AN ANALYSIS OF AVENA COLEOPTILE PECTIN FRACTIONS

1965 ◽  
Vol 43 (9) ◽  
pp. 1083-1095 ◽  
Author(s):  
D. James Morré ◽  
Alfred C. Olson
Keyword(s):  
Cell Wall ◽  
Galacturonic Acid ◽  
Water Soluble ◽  
Hot Water ◽  
Plant Tissues ◽  
Cytoplasmic Fraction ◽  
Avena Coleoptile ◽  
Heat Stable ◽  
Heat Stable Protein

Extraction and determination of pectic materials from growing plant tissues is often complicated by overlapping solubilities and lack of specificity of the pectin assay utilized. We find that the hot water soluble, hot versene soluble, and residual uronide components of Avena coleoptile cell wall represent at least three distinct pectin fractions with little or no overlap in solubility. In situations where hexose interference in colorimetric pectin determinations became appreciable, the polyanhydrogalacturonic acid content of the extract was determined by measurement of isolated galacturonic acid released through the specific action of polygalacturonase.A fourth fraction containing pectin-like materials was extracted from whole tissue in cold acetate buffer. This fraction was associated with heat-stable protein. No pectin identified as polyanhydrogalacturonic acid was found in the cytoplasmic fraction by the same techniques used for identifying pectin on cell wall derived fractions.

scholarly journals Ultrastructural and biochemical analyses reveal cell wall remodelling in lichen-forming microalgae submitted to cyclic desiccation–rehydration

2019 ◽  
Vol 125 (3) ◽  
pp. 459-469 ◽  
Author(s):  
María González-Hourcade ◽  
Marcia R Braga ◽  
Eva M del Campo ◽  
Carmen Ascaso ◽  
Cristina Patiño ◽  
...  
Keyword(s):  
Cell Wall ◽  
Close Contact ◽  
Freeze Substitution ◽  
Water Soluble ◽  
Hot Water ◽  
Cell Shrinkage ◽  
Distinctive Features ◽  
Biochemical Analyses ◽  
Species Specific ◽  
Environmental Sem

Abstract Background and Aims One of the most distinctive features of desiccation-tolerant plants is their high cell wall (CW) flexibility. Most lichen microalgae can tolerate drastic dehydration–rehydration (D/R) conditions; however, their mechanisms of D/R tolerance are scarcely understood. We tested the hypothesis that D/R-tolerant microalgae would have flexible CWs due to species-specific CW ultrastructure and biochemical composition, which could be remodelled by exposure to cyclic D/R. Methods Two lichen microalgae, Trebouxia sp. TR9 (TR9, adapted to rapid D/R cycles) and Coccomyxa simplex (Csol, adapted to seasonal dry periods) were exposed to no or four cycles of desiccation [25–30 % RH (TR9) or 55–60 % RH (Csol)] and 16 h of rehydration (100 % RH). Low-temperature SEM, environmental SEM and freeze-substitution TEM were employed to visualize structural alterations induced by D/R. In addition, CWs were extracted and sequentially fractionated with hot water and KOH, and the gel permeation profile of polysaccharides was analysed in each fraction. The glycosyl composition and linkage of the main polysaccharides of each CW fraction were analysed by GC–MS. Key Results All ultrastructural analyses consistently showed that desiccation caused progressive cell shrinkage and deformation in both microalgae, which could be rapidly reversed when water availability increased. Notably, the plasma membrane of TR9 and Csol remained in close contact with the deformed CW. Exposure to D/R strongly altered the size distribution of TR9 hot-water-soluble polysaccharides, composed mainly of a β-3-linked rhamnogalactofuranan and Csol KOH-soluble β-glucans. Conclusions Cyclic D/R induces biochemical remodelling of the CW that could increase CW flexibility, allowing regulated shrinkage and expansion of D/R-tolerant microalgae.

Contributions to the Analysis of Rubber. I. Determination of the Water-Soluble Components of Rubber

1937 ◽  
Vol 10 (3) ◽  
pp. 574-583
Author(s):  
P. Dekker
Keyword(s):  
Acetic Acid ◽  
Acid Reflux ◽  
Water Soluble ◽  
Hot Water ◽  
Water Bath ◽  
Vulcanized Rubber ◽  
Magnesium Compounds ◽  
Calcium Compounds ◽  
Soluble Components

Abstract 1. It is shown that the methods which are ordinarily used for determining water-soluble substances in raw rubber give low results, and are quite useless for vulcanized rubber. 2. New analytical procedures are developed for determining the water-soluble substances in raw rubber and in vulcanized rubber. These procedures are carried out in the following manner. (a) Raw Rubber.—Heat 2 grams of rubber in 80 cc. of xylene and 5 cc. of acetic acid on a water bath until the rubber is completely dissolved, add 5 cc. of acetic acid and 10 cc. of water, heat for 3–4 hours on the water bath with frequent agitation, transfer to a distilling flask (rinsing the first flask with 50 cc. of hot water), distill the xylene with steam, filter the residual solution, evaporate the filtrate on a water bath; and dry at 100° C. (b) Vulcanized Rubber and Rubber Mixtures.—First extract the sample with acetone, heat 2 grams of the acetone-extracted sample with 80 cc. of xylene on a water bath, add 5 cc. of acetic acid, reflux the mixture on an oil bath, after complete dissolution add 5 cc. of acetic acid and 10 cc. of water, heat the solution for 2 hours on an oil bath at 110–120° C., distill the xylene, as in the determination with raw rubber, filter the residue, evaporate the filtrate to dryness, take up the residue in 50 cc. of water, pass a current of hydrogen sulfide through the solution for 10 minutes to precipitate zinc as sulfide, filter, evaporate the filtrate, and dry the residue at 100° C. 3. In the presence of calcium compounds, magnesium compounds, glue and textiles, the method gives false results. Modifications of the method are therefore recommended, whereby these substances are eliminated.

Isolation and Characterization of Secretory Vesicles in Germinated Pollen of Lilium longiflorum

1971 ◽  
Vol 8 (2) ◽  
pp. 331-351 ◽  
Author(s):  
W. J. VAN DER WOUDE ◽  
D. J. MORRÉ ◽  
C. E. BRACKER
Keyword(s):  
Cell Wall ◽  
Secretory Pathway ◽  
Periodic Acid ◽  
Lilium Longiflorum ◽  
Water Soluble ◽  
Hot Water ◽  
Secretory Vesicles ◽  
Vesicle Membrane ◽  
Isolation And Characterization ◽  
Germinated Pollen

Secretory vesicles containing polysaccharide were isolated from germinated pollen of Lilium longiflorum and characterized by biochemical and ultrastructural investigation. Pollen tubes exhibit a secretory pathway in which the vesicles concentrated in the tube apex are produced by the Golgi apparatus and contributed to the cell wall at the apex upon fusion of the vesicle membrane with the plasma membrane. Secretory vesicles were isolated by a method involving the size discrimination of cytoplasmic components using Millipore filters. Cells were disrupted under conditions which minimized membrane vesiculation. Identification was made by electron-microscopic comparison of the periodic acid-silver hexamine (PASH) reactivities of in situ and isolated secretory vesicles. The secretory vesicles contained polysaccharides which were high in galacturonic acid and similar in sugar composition to those of the hot-water-soluble fraction of pollen tube cell wall. A hot-water-insoluble, non-cellulosic glucan was the major component of the cell wall. Less than 7% of the wall was cellulosic. Chitin was absent. Similarities in the ultrastructure and PASH staining of apical secretory vesicles and an amorphous component of the cell wall support a precursor-product relationship between these 2 cell components. Ultrastructural investigations revealed complexes of the endoplasmic reticulum (ER) associated with electron-translucent regions of cytoplasm, suggesting a possible function of the ER in cell wall formation. Additionally, patterns of PASH staining show that changes in polysaccharides occur in secretory vesicles after vesicles have been formed by dictyosomes. Therefore, secretory vesicles may have a role in polysaccharide synthesis as well as in membrane and product transport.

scholarly journals STUDIES ON THE GROWTH HORMONE OF PLANTS

1934 ◽  
Vol 18 (1) ◽  
pp. 23-34 ◽  
Author(s):  
Kenneth V. Thimann
Keyword(s):  
Growth Hormone ◽  
Growth Substance ◽  
Root Tip ◽  
Plant Tissues ◽  
Root Tips ◽  
Direct Extraction ◽  
Simple Method ◽  
Avena Coleoptile ◽  
Method Of Extraction

1. It is shown that when plant tissues are ground with water the growth substance contained therein is inactivated by the oxidizing enzymes. 2. A simple method of extraction is described which enables the quantitative determination of growth substance in such tissues. 3. The amount and distribution of growth substance in the Avena coleoptile is determined by this method, and it is shown that while the substance does not diffuse out from the lower parts of the coleoptile, it is nevertheless present in considerable amounts, the concentration decreasing steadily with the distance from the tip. 4. Growth substance is also present in considerable amounts in Avena roots, and here also its concentration decreases steadily with distance from the tip. 5. The amount of growth substance diffusing out of root tips into dextrose agar, even during long periods of time, is not greater than the amount obtainable by direct extraction. Actual production in the root tip therefore either does not take place at all, or else takes place under quite different conditions from the production in the tip of the coleoptile.

Studies of the structure and chemical composition of the cell walls of Vaucheriaceae and Saprolegniaceae

1963 ◽  
Vol 158 (973) ◽  
pp. 435-445 ◽  
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Insoluble Fraction ◽  
Water Soluble ◽  
Hot Water ◽  
Cellulose Microfibrils ◽  
Wall Material ◽  
Native Cellulose ◽  
A Cell ◽  
Crystalline Component

The cell walls of members of the Vaucheriaceae and Saprolegniaceae have been examined by X-ray analysis and electron microscopy, and their composition determined by hydrolysis and paper partition chromatography of the hydrolysates. Both differences and similarities between the members of these two species examined are found to supplement the comparative morphological and physiological information at present available. Saprolegnia , Achlya , Brevilegnia and Dictyuchus among the Saprolegniaceae possess hot-water soluble polysaccharides containing glucose residues only. This polysaccharide is not crystallographically identical with the polysaccharide found in Vaucheria sessilis with a similar solubility. The members of the Saprolegniaceae contain large amounts of alkali-soluble polysaccharides in contrast with the negligible amount found in V. sessilis . These polysaccharides are only weakly crystalline, but the indications are that the same polysaccharides may occur through­out the Saprolegniaceae. The alkali-insoluble wall material of Vaucheria species consists of highly crystalline native cellulose with large, apparently randomly arranged, microfibrils. The hydrolysate of this material contains ribose, xylose and arabinose in addition to glucose, presumably representing strongly bound pentosans. Native cellulose also occurs in the Saprolegniaceae but only in small proportion. The bulk of the alkali-insoluble fraction in the walls of these fungi appears amorphous in the electron microscope and is only weakly crystalline. It consists of one or m ore substances containing glucose, mannose, ribose and possibly other sugars together with traces of glucosamine. These substances presumably cover the cellulose microfibrils. The total quantity of non-cellulosic polysaccharide in the Saprolegniaceae approaches 85% of the total wall weight in contrast with the situation in Vaucheria where the cellulose alone approaches 90% of the total cell wall. Dichotomosiphon is unique among the organism s studied in this paper, in possessing a cell wall entirely soluble in alkali and composed of approximately equal quantities of glucose and xylose. The crystalline component is aβ-1,3-linked xylan, as already reported for some of the Siphonales (closely related algae) by Frei & Preston.

SOME FACTORS AFFECTING THE DETERMINATION OF HOT-WATER-SOLUBLE BORON FROM PODZOL SOILS USING AZOMETHINE-H

1979 ◽  
Vol 59 (3) ◽  
pp. 241-247 ◽  
Author(s):  
UMESH C. GUPTA
Keyword(s):  
Prince Edward Island ◽  
Sandy Loam ◽  
Water Soluble ◽  
Hot Water ◽  
Colorimetric Determination ◽  
Factors Affecting ◽  
Water Extracts ◽  
Percent Recovery

A study was conducted on some factors affecting the colorimetric determination of B using the azomethine-H reagent on soils from Prince Edward Island. Two fine sandy loam soils (A and B) were used for the main study and additional soil samples varying in organic matter (OM) were used to assess the role of OM. Soils containing less than 3.0% OM and 3.1–4.1% OM required 0.4 g and 0.8 g charcoal per 25 g soil, respectively, to produce clear hot-water extracts. Quantities of greater than 0.8 g charcoal were necessary to produce clear extracts from soils containing more than 4.1% OM. Colored hot-water extracts of soil resulted in higher absorbance than those hot-water extracts treated with charcoal as measured at 430 mμ. Additions of 0.8 and 1.6 g charcoal or greater to the soils (A and B) resulted in considerably lower recoveries of B as noted by comparing the absorbance obtained using 0.4 and 0.8 g, respectively. Storage of azomethine-H up to 7 days did not affect the absorbance of the B-azomethine-H complex. One hour after the addition of azomethine-H, a maximum absorbance was found which persisted for up to 4 h. The percent recovery of B added to the two soils was about 10–12% less using azomethine-H as compared to those obtained using the carmine method. However, the mean hot-water-soluble B contents of 10 soils as measured using the carmine and azomethine-H reagents were 0.70 and 0.66 ppm. Pure B solutions when boiled with charcoal resulted in losses of B added. Such losses of B increased with increasing rates of charcoal.

scholarly journals Heat-stable protein that stimulates acid α-glucosidase

1989 ◽  
Vol 264 (3) ◽  
pp. 845-849 ◽  
Author(s):  
N S Radin ◽  
A Shukla ◽  
G S Shukla ◽  
A Sano
Keyword(s):  
Direct Action ◽  
Water Extract ◽  
Hot Water ◽  
Rat Tissues ◽  
Dialysis Tubing ◽  
Heat Stable ◽  
Hot Water Extract ◽  
Heat Stable Protein ◽  
Alpha Glucosidase ◽  
Guinea Pig Liver

A hot-water extract of bovine spleen and guinea pig liver exhibited the ability to enhance acid alpha-glucosidase activity, with methylumbelliferyl alpha-glucoside, glycogen or maltose as substrate. The level of activator required for maximal stabilization was similar for all three substrates, indicating direct action on the enzyme rather than on substrate. The stimulator was partially purified by chromatography with gel-permeation (apparent Mr 20,000-24,000), ion-exchange and C4 reverse-phase columns. It was retained by a narrow-pore dialysis tubing and destroyed by treatment with Pronase, and is presumably a protein. The stimulating protein protected the enzyme against denaturation by heat or incubation with a buffer of high ionic strength in the absence of substrate. RNA inhibited the enzyme, and the activator protein was able to counteract the effect. Activating material was found in a variety of mouse and rat tissues, as well as human urine.

Determination of Water-Insoluble Cell Walls in Feeds: Interlaboratory Study

1989 ◽  
Vol 72 (3) ◽  
pp. 463-467 ◽  
Author(s):  
Bernard Carré ◽  
Jean-Marc Brillouet
Keyword(s):  
Cell Wall ◽  
Dietary Fiber ◽  
Collaborative Study ◽  
Sodium Dodecylsulfate ◽  
Neutral Detergent Fiber ◽  
Total Dietary Fiber ◽  
Insoluble Dietary Fiber ◽  
Heat Stable ◽  
Coefficients Of Variation

Abstract A collaborative study was conducted to test a new rapid procedure for determination of water-insoluble cell wall (WICW) content in feeds. In the method, starch is solubilized near boiling temperature with Termamyl, a heat-stable alpha-amylase, and proteins are solubilized at 40 °C with sodium dodecylsulfate and Pronase. Then, the organic matter of the residue is determined by incineration. Three hours were required to treat 12 different samples, including solubilization treatments, filtrations, and rinses. Eleven unknown products including 9 common feedstuffs of various origin and 2 mixed diets for poultry were analyzed by 7 analysts in France. Coefficients of variation ranged from 2.3 to 6.1%. The results were compared to those for water-insoluble dietary fiber (WIDF), total dietary fiber, and neutral detergent fiber. Agreement was best with the water-insoluble dietary fiber procedure. For most samples, the ratios of WIDF/WICW ranged from 0.981 to 0.842. The differences between WICW and WIDF values correspond to cell wall protein which is accounted for in WICW, but not in WIDF.

scholarly journals Hot Water Treatment Maintains Normal Ripening and Cell Wall Metabolism in Mango (Mangifera indica L.) Fruit

HortScience ◽  
2012 ◽  
Vol 47 (10) ◽  
pp. 1466-1471 ◽  
Author(s):  
Zhengke Zhang ◽  
Zhaoyin Gao ◽  
Min Li ◽  
Meijiao Hu ◽  
Hui Gao ◽  
...  
Keyword(s):  
Cell Wall ◽  
Water Treatment ◽  
Low Temperature ◽  
Mangifera Indica ◽  
Water Soluble ◽  
Hot Water ◽  
Hot Water Treatment ◽  
Cell Wall Metabolism ◽  
Low Temperature Storage ◽  
Temperature Storage

‘Tainong 1’ mango fruit were treated with hot water for 10 minutes at 55 °C and then stored at 5 °C for 3 weeks. After removal from low-temperature storage, the effects of hot water treatment (HWT) on chilling injury (CI), ripening and cell wall metabolism during storage (20 °C, 5 days) were investigated. HWT reduced the CI development of the fruit as manifested by firmer texture, external browning, and fungal lesions. A more rapid ripening process, as indicated by changes in firmness, respiration rate, and ethylene production, occurred in heated fruit after exposure to low temperature as compared with non-heated fruit. At the same time, the cell wall components in heated fruit contained more water-soluble pectin and less 1,2-cyclohexylenedinitrilotetraactic acid (CDTA)-soluble pectin than those in non-heated fruit. HWT also maintained higher polygalacturonase [enzyme classification (EC) 3.2.1.15] and β-galactosidase (EC 3.2.1.23) activities as well as lower pectin methylesterase (EC 3.1.1.11) activity. In general, the changes of ripening and cell wall metabolism parameters in the heated fruit after low-temperature storage exhibited a comparable pattern to that of non-cold-stored fruit.

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