Cell wall growth and protein secretion in fungi

1995 ◽  
Vol 73 (S1) ◽  
pp. 388-395 ◽  
Author(s):  
J. H. Sietsma ◽  
H. A. B. Wösten ◽  
J. G. H. Wessels
Keyword(s):  
Schizophyllum Commune ◽  
Outer Wall ◽  
Rigid Wall ◽  
Wall Material ◽  
Aerial Hyphae ◽  
Noncovalent Bonds ◽  
Wall Growth ◽  
Hyphal Wall ◽  
Wall Components ◽  
Hyphal Apex

Secretion of proteins is a vital process in fungi. Because hyphal walls form a diffusion barrier for proteins, a mechanism different from diffusion probably exist to transport proteins across the wall. In Schizophyllum commune, evidence has been obtained for synthesis at the hyphal apex of wall components, 1,3-β-glucan and chitin, as separate components. These become subapically cross-linked by formation of covalent and noncovalent bonds, producing a rigid wall (steady-state wall growth). Because the wall at the apex apparently grows by apposition of plastic wall material, proteins excreted at the apex may pass the wall by being carried with the flow of wall material (bulk flow), making pores in the wall less important than previously thought. A large portion of excreted proteins leaves hyphae at the growing apices, another portion is retained by the wall and slowly released from the mature wall into the environment. Among proteins that can be permanently retained by the wall are the hydrophobins that self-assemble at the outer wall surface when confronted with a hydrophilic–hydrophobic interface. They were shown to mediate both the emergence of aerial hyphae and the attachment of hyphae to hydrophobic substrates. Key words: hyphal wall, secretion of proteins, hydrophobins, aerial hyphae, apical growth, hyphal adhesion, wall growth.

scholarly journals Cell wall biosynthesis and the molecular mechanism of plant enlargement

2009 ◽  
Vol 36 (5) ◽  
pp. 383 ◽  
Author(s):  
John S. Boyer
Keyword(s):  
Cell Wall ◽  
Critical Level ◽  
Turgor Pressure ◽  
Chara Corallina ◽  
Wall Material ◽  
Primary Wall ◽  
Terrestrial Plants ◽  
Green Plants ◽  
Wall Deposition ◽  
Wall Growth

Recently discovered reactions allow the green alga Chara corallina (Klien ex. Willd., em. R.D.W.) to grow well without the benefit of xyloglucan or rhamnogalactan II in its cell wall. Growth rates are controlled by polygalacturonic acid (pectate) bound with calcium in the primary wall, and the reactions remove calcium from these bonds when new pectate is supplied. The removal appears to occur preferentially in bonds distorted by wall tension produced by the turgor pressure (P). The loss of calcium accelerates irreversible wall extension if P is above a critical level. The new pectate (now calcium pectate) then binds to the wall and decelerates wall extension, depositing new wall material on and within the old wall. Together, these reactions create a non-enzymatic but stoichiometric link between wall growth and wall deposition. In green plants, pectate is one of the most conserved components of the primary wall, and it is therefore proposed that the acceleration-deceleration-wall deposition reactions are of wide occurrence likely to underlie growth in virtually all green plants. C. corallina is one of the closest relatives of the progenitors of terrestrial plants, and this review focuses on the pectate reactions and how they may fit existing theories of plant growth.

Seismic Response Analysis on the External Walls of the LNG Storage Tank for Spill Conditions in Different Liquid Height

2012 ◽  
Vol 256-259 ◽  
pp. 2677-2687
Author(s):  
Yun Feng Zhang ◽  
Xin Yu Zhou ◽  
Zhao Zhang
Keyword(s):  
Seismic Response ◽  
Prestressed Concrete ◽  
Outer Wall ◽  
Rigid Wall ◽  
Response Analysis ◽  
Safe Operation ◽  
Fluent Software ◽  
Secondary Disasters ◽  
Temperature Liquid ◽  
Lng Tank

As an important equipment in the gas receiving station, LNG storage tanks is an imprortant department to guarantee the gas providing for the significant gas sectors as well as their facilities safe operation, who has the role that cannot be replaced ,LNG in the tank is flammable and explosive medium,once the tank damaged, a large number of flammable low temperature liquid will leak, nevitably have influence on the structure of prestressed concrete performance and seismic response of the rigid wall, and destructive secondary disasters may be happened. So reseaching the heat transfer of LNG outside wall during leaking and the seismic response is very necessary. This paper takes a 50000m3 overground LNG tank as the research object, using fluent software to simulate the temperature field and using ADINA to research the seismic response of outer wall, analyzes the the change rule of temperature along the thickness and height during LNG leakage, and seismic response of outer wall when leakage happened at different height, the results can provide theoretical basis for the security calculated during LNG tanks leakage.

Distribution of Autofluorescence and Esterase and Peroxidase Activities in the Epidermis of Wheat Roots

1979 ◽  
Vol 6 (2) ◽  
pp. 201 ◽  
Author(s):  
MM Smith ◽  
TP O'brien
Keyword(s):  
Cell Walls ◽  
Outer Wall ◽  
Wheat Root ◽  
Root Cell ◽  
Gaeumannomyces Graminis ◽  
Wall Material ◽  
Wheat Roots ◽  
Pig Liver Esterase ◽  
Auto Fluorescence ◽  
Root Cell Walls

In the wheat root, peroxidases and esterases specific for a-naphthyl esters of acetate, propionate and butyrate are concentrated in cell walls, particularly the outer wall of epidermal cells undergoing extension. In contrast esterases specific for β-naphthyl esters of propionate and butyrate were intra- cellular and concentrated in epidermal and outer root-cap cells of the wheat root. Both α-naphthyl and β-naphthyl esters of longer-chain fatty acids proved to be poor substrates. The esterases and peroxidases associated with the outer epidermal wall may well be involved in turnover of phenolic acids cross-linked to polysaccharides. In this regard, ferulic acid and diferulate were shown to be constituents of wheat-root cell walls. The distribution of these substances can also be inferred from autofluorescence. Treatment with a commercial pig-liver esterase was without effect on the auto- fluorescence of the root cell-walls. Culture filtrates from Gaeumannomyces graminis did remove significant amounts of autofluorescent wall material. These preparations contained α-naphthyl acetate esterase as well as many polysaccharide hydrolase activities.

scholarly journals The thn mutation of Schizophyllum commune, which suppresses formation of aerial hyphae, affects expression of the Sc3 hydrophobin gene

1991 ◽  
Vol 137 (10) ◽  
pp. 2439-2445 ◽  
Author(s):  
J. G. H. Wessels ◽  
O. M. H. De Vries ◽  
S.A. Asgeirsdottir ◽  
J. Springer
Keyword(s):  
Schizophyllum Commune ◽  
Aerial Hyphae

Ultrastructural and cytochemical changes in the wall of a vesicular–arbuscular mycorrhizal fungus during symbiosis

1982 ◽  
Vol 60 (11) ◽  
pp. 2303-2312 ◽  
Author(s):  
Paola Bonfante-Fasolo ◽  
Roberto Grippiolo
Keyword(s):  
Arbuscular Mycorrhizal Fungus ◽  
Mycorrhizal Fungus ◽  
Arbuscular Mycorrhizal ◽  
Vitis Vinifera L ◽  
Symbiotic Association ◽  
Extraradical Hyphae ◽  
Vesicular Arbuscular ◽  
Cv Barbera ◽  
Hyphal Wall ◽  
Wall Components

During the various stages of the symbiotic association of the vesicular–arbuscular mycorrhizal (VAM) fungus Glomus fasciculatus (Thaxter) Gerd, et Trappe with the roots of Vitis vinifera L. cv. Barbera, the hyphal wall undergoes marked modifications as follows: (i) a gradual thinning out, from the extraradical hyphae to the intraradical hyphae; (ii) changes in its ultrastructural architecture, in that the wall consists of stacked lamellae in both the extraradical and coiled hyphae occurring in the outer layers of the cortical parenchyma, whereas it is monostratified in the intercellular and arbuscular hyphae occurring in the inner parenchymal layers; and (iii) different responses to cytochemical reactions. The protein and polysaccharide components, though consistently present in the fungal wall at all stages, vary in their staining characteristics after the PATAg and Swift procedure and in their responses to alkali extraction, suggesting a gradual simplification of the wall components from the extraradical hyphae to the intraradical ones.

The modulus of elasticity of equine hoof wall: implications for the mechanical function of the hoof.

1996 ◽  
Vol 199 (8) ◽  
pp. 1829-1836 ◽  
Author(s):  
J E Douglas ◽  
C Mittal ◽  
J J Thomason ◽  
J C Jofriet
Keyword(s):  
Moisture Content ◽  
Modulus Of Elasticity ◽  
Weight Bearing ◽  
Outer Wall ◽  
Wall Material ◽  
Detectable Effect ◽  
Dorsal Wall ◽  
The Mean ◽  
The Difference ◽  
Equine Hoof

During normal weight-bearing and locomotion, the equine hoof wall deforms in a consistent pattern; the proximal dorsal wall rotates caudo-ventrally about the distal dorsal border and there is latero-medial flaring posteriorly. The aim of this study is to examine whether there are regional differences in the modulus of elasticity of hoof wall material and whether such differences correlate with the pattern of deformation which occurs in vivo. The modulus of elasticity of equine hoof wall was determined in tension and compression for samples from six forefeet. Samples were tested at the mid-point of the inner and outer halves of the wall thickness at two positions along the proximo-distal axis of the dorsal wall, and from the mid-point of its thickness at the lateral and medial quarters. Test samples were oriented both parallel and perpendicular to the tubules that characterise the microstructure of the wall. The colour of each sample was noted, and the moisture content measured. The range in the mean modulus of elasticity for all samples and tests was 460-1049 MPa, the dorsal outer wall having the highest values, the dorsal inner wall the lowest, and the quarters having intermediate values. The mean value obtained for the quarters was similar to the average of the values for the dorsal inner and outer walls. At all sites, the modulus of elasticity was marginally higher in compression than in tension, possibly owing to microstructural defects. The difference in stiffness between the outer wall and the inner wall was inversely related to moisture content. The difference in stiffness between the dorsal outer and inner walls demonstrates that the equine hoof wall has a comparatively rigid external capsule with a lining of lower stiffness. This arrangement presumably provides some stress protection to the internally adjacent living tissues. The similarity in stiffness between the samples from the quarters and the mean of the two dorsal wall sites suggests that the wall at the quarters has a similar change in stiffness across its thickness as the dorsal wall. However, the reduced thickness of the wall at the quarters compared with the dorsal wall means that, functionally, the quarters are more flexible than the dorsal wall. This will facilitate the flaring of the lateral and medial walls which occurs during weight-bearing. Anisotropy was evident only in tensile tests of the dorsal wall samples. Contrary to popular assertions that white hooves are mechanically inferior, horn pigmentation had no detectable effect on stiffness.

scholarly journals The Mode of Cell Wall Growth in Selected Archaea Is Similar to the General Mode of Cell Wall Growth in Bacteria as Revealed by Fluorescent Dye Analysis

2010 ◽  
Vol 77 (5) ◽  
pp. 1556-1562 ◽  
Author(s):  
Reinhard Wirth ◽  
Annett Bellack ◽  
Markus Bertl ◽  
Yvonne Bilek ◽  
Thomas Heimerl ◽  
...  
Keyword(s):  
Cell Wall ◽  
Fluorescent Dyes ◽  
Pyrococcus Furiosus ◽  
Wall Material ◽  
Cell Wall Material ◽  
Cell Wall Growth ◽  
Archaeal Species ◽  
Dye Analysis ◽  
Wall Growth ◽  
Methanopyrus Kandleri

ABSTRACTThe surfaces of 8 bacterial and 23 archaeal species, including many hyperthermophilicArchaea, could be stained using succinimidyl esters of fluorescent dyes. This allowed us for the first time to analyze the mode of cell wall growth inArchaeaby subculturing stained cells. The data obtained show that incorporation of new cell wall material inArchaeafollows the pattern observed forBacteria: in the coccoid speciesPyrococcus furiosusincorporation was in the region of septum formation while for the rod-shaped speciesMethanopyrus kandleriandMethanothermus sociabilis, a diffuse incorporation of cell wall material over the cell length was observed. Cell surface appendages like fimbriae/pili, fibers, or flagella were detectable by fluorescence staining only in a very few cases although their presence was proven by electron microscopy. Our data in addition prove that Alexa Fluor dyes can be used forin situanalyses at temperatures up to 100°C.

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