Polysaccharides: Plant Noncellulosic


Plant cell walls are composites that consist of polysaccharides, proteins and, if they are secondary cell walls, lignin as well as a number of minor constituents. The major components are the polysaccharides and, owing to their complexity, they are usually subdivided into cellulose and others, namely the noncellulosic polysaccharides. These noncellulosic polysaccharides encompass pectins (d‐galacturonans) and hemicelluloses (d‐xylans, d‐glucans, d‐mannans, etc.) and each has its own specific function and responsibility within a particular type of cell wall.

Keywords: hemicelluloses; pectin; function in plant cell wall; biosynthesis; enzymatic degradation

Figure 1.

Structures of an arabinoxylan, a glucomannan, a xyloglucan and a pectin as found in plant cell walls. Ara, arabinose; Fuc, fucose; Gal, galactose; GalA, galacturonic acid; Glc, glucose; Man, mannose; Rha, rhamnose; Xyl, xylose; OAc, acetyl; OMe, methyl.

Figure 2.

(a) Model of the primary cell wall of onion as proposed by McCann and Roberts and (b) model of an expanding type I plant cell wall as proposed by Carpita and Gibeaut . Figure 2a is printed with permission from Academic Press, London and Figure 2b is printed with permission from Blackwell Science, Oxford.



Carpita NC and Gibeaut DM (1993) Structural models of primary cell walls in flowering plants: consistency of molecular structure with the physical properties of the walls during growth. The Plant Journal 3: 1–30.

Edwards M, Scott C, Gidley MJ and Reid JSG (1992) Control of mannose to galactose ratio during galactomannan formation in developing legume seeds. Planta 187: 67–74.

Gibeaut DM and Carpita NC (1994) Biosynthesis of plant cell wall polysaccharides. FASEB Journal 8: 904–915.

McCann MC and Roberts K (1991) Architecture of the primary cell wall. In: Lloyd CW (ed.) The Cytoskeletal Basis of Plant Growth or Form, pp. 109–129. London: Academic Press.

Matheson NK (1990) Mannose‐based polysaccharides. In: Dey PM (ed.) Methods in Plant Biochemistry, vol. 2, Carbohydrates, pp. 371–413. London: Academic Press.

Micard V, Grabber JH, Ralph J, Renard CMGC and Thibault J‐F (1997) Dehydrodiferulic acids from sugar‐beet pulp. Phytochemistry 44: 1365–1368.

O'Neill M, Albersheim P and Darvill A (1990) The pectic polysaccharides of primary cell walls. In: Dey PM (ed.) Methods in Plant Biochemistry, vol. 2, Carbohydrates, pp. 415–441. London: Academic Press.

Wood WA and Kellogg ST (1988a) Biomass. Part A. Cellulose and hemicellulose. Methods in Enzymology 160. [whole issue]

Wood WA and Kellogg ST (1988b) Biomass. Part B. Lignin, pectin and chitin. Methods in Enzymology 160. [whole issue]

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Morrison, Ian M(Apr 2001) Polysaccharides: Plant Noncellulosic. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1038/npg.els.0000696]