Carbohydrates of the brown seaweeds himanthalia lorea, bifurcaria bifurcata, and Padina pavonia

Mian, A. Jabbar; Percival, Elizabeth

doi:10.1016/s0008-6215(00)85030-2

Cited by 96 publications

(32 citation statements)

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“…However, even in the most highly purified samples of the cellulose fraction from embryo walls, we always find 5 to 15% of the neutral sugars to be comprised of equal quantities of xylose and fucose, the remaining being only glucose (25). Traces of xylose have also been reported in cellulose preparations from the brown alga Himanthalia (13). The fact that F1 appears as the earliest matrix component in the developing wall, coincident with the acquisition of structural integrity and birefringence of the wall, tightly associated with cellulose, and to require harsh chemical treatment for removal, argues for its basic structural role in wall assembly and function.…”

Section: Resultsmentioning

confidence: 99%

“…2). By sequentially extracting cell walls of F. vesiculosus with weak acid, weak base, and strong alkali, the percentage of well characterized polysaccharide fractions could be determined (8,13). The wall at 30 min possessed equal FIG. 3.…”

Section: Resultsmentioning

confidence: 99%

“…Preliminary results suggest that purified F1 from embryos possesses these sugar ratios. Mian and Percival (13) describe a fraction with a similar composition to F, in an acid and an ammonium oxalate-oxalic acid extract from three other genera of brown algae. Because of its low concentration in walls and its low sulfate content, TBO staining procedures apparently cannot detect this fucan in vivo, since Novotny and Forman did not detect fucans in isolated walls of 6-hr F. distichus embryos (18).…”

Section: Resultsmentioning

confidence: 99%

“…The procedure of Mian and Percival (13) The dried chromatograms were cut into strips (2 x 3 cm) and counted by liquid scintillation spectrometry. Standards were detected by silver nitrate (26).…”

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Cell Wall Assembly in Fucus Zygotes

Quatrano

Stevens

1976

Plant Physiol.

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Fertilization triggers the assembly of a ceDl wai around the egg cell of three brown algae, Fucus vesiculosus, F. distichus, and F. inflatus ratio of fucose to xylose and high levels of sulfate, and contain a second fucan (F2) which is electrophoreticaDly distinct from F1. F2 appears to be deposited in only a localized region of the wall, that which elongates to form the rhizoid ceDl. Throughout wall assembly, the polyuronide block co-polymer alginic acid did not significantly vary its mannuronic (M) to guluronic (G) acid ratio (0.33-0.55) or its block distribution (MG, 54%; GG, 30%; MM, 16%). From 6 to 24 hours of embryo development, the proportion of the major polysaccharide components found in purified walls is stable. Alginic acid is the major polymer and comprises about 60% of the total wall, while cellulose and the fucans each make-up about 20% of the remainder. During the extracellular assembly of this wall, the intrcellular levels of the storage glucan laminaran decreases. A membrane-bound 3-1,3-exoglucanase is found in young zygotes which degrades laminaran to glucose. It is postulated that hydrolysis of laminaran by this glucanase accounts, at least in part, for glucose availability for wall biosynthesis and the increase in respiration triggered by fertilization. The properties and function of alginic acid, the fucans, and cellulose are discussed in relation to changes in wall structure and function during development.The developmental processes of growth, differentiation, and morphogenesis in plant cells are all intimately associated with I

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

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confidence: 99%

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Cell Wall Assembly in Fucus Zygotes

Quatrano

Stevens

1976

Plant Physiol.

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“…Although fucose is the predominant sugar, xylose, mannose, glucose, galactose, and glucuronic acid are also found, but in an unsulfated form. At least a portion of the galactose is found as the terminal sugar in the chain(s) (11), and various chemical fractionation schemes have described a range of polymers with differing amounts of these sugar and uronic acid residues (10). However, by electrophoresis in two different buffers, the sulfated polysaccharides from each of the three major chemical fractions displayed essentially the same two subfractions (20).…”

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confidence: 99%

Sulfation of fucoidin in focus embryos: III. Required for localization in the rhizoid wall

Hogsett¹,

Rs²

1978

The Journal of Cell Biology

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Zygotes of the brown alga Fucus distichus L. Powell accumulate a sulfated polysaccharide (fucoidin) in the cell wall at the site of rhizoid formation. Previous work indicated that zygotes grown in seawater minus sulfate do not sulfate the preformed fucan (an unsulfated fucoidin) but form rhizoids. Under these conditions, we determined whether sulfation of the fucan is required for its localization in the rhizoid wall. This was accomplished by developing a specific stain for both the fucan and fucoidin. Using a precipitin assay, we demonstrated in vitro that the lectin ricin (RCAz) specifically complexes with both the sulfated and desulfated polysaccharide. No precipitate is observed when either is incubated in 0.1 M o-galactose or when RCAI is mixed with laminarin or alginic acid, the other major polysaccharides in Fucus. RCA~ conjugated with fluorescein isothiocyanate (FITC) is also shown to bind specifically to fucoidin using a filter paper (DE81) assay. When added to zygotes, RCArFITC binds only to the site of fucoidin localization, i.e., the rhizoid cell wall. However, RCArFITC is not observed in the rhizoid wall of zygotes grown in the absence of sulfate. This observation is not due to the inability of RCAI-FITC to bind to the fucan in vivo. Chemically desulfated cell walls that contained fucoidin in the rhizoid wall bind RCAI-FITC only in the rhizoid region. Also, the concentration of fucose-containing polymers and polysaccharides that form precipitates with RCA~ is the same in embryos grown in the presence or absence of sulfate. If sulfate is added back to cultures of zygotes grown without sulfate, fucoidin is detected at the rhizoid tip by RCA[-FITC several hours later. These results support the conclusion that the enzymatic sulfation of the fucan is a modification of the polysaccharide required for its localization and/or assembly into a specific region of the cell wall. KEY WORDS Fucus distichusricin 9 fluorescence microscopy fucoidin sulfation cell wall cytoplasmic localization rhizoidThe localization of subcellular components into specific regions of a variety of plant and animal cells is a common and important aspect of cellular differentiation (c.f. reference 17). However, the mechanism by which macromolecules are sequestered into localized regions or structures of cells is not well understood. The rhizoid of the Fucus zygote provides a model system to investigate the regulation of intracellular localization. Previous reports indicated that a new and different sulfated polysaccharide is deposited in only that region of the zygote cell wall that forms the rhizoid (4, 20).

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Hypolipidaemic Activity of a Polysaccharide Extract from Fucus vesiculosus L.

1996

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The effects of a polysaccharide extract from the seaweed Fucus vesiculosus on serum lipid levels were evaluated in normal and hyperlipaemic rats. In screening tests of immediate (4 h) effects in normal rats, the highest dose assayed (10 mgkg) significantly lowered total cholesterol and low-density-lipoprotein-cholesterol (LDLcholesterol) levels, and significantly increased the antiatherogenic index (AAI, i.e. 100 x HDL-C/[totalC-HDL-C]).In screening tests of short-term (24 h) effects in %ton-induced-hyperlipaemic (TIH) rats, the extract caused marked dose-dependent reductions in total cholesterol and triglyceride levels. Tests in TIH rats suggested that the observed hypolipaemic activity was due to inhibition of cholesterol synthesis. Subsequent tests of longer-term (12 day) effects in diet-induced-hyperlipaemic rats provided support for this hypothesis: the extract at 10 mgkg did not have significant effects on total cholesterol or LDL-cholesterol, but caused moderate increases in highdensity-lipoprotein-cholesterol (HDL-cholesterol) level and AAI.

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Carbohydrates of the brown seaweeds himanthalia lorea, bifurcaria bifurcata, and Padina pavonia

Cited by 96 publications

References 18 publications

Cell Wall Assembly in Fucus Zygotes

Cell Wall Assembly in Fucus Zygotes

Sulfation of fucoidin in focus embryos: III. Required for localization in the rhizoid wall

Hypolipidaemic Activity of a Polysaccharide Extract from Fucus vesiculosus L.

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