Cellulose xyloglucans

This essay was written in an attempt to explain our overview of primary cell walls and to reach consensus on the nomenclature of primary cell wall polysaccharides. We present evidence supporting the hypothesis that cellulose, xyloglucan, arabinoxylan, homogalacturonan, RG-I, and RG-II are the six polysaccharides common to all primary cell walls of higher plants. In many cells, these six polysaccharides account for all or nearly all of the primary wall polysaccharides. Like the physically interacting proteins that constitute the electron transport machinery of mitochondria, the structures of the six patently ubiquitous polysaccharides of primary cell walls have been conserved during evolution. Indeed, we hypothesize that the common set of six structural polysaccharides of primary cell walls have been structurally... 

The Fourier Trairsform Infrared (FTIR) spectrum obtained from non-adapted tomato cell walls is very similar to that from the onion parenchyma cell wall (both contain cellulose, xyloglucan and pectin) although there is more protein in the tomato walls (amide stretches at 1550 and 1650 cm-i) (Fig 4). In DCB-adapted tomato cell walls, the spectrum more closely resembles that of either purified pectins or of a commercial polygalacturonic acid sample from Sigma with peaks in common at 1140, 1095, 1070, 1015 and 950 cm-t in the carbohydrate region of the spectrum as well as the free acid stretches at 1600 and 1414 cm-i and an ester peak at 1725 cm-k An ester band at 1740 cm-i is evident in both onion parenchyma and non-adapted tomato cell wall samples. It is possible that this shift in the ester peak simply reflects the different local molecular environment of this bond, but it is also possible that a different ester is made in the DCB-adapted cell walls, as phenolic esters absorb around 1720 cm-i whilst carboxylic esters absorb at 1740 cm-k The... 

If we compare liquefaction to maceration, more activities are needed to liquefy the cell wall. Since 1991, new pectinases activities such as rhamnogalacturonase, pectin acetylesterase and xyloglucanases complex have been found to be important in the apple liquefaction by Henck Schols, Jean-Paul Vincken and Voragen [3]. The cellulose-xyloglucan complex accounts approximatively 57% of the apple cell-wall matrix. In a liquefaction process, an efficient enzymic degradation of this complex is crucial to increase the sugars extraction, to decrease the viscosity of the pulp then to be able to ultra-filtrate the juice without second depectinisation, at last to have negative alcohol tests required by some concentrate customers. 

Figure 3.5 A simplified model of the molecular architecture of a primary cell wall rich in pectic polysaccharides, such as a potato cell wall. Two co-extensive, but independent polysaccharide networks are shown a cellulose-xyloglucan network and a pectic-polysaccharide network. The middle lamella is located between the primary cell walls of adjacent cells and is responsible for cell-cell adhesion. Reprinted with permission from McCann and Roberts (1991).

Jean, B., Heux, L., Dubreuil, F., Chambat, G., Cousin, F. Non-electrostatic building of biomimetic cellulose-xyloglucan multilayers. Langmuir. 25, 3920-3923 (2009)... 

M. Pauly, P. Albersheim, A. Darvill, W.S. York. A model for the cellulose/xyloglucan network in the cell walls of higher plants. Plant J, 2000, in press... 

S.E.C. Whitney, J.E. Brigham, A.H. Drake, J.S.G. Reid, M.J. Gidley. In vitro assembly of cellulose-xyloglucan networks Ultrastructural and molecular aspects. Plant J, 1995,8,491-504... 

J.K.C. Rose, A.B. Bennett. Copperative dissasembly of the cellulose-xyloglucan network of plant cell walls parallels between cell expansion and fruit ripening. Trends Plant Sci, 1999, 4, 176-183... 

E. Shedletzky, M. Shmuel, D.P. Delmer, D.T.A. Lamport DTA. Adaptation and growth of tomato cells on the herbidde 2,6-dichIorobenzonitrile leads to production of unique cell walls virtually lacking a cellulose-xyloglucan network. Plant Physiol 1990, 94, 980 987... 

Fruits and Cellulose, xyloglucans, arabinogalactans. Polysaccharides fiber... 

Legume seeds Cellulose, xyloglucans, galactomannans. Wholemeal bread 5.0 7.0... 

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