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1.
Summary A time-course study of lipid accumulation in microspore-derived embryos and developing zygotic embryos of rapeseed (Brassica napus L. ssp.oleifera) is presented. Rapid storage fat (triacylglycerol) biosynthesis was induced in microspore-derived embryos of oilseed rape (cv Topas) when the embryos were transferred from standing cultures (10 ml) to fresh medium (75 ml) and shake cultured. Triacylglycerols accumulated, after a lag period of 7 days, at a linear rate of approximately twice that of the developing zygotic embryo. The fatty acid composition of triacylglycerols in microspore-derived embryos closely parallelled that of the developing zygotic embryos. In the microspore-derived embryos, the amount of phosphatidylcholine, the major substrate for the production of polyunsaturated fatty acids in oilseeds, remained constant during the linear phase of triacylglycerol production, whereas it increased steadily in the zygotic embryos. The fatty acid composition of individual cotyledons from microspore embryos shake cultured for 15 days was compared with that of individual mature seeds. Relative amounts of the major fatty acids, i.e. palmitic, oleic and linoleic acids, were essentially the same, whereas the microspore-derived embryos had about 35% less stearic acid and 35% more linolenic acid than the mature seeds. Variation in the amounts of oleic, linoleic and linolenic acids between seeds was similar to that found between cotyledons of microspore-derived embryos, whereas variation in palmitic and stearic acid levels was significantly lower between microsporederived cotyledons than between the seeds. The results indicate that microspore-derived embryos from shake cultures should be convenient for use in studying the regulation of oil biosynthesis and for rapidly screening for oil quality in genetically altered rapeseed.  相似文献   

2.
Five major fatty acids, palmitic (16:0), stearic (18:0), oleic (18:1), linoleic (18:2), and linolenic (18:3), were identified in polar lipid extracts from pulvini of Samanea saman and Phaseolus coccineus. In P. coccineus their distribution varied quantitatively in the laminar pulvinus, petiolar pulvinus, petiole, stem, leaf and root. Short pulses of red light did not greatly affect the relative quantities of fatty acids in dark grown P. coccineus, but a 30-minute exposure of red light generally increased the degree of unsaturation by increasing linolenic acid and decreasing linoleic and palmitic acids.  相似文献   

3.
The question of whether membrane expansion, which is caused by anesthetics in animal systems, alters the lipid composition of plant cell membranes was investigated. We have measured the effects of several anesthetics on the relative amounts of the principal fatty acids from the polar lipids of barley (Hordeum vulgare L.) root membranes. Procaine, dibucaine, tetracaine, chloroform and, to a lesser degree, methanol increased the proportions of palmitic, stearic and oleic acids and decreased the proportions of linoleic and linolenic acids. Ethanol had no significant effect. Total amounts of the fatty acids from the polar lipids of roots in procaine solution decreased markedly so that all of the acids decreased in amount. The anesthetic was effective as soon as the roots were introduced to the solution and the changes progressed at constant rates for 6 h. Only the polar membrane lipids were altered; other lipids were not affected. Increased hydrostatic pressure of about 1.0 MPa largely prevented the anesthetic effects, including the decrease in the total amounts of the fatty acids. Hydrostatic pressure as high as 2 MPa had no effect per se on the membrane lipid composition. These results indicate that anesthetics cause expansion of the root membranes which results in the lipid changes. That a compositional change in the membrane lipids involves a conformational change such as expansion is an indication of the nature of the link between changes in the membrane lipids and changes in function of areas where hydrophilic ions permeate.Abbreviations 16:0 palmitic acid - 18:0 stearic acid - 18:1 oleic acid - 18:2 linoleic acid - 18:3 linolenic acid  相似文献   

4.
Cell growth, lipid accumulation and cellular lipid composition of Yarrowia lipolytica growing on mixtures of industrial fats containing stearic, oleic, linoleic and palmitic acid have been studied. During growth, the strain incorporated oleic and linoleic acids more rapidly than the saturated fatty acids. Relatively high lipid accumulation (up to 0.44 g of lipids per g of dry matter) was observed when stearic acid was included in the culture medium. In contrast, substrates rich in oleic acid did not favor cellular lipid accumulation. The accumulated lipids, mainly composed of triacylglycerols (45-55% w/w), demonstrated a different total fatty acid composition compared with that of the substrate; in all cases, the microorganism showed the unusual capacity to increase its cellular stearic acid level, even if this fatty acid was not found in high concentrations in the substrate. This permitted the synthesis of interesting lipid profiles with high percentages of stearic acid and non-negligible percentages of palmitic and oleic acid, with a composition resembling that of cocoa-butter.  相似文献   

5.
甘肃胡麻地方种质资源品质特性研究   总被引:4,自引:0,他引:4  
赵利  党占海  李毅 《西北植物学报》2006,26(12):2453-2457
对甘肃省116份胡麻地方品种的重要品质指标———粗脂肪、硬脂酸、棕榈酸、油酸、亚油酸、亚麻酸含量和碘值进行测定,并根据这些品质指标对供试品种进行聚类分析。结果显示:(1)供试品种粗脂肪含量平均值为37.48%,变异系数3.8%;硬脂酸、油酸含量平均值分别为5.32%和29.05%,变异系数分别为19.5%和11.6%;棕榈酸、亚麻酸、亚油酸含量平均值分别为5.9%、48.76%、10.95%,变异系数分别为8.4%、8%、8%;平均碘价175.60,变异系数2.76%;(2)聚类分析结果显示,116个品种聚为7大类,其中:b亚组群硬脂酸和油酸含量最高,而亚麻酸含量最低;d亚组群品种亚麻酸含量最高;e亚组群粗脂肪含量和碘价最高,油酸含量最低;f亚组群硬脂酸含量最低;g亚组群棕榈酸含量最高,碘价最低。  相似文献   

6.
1. Qualitative and quantitative changes in phosphatidylinositol (PI) were analyzed in the eggs, embryos and tadpoles of the Japanese pond frog, Rana nigromaculata, at various stages of development. 2. The weight percentage of PI to total phospholipid and lipid was about 8.4-15.2% and 1.4-2.6%, respectively, during embryonic life. 3. At the early stages of the unfertilized egg and the two-cell embryo, the predominant fatty acids are palmitic, stearic, oleic and linoleic acid. From the dorsal lip, early gastrula stage and beyond, the percentage of linoleic acid declines and there is an increase in palmitoleic acid. A relatively large amount of arachidonic acid was noted at the unfertilized egg stage at the 1-position. 4. A large amount of arachidonic acid was also observed at the 2-position of PI in the unfertilized egg, hatching embryo and post-hatching tadpole stages, relative to palmitic and stearic acid. 5. Palmitic and stearic acid were increased at the 2-position of PI in the other embryo and the feeding tadpole stages, relative to arachidonic acid, indicating a shift in these molecular species. 6. Thus, there were marked changes in the positional distribution of the constituent fatty acids in PI during early development of R. nigromaculata.  相似文献   

7.
The moisture, lipids and fatty acid composition of developing winged bean (Psophocarpus tetragonolobus) seeds were studied. The moisture content decreased steadily as the seeds matured. The lipid content increased gradually and reached a maximum ca 6 weeks after flowering (WAF). In the early stage (2 WAF) of the developing seeds there were more polar lipids (glycolipids and phospholipids) than neutral lipids but, as the seeds developed, neutral lipids gradually accumulated while the polar lipids decreased until 6 WAF. Thereafter, both the neutral lipid and polar lipid levels remained little changed. The amounts of palmitic and stearic acids decreased, but the level of behenic acid increased as the seeds matured. On the other hand, the oleic acid content increased while that of linolenic acid decreased rapidly as the seeds matured. The concentration of linoleic acid, however, fluctuated during the development of the seeds.  相似文献   

8.
Qualitative and quantitative changes in phosphatidylethanolamine (PE) were analyzed in the eggs, embryos and tadpoles of the Japanese pond frog, Rana nigromaculata, at various stages of development. The weight percentage of PE to total phospholipid and to total lipid was about 15-18% and about 3-4%, respectively, during embryonic life. At all stages from the unfertilized egg to the feeding tadpole, the major fatty acids at the 1-position of PE were palmitic, stearic and oleic acids. At the 2-position, arachidonic, oleic, palmitic, stearic and linoleic acids were present during embryonic life. The most abundant fatty acid at the 2-position was arachidonic acid at the unfertilized egg and hatching embryo stages. However, palmitic acid was the most prevalent 2-fatty acid at the posthatching tadpole and the feeding tadpole stages. Thus, there were marked changes in the positional distribution of the constituent fatty acids in PE during development.  相似文献   

9.
Yarrowia lipolytica was cultivated on mixtures of saturated free fatty acids (an industrial derivative of animal fat called stearin), technical glycerol (the main by-product of bio-diesel production facilities), and glucose. The utilization of technical glycerol and stearin as co-substrates resulted in higher lipid synthesis and increased citric acid production than the combination of glucose and stearin. The lipids produced contained significant amounts of stearic acid (50–70%, wt/wt) and lower ones of palmitic (15–20%, wt/wt), oleic (7–20%, wt/wt), and linoleic (2–7%, wt/wt) acid. Single-cell oil having a composition similar to cocoa-butter up to 3.4 g/L was produced, whereas in some cases relatively increased citric acid quantities (up to 14 g/L) were excreted into the growth medium. The microorganism presented a high specificity for lauric, myristic, and palmitic acid, while a discrimination for the stearic acid was observed. As a conclusion, microbial metabolism could be directed by using mixtures of inexpensive saturated fats, glycerol, and glucose as co-substrates, in order to accumulate lipids with predetermined composition, e.g., cocoa-butter equivalents. Received: 1 April 2002 / Accepted: 4 May 2002  相似文献   

10.
Cells of Acer pseudoplatanus were grown in batch suspension culture for 22 days. The cultures were initiated at high cell density of 2 × 105 cells per ml of culture. Growth was characterised by a short lag phase, an exponential phase of rapid cell division and growth, and finally a stationary phase. Quantitative but not qualitative changes were observed in total lipid content, fatty acids and phospholipids at different stages of growth. Total lipids, phospholipids and fatty acids showed maximum concentrations in 12 day old cells. The major phospholipids isolated were phosphatidylcholine and phosphatidylethanolamine with minor amounts of phosphatidic acid and lysophosphatides. Other lipid components present were mono- and digalactosyl diglycerides, cerebrosides, sterol glucosides, free fatty acids and esterified sterol glucosides. The major constituent fatty acids were myristic acid (14:0), palmitic acid (16:0), stearic acid (18:0), oleic acid (18:1), linoleic acid (18:2) and linolenic acid (18:3). During exponential cell growth the proportion of 16:0, 18:2 and 18:3 constituted nearly 90% of the total fatty acids. Triglycerides were the major repository of myristic acid (14:0) with substantial amounts of palmitic acid (16:0), whereas phospholipids contained 16:0, 18:2 and 18:3 in high amounts.  相似文献   

11.
Somatic embryogenesis was developed as a method of mass propagation for Lepidosperma drummondii (Cyperaceae), a difficult to propagate but important species for post-mining restoration in a region of high plant biodiversity, in the southwest of Western Australia. Cultures were initiated from excised zygotic embryos, shoot cultures to rhizomes. Only zygotic embryos of L. drummondii developed somatic embryos, with half strength Murashige and Skoog basal medium (BM) and 1 μM 2,4-dichlorophenoxyacetic acid (2,4-D) being the most effective combination. The first culture cycle yielded a mean of 30 somatic embryos per excised zygotic embryo forming an embryo cluster. After a further 6 wk in culture (on fresh BM with 1 μM 2,4-D), approximately 350 somatic embryos per starting embryo cluster were recorded. Following regular sub-culturing of primary somatic embryo clusters onto fresh media (every 4 wk), more than 74,000 secondary somatic embryos were estimated to have been produced after eight subculture periods. This translates to between 1,000 and 2,000 somatic embryos produced from an estimated 45 mg of starting tissue per culture plate or potentially 22,0000–44,000 somatic embryos per gram of tissue. This is a significant improvement over all previous methods used to propagate L. drummondii, in which typical in vitro shoot multiplication rates are as low as 1.43 per 8 wk. This also compared favourably with published data and concurrent experiments undertaken in this study (as an extra control measure) on somatic embryo production for a related species Baloskion tetraphyllum (using the same BM with 1 μM 2,4-D and coleoptile segments as explants). Various media combinations were investigated for efficacy in converting somatic embryos into plants with best results ranging from 86% to 100% conversion for B. tetraphyllum on BM without plant growth regulators. Development of L. drummondii somatic embryos into plants was not observed on BM without plant growth regulators. However, a best result of 39% conversion to plants was observed on BM with 1 μM thidiazuron. This is the first report of successful development of somatic embryogenesis and conversion of somatic embryos into plants using thidiazuron for the Australian cyperale L. drummondii.  相似文献   

12.
Linolenic, linoleic, oleic, palmitic and stearic acids (FFA) collapse the electrical potential of pea stem mitochondria in the absence or in the presence of 0.5 mM Mg2+. Higher concentrations of this cation (5 mM) lower the rate of dissipation caused by linoleic, oleic and palmitic acids, while abolishing that induced by stearic acid. Carboxyatractyloside and ADP do not reverse the FFA-induced collapse both in the presence or absence of Mg2+. EDTA, EGTA or BHT do not influence the dissipation caused by FFA that, in addition, is not linked to lipid peroxidation evaluated as malondialdehyde or conjugated diene formation. Only linolenic acid sustains a peroxidation which, however, appears to be caused by its own oxidation catalysed by lipoxygenases rather than by membrane lipoperoxidation induced by this free fatty acid. These results suggest that neither the ATP/ADP exchanger nor lipid peroxidation appear to be involved in FFA-induced uncoupling in pea stem mitochondria.  相似文献   

13.
The effect of growth temperature on the lipid fatty acid composition was studied over a temperature range from 35 to 10° C with 5° C intervals in four exponentially growing fungi: Aspergillus niger, Neurospora crassa, Penicillium chrysogenum, and Trichoderma reesei. Fatty acid unsaturation increased in A. niger, P. chrysogenum, and T. reesei when the temperature was lowered to 20–15, 20, and 26–20° C, respectively. In A. niger and T. reesei, this was due to the increase in linolenic acid content. In P. chrysogenum, the linolenic acid content increased concomitantly with a more pronounced decrease in the less-unsaturated fatty acid, oleic acid, and in palmitic and linoleic acids; consequently, the fatty acid content decreased as the temperature was lowered to 20° C. In T. reesei, when the growth temperature was reduced below 26–20° C, fatty acid unsaturation decreased since the mycelial linolenic acid content decreased. In A. niger and P. chrysogenum, the mycelial fatty acid content increased greatly at temperatures below 20–15° C. In contrast, in N. crassa, fatty acid unsaturation was nearly temperature-independent, although palmitic and linoleic acid contents clearly decreased when the temperature was lowered between 26 and 20° C; concomitantly, the growth rate decreased. Therefore, large differences in the effects of growth temperature on mycelial fatty acids were observed among various fungal species. However, the similarities found may indicate common regulatory mechanisms causing the responses. Received: 1 March 1995 / Accepted: 8 May 1995  相似文献   

14.
F.I. Opute 《Phytochemistry》1975,14(4):1023-1026
The lipid classes, fatty acid methyl esters and the sterols of oilpalm pollen were analysed. The neutral lipid fraction consisted of triglycerides, esterified and free sterols and trace amounts of hydrocarbons. Monogalactosyl and digalactosyl diglycerides, phosphatidyl choline, phosphatidyl inositol and phosphatidyl ethanolamine represented the polar lipids. The major fatty acids were linoleic, palmitic and linolenic acids together with small to trace amounts of oleic, stearic, arachidic, myristic, lauric, palmitoleic and margaric acids. Unsaturated fatty acids predominated over saturated ones in the ratio of 3:2. The 4-desmethyl sterols were the major phytosterols in the free form but they constituted a lower proportion of the sterols in the esterified state. 28-Isofucosterol was isolated and characterized as the principal sterol.  相似文献   

15.
Seasonal changes in the fatty acid composition of the total lipid extracted from the whole body of Cydia pomonella L. larvae were determined by gas chromatography. The six most abundant fatty acids in both non-diapause and diapause larvae of codling moth were oleic (35%-39%), palmitic (23%-33%), linoleic (16%-30%), palmitoleic (5%-10%), stearic (1.5%-3.0%) and linolenic acids (1.0%-2.5%). This represents a typical complement of Lepidopteran fatty acids. The fatty acid composition of total lipid of C. pomonella larvae was related to diapause. In similarity to most other reports, the proportion of unsaturated fatty acids increased in diapause initiation state. The total lipid of diapause larvae contained more linoleic acid (25.8% vs. 16.1%) and less palmitic acid (24.7% vs. 33.4%), than that of non-diapause larvae. The weight percentage of linoleic acid (C 18:2) increased from 16% to 26% from early-August through early-September during transition to diapause, while palmitic acid (C16:0) decreased from 33% to 25% at the same time. These changes resulted in an increase in the ratio of unsaturated to saturated fatty acids (UFA/SFA) from 1.72 in non-diapause larvae to 2.63 in diapause larvae.  相似文献   

16.
The effect of methyl jasmonate (JA-Me), applied to mature green tomato fruits cv. Modena, on the content of some fatty acids in ripe fruits was studied. Methyl jasmonate greatly increased content of linolenic acid and in the lesser degree decreased the amount of linoleic acid. The ratio of linolenic acid to linoleic acid content increased 4.5–7.7 times in methyl jasmonate treated samples in comparison to untreated-controls. JA-Me did not affect the contents of lauric, myristic, palmitic, stearic, palmitoleic and oleic acids.  相似文献   

17.
The biosynthesis of lipid molecular species was studied in Anabaena variabilis by pulse-labeling with NaH14CO3 and chasing. The experimental results indicate that the primary products of lipid biosynthesis are 1-stearoyl-2-palmitoyl species of monoglucosyl diacylglycerol, phosphatidylglycerol and sulfoquinovosyl diacylglycerol. In monoglucosyl diacylglycerol, stearic acid is desaturated rapidly to oleic acid and further to linoleic acid, whereas palmitic acid is hardly desaturated to palmitoleic acid. The stearoyl-palmitoyl, oleoyl-palmitoyl and linoleoyl-palmitoyl species of monoglucosyl diacylglycerol are converted to the corresponding species of monogalactosyl diacylglycerol. Desaturation of the fatty acids also takes place in monogalactosyl diacylglycerol. At 38° C the stearoyl-palmitoyl species is converted to oleoyl-palmitoyl, then to either linoleoyl-palmitoyl or oleoyl-palmitoleoyl, and finally to linoleoyl-palmitoleoyl species, and at 22°C the stearoyl-palmitoyl molecular species is sequentially converted to oleoyl-palmitoyl, linoleoyl-palmitoyl, linolenoyl-palmitoyl and linolenoyl-palmitoleoyl species. The molecular species of digalactosyl diacylglycerol are synthesized from the corresponding species of monogalactosyl diacylglycerol. Desaturation does not seem to occur in digalactosyl diacylglycerol. In phosphatidylglycerol and sulfoquinovosyl diacylglycerol, stearic acid is desaturated to oleic and to linolenic acids at 38° C, and further to linoleic acid at 22° C, whereas palmitic acid is hardly desaturated.  相似文献   

18.
The objective of this study was to investigate the effect of salinity on growth, fatty acid composition, phenol content and antioxidant activity of Nigella sativa organs. Plants were grown hydroponically under NaCl stress (0, 20 40 and 60 mM). The results indicated that salinity affected N. sativa growth. The fatty acid composition of the leaves and the roots was investigated for the first time and major fatty acids were linolenic acid (58.1%) in the leaves and linoleic (43.9%) and palmitic (33.3%) acids and in the roots. Total fatty acid (TFA) content of the leaves decreased at 60 mM NaCl while root TFA increased at 20 and 40 mM NaCl. Moreover, the fatty acid composition was affected by NaCl; in leaves, the double bond index (DBI) decreased accompanied by a decrease of the level of linolenic acid which reached 14% at 60 mM NaCl. However, root DBI degree increased at 40 at 60 mM NaCl provoked mainly by the increase of the amount of linoleic acid by 15 and 8%, respectively, and the decrease of the amount of palmitic acid by 20 and 14%, respectively. Salt stress increased total polyphenol and individual phenolic acid contents in shoots. Moreover, the antiradical activity of the shoots (DPPH) increased at 60 mM NaCl. However, in roots, the total polyphenol content and the antiradical activity decreased sharply with increasing NaCl doses. Data reported here revealed the variation of fatty acids and phenolic compound contents in different organs of N. sativa, and the possible role of theses changes in the plant salt response were discussed.  相似文献   

19.
Fatty acid compositions of peach (Prunus persica L. Batsch) mesocarp tissues from ‘Kawanakajima Hakuto’ and its firm-fleshed mutant ‘Shuangjiuhong’ were examined by gas chromatography during the developmental stages from 20 days before to 20 days after fruit ripening. Fruits were harvested at 4-day intervals from July to September. The predominant fatty acids were linoleic, palmitic and linolenic acids with 27.66–48.93 %, 23.59–31.65 %, and 12.08–28.35 % in ‘Shuangjiuhong’, and 32.64–42.79 %, 23.53–28.95 %, 16.14–39.15 % in ‘Kawanakajima Hakuto’, respectively. Saturated fatty acids (palmitic and stearic acids) remained relatively constant throughout the ripeness period. On the contrast, from 15 days before ripening, notable decline in oleic acid and increase of linoleic and linolenic acids were observed in both cultivars. In addition, from 10 days before ripening, much lower levels of oleic and linolenic acids and higher proportion of linoleic acid were observed in ‘Shuangjiuhong’ than those found in ‘Kawanakajima Hakuto’. And notably higher SFA level, lower levels of UFA and IUFA in the firm-fleshed peach were investigated during those stages. Correlation analysis showed that oleic acid and SFA had very significantly positive, whereas linolenic acid, UFA and IUFA had significantly negative correlation with fruit firmness. These results above suggest that lower levels of oleic and linolenic acids, UFA and IUFA, and higher linoleic acid and SFA content represent fruits with firmer flesh and help to retain the fruit texture.  相似文献   

20.
Bioassays using gravid females of the adzuki bean borer, Ostrinia scapulalis (Walker), and the Asian corn borer, O. furnacalis (Guenée) (Lepidoptera: Crambidae), showed that the presence of an egg mass of a conspecific deters oviposition. Volatile chemicals emanating from the egg mass were responsible for the deterrence, and these deterrents could be extracted from the egg mass with hexane. When fractionated using a Sep‐Pak® Plus NH2 cartridge, the deterrents were eluted with a 98 : 2 mixture of diethyl ether and acetic acid (polar lipid fraction). The polar lipid fraction contained free fatty acids with 14–20 carbons, and palmitic acid, palmitoleic acid, and oleic acid were predominant. A blend of all identified fatty acids, a blend of six major fatty acids (palmitic, palmitoleic, stearic, oleic, linoleic, and linolenic acids), a blend of the two Z‐9‐alkenoic acids (palmitoleic and oleic acids), palmitoleic acid alone, and oleic acid alone showed deterrence against O. scapulalis which was comparable to that provoked by the full egg extract. The dose‐dependency of the deterrent effects of palmitoleic acid and oleic acid was verified in O. scapulalis. The binary blend of palmitoleic acid and oleic acid was also confirmed to deter oviposition in O. furnacalis.  相似文献   

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