Glycosyl transferases in family 61 mediate arabinofuranosyl transfer onto xylan in grasses.

摘要: Xylan, a hemicellulosic component of the plant cell wall, is one most abundant polysaccharides in nature. In contrast to dicots, xylan grasses extensively modified by α-(1,2)– and α-(1,3)–linked arabinofuranose. Despite importance grass arabinoxylan human animal nutrition for bioenergy, enzymes adding arabinosyl substitutions are unknown. Here we demonstrate that knocking-down glycosyltransferase (GT) 61 expression wheat endosperm strongly decreases substitution xylan. Moreover, heterologous rice GT61s Arabidopsis leads arabinosylation xylan, therefore provides gain-of-function evidence α-(1,3)-arabinosyltransferase activity. Thus, GT61 proteins play key role biosynthesis evolutionary divergence walls.