CEREALS | Chemistry of Nonstarch Polysaccharides

The Genetics and Transcriptional Profiles of the Cellulose Synthase-Like HvCslF Gene Family in Barley

“…Although the rice OsCslF genes appear to be involved in (1,3;1,4)-b-D-glucan synthesis and the QTL analyses performed here (Fig. 3) support a similar role for the HvCslF genes in barley, it remains possible or even likely that the biosynthesis of (Staudte et al, 1983) means that there is no strictly repeating structure (Fincher and Stone, 2004). In addition, a small proportion of much longer blocks of adjacent (1,4)-linked b-D-glucosyl residues are found in the polysaccharide.…”

“…The levels of (1,3;1,4)-b-D-glucan in cell walls of different tissues and organs of barley vary from about 5% by weight in walls from stems to as much as 70% or more by weight in walls of the starchy endosperm (Fincher and Stone, 2004). More detailed analyses of transcript abundance during the growth and development of barley coleoptiles showed that HvCslF6 mRNA was again the most abundant (Fig.…”

“…In addition, a small proportion of much longer blocks of adjacent (1,4)-linked b-D-glucosyl residues are found in the polysaccharide. The complexity of this structure can be related to the function of (1,3;1,4)-b-D-glucans in cell walls (Fincher and Stone, 2004), and is also suggestive of a similar complexity in the enzymology of (1,3;1,4)-b-D-glucan biosynthesis (Buckeridge et al, 2001), where one might again infer that multiple enzymes are required.…”

“…Primary walls are composed mainly of cellulose and a range of noncellulosic polysaccharides, together with smaller amounts of proteins and other components Trethewey et al, 2005). Although the chemical structures of most wall polysaccharides have been determined (Fincher and Stone, 2004), there is relatively little information on the enzymes involved in their biosynthesis. Within the overall glycosyltransferase (GT) class of carbohydrate-modifying enzymes (Coutinho and Henrissat, 1999; http://afmb.cnrs-mrs. fr/CAZY/) two distinct groups of enzymes have been implicated in wall polysaccharide biosynthesis, namely the type I polysaccharide synthases and the type II GTs.…”

Pattern of Deposition of Cell Wall Polysaccharides and Transcript Abundance of Related Cell Wall Synthesis Genes during Differentiation in Barley Endosperm

“…Pretreating the sections with alkali did not change the pattern of LM11 labeling. (Fincher and Stone, 2004;York and O'Neill, 2008). To examine the temporal pattern of feruloylation throughout endosperm differentiation, we applied a polyclonal antibody specific for ferulic acid ester linked at the C(O)5 position to a-L-arabinosyl residues of arabino-(1→4)-b-D-xylans (Philippe et al, 2007).…”