Overexpression of the scopoletin biosynthetic pathway enhances lignocellulosic biomass processing

Lennart Hoengenaert; Marlies Wouters; Hoon Kim; Barbara De Meester; Kris Morreel; Steven Vandersyppe; Jacob Pollier; Sandrien Desmet; Geert Goeminne; John Ralph; Wout Boerjan; Ruben Vanholme

doi:10.1126/sciadv.abo5738

Overexpression of the scopoletin biosynthetic pathway enhances lignocellulosic biomass processing

Sci Adv. 2022 Jul 15;8(28):eabo5738. doi: 10.1126/sciadv.abo5738. Epub 2022 Jul 13.

Authors

Lennart Hoengenaert^{1

2}, Marlies Wouters^{1

2}, Hoon Kim³, Barbara De Meester^{1

2}, Kris Morreel^{1

2}, Steven Vandersyppe^{1

2

4}, Jacob Pollier^{1

2

4}, Sandrien Desmet^{1

2

4}, Geert Goeminne^{1

2

4}, John Ralph³, Wout Boerjan^{1

2}, Ruben Vanholme^{1

2}

Affiliations

¹ Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.
² Center for Plant Systems Biology, VIB, Ghent, Belgium.
³ Department of Biochemistry and U.S. Department of Energy's Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, WI, USA.
⁴ VIB Metabolomics Core, Ghent, Belgium.

Abstract

Lignin is the main factor limiting the enzymatic conversion of lignocellulosic biomass into fermentable sugars. To reduce the recalcitrance engendered by the lignin polymer, the coumarin scopoletin was incorporated into the lignin polymer through the simultaneous expression of FERULOYL-CoA 6'-HYDROXYLASE 1 (F6'H1) and COUMARIN SYNTHASE (COSY) in lignifying cells in Arabidopsis. The transgenic lines overproduced scopoletin and incorporated it into the lignin polymer, without adversely affecting plant growth. About 3.3% of the lignin units in the transgenic lines were derived from scopoletin, thereby exceeding the levels of the traditional p-hydroxyphenyl units. Saccharification efficiency of alkali-pretreated scopoletin-overproducing lines was 40% higher than for wild type.