences of rumen bypass fats on meat quality, fatty acid and metabolic profiles in male Dorper sheep (n = 36) with 24.66 ± 0.76 kg (mean ± standard error) initial body weight. Treatment comprised a basal diet (30:70 rice straw to concentrate) with no added RBF as a control (CON), basal diet with prilled fat (PF), basal diet with prilled fat plus lecithin (PFL) and basal diet with calcium soap of palm fatty acids (CaS). The findings revealed that cooking loss, drip loss and shear force in longissimus dorsi (LD) muscle were not affected by RBF supplementation, while meat pH was significantly higher in the CaS on aging day 1. However, the diet supplemented with prilled fat and lecithin modified the meat’s fatty acid profile significantly by increasing unsaturated fatty acids and decreasing saturated fats. The relative quantification of the major differentiating metabolites found in LD muscle of sheep showed that total cholesterol, esterified cholesterol, choline, glycerophosphocholine and glycerophospholipids were significantly lower in CaS and PFL diets, while glycerol and sphingomyelin were significantly higher in CaS and PFL diets. Most of the metabolites in the liver did not show any significant difference. Based on our results, the supplementation of protected fats did not have a negative influence on meat quality and the meat from Dorper sheep fed prilled fat with lecithin contained more healthy fatty acids compared to other diets.


Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1366
Author(s):  
Cristina Soares ◽  
Sara Sousa ◽  
Susana Machado ◽  
Elsa Vieira ◽  
Ana P. Carvalho ◽  
...  

The total lipid content and lipidic profile of seaweeds harvested in the North Coast and purchased in Portugal were determined in this paper. The amount of total lipids in the different species of seaweeds varied between 0.7 ± 0.1% (Chondrus crispus) and 3.8 ± 0.6% (Ulva spp.). Regarding the fatty acid content, polyunsaturated fatty acids (PUFA) ranged between 0–35%, with Ulva spp. presenting the highest amount; monounsaturated fatty acids (MUFA) varied between 19 and 67%; and saturated fatty acids (SFA) were predominant in C. crispus (45–78%) and Gracilaria spp. (36–79%). Concerning the nutritional indices, the atherogenicity index (AI) was between 0.4–3.2, the thrombogenicity index (TI) ranged from 0.04 to 1.95, except for Gracilaria spp., which had a TI of 7.6, and the hypocholesterolemic/hypercholesterolemic ratio (HH) values ranged between 0.88–4.21, except for Gracilaria spp., which exhibited values between 0.22–9.26. The n6/n3 ratio was below 1 for most of the species evaluated, except for Ascophyllum nodosum, which presented a higher value, although below 2. Considering the PUFA/SFA ratio, seaweeds presented values between 0.11–1.02. The polycyclic aromatic hydrocarbons (PAHs) and aliphatic hydrocarbons (AHCs) contamination of seaweeds under study was also quantified, the values found being much lower than the maximum levels recommended for foodstuff.


2009 ◽  
Vol 2009 ◽  
pp. 212-212
Author(s):  
S J Hosseini Vashan ◽  
N Afzali ◽  
A Golian ◽  
M Malekaneh ◽  
A Allahressani

Palm oil is the most abundant of all oils produced globally. It is very high in saturated fatty acids specifically palmitic acid, but other fatty acids (monounsaturated (MUFA) and polyunsaturated) are presented at low concentrations. In the processing plant some high amount of oleic acid with some other unsaturated fatty acids are extracted and marketed as Palm olein oil, and used to reduce blood or egg cholesterol (Rievelles et al., 1994). The objective of this study was to determine the optimum level of dietary palm olein oil required to enrich the mono-unsaturated fatty acid content of yolk, egg cholesterol and antibody titre.


2018 ◽  
Vol 19 (11) ◽  
pp. 3515 ◽  
Author(s):  
Krizia Sagini ◽  
Lorena Urbanelli ◽  
Eva Costanzi ◽  
Nico Mitro ◽  
Donatella Caruso ◽  
...  

Extracellular vesicles (EVs) are lipid bilayer surrounded particles that are considered an additional way to transmit signals outside the cell. Lipids have not only a structural role in the organization of EVs membrane bilayer, but they also represent a source of lipid mediators that may act on target cells. Senescent cells are characterized by a permanent arrest of cell proliferation, but they are still metabolically active and influence nearby tissue secreting specific signaling mediators, including those carried by EVs. Notably, cellular senescence is associated with increased EVs release. Here, we used gas chromatography coupled to mass spectrometry to investigate the total fatty acid content of EVs released by fibroblasts undergoing H-RasV12-induced senescence and their parental cells. We find that H-RasV12 fibroblasts show increased level of monounsaturated and decreased level of saturated fatty acids, as compared to control cells. These changes are associated with transcriptional up-regulation of specific fatty acid-metabolizing enzymes. The EVs released by both controls and senescent fibroblasts show a higher level of saturated and polyunsaturated species, as compared to parental cells. Considering that fibroblasts undergoing H-RasV12-induced senescence release a higher number of EVs, these findings indicate that senescent cells release via EVs a higher amount of fatty acids, and in particular of polyunsaturated and saturated fatty acids, as compared to control cells.


1982 ◽  
Vol 243 (2) ◽  
pp. G127-G133
Author(s):  
L. M. McLeay ◽  
J. M. Fitzgerald

Effects on ovine gastric function of procedures that increase intestinal unsaturated fatty acid content are unknown, and the present aim was to compare the effects of duodenal unsaturated and saturated fatty acids on gastric secretion in conscious sheep. During the maximal gastric secretory response to a meal, 10 ml gallbladder bile alone or with myristic, palmitic, and stearic acids and oleic, linoleic, and linolenic acids were infused into the duodenum at a rate of 5 g fatty acid . h-1 for 1 h. Compared with control 154 mM NaCl (100%), acid output was reduced to 4-7% of control with infusion of oleic, linoleic, and linolenic acids and myristic acids plus bile. Reductions in acid secretion persisted for up to 5 h from the end of infusion. In contrast, the infusion of palmitic and stearic acids with bile caused mean maximal reductions in acid output, respectively, to only 64 and 55% of control, and levels returned to control within 1 h of the end of infusion. Bile infusion alone caused no reduction in acid secretion. Under the conditions used, C18 unsaturated fatty acids and myristic acid were potent inhibitors of ovine gastric acid secretion. The lesser effects of palmitic and stearic acids were probably related to their reduced solubility and absorption.


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