Characterization of a Gel in the Cell Wall To Elucidate the Paradoxical Shrinkage of Tension Wood

2008 ◽  
Vol 9 (2) ◽  
pp. 494-498 ◽  
Author(s):  
Bruno Clair ◽  
Joseph Gril ◽  
Francesco Di Renzo ◽  
Hiroyuki Yamamoto ◽  
Françoise Quignard
Keyword(s):  
Cell Wall ◽  
Tension Wood

scholarly journals Characterization of TseB: A new actor in cell wall elongation in Bacillus subtilis

2021 ◽  
Author(s):  
Jordan Delisle ◽  
Baptiste Cordier ◽  
Stéphane Audebert ◽  
Matthieu Pophillat ◽  
Caroline Cluzel ◽  
...  
Keyword(s):  
Cell Wall ◽  
Bacillus Subtilis

scholarly journals Characterization of a Natural, Stable, Reversible and Colourful Anthocyanidin Network from Sphagnum Moss Based Mainly on the Yellow Trans-Chalcone and Red Flavylium Cation Forms

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 709
Author(s):  
Helge Berland ◽  
Øyvind M. Andersen
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Cell Wall ◽  
Peat Moss ◽  
Sphagnum Moss ◽  
Naturally Occurring ◽  
Two Component ◽  
Colour System ◽  
The Common ◽  
Cis And Trans

Anthocyanins with various functions in nature are one of the most important sources of colours in plants. They are based on anthocyanidins or 3-deoxyanthocyanidins having in common a C15-skeleton and are unique in terms of how each anthocyanidin is involved in a network of equilibria between different forms exhibiting their own properties including colour. Sphagnorubin C (1) isolated from the cell wall of peat moss (Sphagnum sp.) was in fairly acidic and neutral dimethyl sulfoxide characterized by nuclear magnetic resonance (NMR) and ultraviolet–visible (UV–vis) absorption techniques. At equilibrium, the network of 1 behaved as a two–component colour system involving the reddish flavylium cationic and the yellow trans–chalcone forms. The additional D- and E-rings connected to the common C15-skeleton extend the π-conjugation within the molecule and provide both bathochromic shifts in the absorption spectra of the various forms as well as a low isomerization barrier between the cis- and trans-chalcone forms. The hemiketal and cis-chalcone forms were thus not observed experimentally by NMR due to their short lives. The stable, reversible network of 1 with good colour contrast between its two components has previously not been reported for other natural anthocyanins and might thus have potential in future photochromic systems. This is the first full structural characterization of any naturally occurring anthocyanin chalcone form.

scholarly journals Characterization of Glycoside Hydrolase Family 5 Proteins in Schizosaccharomyces pombe

2010 ◽  
Vol 9 (11) ◽  
pp. 1650-1660 ◽  
Author(s):  
Encarnación Dueñas-Santero ◽  
Ana Belén Martín-Cuadrado ◽  
Thierry Fontaine ◽  
Jean-Paul Latgé ◽  
Francisco del Rey ◽  
...  
Keyword(s):  
Cell Wall ◽  
Schizosaccharomyces Pombe ◽  
Protein Characterization ◽  
Wall Material ◽  
Glycoside Hydrolase Family ◽  
Content Type ◽  
Hydrolysis Of ◽  
Controlled Hydrolysis ◽  
Hydrolase Family

ABSTRACT In yeast, enzymes with β-glucanase activity are thought to be necessary in morphogenetic events that require controlled hydrolysis of the cell wall. Comparison of the sequence of the Saccharomyces cerevisiae exo-β(1,3)-glucanase Exg1 with the Schizosaccharomyces pombe genome allowed the identification of three genes that were named exg1 + (locus SPBC1105.05), exg2 + (SPAC12B10.11), and exg3 + (SPBC2D10.05). The three proteins have different localizations: Exg1 is secreted to the periplasmic space, Exg2 is a membrane protein, and Exg3 is a cytoplasmic protein. Characterization of the biochemical activity of the proteins indicated that Exg1 and Exg3 are active only against β(1,6)-glucans while no activity was detected for Exg2. Interestingly, Exg1 cleaves the glucans with an endohydrolytic mode of action. exg1 + showed periodic expression during the cell cycle, with a maximum coinciding with the septation process, and its expression was dependent on the transcription factor Sep1. The Exg1 protein localizes to the septum region in a pattern that was different from that of the endo-β(1,3)-glucanase Eng1. Overexpression of Exg2 resulted in an increase in cell wall material at the poles and in the septum, but the putative catalytic activity of the protein was not required for this effect.

The nature of reaction wood. IV. Variations in cell wall organization of tension wood fibres

1955 ◽  
Vol 3 (2) ◽  
pp. 177 ◽  
Author(s):  
AB Wardrop ◽  
HE Dadswell
Keyword(s):  
Cell Wall ◽  
Tension Wood ◽  
Secondary Wall ◽  
Degree Of Crystallinity ◽  
Tropical Species ◽  
Normal Wood ◽  
Reaction Wood ◽  
Gelatinous Layer ◽  
Wood Fibres ◽  
Cell Wall Organization

The cell wall organization, the cell wall texture, and the degree of lignification of tension wood fibres have been investigated in a wide variety of temperate and tropical species. Following earlier work describing the cell wall structure of tension wood fibres, two additional types of cell wall organization have been observed. In one of these, the inner thick "gelatinous" layer which is typical of tension wood fibres exists in addition to the normal three-layered structure of the secondary wall; in the other only the outer layer of the secondary wall and the thick gelatinous layer are present. In all the tension wood examined the micellar orientation in the inner gelatinous layer has been shown to be nearly axial and the cellulose of this layer found to be in a highly crystalline state. A general argument is presented as to the meaning of differences in the degree, of crystallinity of cellulose. The high degree of crystallinity of cellulose in tension wood as compared with normal wood is attributed to a greater degree of lateral order in the crystalline regions of tension wood, whereas the paracrystalline phase is similar in both cases. The degree of lignification in tension wood fibres has been shown to be extremely variable. However, where the degree of tension wood development is marked as revealed by the thickness of the gelatinous layer the lack of lignification is also most marked. Severity of tension wood formation and lack of lignification have also been correlated with the incidence of irreversible collapse in tension wood. Such collapse can occur even when no whole fibres are present, e.g. in thin cross sections. Microscopic examination of collapsed samples of tension wood has led to the conclusion that the appearance of collapse in specimens containing tendon wood can often be attributed in part to excessive shrinkage associated with the development of fissures between cells, although true collapse does also occur. Possible explanations of the irreversible shrinkage and collapse of tension wood fibres are advanced.

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