The major components of cell walls in the commercially important grass family are cellulose,lignin and a range of non-cellulosic polysaccharides.Examinations of spatial gradients in wall composition and transcriptional profiles in internodes of species from the Poaceae show different patterns of lignin and wall polysaccharide synthesis,and implicate genes involved in monolignol biosynthesis,sugar nucleotide interconversion and cellulose synthesis as points of regulation of wall composition and physicochemical properties.