Abstract
Plant cell walls are highly sophisticated fiber composite structures composed mostly of polysaccharides and glycoproteins. In the majority of seed plant species, the dominant structural feature of the primary cell wall is the cellulose/xyloglucan networks which is embedded in an amorphous matrix of pectins and glycoproteins. However, various kinds of cell walls have evolved to fulfill a wide range of biological roles during the diversification of land plants. For example, the primary cell walls from commelinoid monocotyledons, which include cereals, have relatively little xyloglucan, and the predominant glycan that cross-links the cellulose microfibrils is instead (1,3)(1,4)-beta-D-glucan (MLG) and glucuronoarabinoxylan (GAX). Moreover, the cell wall contains less pectin and higher amounts of phenylpropanoids.
Today, cereals represent potential feedstocks for biofuel production. In rice, MLGs, GAXs and xyloglucans are considered to be essential roles in not only regulation of plant growth that directly affect biomass production but also accessibility of cellulase to the cellulose microfibrils. For this reason, we specifically aimed at elucidating roles of these polysaccharides.
