Fatty-acid-induced release of manganes from chloroplasts

The effect of both endogenous and exogenous unsaturated free fatty acids on manganese release from chloroplasts of chill-resistant (spinach) and chill-sensitive (tomato, bean) plants was studied. The level of endogenous free fatty acids increased 2–3-fold during cold and dark storage of leaves of chill-sensitive plants and was accompanied by depletion of about 60% of total chloroplast manganese content. Similar effects were observed when accumulation of free fatty acids in chloroplasts was achieved by storage of growing tomato plants for a few days in the dark at room temperature. In contrast, the cold and dark treatment of leaves of chill-resistant plant (spinach) affected neither free fatty acid, manganese levels nor Hill-reaction activity in chloroplasts. Incubation of chloroplasts of both chill-sensitive and chill-resistant plants with bean leaf galactolipase resulted in an accumulation of free fatty acids and a release of approx. 60% of total manganese content. The same amount of total manganese content was released following 3 h incubation of chloroplasts with linolenic acid at fatty acid/chlorophyll ratio (w/w, 2:1–10:1). The efficiency of C₁₈ unsaturated fatty acids/linolenic, linoleic, oleic on manganese release from chloroplasts was established in decreasing order C_18:3 > C_18:2 > C_18:1. The results indicate that the inhibitory effect of both endogenous and exogenous fatty acids on Hill reaction depends on the release from chloroplasts of functionally active, loosely bound manganese. Thus, similarly to both Tris and hydroxylamine treatments of chloroplasts, the incubation of chloroplast preparations with unsaturated fatty acids may be a useful tool for manganese depletion of chloroplasts.     

PHYSIOLOGICAL EFFECTS OF MANGANESE DEFICIENCY RELATED TO AGE IN SOYBEANS (GLYCINE MAX)

Cooper , Eugene E., and Raymond E. Girton . (Purdue U., Lafayette, Ind.) Physiological effects of manganese deficiency related to age in soybeans (Glycine max). Amer. Jour. Bot. 50(2): 105–110. Illus. 1963.—Soybean plants when grown in manganese-deficient silica sand cultures developed typical manganese deficiency symptoms of interveinal chlorosis and necrosis. Physiological effects including depression of photosynthesis, respiration, growth, and relative chlorophyll contents were studied. The depression of photosynthesis was not always proportional to reduced chlorophyll content. This is taken to indicate the importance of manganese in reactions concerned in photosynthesis in addition to chlorophyll formation. Age of leaves related to position on the plant and actual aging of the plants with time sometimes produced different results when related to photosynthetic rates, which mainly decreased with age of plants. Chlorophyll content in young leaves increased with plant age, except for a consistent decrease after leaf maturity. Respiration rates generally decreased with age. For the most part, the effects of aging on photosynthesis, respiration, and chlorophyll contents were the same for soybeans as for other species reported in the literature.     

Lipid Composition of the Yeastlike and Mycelial Mucor hiemalis Cells Grown in the Presence of 4-Chloroaniline

The fungus Mucor hiemalis F-1156, which is commonly thought to be monomorphic, produced two types of cells, yeastlike and mycelial, during growth in a medium containing 4-chloroaniline. Among the polar lipids of yeastlike cells, diphosphatidylglycerol was dominant, while phosphatidylcholine and phosphatidylethanolamine were present in minor amounts. Conversely, mycelial cells mainly contained phosphatidylcholine and phosphatidylethanolamine, whereas the content of diphosphatidylglycerol was low. The neutral lipids of yeastlike cells were dominated by diacylglycerides, sterols, and fatty acids. The content of triacylglycerides and sterol esters was low. Yeastlike cells contained higher amounts of saturated fatty acids and lower amounts of unsaturated fatty acids than the mycelium. The content of stearic acid in the fatty acids of the mycelium grown in the presence of 4-chloroaniline was as high as 25.3–29.9%.     

Lipid biosynthesis by chloroplasts isolated from developing Zea mays

Fatty acid biosynthesis by isolated plastids has been examined in relation to chloroplast development and differentiation in leaves of maize plants grown in light for 7 days. Biosynthesis of fatty acids from acetate by proplastids prepared from the basal regions of the leaf was low and mainly palmitate was synthesized. The greatly increased utilization of acetate for fatty acid biosynthesis as the plastids increased in size was due to an increased synthesis of oleate. The maximum synthesis of total fatty acids and monoenoic fatty acids was obtained in chloroplasts prepared from leaf tissue 6–8 cm from the base of the plant where granal formation was most active. Fully-developed chloroplasts prepared from distal regions of the leaf were less active in fatty acid biosynthesis. Maize chloroplasts failed to synthesize fatty acids when isolated by methods commonly used to prepare active spinach chloroplasts. The method of isolation which included a density gradient gave a high proportion of Class I chloroplasts from maize leaves and incorporated up to about 10% of the acetate used. Biosynthesis of unsaturated fatty acids, especially with chloroplasts prepared from the most mature tissue, was increased by the addition of both mitochondrial and microsomal fractions. Increases in polyunsaturated fatty acids were also obtained but the proportions in the newly-synthesized fatty acids were well below the endogenous levels. Monoenoic synthesis was greatly stimulated by increasing the pH in the range 7·0–8·0 and also the highest proportions of unsaturated fatty acids were obtained at short incubation times.     

Lipid content and fatty acid composition in N2-fixing cyanobacterium Anabaena doliolum as affected by molybdenum deficiency

Anabaena doliolum grown under molybdenum deficiency produced less biomass (on a dry wt basis) and the cells had lower protein content but higher carbohydrate content than Mo-grown material. Molybdenum deficiency led to a slight decrease in chlorophyll a, a 1.5-fold increase in carotenoids and a 1.4-fold increase in total lipid but there was no difference in the lipid profiles of Mo-enriched and Mo-deficient cells. Molybdenum deficiency caused increases in the cell contents of digalactosyl diacylglycerol and phosphatidylglycerol and decreases in monogalactosyl diacylglycerol and sulphoquinovosyl diacylglycerol lipids. The concentration of unsaturated C₁₈ fatty acids was lower in the Mo-deficient cells.     

Effects of dietary manganese on arterial glycosaminoglycan metabolism in sprague—dawley rats

The objectives of this study were to determine whether dietary manganese deficiency alters total glycosaminoglycan (GAG) concentration and composition and glycosyltransferase activity in rat aortas. Sprague-Dawley rats were fed either a manganese-deficient or a manganese-sufficient diet. Arterial GAGs were isolated and quantified by measuring uronic acid content. The individual GAGs were separated and quantified with cellulose acetate electrophoresis. The activity of the enzyme galactosyltransferase I was measured using a 100,000g particulate fraction and 4-methylumbelliferylxyloside (Xyl-MU) as an acceptor. There was a significant decrease (p <- 0.05) in uronic acid content in the manganese-deficient (1.18 ± 0.08 mg/g) rat aortas as compared with the manganese-sufficient (1.59 ± 0.10 mg/g) ones. Chondroitin sulfate and heparan sulfate concentrations were decreased by 38% (p < 0.01) and 36% (p < 0.05), respectively, in the manganese-deficient rat aortas. The incorporation of UDP-galactose to acceptors by the manganese-deficient rat aorta preparations was increased by 28% as compared to the manganese-sufficient preparations. These results indicate that manganese is involved in arterial GAG metabolism by affecting the enzyme galactosyltransferase and that changes in GAG concentration and composition with manganese deficiency may ultimately affect arterial wall integrity and subsequently cardiovascular health. This is the first work to demonstrate that manganese nutrition is important in arterial GAG metabolism.     

Effects of Manganese Deficiency and Added Cerium on Nitrogen Metabolism of Maize

Manganese is one of the essential microelements for plant growth, and cerium is a beneficial element for plant growth. However, whether manganese deficiency affects nitrogen metabolism of plants and cerium improves the nitrogen metabolism of plants by exposure to manganese-deficient media are still unclear. The main aim of the study was to determine the effects of manganese deficiency in nitrogen metabolism and the roles of cerium in the improvement of manganese-deficient effects in maize seedlings. Maize seedlings were cultivated in manganese present Meider's nutrient solution. They were subjected to manganese deficiency and to cerium chloride administered in the manganese-present and manganese-deficient media. Maize seedlings grown in the various media were measured for key enzyme activities involved in nitrogen metabolism, such as nitrate reductase, glutamate dehydrogenase, glutamine synthetase, and glutamic-oxaloace transaminase. We found that manganese deficiency restricted uptake and transport of NO(3)(-), inhibited activities of nitrogen-metabolism-related enzymes, such as nitrate reductase, glutamine synthetase, and glutamic-oxaloace transaminase, thus decreasing the synthesis of chlorophyll and soluble protein, and inhibited the growth of maize seedlings. Manganese deficiency promoted the activity of glutamate dehydrogenase and reduced the toxicity of excess ammonia to the plant, while added cerium relieved the damage to nitrogen metabolism caused by manganese deficiency in maize seedlings. However, cerium addition exerted positively to relieve the damage of nitrogen metabolism process in maize seedlings caused by exposure to manganese-deficient media.     

Effects of a first exposure to ethanol on the compositions of neutral and polar lipids in Euglena gracilis Z, taken as a hepatic cell model: equilibration by citrulline-malate

In comparison to the lipid composition of Euglena cells fed with lactate, a first exposure of the cells to ethanol favors the production of neutral lipids containing mainly unsaturated fatty acids. The ethanol diminishes drastically the proportion of PC and weakly that of PE. In contrast, it increases slightly the proportion of DPG. The ethanol induces important changes in the fatty acid distributions of each lipid class, suggesting modifications of the elongation-desaturation system. On the one hand the proportion of unsaturated fatty acids is increased and, on the other hand, the last double bond is predominantly situated in the delta 6 position in place of delta 3. The addition of the complex citrulline-malate corrects most of these changes.     

Biogenesis of mitochondria: The effects of altered steady-state membrane lipid composition on mitochondrial-energy metabolism in Saccharomyces cerevisiae

A chemostat culture technique has been developed for the growth of an unsaturated fatty acid auxotroph of Saccharomyces cerevisiae. Any chosen steady-state cellular unsaturated fatty acid level between 75 and 15% of the total fatty acids could be established and maintained. In all cultures the steady-state glucose concentrations were maintained at levels below that which induces catabolite repression.The efficiency of oxidative phosphorylation as determined from the molar growth yield decreased as the cellular unsaturated fatty acid composition was lowered. The number of moles of ATP produced by oxidative phosphorylation per mole of glucose utilized was 7.2, 4.8, 0.7, and 0.4 for cells in which 75, 50, 44, and 34%, respectively, of the total fatty acids were unsaturated.The lesion in oxidative phosphorylation was a direct result of lowering the membrane unsaturated fatty acid composition as the respiratory activities and cytochrome content of cells and mitochondria were unaffected by a decrease in the cellular unsaturated fatty acid level from the wild-type value of about 75% down to about 34%.In cells which contained lipids with 22–28% unsaturated fatty acids, cyanide-sensitive respiration was absent, and the levels of all mitochondrial cytochromes were less than 10% of normal. The reduction in the levels of cytochromes aa₃ and b appeared to be a consequence of a loss of mitochondrial protein synthetic activity in such cells. The level of cytochrome c was also greatly decreased, indicating that the cellular unsaturated fatty acid composition was affecting either the synthesis in the cytoplasm of mitochondrial proteins or the assembly of these proteins in the mitochondria.     

Lipid and fatty acid composition of Eisenia foetida

It is found out that the content of lipids in the biomass of the studied populations of Eisenia foetida is rather high: 2.5-5.2% of the wet mass. The content of phospholipids is 40-55%, C27-sterols--1.5-3.4% of the mass of coarse extracts of lipids. Lipids of tissues contain also 47-54% of saturated (C10-C24) fatty acids as well as to 23% of monoene and to 13% of polyene unsaturated (C14-C22) fatty acids. The acids with the odd number of carbon atoms compose about 25% and acids with a branched carbon chain about 23% of the above percentage. Considerable content of lipids and biologically active fatty acids in tissues of the studied object permits considering it as a promising source of raw materials for production of valuable pharmacological preparations.     

Role of micronutrient elements in the metabolism of higher plants. I. Changes in oxidative enzyme constitution of tomato leaves deficient in micronutrient elements

Cell-free extracts of tomato leaves from plants grown on media individually deficient in each of the micronutrient elements showed marked changes in enzymatic constitution. Each deficiency caused an alteration in the over-all enzyme pattern which was characteristic of the micronutrient element in question. The metallo-enzymes such as polyphenol oxidase, ascorbic acid oxidase, and peroxidase lost approximately half their activity in plants deficient in the specific metal concerned. In the cases of all other metal deficiencies, however, polyphenol oxidase and peroxidase were elevated in concentration at least two to six times that of the control. Ascorbic acid oxidase was doubled in zinc- and manganese-deficient material. Glycolic acid dehydrogenase and lactic acid dehydrogenase showed smaller parallel rises averaging a one and a half fold increase in content in zinc- and manganese-deficient plants. Reduced diphosphopyridine nucleotide diaphorase was doubled by copper and manganese deficiencies and was increased to almost one and a half fold by zinc deficiency. Endogenous oxygen uptake in boron-deficient, copper-deficient, and manganese-deficient leaf homogenates was increased, and almost lacking in molybdenum-deficient material.     

Composition of Fatty Acids and Carbohydrates in Leptospira

The fatty acid and monosaccharide composition of four pathogenic and two saprophytic strains of Leptospira was analyzed by gas chromatography (GC) and GC-mass spectrometry. Among the fatty acids, palmitic acid was most abundant and constituted 30 to 50% of the total fatty acids. Even-numbered unsaturated acids including octadecenoic, hexadecenoic, octadecadienoic, and tetradecadienoic acids comprised 40 to 60% of the total fatty acids. Tetradecanoic acid was about 5% in saprophytic strains, but 1% or less in pathogenic strains. The amount of chloroform-methanol extract of L. biflexa strain Ancona was 14 to 20% of the dry weight of the cell. Tetradecadienoic acid was found in the chloroform-methanol insoluble fraction, suggesting the presence of the acid in a bound form. GC analysis of monosaccharides revealed the existence of arabinose, xylose, rhamnose, mannose, galactose, glucose, glucosamine, and muramic acid in the cells. Among the neutral sugars, glucose was a minor component and was especially low in pathogenic strains. Total pentose content was about two to three times greater than total hexose.     

Manipulation of fatty acid composition of membrane phospholipid and its effects on cell growth in mouse LM cells

Fatty acid composition of the phospholipids of mouse LM cells grown in suspension culture in serum-free chemically defined medium was modified by supplementing the medium with various fatty acids bound to bovine serum albumin.Following supplementation with saturated fatty acids of longer than 15 carbons (100 μM) profound inhibition of cell growth occurred; this inhibitory effect was completely abolished when unsaturated fatty acids were added at the same concentration. Supplementing with unsaturated fatty acids such as linoleic acid, linolenic acid or arachidonic acid had no effect on the cell growth.Fatty acid composition of membrane phospholipids could be manipulated by addition of different fatty acids. The normal percentage of unsaturated fatty acids in LM cell membrane phospholipids (63%) was reduced to 35–41% following incorporation of saturated fatty acids longer than 15 carbon atoms and increased to 72–82% after addition of unsaturated fatty acids.A good correlation was found between the unsaturated fatty acid content of membrane phospholipids and cell growth. When incorporated saturated fatty acids reduced the percentage of unsaturated fatty acids in membrane phospholipids to less than 50%, severe inhibition of the cell growth was found. Simultaneous addition of an unsaturated fatty acid completely abolished this effect of saturated fatty acids.     

THE BIOGENESIS OF MITOCHONDRIA : III. The Lipid Composition of Aerobically and Anaerobically Grown Saccharomyces cerevisiae as Related to the Membrane Systems of the Cells

The growth conditions known to influence the occurrence of mitochondrial profiles and other cell membrane systems in anaerobic cells of S. cerevisiae have been examined, and the effect of the several growth media on the lipid composition of the organism has been determined. The anaerobic cell type containing neither detectable mitochondrial profiles nor the large cell vacuole may be obtained by the culture of the organism on growth-limiting levels of the lipids, ergosterol, and unsaturated fatty acids. Under these conditions, the organism has a high content of short-chain saturated fatty acids (10:0, 12:0), phosphatidyl choline, and squalene, compared with aerobically grown cells, and it is especially low in phosphatidyl ethanolamine and the glycerol phosphatides (phosphatidyl glycerol + cardiolipin). The high levels of unsaturated fatty acids normally found in the phospholipids of the aerobic cells are largely replaced by the short-chain saturated acids, even though the phospholipid fraction contains virtually all of the small amounts of unsaturated fatty acid present in the anaerobic cells. Such anaerobic cells may contain as little as 0.12 mg of ergosterol per g dry weight of cells while the aerobic cells contain about 6 mg of ergosterol per g dry weight. Anaerobic cell types containing mitochondrial profiles can be obtained by the culture of the organism in the presence of excess quantities of ergosterol and unsaturated fatty acids. Such cells have increased levels of total phospholipid, ergosterol, and unsaturated fatty acids, although these compounds do not reach the levels found in aerobic cells. The level of ergosterol in anaerobic cells is markedly influenced by the nature of the carbohydrate in the medium; those cells grown on galactose media supplemented with ergosterol and unsaturated fatty acids have well defined mitochondrial profiles and an ergosterol content (2 mg per g dry weight of cells) three times that of equivalent glucose-grown cells which have poorly defined organelle profiles. Anaerobic cells which are low in ergosterol synthesize increased amounts of squalene.     

Lipid composition of azolla caroliniana biomass and its seasonal variation

The chemical composition of the lipid fraction of the aquatic fern, Azolla caroliniana, grown in outdoor mass culture in Florence, was investigated. Palmitic acid was the main fatty acid, particularly in summer when it reached 51.6% of the total fatty acids. In autumn a decrease in palmitic acid content and an increase in α-linolenic acid content occurred. The percentage of unsaturated fatty acids changed from 36.1% in summer to 54% in the biomass harvested in November.     

DIFFERENCES IN PHOTOSYNTHESIS-ASSOCIATED PROPERTIES OF THE BLUEGREEN ALGA SYNECHOCOCCUS CEDRORUM CROWN AT 30 AND 40 C1

The growth of Synechococcus cedrorum Saug. (UTEX 1191) at 40 C resulted in structural and functional alteratons relative to cells grown at 30 C. Structural variations included cell morphology and the chemical composition of the membrane. Growth at 40 C. produced cells that were longer and thinner than those at 30 C. The fatty acid composition changed substantially upon growth at 40 C. yielding a distribution with a higher ratio of: i) saturated to unsaturated fatty acids and; ii) longer chain unsaturated fatty acids. Furthermore, the pattern of membrane proteins as determined by sodium dodecyl sulfate electrophoresis was distinctly different. The functional changes were typified by photosynthetic rates which were approximately half those of the 30 C grown cells. A number of spectral parameters were also seen to change in 40 C. grown cells: absorption spectra indicated a higher phycocyanin : chlorophyll ratio. Low temperature fluorescence spectra were consistent with a lowered efficiency of energy transfer from phycocyanin to chlorophyll. It is suggested that the fatty acid changes at 40 C. yield a more fluid membrane which is responsible for the functional alterations. The modification of phycocyanin. chlorophyll ratios, as well as the appearance of P750, is discussed with respect to membrane fluidity.     

Molybdenum-induced alteration of fatty acids of thylakoid membranes contributed to low temperature tolerance in wheat

The fact that molybdenum (Mo) applications can alleviate low temperature stress (LTS) in plants has been widely reported, but the underlying mechanisms are not fully understood. The effects of Mo (0 and 0.15 mg kg^?1) on photosynthetic pigments, fatty acids and the chlorophyll–protein complex of wheat seedlings in pot culture were investigated at 0, 2, 4 and 6 days of LTS. Chlorophyll a and b, total chlorophyll and carotenoid contents were significantly enhanced by Mo application. The palmitic acid (C16:0) content and total saturated fatty acids (TSFA) were drastically decreased in wheat cultivar 97003 at 2 and 4 days of LTS and in wheat cultivar 97014 at 2 days of LTS. The linolenic acid (C18:3) content and total unsaturated fatty acids (TUSFA) were significantly increased in both cultivars at 2 and 4 days of LTS. The palmitoleic acid (C16:1) content was also drastically increased in cultivar 97003 at 2 days of LTS, suggesting that Mo induced a greater production of unsaturated fatty acids or the conversion of TSFA to TUSFA. The ratio of unsaturated to saturated fatty acids and the index of unsaturated fatty acids in the thylakoid membranes were enhanced with supplemental Mo, suggesting that Mo might improve the degree of unsaturation. However, no significant differences were observed in the chlorophyll–protein complexes between the +Mo and ?Mo treatments. These results indicated that the alteration of fatty acids induced by Mo application in the thylakoid membranes of wheat contributed to LTS tolerance.     

Quantitative and compositional changes in monogalactosyl and digalactosyl diglycerides during light-induced formation of chloroplasts in Euglena gracilis

The formation of chloroplasts in dark-grown cells of Euglena gracilis was induced by exposing the cells to constant illumination. Following a lag, the cells accumulated chlorophyll and galactosyl diglycerides simultaneously at almost linear rates. The monogalactosyl diglyceride content rose from approximately 2 micromoles in 100 mg of dark-grown cells to 27 micromoles in fully green cells; the digalactosyl diglyceride content increased from 1 micromole to 11 micromoles. The digalacto compounds increased more rapidly than the monogalacto compounds at first, but their rate of accumulation began to diminish long before greening of the cell was complete. The sole exception was the digalactosyl diglyceride fraction that contained hexadecadienoic (16:2) fatty acid. This fraction increased continuously during greening. As accumulation of the digalacto compounds diminished, that of the monogalacto compounds increased. Towards the end of greening, the major fatty acids were 16:2, 16:3, 16:4, 18:2, and 18:3 in the monogalacto and 16:2 in the digalacto compounds. The results of this study suggest that monogalactosyl and digalactosyl diglycerides that contain particular fatty acid components have a function in the assembly of chloroplasts.     

稻曲病菌厚垣孢子脂肪酸组成的研究

【目的】为探明细胞壁和细胞内脂肪酸成分及含量与细胞抗逆性的关系,【方法】采用酸热法、索氏提取法、有机溶剂法对稻曲病菌的厚垣孢子壁进行脂肪酸提取,并采用气相色谱检测其脂肪酸的组成和含量。【结果】采用酸热法提取脂肪酸效果最好,以该方法提取测定稻曲病菌黄色、黄绿色、黑色厚垣孢子壁饱和脂肪酸相对含量分别为26.92%、17.23%、23.71%,其不饱和脂肪酸相对含量分别为60.46%、61.52%、70.64%;厚垣孢子总(沉淀孢子壁和上清液)饱和脂肪酸相对含量分别为28.87%、21.00%、24.04%,厚垣孢子总不饱和脂肪酸相对含量分别为55.43%、55.87%、63.89%。硬脂酸在厚垣孢子壁中的含量:黄色>黄绿色>黑色;不饱和脂肪酸中顺式-5,8,11,14,17二十碳五烯酸(EPA)在厚垣孢子壁的含量:黑色>黄绿色>黄色。【结论】在3种颜色厚垣孢子中,黑色休眠型厚垣孢子在孢子壁、总不饱和脂肪酸含量均最高,表明不饱和脂肪酸的含量提高,有利于厚垣孢子的休眠越冬。     

Composition of lipids from yeast-like and mycelial cells of the fungus Mucor hiemalis, grown in the presence of 4-chloroaniline

The fungus Mucor hiemalis, which is commonly thought to be monomorphic, produced two types of cells, yeastlike and mycelial, during growth in a medium containing 4-chloroaniline. Among the polar lipids of yeastlike cells, diphosphatidylglycerol was dominant, while phosphatidylcholine and phosphatidylethanolamine were present in minor amounts. Conversely, mycelial cells mainly contained phosphatidylcholine and phosphatidylethanolamine, whereas the content of diphosphatidylglycerol was low. The neutral lipids of yeastlike cells were dominated by diacylglycerides, sterols, and fatty acids. The content of triacylglycerides and sterol esters was low. Yeastlike cells contained higher amounts of saturated fatty acids and lower amounts of unsaturated fatty acids than the mycelium. The content of stearic acid in the fatty acids of the mycelium grown in the presence of 4-chloroaniline was as high as 25.3-29.9%.