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  • Articles: DFG German National Licenses  (9)
  • Cell wall  (6)
  • cellulose  (3)
  • 1
    Electronic Resource
    Electronic Resource
    Liquid crystal-type assembly of native cellulose-glucuronoxylans extracted from plant cell wall
    Amsterdam : Elsevier
    Biology of the Cell 73 (1991), S. 173-178 
    Details
    ISSN: 0248-4900
    Keywords: cellulose ; liquid-crystal ; quince ; self-assembly ; xylans
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0248-4900(91)90100-2
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    The helicoidal plant cell wall as a performing cellulose-based composite
    Amsterdam : Elsevier
    Biology of the Cell 67 (1989), S. 209-220 
    Details
    ISSN: 0248-4900
    Keywords: cell walls ; cellulose ; fiber composite ; helicoids
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0248-4900(89)90056-7
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  • 3
    Electronic Resource
    Electronic Resource
    Affinodetection of the sites of formation and of the further distribution of polygalacturonans and native cellulose in growing plant cells
    Amsterdam : Elsevier
    Biology of the Cell 71 (1991), S. 43-55 
    Details
    ISSN: 0248-4900
    Keywords: cell wall ; cellulose ; enzyme-gold complex ; helicoidal pattern ; monoclonal antibodies ; polygalacturonans
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0248-4900(91)90050-W
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  • 4
    Electronic Resource
    Electronic Resource
    Morphogenesis of plant cell walls at the supramolecular level: Internal geometry and versatility of helicoidal expression (1987)
    Springer
    Protoplasma 140 (1987), S. 75-91 
    Details
    ISSN: 1615-6102
    Keywords: Cell wall ; Helicoidal texture ; Modelling ; Flexibility ; Cellulose
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The concept of the cell wall organized in a helicoidal pattern was outlined. When studied in transmission electron microscopy, the observed textures appear as a deceptive figure,i.e., as a “trompe l'oeil”. Difficulties—both technological and visual in the reconstitution of the actual geometry (exposure of the microfibrillar framework, 3-dimensional and 4-dimensional restoration), and the interest of simple modelling to understand the changes in cellulose orientation according to space and time are emphasized. The morphogenesis of helicoidal walls presents two main characteristics: it is both very defined and flexible, thus adaptable to varied programs of differentiation and to different environmental conditions. The observations of various cell examples and of responses to experimental treatments, lead to the following considerations: a) the shift of cellulose occurs continuously with time through a constant mutual angle. The wall seems to be built up as an indefinite continuum and forms a monotonous oscillatory system (unvarying motion); b) the shift of cellulose occurs through a mutual angle variable with time (varying motion, change from monotonous helicoid to bimodal helicoid, or sporadic bursts with arrested motion). The helicoidal wall appears as a fibrous composite with multifunctional possibilities ranging from fluidity to stiffness. The helicoidal assembly is remarkably adaptable to different physiological conditions of growth and specialization.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01273716
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  • 5
    Electronic Resource
    Electronic Resource
    Cholesteric-like crystal analogs in glucuronoxylan-rich cell wall composites: Experimental approach of acellular re-assembly from native cellulosic suspension (1994)
    Springer
    Protoplasma 180 (1994), S. 70-81 
    Details
    ISSN: 1615-6102
    Keywords: Cell wall ; Cellulose/glucuronoxylan ; Acellular assembly ; Cholesteric analog
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Many plant cell walls are constructed according to a helicoidal pattern that is analog to a cholesteric liquid crystal order. This raises the question whether the wall assembly passes through a true but temporary liquid crystal state. The paper focuses on experiments performed from aqueous suspensions of extracted quince slime, i.e., a cellulose/glucuronoxylan wall composite that presents a helicoidal order when observed in situ, within the enlarged periplasm of the seed epidermal cells. Experiments carried out in acellular conditions showed that a spontaneous reassociation into a helicoidal order can be obtained from totally dispersed suspensions. The ultrastructural aspect of the reassembled mucilage suspension was different according to the resin used (LR White or nanoplast, a water-soluble melamin resin). It was always typically polydomain, and when an order was visible it was cholesteric-like and similar to the in situ native organization. Transition states with many imperfections expressed the difficulty of the system to reassemble in the absence of constraining surfaces. The possible intervention of glucuronoxylan (GX) in the ordered assembly of the microfibrils was checked by: (1) progressive extraction of GX by trifluoroacetic acid (TFA). The extraction was associated to a control of the fraction by analysis of uronic acid contents and observation at the electron microscope level. Extraction of GX provoked the formation of a flocculent mass, the flocculation being more intense when the TFA was more concentrated; (2) progressive change of pH in order to analyze the influence of pH on flocculation. Low pH (ca. pH 3) led also to a flocculation of the suspension, but the floc was reversibly lost after dialysis against distilled water. The results indicate the antifloc role of the GX due to the anionic charges carried by the side-chains. However, the function of GX as helper twisting agent in the cholesteric-like reassembly must not be ruled out.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01379225
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  • 6
    Electronic Resource
    Electronic Resource
    The glucuronoxylans and the helicoidal shift in cellulose microfibrils in linden wood: Cytochemistryin muro and on isolated molecules (1986)
    Springer
    Protoplasma 131 (1986), S. 185-199 
    Details
    ISSN: 1615-6102
    Keywords: Cell wall ; Enzyme-gold method ; Twisted morphogenesis ; Hemicelluloses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In fibres of wood, the classical S1 and S2 layers are connectedvia a transition zone where a helicoidal texture occurs. In order to understand the actual mechanism of cellulose microfibril rotation in this zone, the study of relationship between cellulose and matrix was undertaken cytochemically at the ultrastructural level. Glucuronoxylans,i.e., the main hemicellulose component of hardwood, were studied in cell walls of linden tree. Xylanase-gold complexes were used as a new cytochemical tool to directly and specifically label glucuronoxylans within the wall of fibres. Subtractive localization (KOH or DMSO extraction and PATAg test or shadowing) associated with chemical analysis was carried out as control. The study of isolated glucuronoxylan molecules was undertaken in parallel. Both from direct (xylanase-gold labeling) and indirect techniques (extractions), glucuronoxylans appear preferentially concentrated in the transition zone which overlaps the layers S1 and S2. A comparison between KOH and DMSO extraction indicates a difference in accessibility of glucuronoxylans distributed across the whole wall and those located in the transition zone. Isolated molecules have a rodlike aspect and show a tendancy to spatially organize in parallel alignment. Cytochemical labeling of the isolated molecules concerns covalent linkages, vic-glycol groups and acid side groups along the main chain. The preferential localization indicates that in the helicoidal zone glucuronoxylans constitute a thick matrix embedding the cellulose microfibrils in the course of rotation. This data leads to a discussion of how these localized matrix molecules could intervene in the assembly and the twisted morphogenesis of the fibre cell wall.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01285040
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  • 7
    Electronic Resource
    Electronic Resource
    Immunocytochemical location of hydroxyproline rich glycoproteins at the interface between a mycorrhizal fungus and its host plants (1991)
    Springer
    Protoplasma 165 (1991), S. 127-138 
    Details
    ISSN: 1615-6102
    Keywords: Cell wall ; Hydroxyproline rich glycoproteins ; Interface zone ; Mycorrhizal fungi ; Pea ; Leek
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary When vesicular-arbuscular mycorrhizal (VAM) fungi colonize the cortical cells of their host plant roots, the hyphae are separated from the host cytoplasm by the invaginated host plasmalemma and interfacial material. The presence of hydroxyproline rich glycoproteins (HRGPs) at the interface was investigated with a polyclonal antibody obtained against melon callus HRGP2b. By using a combination of cytochemical methods, antigens were detected in pea, in both the presence and absence ofGlomus versiforme, a mycorrhizal fungus. For comparison, observations were performed in parallel with leek as a monocot host. Antigens were localized over the pea cell wall in root tissues. At the ultrastructural level, gold granules were mostly present in the periplasmic space. In mycorrhizal plants, the most substantial deposition occurred at the interface between the fungal wall and the host membrane. Dot blot experiments revealed HRGP2b antigens in soluble root fractions from both uninfected and mycorrhizal samples. The results demonstrate that HRGP2b antigens can be localized over the cell wall of both dicot and monocot hosts, although they mostly occur in the contact zone in infected samples. Their presence-in the company of localized glucans and pectins-means that the contact zone can be regarded as an apoplastic space presenting a structural response to the symbiotic mycorrhizal status.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01322283
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  • 8
    Electronic Resource
    Electronic Resource
    The sustained and warped helicoidal pattern of a xylan-cellulose composite: the stony endocarp model (1992)
    Springer
    Protoplasma 166 (1992), S. 21-34 
    Details
    ISSN: 1615-6102
    Keywords: Cell wall ; Cellulose ; Xylan ; Disclinations ; Liquid crystal ; Cholesteric mesophases
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The study was devoted to the microstructure of the thick walled cells of the endocarp of prune (Prunus domestica L.), cherry (Prunus cerasus L.), walnut (Juglons regia L.). The tissue is formed of closely associated cells showing a homogeneous development characterized by an intense constructive activity of ordered walls with a typically twisted pattern (cholesteric-like). The arced layers are produced in tens, each corresponding to a 180° full rotation of the molecules (axis of rotation oriented radially) and their succession gives rise to a basic regular and monotonous periodicity. On the other hand, observation of the tissue revealed the large capacity of the helicoidal morphogenesis to adjust itself under the influence of two topological contingent constraints: (1) the spherical shape (and derivated shapes) of the cell and (2) the numerous pit canals which maintain the symplastic transport and produce a recess during the construction of the wall. Spherical shape (closed surfaces) and recess both introduce additional internal strains which are relieved by deviations of the molecular array in the basic pattern (moiré and knotty aspects). Special attention was given to the defects integrated in the spherical twist. The defects emerging in the angled stacks of microfibrils (disclinations, distortions) were a diagnostic feature of an actual liquid crystal behaviour under mechanical constraints. The abundance of such defects, of cusps and spiral motions strengthened the hypothesis that a transient fluid phase, later on consolidated and stiffened, operates during the cellulose ordering. The saddle-like figures developed in the complex polylobed situation of walnut were particularly demonstrative. The fractionation of the secondary wall yielded the glucidic matrix in the same ratio as cellulose. The bulk of this embedding matrix was composed of acidic xylans more or less tightly bound to the microfibrils. The coat of negatively charged polysaccharides visualized by the binding of cationic gold to wall strips might be expected to act as a surfactant generating an electrostatic repulsion between microfibrils. This could be a cooperative mechanism for the self-positioning (aligment in sheets and progressive rotation) of the composite.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01320139
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  • 9
    Electronic Resource
    Electronic Resource
    Morphogenesis of twisted cell wall: Chronology following an osmotic shock (1985)
    Springer
    Protoplasma 126 (1985), S. 36-46 
    Details
    ISSN: 1615-6102
    Keywords: Cell wall ; Growth ; Osmotic shock ; Rhythm ; Twisted assembly
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The effect of an osmotic shock on the subsequent growth and cell wall texture was studied at 0, 1/2, 1, 2, 4 and 24 hours. Cells were taken at the beginning of their exponential growth from mung bean hypocotyl. The shock reveals the instability and the fragility of the assembly mechanisms. It induces a rupture in the texture (formation of a loose layer) or, occasionally, the apparition of a swirling pattern. After the shock, the twisting positioning can be restored. The “post-shock” deposit appears similar to the “pre-shock” deposit. The loose layer provides a visible guide-mark (time marker) within the wall. It allows one to evaluate the oscillatory period (i.e., the duration necessary for a 180° rotation of the microfibrils). This period was found to be ca. 3 hours following a lag period of ca. 1 hour. It confirms the endogenous ultradian character of the rhythm of the assembly.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01287671
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