scholarly journals Cell walls as taxonomic markers in Polish species of the genus Odontoschisma (Dum.) Dum. (Hepaticae, Cephaloziaceae)

2014 ◽  
Vol 68 (1) ◽  
pp. 39-45 ◽  
Author(s):  
Jerzy Szweykowski ◽  
Katarzyna Buczkowska

To get valuable diagnostic characters, the structure of cell walls was studied with use of two stains (Ruthenium Red -RR and Resorcine Blue - RB) and in polarized light. As far as the stem structure is concerned, European species of the genus <em>Odontoschisma</em> fall into two groups: in <em>Odontoschisma elongatum</em> and in <em>Odontoschisma macounii</em> a thick, frequently completely obscuring cell lumen, "lining layer" is present. It frequently, particularly after staining in RB, detaches from the rest of the cell wall. Such a layer is completely lacking in the two remaining species, viz. <em>O. sphagni</em> and <em>0. denudatum</em>. In polarized light only leaves of <em>O. sphagni</em> show a distinct bright border. The thin cellulose layer (bright in polarized light) embrace the angular thickenings in <em>0. sphagni</em> and <em>0. denudatum</em>, but is entering the inside of these thickenings in the two remaining species. Keys for determination of the four European species based on the staining properties of cell walls and their look in polarized light are provided.

1968 ◽  
Vol 46 (4) ◽  
pp. 317-327 ◽  
Author(s):  
M. T. Tyree

Transport coefficients LPP, LPE, LEP, and LEE for electrokinetic equations according to irreversible thermodynamics, the Onsager coefficients, were measured for isolated Nitella flexilis cell walls in KCl solutions ranging from 10−4 to 100 normal. LPP and LPE (= LEP) were found to be independent of KCl concentration and equal to 1.4 × 10−6 cm3 sec−1 cm−2 (joule cm−3)−1 cm and 6 × 10−5 cm3 sec−1 cm−2 volt−1 cm respectively. LEE was a function of the salt concentration, reaching a limiting value of about 1.2 × 10−3 mho cm−1 in 10−4 N KCl. The activation energy for movement of KCl in cell walls was found to be 4.33 Kcal mole−1; the diffusion coefficient for KCl in cell walls was calculated by two methods to be 8 × 10−6 cm2 sec−1; and the concentration of the fixed ions in Nitella cell walls from the above data was estimated at greater than 0.04 equivalent per liter of cell wall. Electroosmosis in Nitella membranes is re-examined in the light of the measured transport coefficients and it is concluded that under proper conditions the cell wall of Nitella can contribute significantly (~20% or more) to the observed electroosmosis of living Nitella cells.


1997 ◽  
Vol 28 (2) ◽  
pp. 147-157 ◽  
Author(s):  
Albert van der Wal ◽  
Willem Norde ◽  
Bernd Bendinger ◽  
Alexander J.B Zehnder ◽  
Johannes Lyklema

2009 ◽  
Vol 8 (11) ◽  
pp. 1626-1636 ◽  
Author(s):  
Enrico Cabib

ABSTRACT Previous work, using solubilization of yeast cell walls by carboxymethylation, before or after digestion with β(1-3)- or β(1-6)glucanase, followed by size chromatography, showed that the transglycosylases Crh1p and Crh2p/Utr2p were redundantly required for the attachment of chitin to β(1-6)glucan. With this technique, crh1Δ crh2Δ mutants still appeared to contain a substantial percentage of chitin linked to β(1-3)glucan. Two novel procedures have now been developed for the analysis of polysaccharide cross-links in the cell wall. One is based on the affinity of curdlan, a β(1-3)glucan, for β(1-3)glucan chains in carboxymethylated cell walls. The other consists of in situ deacetylation of cell wall chitin, generating chitosan, which can be extracted with acetic acid, either directly (free chitosan) or after digestion with different glucanases (bound chitosan). Both methodologies indicated that all of the chitin in crh1Δ crh2Δ strains is free. Reexamination of the previously used procedure revealed that the β(1-3)glucanase preparation used (zymolyase) is contaminated with a small amount of endochitinase, which caused erroneous results with the double mutant. After removing the chitinase from the zymolyase, all three procedures gave coincident results. Therefore, Crh1p and Crh2p catalyze the transfer of chitin to both β(1-3)- and β(1-6)glucan, and the biosynthetic mechanism for all chitin cross-links in the cell wall has been established.


2020 ◽  
Vol 21 (17) ◽  
pp. 6094
Author(s):  
Fabien Baldacci-Cresp ◽  
Julien Le Roy ◽  
Brigitte Huss ◽  
Cédric Lion ◽  
Anne Créach ◽  
...  

Lignin is present in plant secondary cell walls and is among the most abundant biological polymers on Earth. In this work we investigated the potential role of the UGT72E gene family in regulating lignification in Arabidopsis. Chemical determination of floral stem lignin contents in ugt72e1, ugt72e2, and ugt72e3 mutants revealed no significant differences compared to WT plants. In contrast, the use of a novel safranin O ratiometric imaging technique indicated a significant increase in the cell wall lignin content of both interfascicular fibers and xylem from young regions of ugt72e3 mutant floral stems. These results were globally confirmed in interfascicular fibers by Raman microspectroscopy. Subsequent investigation using a bioorthogonal triple labelling strategy suggested that the augmentation in lignification was associated with an increased capacity of mutant cell walls to incorporate H-, G-, and S-monolignol reporters. Expression analysis showed that this increase was associated with an up-regulation of LAC17 and PRX71, which play a key role in lignin polymerization. Altogether, these results suggest that UGT72E3 can influence the kinetics of lignin deposition by regulating monolignol flow to the cell wall as well as the potential of this compartment to incorporate monomers into the growing lignin polymer.


1960 ◽  
Vol 7 (2) ◽  
pp. 289-296 ◽  
Author(s):  
Paul B. Green

Plant cell walls typically consist of crystalline microfibrils embedded in a non-crystalline matrix. The growing cylindrical Nitella cell wall contains microfibrils predominantly oriented in the transverse direction. The present study has shown that the transversely oriented microfibrils are primarily located toward the inner surface of the wall and that, proceeding outward from the inner surface, the wall contains microfibrils of ever poorer transverse orientation, the fibrils being randomly or axially arranged in the outermost regions of the wall. Because cell expansion is primarily in the axial direction, the texture of the fibrillar elements of the wall can be explained by assuming that new microfibrils of transverse orientation are added only at the inner surface of the wall and that they become passively reoriented to the axial direction during cell elongation. The described structure corresponds to that proposed by Roelofsen and Houwink for cells showing "multi-net growth." The demonstration of a continuous gradient of microfibrillar arrangement and its partial quantitative description was accomplished by the analysis, with the polarized light and interference microscopes, of wedge-like torn edges of developing cell walls which were 1 micron or less in optical thickness.


1995 ◽  
Vol 73 (4) ◽  
pp. 662-672 ◽  
Author(s):  
Claude Roux ◽  
Olivier Bricaud ◽  
Didier Le Coeur ◽  
Dagmar Triebel

Stigmidium lecidellae Triebel, Roux et Le Coeur sp.nov., a mild pathogenic lichenicolous fungus growing on the apothecia of Lecidella elaeochroma (Ach.) M. Choisy is described in detail and compared with other species of Stigmidium that grow on the apothecia of the host. The staining of parts of cell walls with cresyl blue is constant at species level and, therefore, is taxonomically relevant in the genus Stigmidium. The dye also allows to distinguish some ultrastructural details of the vegetative hyphal cells, asci, and ascospores. Among the fungi species growing on the apothecia of lichens, three groups are distinguished on the basis of their hamathecial structure, one of which should be excluded from the genus Stigmidium and included in the genus Sphaerellothecium. A key to the determination of the species is presented. Key words: lichenicolous fungi, Stigmidium, Sphaerellothecium, taxonomy, taxonomic key, cell wall, staining reactions, hamathecium.


2002 ◽  
Vol 68 (4) ◽  
pp. 1610-1615 ◽  
Author(s):  
Koichiro Murashima ◽  
Akihiko Kosugi ◽  
Roy H. Doi

ABSTRACT Clostridium cellulovorans produces a cellulase enzyme complex (cellulosome). In this study, we isolated two plant cell wall-degrading cellulosomal fractions from culture supernatant of C. cellulovorans and determined their subunit compositions and enzymatic activities. One of the cellulosomal fractions showed fourfold-higher plant cell wall-degrading activity than the other. Both cellulosomal fractions contained the same nine subunits (the scaffolding protein CbpA, endoglucanases EngE and EngK, cellobiohydrolase ExgS, xylanase XynA, mannanase ManA, and three unknown proteins), although the relative amounts of the subunits differed. Since only cellobiose was released from plant cell walls by the cellulosomal fractions, cellobiohydrolases were considered to be key enzymes for plant cell wall degradation.


Zootaxa ◽  
2009 ◽  
Vol 2197 (1) ◽  
pp. 31-42 ◽  
Author(s):  
WOJCIECH GIŁKA ◽  
LAURI PAASIVIRTA

Tanytarsus salmelai sp. n. collected from the northernmost sites of the Finnish Lapland is described. The new species and two sibling Tanytarsus, T. brundini Lindeberg, 1963 and T. curticornis Kieffer, 1911, are compared, diagnosed and illustrated in detail. Morphological variability and diagnostic characters of the three related species are discussed. An emended diagnosis for adult males of the Tanytarsus chinyensis species group and a key to determination of European species of the group are also provided.


Development ◽  
2021 ◽  
Author(s):  
Bruce D. Kohorn ◽  
Frances D. H. Zorensky ◽  
Jacob Dexter-Meldrum ◽  
Salem Chabout ◽  
Gregory Mouille ◽  
...  

Plant growth, morphogenesis and development involves cellular adhesion, a process dependent on the composition and structure of the extracellular matrix (ECM) or cell wall. Pectin in the cell wall is thought to play an essential role in adhesion, and its modification and cleavage are suggested to be highly regulated so as to change adhesive properties. To increase our understanding of plant cell adhesion a population of EMS mutagenized Arabidopsis were screened for hypocotyl adhesion defects using the pectin binding dye Ruthenium Red that penetrates defective but not WT hypocotyl cell walls. Genomic sequencing was used to identify a mutant allele of ELMO1 which encodes a 20 kDa Golgi membrane protein that has no predicted enzymatic domains. ELMO1 colocalizes with several Golgi markers and elmo1−/- plants can be rescued by an ELMO1-GFP fusion. elmo1−/- exhibits reduced mannose content relative to WT but no other cell wall changes and can be rescued to WT phenotype by mutants in ESMERALDA1 that also suppresses other adhesion mutants. elmo1 describes a previously unidentified role for the ELMO1 protein in plant cell adhesion.


1997 ◽  
Vol 87 (8) ◽  
pp. 846-852 ◽  
Author(s):  
Akinori Kiba ◽  
Chizu Miyake ◽  
Kazuhiro Toyoda ◽  
Yuki Ichinose ◽  
Tetsuji Yamada ◽  
...  

Fractions solubilized with NaCl from cell walls of pea and cowpea plants catalyzed the formation of blue formazan from nitroblue tetrazolium. Because superoxide dismutase decreased formazan production by over 90%, superoxide anion (O2¯) may participate in the formation of formazan in the solubilized cell wall fractions. The formazan formation in the fractions solubilized from pea and cowpea cell walls was markedly reduced by exclusion of NAD(P)H, manganese ion, or p-coumaric acid from the reaction mixture. The formazan formation was severely inhibited by salicylhydroxamic acid and catalase, but not by imidazole, pyridine, quinacrine, and diphenyleneiodonium. An elicitor preparation from the pea pathogen Mycosphaerella pinodes enhanced the activities of formazan formation nonspecifically in both pea and cowpea fractions. The suppressor preparation from M. pinodes inhibited the activity in the pea fraction in the presence or absence of the elicitor. In the cowpea fraction, however, the suppressor did not inhibit the elicitor-enhanced activity, and the suppressor alone stimulated formazan formation. These results indicated that O2¯ generation in the fractions solubilized from pea and cowpea cell walls seems to be catalyzed by cell wall-bound peroxidase(s) and that the plant cell walls alone are able to respond to the elicitor non-specifically and to the suppressor in a species-specific manner, suggesting the plant cell walls may play an important role in determination of plant-fungal pathogen specificity.


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