title: Grass lignin acylation: p-coumaroyl transferase activity and cell wall characteristics of C3 and C4 grasses.
abstract: Grasses are a predominant source of nutritional energy for livestock systems around the world. Grasses with high lignin content have lower energy conversion efficiencies for production of bioenergy either in the form of ethanol or to milk and meat through ruminants. Grass lignins are uniquely acylated with p-coumarates (pCA), resulting from the incorporation of monolignol p-coumarate conjugates into the growing lignin polymer within the cell wall matrix. The required acyl-transferase is a soluble enzyme (p-coumaroyl transferase, pCAT) that utilizes p-coumaroyl-CoenzymeA (pCA-CoA) as the activated donor molecule and sinapyl alcohol as the preferred acceptor molecule. Grasses (C3and C4) were evaluated for cell wall characteristics; pCA, lignin, pCAT activity, and neutral sugar composition. All C3 and C4 grasses had measurable pCAT activity, however the pCAT activities did not follow the same pattern as the pCA incorporation into lignin as expected.
authors.affiliation: U.S. Dairy Forage Research Center, USDA-Agricultural Research Service, 1925 Linden Drive, Madison, WI 53706, USA. ronald.hatfield@ars.usda.gov
authors.forename: Ronald D
authors.initials: RD
authors.lastname: Hatfield
authors.forename: Jane M
authors.initials: JM
authors.lastname: Marita
authors.forename: Kenneth
authors.initials: K
authors.lastname: Frost
authors.forename: John
authors.initials: J
authors.lastname: Grabber
authors.forename: John
authors.initials: J
authors.lastname: Ralph
authors.forename: Fachuang
authors.initials: F
authors.lastname: Lu
authors.forename: Hoon
authors.initials: H
authors.lastname: Kim
mesh_terms: D000217:Acyltransferases / Q000378:metabolism*; D002473:Cell Wall / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D003373:Coumaric Acids / Q000737:chemistry / Q000378:metabolism; D008031:Lignin / Q000378:metabolism*; D013058:Mass Spectrometry; D015394:Molecular Structure; D010636:Phenols / Q000737:chemistry / Q000378:metabolism; D010666:Phenylpropionates / Q000737:chemistry / Q000378:metabolism; D006109:Poaceae / Q000145:classification / Q000201:enzymology / Q000378:metabolism*; D045868:Sorghum / Q000201:enzymology / Q000378:metabolism; D013379:Substrate Specificity; D003313:Zea mays / Q000201:enzymology / Q000378:metabolism
chemical_list: D003373:Coumaric Acids; D010636:Phenols; D010666:Phenylpropionates; C496130:sinapyl alcohol; D008031:Lignin; C010559:coniferyl alcohol; D000217:Acyltransferases