title: Maize Tricin-Oligolignol Metabolites and Their Implications for Monocot Lignification.
abstract: Lignin is an abundant aromatic plant cell wall polymer consisting of phenylpropanoid units in which the aromatic rings display various degrees of methoxylation. Tricin [5,7-dihydroxy-2-(4-hydroxy-3,5-dimethoxyphenyl)-4H-chromen-4-one], a flavone, was recently established as a true monomer in grass lignins. To elucidate the incorporation pathways of tricin into grass lignin, the metabolites of maize (Zea mays) were extracted from lignifying tissues and profiled using the recently developed 'candidate substrate product pair' algorithm applied to ultra-high-performance liquid chromatography and Fourier transform-ion cyclotron resonance-mass spectrometry. Twelve tricin-containing products (each with up to eight isomers), including those derived from the various monolignol acetate and p-coumarate conjugates, were observed and authenticated by comparisons with a set of synthetic tricin-oligolignol dimeric and trimeric compounds. The identification of such compounds helps establish that tricin is an important monomer in the lignification of monocots, acting as a nucleation site for starting lignin chains. The array of tricin-containing products provides further evidence for the combinatorial coupling model of general lignification and supports evolving paradigms for the unique nature of lignification in monocots.
authors.affiliation: Department of Energy Great Lakes Bioenergy Research Center, Wisconsin Energy Institute (W.L., F.L., J.Ra.), Department of Biological System Engineering (W.L., J.Ra.), and Department of Biochemistry (F.L., J.Ra.), University of Wisconsin, Madison, Wisconsin 53726;Department of Plant Systems Biology, Vlaams Instituut voor Biotechnologie, B-9052 Ghent, Belgium (K.M., W.Vo., W.B.);Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium (K.M., W.Vo., W.B.);State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, 510641 Guangzhou, People's Republic of China (F.L.);Instituto de Recursos Naturales y Agrobiologia de Sevilla, Consejo Superior de Investigaciones Científicas, 41012 Seville, Spain (J.Re., J.C.d.R.); andDepartment of Microbiology and Cell Science, Institute of Food and Agricultural Sciences (IFAS), and Genetics Institute, University of Florida, Gainesville, Florida 32611 (W.Ve.).
authors.forename: Wu
authors.identifier: 0000-0002-0677-3085
authors.initials: W
authors.lastname: Lan
authors.affiliation: Department of Energy Great Lakes Bioenergy Research Center, Wisconsin Energy Institute (W.L., F.L., J.Ra.), Department of Biological System Engineering (W.L., J.Ra.), and Department of Biochemistry (F.L., J.Ra.), University of Wisconsin, Madison, Wisconsin 53726;Department of Plant Systems Biology, Vlaams Instituut voor Biotechnologie, B-9052 Ghent, Belgium (K.M., W.Vo., W.B.);Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium (K.M., W.Vo., W.B.);State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, 510641 Guangzhou, People's Republic of China (F.L.);Instituto de Recursos Naturales y Agrobiologia de Sevilla, Consejo Superior de Investigaciones Científicas, 41012 Seville, Spain (J.Re., J.C.d.R.); andDepartment of Microbiology and Cell Science, Institute of Food and Agricultural Sciences (IFAS), and Genetics Institute, University of Florida, Gainesville, Florida 32611 (W.Ve.).
authors.forename: Kris
authors.identifier: 0000-0002-3121-9705
authors.initials: K
authors.lastname: Morreel
authors.affiliation: Department of Energy Great Lakes Bioenergy Research Center, Wisconsin Energy Institute (W.L., F.L., J.Ra.), Department of Biological System Engineering (W.L., J.Ra.), and Department of Biochemistry (F.L., J.Ra.), University of Wisconsin, Madison, Wisconsin 53726;Department of Plant Systems Biology, Vlaams Instituut voor Biotechnologie, B-9052 Ghent, Belgium (K.M., W.Vo., W.B.);Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium (K.M., W.Vo., W.B.);State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, 510641 Guangzhou, People's Republic of China (F.L.);Instituto de Recursos Naturales y Agrobiologia de Sevilla, Consejo Superior de Investigaciones Científicas, 41012 Seville, Spain (J.Re., J.C.d.R.); andDepartment of Microbiology and Cell Science, Institute of Food and Agricultural Sciences (IFAS), and Genetics Institute, University of Florida, Gainesville, Florida 32611 (W.Ve.).
authors.forename: Fachuang
authors.initials: F
authors.lastname: Lu
authors.affiliation: Department of Energy Great Lakes Bioenergy Research Center, Wisconsin Energy Institute (W.L., F.L., J.Ra.), Department of Biological System Engineering (W.L., J.Ra.), and Department of Biochemistry (F.L., J.Ra.), University of Wisconsin, Madison, Wisconsin 53726;Department of Plant Systems Biology, Vlaams Instituut voor Biotechnologie, B-9052 Ghent, Belgium (K.M., W.Vo., W.B.);Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium (K.M., W.Vo., W.B.);State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, 510641 Guangzhou, People's Republic of China (F.L.);Instituto de Recursos Naturales y Agrobiologia de Sevilla, Consejo Superior de Investigaciones Científicas, 41012 Seville, Spain (J.Re., J.C.d.R.); andDepartment of Microbiology and Cell Science, Institute of Food and Agricultural Sciences (IFAS), and Genetics Institute, University of Florida, Gainesville, Florida 32611 (W.Ve.).
authors.forename: Jorge
authors.identifier: 0000-0003-2728-7331
authors.initials: J
authors.lastname: Rencoret
authors.affiliation: Department of Energy Great Lakes Bioenergy Research Center, Wisconsin Energy Institute (W.L., F.L., J.Ra.), Department of Biological System Engineering (W.L., J.Ra.), and Department of Biochemistry (F.L., J.Ra.), University of Wisconsin, Madison, Wisconsin 53726;Department of Plant Systems Biology, Vlaams Instituut voor Biotechnologie, B-9052 Ghent, Belgium (K.M., W.Vo., W.B.);Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium (K.M., W.Vo., W.B.);State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, 510641 Guangzhou, People's Republic of China (F.L.);Instituto de Recursos Naturales y Agrobiologia de Sevilla, Consejo Superior de Investigaciones Científicas, 41012 Seville, Spain (J.Re., J.C.d.R.); andDepartment of Microbiology and Cell Science, Institute of Food and Agricultural Sciences (IFAS), and Genetics Institute, University of Florida, Gainesville, Florida 32611 (W.Ve.).
authors.forename: José
authors.identifier: 0000-0002-3040-6787
authors.initials: J
authors.lastname: Carlos Del Río
authors.affiliation: Department of Energy Great Lakes Bioenergy Research Center, Wisconsin Energy Institute (W.L., F.L., J.Ra.), Department of Biological System Engineering (W.L., J.Ra.), and Department of Biochemistry (F.L., J.Ra.), University of Wisconsin, Madison, Wisconsin 53726;Department of Plant Systems Biology, Vlaams Instituut voor Biotechnologie, B-9052 Ghent, Belgium (K.M., W.Vo., W.B.);Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium (K.M., W.Vo., W.B.);State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, 510641 Guangzhou, People's Republic of China (F.L.);Instituto de Recursos Naturales y Agrobiologia de Sevilla, Consejo Superior de Investigaciones Científicas, 41012 Seville, Spain (J.Re., J.C.d.R.); andDepartment of Microbiology and Cell Science, Institute of Food and Agricultural Sciences (IFAS), and Genetics Institute, University of Florida, Gainesville, Florida 32611 (W.Ve.).
authors.forename: Wannes
authors.identifier: 0000-0001-9254-1557
authors.initials: W
authors.lastname: Voorend
authors.affiliation: Department of Energy Great Lakes Bioenergy Research Center, Wisconsin Energy Institute (W.L., F.L., J.Ra.), Department of Biological System Engineering (W.L., J.Ra.), and Department of Biochemistry (F.L., J.Ra.), University of Wisconsin, Madison, Wisconsin 53726;Department of Plant Systems Biology, Vlaams Instituut voor Biotechnologie, B-9052 Ghent, Belgium (K.M., W.Vo., W.B.);Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium (K.M., W.Vo., W.B.);State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, 510641 Guangzhou, People's Republic of China (F.L.);Instituto de Recursos Naturales y Agrobiologia de Sevilla, Consejo Superior de Investigaciones Científicas, 41012 Seville, Spain (J.Re., J.C.d.R.); andDepartment of Microbiology and Cell Science, Institute of Food and Agricultural Sciences (IFAS), and Genetics Institute, University of Florida, Gainesville, Florida 32611 (W.Ve.).
authors.forename: Wilfred
authors.identifier: 0000-0002-4582-3436
authors.initials: W
authors.lastname: Vermerris
authors.affiliation: Department of Energy Great Lakes Bioenergy Research Center, Wisconsin Energy Institute (W.L., F.L., J.Ra.), Department of Biological System Engineering (W.L., J.Ra.), and Department of Biochemistry (F.L., J.Ra.), University of Wisconsin, Madison, Wisconsin 53726;Department of Plant Systems Biology, Vlaams Instituut voor Biotechnologie, B-9052 Ghent, Belgium (K.M., W.Vo., W.B.);Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium (K.M., W.Vo., W.B.);State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, 510641 Guangzhou, People's Republic of China (F.L.);Instituto de Recursos Naturales y Agrobiologia de Sevilla, Consejo Superior de Investigaciones Científicas, 41012 Seville, Spain (J.Re., J.C.d.R.); andDepartment of Microbiology and Cell Science, Institute of Food and Agricultural Sciences (IFAS), and Genetics Institute, University of Florida, Gainesville, Florida 32611 (W.Ve.) woboe@psb.vib-ugent.be jralph@wisc.edu.
authors.forename: Wout
authors.identifier: 0000-0003-1495-510X
authors.initials: W
authors.lastname: Boerjan
authors.affiliation: Department of Energy Great Lakes Bioenergy Research Center, Wisconsin Energy Institute (W.L., F.L., J.Ra.), Department of Biological System Engineering (W.L., J.Ra.), and Department of Biochemistry (F.L., J.Ra.), University of Wisconsin, Madison, Wisconsin 53726;Department of Plant Systems Biology, Vlaams Instituut voor Biotechnologie, B-9052 Ghent, Belgium (K.M., W.Vo., W.B.);Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium (K.M., W.Vo., W.B.);State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, 510641 Guangzhou, People's Republic of China (F.L.);Instituto de Recursos Naturales y Agrobiologia de Sevilla, Consejo Superior de Investigaciones Científicas, 41012 Seville, Spain (J.Re., J.C.d.R.); andDepartment of Microbiology and Cell Science, Institute of Food and Agricultural Sciences (IFAS), and Genetics Institute, University of Florida, Gainesville, Florida 32611 (W.Ve.) woboe@psb.vib-ugent.be jralph@wisc.edu.
authors.forename: John
authors.identifier: 0000-0002-6093-4521
authors.initials: J
authors.lastname: Ralph
mesh_terms: D000215:Acylation; D053898:Biosynthetic Pathways; D002473:Cell Wall / Q000737:chemistry / Q000378:metabolism; D047309:Flavones / Q000737:chemistry / Q000378:metabolism*; D005419:Flavonoids / Q000737:chemistry / Q000378:metabolism*; D008031:Lignin / Q000737:chemistry / Q000378:metabolism*; D011108:Polymers / Q000737:chemistry / Q000378:metabolism; D003313:Zea mays / Q000737:chemistry / Q000378:metabolism*
chemical_list: D047309:Flavones; D005419:Flavonoids; D011108:Polymers; D008031:Lignin; C017769:tricin; C043562:flavone