Sterols and sterylglycosides of oats (<i>Avena sativa</i>). Distribution in the leaf tissue and medium‐induced glycosylation of sterols during protoplast isolation

Kesselmeier, J.; Eichenberger, Waldemar; Urban, Birgit

doi:10.1111/j.1399-3054.1987.tb04313.x

Cited by 16 publications

(11 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Interconversions of free sterols and sterol derivatives have been reported in connection with osmotic or water-deficit stress (6,9,12) and protoplast isolation (11). While net loss of total sterols occurs during these stresses (9,11), the loss is not as great as the loss of total fatty acids (9). The results presented in Table 3 are consistent with these previous studies.…”

Section: Resultssupporting

confidence: 89%

“…Concomitant with this loss of polar lipids is a relative increase in neutral lipids, which are thought to be mostly triacylglycerols in lipid bodies (6-8, 13). Interconversions of free sterols and sterol derivatives have been reported in connection with osmotic or water-deficit stress (6,9,12) and protoplast isolation (11). While net loss of total sterols occurs during these stresses (9,11), the loss is not as great as the loss of total fatty acids (9).…”

Section: Resultsmentioning

confidence: 99%

“…3 and references therein). Other reports (6)(7)(8)(9)(10)(11)(12)(13) have shown that osmotic stress alters the lipid composition of plant cells. While this problem might be best addressed by comparing lateral diffusion characteristics in the membranes of protoplasts and whole cells, the cell wall interferes with selective fluorescence labeling of the plasma membrane and thwarts meaningful measurements on whole cells.…”

mentioning

confidence: 93%

See 2 more Smart Citations

Selective osmotic effect on diffusion of plasma membrane lipids in maize protoplasts.

Furtula

Khan²,

Nothnagel³

1990

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Osmotic levels in the range typically used during plant protoplast isolation and incubation were investigated with regard to effects on the lateral diffusion of lipid probes in the plasma membrane. The lateral diffusion coefficient of a fluorescent sterol probe in the plasma membrane of maize (Zea mays L.) root protoplasts in a medium containing 0.45 M mannitol was 4 times faster than when the medium contained 0.9 M mannitol. The lateral diffusion coefficient of a fluorescent phospholipid probe, however, did not change over this range of mannitol concentrations. Similar diffusion characteristics were observed when the medium contained trehalose instead of mannitol. Slower lateral diffusion of the sterol probe at higher osmolality was also observed when KCI/CaCl2-based osmotic media were used with protoplasts isolated by a mechanical, rather than by an enzymic, method. Extraction and quantitation of total lipids from protoplasts showed that both the phospholipid and sterol contents per protoplast decreased with increasing osmolality, while the sterol/phospholipid ratio increased. These results demonstrate that osmotic stress induces selective changes in both the composition and biophysical properties of plant membranes.Evidence for the existence of lipid domains in plant and other biological membranes has come from a variety of experiments (1). One source of such evidence has been studies of lipid dynamics involving long-range motions-i.e., motions over distances that are large compared to molecular dimensions. Use of fluorescence techniques to measure such lipid motions in the plasma membrane of plant protoplasts was first reported by Metcalf et al. (2). In that work, fluorescence redistribution after photobleaching was used to measure the lateral diffusion of various fluorescent lipid probes in protoplasts from suspension-cultured soybean cells. Two diffusion coefficients, one in the 2-5 x 1010 cm2/sec range and another in the 1-6 x 10-9 cm2/sec range, were simultaneously observed under certain conditions of temperature and probe concentration. The mobile fraction, summed for the two diffusing species, was in the 0.56-0.76 range-i.e., a significant portion of the lipid probe moved so slowly as to appear immobile on the time scale of the experiment. These heterogeneous diffusion parameters were interpreted as evidence for the existence of lipid domains in the plasma membrane of soybean protoplasts (1).Fluorescence photobleaching recovery experiments carried out in our laboratory (3, 4) have yielded results that are comparable to those reported by Metcalf et al. (2). Fluorescent lipid probes (5) were used that enabled the consistent resolution of two diffusion coefficients over a range of conditions. The lateral diffusion coefficient of a fluorescent sterol probe in the plasma membrane of root cortical protoplasts from two different maize lines was 3-7 x 10-10 cm2/sec for temperatures in the 3.50C-370C range (3). Over the same temperature range, the diffusion coefficient of a fluorescent phospholipid prob...

show abstract

Section: Resultssupporting

confidence: 89%

Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 93%

See 1 more Smart Citation

Selective osmotic effect on diffusion of plasma membrane lipids in maize protoplasts.

Furtula

Khan²,

Nothnagel³

1990

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…In the latter the proportion of ASG was increased from 2.7 to 11.2 %. These data are in line with the observation of Kesselmeier et al (1987) that protoplast formation from leaves resulted in a conversion of free sterols to SG and ASG. In this context, attention is drawn to the low proportion of free sterols (3.7 Yo) in barley tonoplasts which were obtained via protoplasts.…”

Section: Lipid Profiles Ofleaf Tonoplastssupporting

confidence: 91%

Lipid Profiles of Leaf Tonoplasts from Plants with Different CO₂‐Fixation Mechanisms*

et al. 1990

View full text Add to dashboard Cite

Tonoplast preparations were obtained from leaves of Hordeum vulgare (C3), Kalanchoe daigremontiana (obligate CAM) and Mesembryanthemum crystallinum (C, and inducible CAM). Lipid analyses showed reproducible patterns comprising free sterols, glycolipids of plastidic origin, glucose-containing lipids (steryl glucoside, acylated steryl glucoside, cerebroside) and phospholipids. Predominant components were sterols, cerebrosides, phosphatidyl choline and phosphatidyl ethanolamine. Very long chain fatty acids were found in phosphatidyl serine and hydroxy fatty acids in cerebrosides. Isolation of tonoplasts via protoplasts and vacuoles may have resulted in reduced levels of free sterols. The data show a similarity between tonoplasts and plasma membranes with respect to lipid profiles. Lipid composition was neither affected by different COzfixation mechanisms nor by salt-induced changes in Mesembryanthemum crystallinum.

show abstract

“…Sterol glycosides and acylglycosides are usually isolated from natural sources as very complicated mixtures that cannot always be separated into, the pure components. However, several physicochemical methods have recently been proposed for separating, analyzing, and identifying them [23][24][25][26][27][28][29][30][31][32][33][34]. Use of these methods greatly facilitates the investigation of glycosides and acylglycosides.…”

mentioning

confidence: 99%

Sterol glycosides and acylglycosides

Ковганко¹,

Kashkan²

1999

Chem Nat Compd

View full text Add to dashboard Cite

The stntctlo'e, properties, distribution in nature, and biological activity of sterol glycosides and acylglycosides are reviewed.Sterols are one of the most widely distributed natural substances [1][2][3]. They exist in animals and plants in the free state and as derivatives. Glycoside and acylglycoside derivatives of sterols have been known for a long time. In the plant world, these compounds are found in higher plants [2,[4][5][6], algae [7], fungi [8][9][10], and bacteria [11][12][13][14][15][16]. In the animal kingdom, these substances have been identified in soft coral [17], holothuriae [18-20[, amphibians [211, snakes [21, 22], and birds [21,23]: Such a wide distribution in nature suggests that sterol glycosides and acylglycosides possess important physiological functions. Therefore, these compounds are constantly under intense scientific scrutiny. Sterol glycosides and acylglycosides are usually isolated from natural sources as very complicated mixtures that cannot always be separated into, the pure components. However, several physicochemical methods have recently been proposed for separating, analyzing, and identifying them [23][24][25][26][27][28][29][30][31][32][33][34]. Use of these methods greatly facilitates the investigation of glycosides and acylglycosides.Owing to the wide distribution in nature and the variety of physiological functions for glycosides and acylglycosides, research articles about them are published in a wide range of scientific literature. However, this subject has not yet been reviewed. The present work is intended to fill that gap. It should be noted that we pay the most attention to discreet natural compounds that can be isolated pure and for which the structures are reliably proved since this is where our interest lies. Substances that have been isolated as mixtures and are insufficiently characterized are examined in less detail.Some of the most widely distributed sterol glycosides are ~sitosterol 3-O-~D-glucopyranoside (1). This compound was isolated from higher plants early in the 20th century under various names: ipuranol, citrullol, trifolianol, etc. [35,36]. Later glycoside 1 was prepared by chemical synthesis via glycosylation of I~-sitosterol [37]. Direct comparision with this synthesized compound provided final structural proof tbr various natural samples of I [36]. Glycoside 1 is the most typical sterol glycoside of higher plants and is usually observed in preliminary phytochemical analysis of them. Hydrolysis of glycoside 1 by sulfuric acid in ethanol with boiling lbr 22 h yields [~-sitosterol and D-glucose [41]. The same result is obtained by hydrolysis in 6% HCI with heating lbr 50 min [46]. Hydrolysis of compound 1 to give ~sitosterol

show abstract

Sterols and sterylglycosides of oats (Avena sativa). Distribution in the leaf tissue and medium‐induced glycosylation of sterols during protoplast isolation

Cited by 16 publications

References 31 publications

Selective osmotic effect on diffusion of plasma membrane lipids in maize protoplasts.

Selective osmotic effect on diffusion of plasma membrane lipids in maize protoplasts.

Lipid Profiles of Leaf Tonoplasts from Plants with Different CO₂‐Fixation Mechanisms*

Sterol glycosides and acylglycosides

Contact Info

Product

Resources

About

Sterols and sterylglycosides of oats (Avena sativa). Distribution in the leaf tissue and medium‐induced glycosylation of sterols during protoplast isolation

Cited by 16 publications

References 31 publications

Selective osmotic effect on diffusion of plasma membrane lipids in maize protoplasts.

Selective osmotic effect on diffusion of plasma membrane lipids in maize protoplasts.

Lipid Profiles of Leaf Tonoplasts from Plants with Different CO2‐Fixation Mechanisms*

Sterol glycosides and acylglycosides

Contact Info

Product

Resources

About

Lipid Profiles of Leaf Tonoplasts from Plants with Different CO₂‐Fixation Mechanisms*