Question

What is the chemical constitution of cell wall matrix?

Answer 1

The cell wall is a biphasic structure consisting of relatively rigid cellulosic microfibrils embedded in the gel-like non-cellulose matrix. The microfibrillar phase consists of only cellulose and the matrix is composed of noncellulosic polysaccharides and other substances like hemicellulose, pectin, proteins phenolics and water.

The matrix contains 65% of water. Rest of the components of matrix vary in proportion from cell to cell. The matrix polysaccharides are partitioned into two classes pectin and hemicellulose. Pectins are present in high concentration in middle lamella where they presumably serve the function of cementing adjacent cells together. The hemicellulose makes up roughly 20 % of the cell wall.

They are sugars like xylan, arabinose and they form cell coatings, Xyloses are thick storage walls of some seeds, Proteins are usually linked with sugars to form glycoproteins. Extensibility of cell is attributed to wall proteins, Phenolic compounds like lignin in walls form waterproof system and resist the pathogens.