Changes in the composition and content of lipids in the leaves of radish plants of different magnetic orientation induced by weak permanent magnetic field

The effect of weak permanent horizontal magnetic field (PMF) with the intensity of 403 A/m on the composition and content of polar and neutral lipids and their constituent FAs was investigated in the leaves of radish plants (Raphanus sativus L., var. radicula D.C.), cv. Rozovo-krasnyi s belym konchikom, which belong to two major types of magnetic orientation (TMO): North-South (NS) and West-East (WE), with the planes of the root grooves oriented along and across the magnetic meridian, respectively. In spring, PMF reduced the level of total lipids in the NS plants and elevated it in the WE plants; in autumn, the content of total lipids in the NS plants increased in the NS plants and decreased in the WE plants. In spring, the ratio between phospholipids and sterols, which indirectly points to enhanced fluidity of membrane lipid bilayer, increased in the plants of both TMOs, while in autumn, it increased only in the NS plants. In the control plants, the relative content of unsaturated FAs, including linolenic and linoleic acids, was greater in the WE plants than in the NS plants. PMF elevated the content of FAs in the leaves of the NS plants and did not affect their level in the WE plants. It was concluded that weak horizontal PMF differently (and sometimes oppositely) affected the content of lipids in the leaves of the NS and WE radish plants, apparently due to their different sensitivity to the effect of the magnetic field associated with their physiological status.     

Lipids and fatty acid composition of developing winged bean seeds

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.     

Fatty acid composition of total lipids from the needles of pine seedlings as related to boron availability

The effect of boron availability on the content of fatty acids (FA) in the total lipids of needles was investigated in two-year-old seedlings of Scots pine (Pinus sylvestris L.). The study was conducted in the forest nursery on the soil deficient in boron. Various rates of boric acid (0.01, 0.03, 0.1, 0.3, 1, 3, and 10 g/m²) were applied to soil three times throughout the growth period. When pine seedlings were supplied with extra boron, the lipid content of the seedling needles declined. The optimal boron supply elevated the content of saturated FA in total needle lipids mostly at the expense of palmitic acid, with a corresponding decline in the level of unsaturated FA and unsaturation index of FA owing to trienoic FA (mainly linolenic and hexadecatrienoic acids). At the same time, the level of monoenoic and to a lesser degree dienoic acids increased. When boron supply of the seedlings was not optimal, the content of unsaturated and low-molecular FA increased.     

Effect of Choline Chloride on the Lipid Content and Composition in the Leaves of Principal Magnetically-Oriented Radish Types

The effects of radish seed treatment with choline chloride on the number and weight of leaves, the weight of roots, as well as the content and composition of polar and neutral lipids and their component fatty acids in the leaves of principal magnetically-oriented types (MOTs) of radish (cv. Rosovo-krasnyi s belym konchikom), that is, North–South (NS) and West–East (WE) ones, were investigated. It was shown that seed treatment with 1% choline chloride increased the proportion of WE MOT in plant population. In spring and in autumn, this treatment increased the weight of roots of the NS MOT plants, but did not affect this index in the WE MOT plants. In the spring NS MOT plants, choline chloride treatment did not change the absolute content of polar lipids as compared to the control, but in autumn, this index increased. Meanwhile, in the WE MOT plants, it increased in spring and did not change in autumn. In the spring NS MOT plants, the content of neutral lipids increased, but in the autumn plants, it did not change. At the same time, in the WE MOT plants, this index decreased both in spring and in autumn. Seed treatment with choline chloride resulted in a substantial increase in the total content of phospholipids, in particular, that of phosphatidylcholine and phosphatidylethanolamine, in the NS and WE MOT plants sampled both in spring and in autumn. In addition, the ratio of unsaturated to saturated fatty acids, as well as that of linolenic to linoleic fatty acids, somewhat increased in the NS MOT leaf lipids, but decreased in the WE MOT ones. Presowing treatment of radish seeds with choline chloride variously and sometimes oppositely affected the content and composition in the NS and WE MOT leaf lipids. This seems to be caused by different response of these MOTs to the environmental factors.     

The effects of a weak permanent magnetic field on the lipid composition and content in the onion leaves of various ages

We have studied the effects of a weak permanent magnetic field (PMF) with strength of 403 A/m on the composition and content of polar and neutral lipids and the composition of their fatty acids (FAs). The lipids were isolated from the third, fourth, and fifth leaves of onion (Allium cepa L., cv. Arzamasskii) plants, and their composition was determined using TLC and GLC techniques. Plants growth under the conditions of a natural geomagnetic field served as a control. Most intense changes in the lipid content induced by PMF were observed in the fourth onion leaf. The content of total lipids and that of polar lipids (glyco-and phospholipids) changed, whereas the content of neutral lipids either decreased or remained unchanged. The phospholipid/sterol ratio increased, causing an increase in the fluidity of the membrane lipid bilayer. PMF induced an increase in the concentration of linolenic acid and the relative content of total unsaturated FAs. The effects of PMF on the content and composition of lipids in the third and fifth onion leaves were less pronounced, demonstrating differences between the leaves of various ages in their sensitivity to the effects of magnetic field. It is concluded that changes in the weak PMF within the limits of changes in the strength of geomagnetic field in the course of evolution can affect biochemical and physiological processes of plants.     

Effect of weak constant magnetic field on the composition and content of lipids in radish seedlings at various temperatures

We studied the effects of weak permanent homogenous hirizontal magnetic field (PMF) (400 A/m) on the composition and content of lipids and composition of their fatty acids (FAs) in radish (Raphanus sativus L. var. radicula D.C., cv. Rosovo-krashyi s belym konchikom) seedlings at temperatures of 20 and 10°C. We compared lipid composition and content in seedlings at the phase of developed cotyledons (20°C, 5-day-old, and 10°C, 8-day-old seedlings) under low light and in darkness with the lipid composition and content in dry seeds. The seedlings grown in geomagnetic field (GMF) served as a control. In dry seeds, about 99% of total lipids comprised neutral lipids (NL) and only 1% were polar lipids (PL). Triacylglycerols predominated among NL comprising 93% of total seed lipids. During seed germination, NLs were consumed and PL were produced: the amount of glycolipids increased in control by 3.5–5 times and the amount of phospholipis, by 1.5–2 times.In the light at 20°C, PMF suppressed the formation of PL (by 18%), whereas in darkness, it stimulated it approximately by 80% as compared with control. In the light at 10°C, PMF slightly stimulated PL formation; in darkness, it did not almost affect their synthesis. In all treatments, PMF increased the ratio of phospholipids to sterols by 30–100%. Among FA, PMF exerted the strongest effect on the content of erucic acid: it increased in the light and in darkness at 20°C approximately by 25% and decreased at 10°C in the light by 13%. PMF behaved as a correction factor affecting lipid metabolism on the background of light and temperature action.     

In vivo incorporation of acetate into the acyl moieties of polar lipids from etiolated leek seedlings

Seven-day-old leek seedlings actively synthesize lipids in vivo from [1-¹⁴C]acetate, both in the light and in the dark. In the dark, phospholipid synthesis is more effective than galactolipid synthesis. Whatever the time of acetate incorporation by the etiolated seedlings, very long chain fatty acids having from 20 to 26 carbon atoms are found in all the polar lipids, including the acyl-CoAs. All of the labelled very long chain fatty acids incorporated into the polar lipids are saturated. On the other hand, the labelled C₁₈-fatty acids are unsaturated in phospholipids and galactolipids and almost no label is found in the saturated or unsaturated C₁₈-fatty acids of the acyl-CoAs.     

Isolation and identification of a new growth inhibitor, raphanusanin, from radish seedlings and its role in light inhibition of hypocotyl growth

A neutral growth inhibitor, for which the name raphanusanin is proposed, has been isolated in crystalline form from light-exposed Sakurajima radish (Raphanus sativus var. hortensis f. gigantissimus Makino) seedlings and identified as a new compound, 3-methoxy-4-methylthio-2-piperithione by spectrometric analyses.

Applied raphanusanin inhibited the hypocotyl growth of etiolated radish and lettuce seedlings at concentrations higher than 1.5 × 10⁻⁶ molar.

The endogenous raphanusanin contents in cotyledons and hypocotyls of radish seedlings increased more under red light, but decreased or maintained the initial level in the dark. Its content in roots showed almost no change between the light and dark materials.

     

Inhibition of linolenic Acid synthesis and modification of chilling resistance in cotton seedlings

The temperature at which cotton seeds (Gossypium hirsutum L.) germinated influenced the fatty acid composition of the polar lipids of developing root tips. Seeds were germinated at 15, 20, 25, and 30 C. As the temperature decreased the linolemic acid content of the polar lipid fraction increased. Sandoz 9785[4-chloro-5-(dimethylamino)-2-phenyl-3(2H)-pyridazinone] reduced the low temperature-induced increase in linolenic acid content of the polar lipids and reduced seedling ability to withstand 8 C chilling. The results are consistent with the conclusion that chilling resistance in cotton seedlings is related to the level of linolenic acid in the polar lipids in the developing root tips.     

Etude comparee des lipides et de la fixation passive du calcium dans les racines et les fractions subcellulaires du Lupinus luteus et de la Vicia faba

In both lupin and broad bean, the root lipids contain paraffins, triglycerides, diglycerides, free fatty acids and polar lipids (phospholipids and galactolipids). The polar lipids and the triglycerides are the more abundant classes. The root galactolipids are mono- and di-galactosyldiglycerides; two steryl glycosides are also present. The phospholipids in both species are: phosphatidylinositol, phosphatidylcholine, phosphatidylglycerol, phosphatidylserine, phosphatidylethanolamine, diphosphatidylglycerol and phosphatidic acid. This last phospholipid represents 8·3% of total lipid phosphorus in Lupinus against 2·3% in Vicia. The other acidic phospholipids represent 30·4% in Lupinus against 20·9% in Vicia. The lipids of Lupinus are rich in linolenic acid whereas those found in Vicia are richer in linoleic acid. The various subcellular fractions prepared from the roots of both species have an homogeneous lipid composition, reflecting exactly that of entire cells. The calcium passive fixation capacity in microsomes and mitochondria of Lupinus roots is more important than that in the same organelles of Vicia faba roots. Thus a relationship is suggested between the amount of phospholipids in membranes and the passive fixation of calcium.     

The effect of radish plant rotation around a vertical axis on leaf morphology and lipid composition

The effects of radish (Raphanus sativus L. var. radicula D.C., cv. Rozovo-krasnyi s belym konchikom) plant clockwise rotation (2 rpm) around the vertical axis during their growth on growth parameters and also on the composition and content of polar lipids (PL) and neutral lipids (NL) in plant leaves and fatty acids included in them were studied. Rotation in the plane of the Earth’s magnetic field horizontal component did not affect the number of leaves but declined their total mass by 25%. However, a reduction of the root mass was observed only at elevated temperature. Rotation reduced the ratio of PL to NL by 1.5–2.0 times as compared with control, decreasing the content of such PL as glycoand phospholipids and increasing the content of NL, triacylglycerols and free sterols. Among glycolipids, the content of monogalactosyldiacylglycerols and digalactosyldiacylglycerols was reduced in comparison with stationary control, and among phospholipids the content of phosphatidylcholin was reduced by ∼50%. The ratio of phospholipids to sterols was reduced more than by 30%, indirectly indicating the decreased fluidity of the lipid bilayer of membranes; the ratio PL/NL was reduced as well, indicating an acceleration of age-dependent changes in the rotated plants. Rotation increased the content of linolenic acid and reduced the contents of oleic and erucic acids, thus increasing the index of fatty acid desaturation. We concluded that radish plant clockwise rotation around the vertical axis is an unfavorable factor inducing the appearance of the signs of premature senescence.     

Lipids in developing and mature rice grain

The neutral fraction of nonstarch lipids in developing brown rice (Oryza sativa L., cv IR42) was accumulated up to 16 days after flowering (DAF), but phospholipids and glycolipids increased only up to 8 DAF. Fatty acids accumulated in nonstarch lipids until 12 DAF. However, the proportion of linolenic acid in the lipid fraction decreased and that of oleic acid increased during this period. Accumulation of fat-by-hydrolysis in the brown rice occurred until 20 DAF and followed closely that of starch. The proportion of linolenic acid decreased and that of linoleic acid increased until 16 DAF. The fatty acid composition of fat-by-hydrolysis and starch lipids were identical and fat-by-hydrolysis accounted for 48% by weight of starch lipids. Nonstarch lipids were mainly composed of triglycerides and were located in the bran and embryo of mature brown rice. Starch lipids were mainly composed of lysophosphatidyl choline, free fatty acids and lysophosphatidyl ethanolamine, and were located in the endosperm.     

Lipid Composition of Tomato Leaves as Related to Plant Cold Tolerance

We studied the effects of a low nonlethal temperature (6°C) on the content and composition of polar lipids and their fatty acids in tomato (Lycopersicon esculentum Mill., cv. Sibirskie skorospelye) leaves. We demonstrated that chilling resulted in a decrease in the content of total polar lipids per 1 mg protein. The content of lipids in chloroplast membranes (monogalactosyldiacylglycerols, digalactosyldiacylglycerols, sulfoquinovosyldiacylglycerols, and phosphatidylglycerols) changed less substantially than the content of phospholipids in other cell organelles and in the cytoplasm. Neutral lipids comprised only 1% of total lipids, and their content also decreased after chilling. The relative amounts of unsaturated and saturated fatty acids in polar lipids were practically unchanged. The conclusion was drawn that the maintenance of a high level of chloroplast membrane lipids under low temperatures could play an important role in the survival of cold-tolerant plants.     

Lipid composition of the entomopathogenic fungus Nomuraea rileyi

The total lipid content, neutral and polar lipid composition, and fatty acid profiles were determined for the different developmental stages of the entomopathogenic fungus, Nomuraea rileyi. In general, the lipid composition of N. rileyi was found to be very similar to that of other Fungi Imperfecti. Triacylglycerides and sterols were the major neutral lipids and phosphatidylethanolamine, phosphatidylinositol, and phosphatidylserine were the major polar lipids. Phosphatidylcholine, resolved in conidial and mycelial samples, was not detected in hyphal body samples. The major fatty acids were palmitic, oleic, and linoleic. Stearic acid was detected as a minor component of hyphal body samples. During conidiogenesis the overall lipid composition was altered in (1) a reduction in total lipid content, (2) an increase in the polar/neutral lipid ratio, and (3) an increase in the degree of fatty acid unsaturation.     

Effect of perfluidone on metabolism of lipids in maize (Zea mays L.) and sunflower (Helianthus annuus L.)

Treatment of germinating maize seedlings with 0.126 mM of the herbicide Perfluidone (Destun) (1,1,1-trifluoro-4′-[phenylsulfonyl]-methanesulfona-o-toluidide) for 2 days in the dark, then 3 days in the light, at 25°C causes decreases in fresh weight, dry weight, shoot length, and in total chlorophyll and carotenoid contents; in contrast, sunflower seedlings seem not to be affected. Perfluidone causes marked decreases in total lipids and in glyco- and phospholipids of maize seedlings. In sunflower cotyledons, total lipids and pigments (chlorophyll, carotenoids) are not affected, but there is an increase in glycolipids at the expense of phospholipids. After Perfluidone treatment, a significant increase in the fatty acid mole ratio (18∶0+18∶1+18∶2)/18∶3 was found for the maize glycolipids, monogalactosyl diacylglycerol (MGD), digalactosyl diacylglycerol (DGD), and sterol glycoside (SG) + esterified sterol glycoside (ESG), and for the phospholipid, phosphatidylcholine (PC). In sunflower seedlings, however, only the fatty acid mole ratio of ESG + SG showed an increase and that of phosphatidylserine (PS) showed a large decrease. The differential response of the two plant species to Perfluidone suggests that the control of linolenic acid biosynthesis may vary depending on plant species and/or on plant tissues.     

Light growth inhibition and growth inhibitors in Sakurajima radish seedlings

Growth of Sakurajima radish seedlings (Raphanus sativus var.hortensis f. gigantissimus Makino) was studied in relation tothe effects of light, the effectiveness of plant hormones, andthe variation in endogenous growth inhibitor content Externally applied GAs and IAA had no effect on the elongationof the hypocotyl in the light as well as in the dark. BA wasslightly promotive in the light, but was not so effective asto nullify the light-induced inhibition of elongation. ABA wasstrongly suppressive in the light as well as in the dark. Growth inhibitors in seedlings were extracted, analyzed by thin-layerchromatography and the Sakurajima radish hypocotyl elongationtest, and 3 acidic and 3 neutral inhibitors were detected. Amongthem all of the acidic and one of the neutral inhibitors increasedwith the time period of illumination, whereas the other 2 neutralsubstances remained almost unchanged in the light but decreasedin the dark. Thus the levels of all 6 inhibitors was higherin light-grown seedlings than in dark-grown ones. This suggeststhat light inhibition in Sakurajima radish hypocotyls may becontrolled by the variation in the inhibitor levels in the seedlings. (Received December 1, 1977; )     

Effect of paclobutrazol on membrane lipids in apple seedlings

The effect of paclobutrazol [( 2RS, 3RS )-1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2, 4-triazol-1-yl) pentan-3-ol] on the fatty acid composition of polar lipids and on the sterol content in apple ( Malus domestica Borkh. cv. York Imperial) seedlings was determined. Polar lipids isolated from leaves, stems and roots included mono- and digalactosyldiglycerides and the phospholipids phosphatidylinositol, phosphatidylcholine, phosphatidylglycerol and phosphatidylethanolamine. The predominant fatty acids in membrane polar lipids were palmitic (C16:0), linolnic (C18:2) and linolenic (C18:3). The predominant sterol, both free and esterified, was β-sitosterol. There were no significant alterations in the fatty-acid composition of glyco- and phospholipids from paclobutrazol-treated apple seedlings. In contrast, a significant decrease in the content of β-sitosterol and campesterol occurred in treated tissues. The decline in sterol content continued with increasing duration of paclobutrazol treatment, and was most pronounced in the root tissue.     

The Effect of Helminthosporic Root Rot on the Composition of Acyl Lipids of Wheat Seedlings

The changes of the molecular species composition of esterified fatty acids (FAs) of total and nonextractable lipids were determined in roots and etiolated shoots of 3- to 10-day-old wheat (Triticum aestivumL.) seedlings infected with the fungus Bipolaris sorokiniana, the agent of helminthosporic root rot. A novel technique of assessing the extent of the infection-induced deviation of FA composition, mol %, from the control value was developed. It consists in the quantitative determination of both the deviations in this composition and the extent of contribution of separate FA species to the deviations observed. The application of this technique has shown that, for the total lipids, the maximum of such a deviation, in accordance with the membrane theory of stress, directly coincided in time with the onset of a decrease in the dry matter content in both roots and shoots. In each of these, the deviation was primarily caused by the change in the content of those FA species that usually dominate in a specific group of membrane lipids prevailing in a given organ, viz., plastid glycolipids in shoots and extraplastidal membrane phospholipids in roots. In both cases, C₂₀–C₂₂FAs significantly contributed to the deviations observed. This fact seems to reflect an enhanced formation of epicuticular waxes rich in these FAs on the shoot and root surfaces as an adaptive response of plants to fungal infection. Nonextractable (annular) membrane lipids, because of their vital importance for the survival of plant cells, differed from the total lipids with a far greater stability of their quantitative FA composition under conditions of infection-induced metabolic disturbances.     

Lipids of Dark-Treated Oat (Avena sativa) Leaf Chloroplast Thylakoids

The lipid content of thylakoids from dark-treated oat plantswas studied. The levels of chlorophyll, monogalactosyl diacylglycerol²,digalactosyl diacylglycerol, and the phospholipids all declined.The lipids declined more rapidly than the chlorophyll. As thequantity of the galactolipids declined, there was little changein the relative concentration of linolenic acid esterified tothem. In contrast, the relative concentration of linolenic acidesterified to the phospholipids increased as the quantity oflipid declined. The total fatty acid composition and the incorporationof label into thylakoid lipids dropped following the dark treatment.     

Lipid biochemistry of echinochloa crus-galli during anaerobic germination

Seven day old seedlings of Echinochloa crus-galli var. oryzicola (Vasing) had a higher total lipid content when germinated under N₂ than in air, although ungerminated seeds contained more lipid than either seedling. The triacylglycerol pool was not depleted under anaerobiosis as it was in air and only air-grown seedlings showed a net increase in free fatty acids and polar lipids. Concentrations of most of the individual acids of the total fatty acid profile declined during germination in air and in the free acid and polar lipid fractions of these seedlings the relative proportion of polyunsaturated fatty acids increased. Compared to air-grown seedlings, ungerminated seeds and N₂-grown seedlings had a similar qualitative and quantitative lipid composition. Our results show that mobilization of storage lipids was apparently severely inhibited under anoxia. The importance of lipid metabolism to the germination and growth of Echinochloa during anoxia is discussed in terms of maintaining membrane integrity and serving (indirectly) to reoxidize pyridine nucleotides.