Lignocellulose biomass such as trees and large-sized grasses is indispensable for establishing sustainable societies. Trees are essential for producing of wood-based materials and paper, which account for half of the total tree lignocellulose biomass consumption, while the other half is for burning. A significant part of the tree biomass used for fuel depends on natural forest logging. Therefore, a reduction of natural deforestation and exploitation of high-productivity biomass are strongly required for sustainable development in harmony with environmental conservation. Large-sized grasses greatly surpass trees in terms of lignocellulose biomass productivity and therefore improvement of grass lignocellulose usability, for example improvement of lignin content and simplification of lignin structures, is critically important. In this context, we produced transgenic plants with increased lignin content, which should be beneficial for the augmentation of heating values and solid fuel use of biomass, using rice as a model of grass biomass plants. We also generated transgenic rice lines with increased content of each of the three aromatic units of lignins (i.e., p-hydroxyphenyl, guaiacyl, and syringyl units). This helped to simplify the composition of lignin-derived aromatic products. These strategies are also applicable for the augmentation of lignin content and simplification of lignin structures in large grasses. In-depth lignin analyses of transgenic rice plants suggested that grasses contain a biosynthetic pathway that produces the grass-specific γ-p-coumaroylated monolignols.

Grass lignin metabolic engineering for primary lignin valorization

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.