Monolignol ferulate conjugates are naturally incorporated into plant lignins

Steven D Karlen; Chengcheng Zhang; Matthew L Peck; Rebecca A Smith; Dharshana Padmakshan; Kate E Helmich; Heather C A Free; Seonghee Lee; Bronwen G Smith; Fachuang Lu; John C Sedbrook; Richard Sibout; John H Grabber; Troy M Runge; Kirankumar S Mysore; Philip J Harris; Laura E Bartley; John Ralph

doi:10.1126/sciadv.1600393

Monolignol ferulate conjugates are naturally incorporated into plant lignins

Sci Adv. 2016 Oct 14;2(10):e1600393. doi: 10.1126/sciadv.1600393. eCollection 2016 Oct.

Authors

Steven D Karlen¹, Chengcheng Zhang², Matthew L Peck², Rebecca A Smith¹, Dharshana Padmakshan³, Kate E Helmich¹, Heather C A Free⁴, Seonghee Lee⁵, Bronwen G Smith⁶, Fachuang Lu¹, John C Sedbrook⁷, Richard Sibout⁸, John H Grabber⁹, Troy M Runge¹⁰, Kirankumar S Mysore¹¹, Philip J Harris¹², Laura E Bartley², John Ralph¹

Affiliations

¹ Department of Energy Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, University of Wisconsin-Madison, Madison, WI 53726, USA.; Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA.
² Department of Microbiology and Plant Biology, The University of Oklahoma, Norman, OK 73019, USA.
³ Department of Energy Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, University of Wisconsin-Madison, Madison, WI 53726, USA.
⁴ School of Biological Sciences, The University of Auckland, Auckland, New Zealand.; School of Chemical Sciences, The University of Auckland, Auckland, New Zealand.
⁵ Department of Horticultural Science, IFAS (Institute of Food and Agricultural Sciences) Gulf Coast Research and Education Center, University of Florida, 14625 County Road 672, Wimauma, FL 33598, USA.
⁶ School of Chemical Sciences, The University of Auckland, Auckland, New Zealand.
⁷ Department of Energy Great Lakes Bioenergy Research Center, School of Biological Sciences, Illinois State University, Normal, IL 61790, USA.
⁸ Institut National de la Recherche Agronomique and AgroParisTech, Institut Jean-Pierre Bourgin UMR 1318, Saclay Plant Science, 78000 Versailles, France.
⁹ U.S. Dairy Forage Research Center, Agricultural Research Service, U.S. Department of Agriculture, 1925 Linden Drive West, Madison, WI 53706, USA.
¹⁰ Department of Energy Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, University of Wisconsin-Madison, Madison, WI 53726, USA.; Department of Biological Systems Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA.
¹¹ Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, OK 73401, USA.
¹² School of Biological Sciences, The University of Auckland, Auckland, New Zealand.

Abstract

Angiosperms represent most of the terrestrial plants and are the primary research focus for the conversion of biomass to liquid fuels and coproducts. Lignin limits our access to fibers and represents a large fraction of the chemical energy stored in plant cell walls. Recently, the incorporation of monolignol ferulates into lignin polymers was accomplished via the engineering of an exotic transferase into commercially relevant poplar. We report that various angiosperm species might have convergently evolved to natively produce lignins that incorporate monolignol ferulate conjugates. We show that this activity may be accomplished by a BAHD feruloyl-coenzyme A monolignol transferase, OsFMT1 (AT5), in rice and its orthologs in other monocots.

Keywords: BAHD transferase; DFRC; GC-MS; Grasses; lignin; monocot; monolignol; phylogenetic tree; rice; transgenic.