Lectins as Cytochemical Probes of the Developing Wheat Grain. Ii. Reaction of Wheat-Germ Lectin With the Nucellar Epidermis.

1982 ◽  
Vol 9 (6) ◽  
pp. 663 ◽  
Author(s):  
BA Baldo ◽  
PA Boniface ◽  
DH Simmonds
Keyword(s):  
Bovine Serum Albumin ◽  
Epidermal Cell ◽  
Cell Walls ◽  
Wheat Germ ◽  
Specific Binding ◽  
Developmental Period ◽  
Wheat Grain ◽  
Wheat Grains ◽  
Probable Presence ◽  
Wheat Germ Lectin

Fluorescein-labelled wheat-germ lectin, which has a specific binding affinity for N-acetyl-D-glucosamine, has been shown to react specifically with nucellar epidermal cell walls in frozen and JB-4-embedded sections of developing wheat grain. The reaction was completely inhibited by preincubation of the lectin with diacetylchitobiose or triacetylchitotriose, two sugars known to be good inhibitors of the wheat-germ lectin combining sites. Labelled lectins with different specificities, and labelled non-lectin proteins such as bovine serum albumin, failed to react. Reaction with the nucellar epidermis increased to a maximum at approximately 14 days post anthesis (p.a.) and then progressively declined. At 35 days p.a., clear fluorescence was visible only in the inner crease area. Labelled wheat-germ lectin did not stain the nucellar projection at any stage of the developmental period studied. Treatment of wheat grain sections with chitinase almost completely abolished reactivity between nucellar epidermal cell walls and the lectin. Reactivity was slightly diminished following treatment with cellulase, but hemicellulase and two preparations of �-N-acetyl-D-glucosaminidase had no effect. These observations indicate the probable presence of a chitin-like structure in nucellar epidermal cell walls, which may be an endogenous saccharide receptor for wheat-germ lectin in developing or germinating wheat grains.

Lectins as Cytochemical Probes of the Developing Wheat Grain. V. Demonstration of Separate Polysaccharides Containing N-Acetyl-D-Glucosamine and D-Galactose in Nuclear Epidermal Cell Walls

1984 ◽  
Vol 11 (3) ◽  
pp. 179 ◽  
Author(s):  
BA Baldo ◽  
D Barnett ◽  
JW Lee
Keyword(s):  
Epidermal Cell ◽  
Cell Walls ◽  
Wheat Germ ◽  
Periodic Acid ◽  
Fluorescein Isothiocyanate ◽  
Wheat Grain ◽  
Periodic Acid Schiff ◽  
Thin Sections ◽  
Lectin Staining ◽  
Wheat Germ Lectin

Fluorescein isothiocyanate-labelled lectin from wheat-gem, which binds N-acetyl-D-glucosamine, and Griffonia simplicifolia, Arachis hypogaea and Glycine max lectins, each of which binds D-galactose, react with nucellar epidermal cell walls in thin sections of plastic-embedded developing wheat grain. Reactivity of these cell walls with periodic acid-Schiff reagent, the absence of staining with protein stains and the failure of a number of proteases and the endoglycosidases D and H to prevent the binding suggested that the lectin-reactive wall components are neither proteins nor N-glycosidically linked glycoproteins. Morphological differences in lectin staining patterns and treatment of sections with chitinase and α-galactosidase, prior to the reaction with the lectins, indicated that two separate polysaccharides are probably involved in the binding. Chitinase removed the reactivity of the nucellar epidermal cell walls for wheat-germ lectin but the binding of D-galactose-specific lectins was unimpaired. Conversely, α-galactosidase did not affect the binding of wheat-germ lectin but reactivity with the galactose-specific lectins was abolished. From the available evidence we conclude that one polysaccharide in the nucellar epidermal cell wall reacts with wheat-germ lectin and contains N-acetyl-D-glucosamine in a chitin-like structure. The other polysaccharide reacts with D-galactose- specific lectins by virtue of terminal α-D-galactose residues. Hydrolysis and subsequent chromatographic analysis of nucellar epidermal cell walls peeled from immature grains revealed the presence of D-glucosamine, D-glucose, D-galactose, D-xylose, L-arabinose and a trace of D-mannose.

Lectins as Cytochemical Probes of the Developing Wheat Grain. IV. Demonstration of Mucilage Containing L-Fucose Associated With Roots in Ungerminated Grain

1983 ◽  
Vol 10 (5) ◽  
pp. 459 ◽  
Author(s):  
BA Baldo ◽  
AL Reid ◽  
PA Boniface
Keyword(s):  
Binding Affinity ◽  
Specific Binding ◽  
Root Cap ◽  
Cereal Grains ◽  
Wheat Grain ◽  
Physiological Maturity ◽  
Wheat Grains ◽  
Ulex Europaeus

Fluorescein-labelled lectins from Ulex europaeus and Lotus tetragonolobus, each with a specific binding affinity for L-fucose, reacted with carbohydrate material in the root cap and surrounding the roots in the embryos of developing wheat grains. The reactions were completely inhibited by preincubation of the lectins with L-fucose and were observed throughout development of the grain from 6 days post-anthesis to physiological maturity 29 days later. These findings provide the first demonstration of the location of L-fucose in the wheat grain. Although a lectin-reactive slime or mucilage containing L-fucose has been studied by others in the roots of germinated cereal grains, particularly maize, our results demonstrate that such a mucilage already occurs around the roots prior to germination.

Lectins used to prepare serum free of glycoprotein hormones for use as a matrix in radioimmunoassay.

1981 ◽  
Vol 27 (1) ◽  
pp. 52-56 ◽  
Author(s):  
M C Stuart ◽  
S Ellis ◽  
L Gowlland ◽  
S Tuff
Keyword(s):  
Human Serum ◽  
Concanavalin A ◽  
Wheat Germ ◽  
Specific Binding ◽  
Beta Subunit ◽  
Glycoprotein Hormones ◽  
Serum Free ◽  
Free Serum ◽  
Wheat Germ Lectin

Abstract Hormone-free serum is required for use as a matrix for standards in the radioimmunoassay of hormones. The glycoprotein hormones are difficult to remove from serum by conventional techniques. We exploited the specific binding of carbohydrates by lectins to extract glycoprotein hormones from human serum. Passing serum over Concanavalin A Sepharose efficiently removed lutropin and the beta subunit of choriogonadotropin. Wheat-Germ Lectin Sepharose completely removed these, and also follitropin and thyrotropin. The latter treatment is shown to provide a suitable matrix for standards in radioimmunoassays of the four hormones.

Effects of some plant lectins on hydrogen peroxide release from macrophages induced with streptococcal preparation OK-432

1980 ◽  
Vol 28 (2) ◽  
pp. 336-343
Author(s):  
H Tomioka ◽  
H Saito
Keyword(s):  
Concanavalin A ◽  
Inhibitory Action ◽  
Wheat Germ ◽  
Specific Binding ◽  
Inhibitory Effect ◽  
Soybean Agglutinin ◽  
Peanut Agglutinin ◽  
Macrophage Phagocytosis ◽  
Receptor Sites ◽  
Wheat Germ Lectin

Concanavalin A and phytohemagglutinin were found to cause marked inhibition of H2O2 release from macrophages induced with killed streptococci (preparation OK-432). The inhibitory effect of these two lectins on the H2O2 release from macrophages was observed with spontaneous and wheat germ lectin-triggered H2O2 release. This suggests that the lectins act directly on the macrophage H2O2-releasing function, per se, but not on the wheat germ lectin-H2O2 release-enhancing process. Concanavalin A exhibited its inhibitory action on macrophage H2O2 release by specific binding to D-mannopyranoside receptor sites on the macrophage cell surface. Galactose-binding lectins, peanut agglutinin, and soybean agglutinin failed to inhibit, but, on the other hand, slightly enhanced macrophage H2O2 release. The effect of these five lectins on the phagocytosis of latex particles by macrophages was tested. Wheat germ lectin, concanavalin A, and phytohemagglutinin significantly depressed the macrophage phagocytosis, whereas peanut agglutinin and soybean agglutinin failed to show any inhibitory action.

Ectodesmata as Revealed By Freeze-Etch Preparations of Plant Epidermal Cell Walls

1973 ◽  
Vol 31 ◽  
pp. 468-469
Author(s):  
N.C. Lyon ◽  
W. C. Mueller
Keyword(s):  
Electron Microscopy ◽  
Acetic Acid ◽  
Nitric Acid ◽  
Oxalic Acid ◽  
Light Microscopy ◽  
Epidermal Cell ◽  
Cell Walls ◽  
Plant Viruses ◽  
Plant Leaves ◽  
Thin Sections

Schumacher and Halbsguth first demonstrated ectodesmata as pores or channels in the epidermal cell walls in haustoria of Cuscuta odorata L. by light microscopy in tissues fixed in a sublimate fixative (30% ethyl alcohol, 30 ml:glacial acetic acid, 10 ml: 65% nitric acid, 1 ml: 40% formaldehyde, 5 ml: oxalic acid, 2 g: mecuric chloride to saturation 2-3 g). Other workers have published electron micrographs of structures transversing the outer epidermal cell in thin sections of plant leaves that have been interpreted as ectodesmata. Such structures are evident following treatment with Hg++ or Ag+ salts and are only rarely observed by electron microscopy. If ectodesmata exist without such treatment, and are not artefacts, they would afford natural pathways of entry for applied foliar solutions and plant viruses.

scholarly journals Aggregation of casein micelle from bovine milk by wheat germ lectin.

1978 ◽  
Vol 42 (10) ◽  
pp. 1923-1926 ◽  
Author(s):  
Masaaki YOSHIKAWA ◽  
Kyoya TAKAHATA ◽  
Ryuzo SASAKI ◽  
Hideo CHIBA
Keyword(s):  
Wheat Germ ◽  
Bovine Milk ◽  
Casein Micelle ◽  
Wheat Germ Lectin

scholarly journals Processes in the Infection of Barley Leaves by Rhynchosporium Secalis

1970 ◽  
Vol 23 (2) ◽  
pp. 300 ◽  
Author(s):  
EN AYESU-OFFEI ◽  
BG CLARE
Keyword(s):  
Epidermal Cell ◽  
Cell Walls ◽  
Rhynchosporium Secalis ◽  
Barley Leaves ◽  
Germ Tubes

Conidia of R. secalis (Oud.) Davis germinated on barley leaves to produoe , short germ tubes and appressoria. Hyphae below the appressoria penetrated the outicle and formed extensive myoelial mats between the cuticle and the outer epidermal cell walls. Epidermal cell walls beneath the subcuticular hyphae became swollen, lamellate, and collapsed so that the inner and outer walls of the epidermis came together.

scholarly journals Clearance and binding of native and defucosylated lactoferrin

1983 ◽  
Vol 212 (2) ◽  
pp. 249-257 ◽  
Author(s):  
M J Imber ◽  
S V Pizzo
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Specific Binding ◽  
Gel Filtration ◽  
Peritoneal Macrophages ◽  
Mononuclear Phagocyte ◽  
Stable Complex

These studies explore the role of carbohydrate recognition systems and the direct involvement of terminal alpha 1-3-linked fucose in the clearance of lactoferrin from the murine circulation and in the specific binding of lactoferrin to receptors on murine peritoneal macrophages. As previously reported, radiolabelled lactoferrin cleared very rapidly (t1/2 less than 1 min) after intravenous injection into mice. However, competing levels of ligands specific for the hepatic galactose receptor (asialo-orosomucoid), the hepatic fucose receptor (fucosyl-bovine serum albumin), and the mononuclear-phagocyte system pathway recognizing mannose, N-acetylglucosamine and fucose (mannosyl-, N-acetylglucosaminyl- and fucosyl-bovine serum albumin) did not block radiolabelled lactoferrin clearance in vivo or binding to mouse peritoneal macrophage monolayers in vitro. Almond emulsin alpha 1-3-fucosidase was used to prepare defucosylated lactoferrin in which 88% of the alpha 1-3-linked fucose was hydrolysed. No difference in clearance or receptor binding was observed between radiolabelled native and defucosylated lactoferrin. Fucoidin, a fucose-rich algal polysaccharide, completely inhibits the clearance in vivo and macrophage binding in vitro of lactoferrin. This effect, however, is probably not the result of competition for binding to the fucose receptor, since gel-filtration studies demonstrated formation of a stable complex between lactoferrin and fucoidin. The present results indicate that the lactoferrin-clearance pathway is distinct from several pathways mediating glycoprotein clearance through recognition of terminal galactose, fucose, N-acetylglucosamine or mannose. Furthermore, alpha 1-3-linked fucose on lactoferrin is not essential for lactoferrin clearance in vivo or specific binding to macrophage receptors in vitro.

scholarly journals Ultrastructure of the Developing Aleurone Cells of Wheat Grain

1963 ◽  
Vol 16 (4) ◽  
pp. 768 ◽  
Author(s):  
MS Buttrose
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Cell Walls ◽  
Osmium Tetroxide ◽  
Aleurone Layer ◽  
Wheat Grain ◽  
Aleurone Cells ◽  
Wheat Kernel ◽  
Large Numbers ◽  
Inner Surface

The developing aleurone layer cells of the wheat kernel have been investigated by electron microscopy and the results compared with those of light microscopy. Two weeks after flowering vacuoles appear in the cells and deposits accumulate in these until maturity when the cells are filled 'with the resulting "vacuolar units" 2-3p. in diameter, corresponding to the aleurone grains of light microscopy. The wheat aleurone grain consists of a bounding membrane (of vacuole origin) enclosing a matrix in which are embedded spherical deposits. Some of these deposits are translucent and others opaque to electrons after potassium permanganate and osmium tetroxide fixation. At all stages examined the cytoplasm of aleurone cells contained large numbers of small unidentified bodies with irregular outline and dense contents. At first they are dispersed, but towards maturity are organized as a monolayer over the surface of each aleurone grain and the inner surface of the cell walls. The apparent specificity of these structures to aleurone cells is discussed in relation to future chemical and physiological studies of the tissue.

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