Title: SbCOMT (Bmr12) is involved in the biosynthesis of tricin-lignin in sorghum

Abstract

Lignin in plant biomass represents a target for engineering strategies towards the development of a sustainable bioeconomy. In addition to the conventional lignin monomers, namely p-coumaryl, coniferyl and sinapyl alcohols, tricin has been shown to be part of the native lignin polymer in certain monocot species. Because tricin is considered to initiate the polymerization of lignin chains, elucidating its biosynthesis and mechanism of export to the cell wall constitute novel challenges for the engineering of bioenergy crops. Late steps of tricin biosynthesis require two methylation reactions involving the pathway intermediate selgin. It has recently been demonstrated in rice and maize that caffeate O-methyltransferase (COMT) involved in the synthesis syringyl (S) lignin units derived from sinapyl alcohol also participates in the synthesis of tricin in planta. In this work, we validate in sorghum (Sorghum bicolor L.) that the O-methyltransferase responsible for the production of S lignin units (SbCOMT / Bmr12) is also involved in the synthesis of lignin-linked tricin. In particular, we show that biomass from the sorghum bmr12 mutant contains lower level of tricin incorporated into lignin, and that SbCOMT can methylate the tricin precursors luteolin and selgin. Our genetic and biochemical data point toward a general mechanism whereby COMTmore » is involved in the synthesis of both tricin and S lignin units.« less

Authors:

Eudes, Aymerick; Dutta, Tanmoy; Deng, Kai; Jacquet, Nicolas; Sinha, Anagh; Benites, Veronica T.; Baidoo, Edward E. K.; Richel, Aurore; Sattler, Scott E.; Northen, Trent R.; Singh, Seema; Simmons, Blake A.; Loqué, Dominique

• Search DOE PAGES for author "Loqué, Dominique"
• Search DOE PAGES for ORCID "0000-0002-2060-6611"

Publication Date:

Thu Jun 08 00:00:00 EDT 2017

Research Org.:

Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)

Sponsoring Org.:

USDOE Office of Science (SC)

OSTI Identifier:

1361947

Alternate Identifier(s):

OSTI ID: 1379876

Grant/Contract Number:  

AC02-05CH11231

Resource Type:

Published Article

Journal Name:

PLoS ONE

Additional Journal Information:

Journal Name: PLoS ONE Journal Volume: 12 Journal Issue: 6; Journal ID: ISSN 1932-6203

Publisher:

Public Library of Science

Country of Publication:

United States

Language:

English

Subject:

59 BASIC BIOLOGICAL SCIENCES