April 2013

Engineering Better Plants for Biofuels

New approach decreases lignin content in plant secondary cell wall.

Click to enlarge photo. Enlarge Photo

Image courtesy of Joint BioEnergy Institute

To optimize plant feedstocks for bioenergy, researchers engineered a viable plant (#89) whose cell walls contain less lignin—a robust, degradation-resistant structural polymer—and more polysaccharides, or sugars that can be converted into biofuels (lower panel).

The Science

Polysaccharides (complex chains of sugar) in plant cell walls are great carbon energy sources for biofuel production. However, these sugars are embedded in lignin, a structural biopolymer that gives plants their required rigidity but also impedes enzymatic release of simple sugars. Previous attempts to reduce lignin content in plant vascular tissue were imprecise and impaired plant growth due to loss of vessel integrity. Researchers have developed a new approach to decrease lignin content, increase the yield of fuel sugars, and still ensure plant tissue integrity.

The Impact

Such an approach demonstrates promise for developing bioenergy feedstocks optimized for more efficient deconstruction and sugar release.

Summary

In this work, researchers engineered lignin and polysaccharide biosynthesis pathways in a cell-type specific manner. In the naturally lignin-rich fiber cells, lignin was significantly reduced, and in vessel cells, polysaccharide content was much greater. The resulting plants were viable and grew normally. When biomass from these engineered plants was subjected to enzymatic digestion, more sugars were released than in wild type plants because of both the increased polysaccharide deposition and reduced lignin content in the cell walls.

Contact

Dominique Loque
Joint BioEnergy Institute, Physical Biosciences Division, Lawrence Berkeley National Laboratory, One Cyclotron Road
Berkeley, CA
dloque@lbl.gov

Funding

This work, conducted by the U.S. Department of Energy (DOE) Joint BioEnergy InstituteExternal link, is supported by the Office of Biological and Environmental Research within the DOE Office of Science through contract DE-AC02-05CH11231 between Lawrence Berkeley National Laboratory and DOE.

Publications

Yang, F., et al. “Engineering secondary cell wall deposition in plants.” Plant Biotech. J. 11 (3), 325–335 (2013). [DOI: 10.1111/pbi.12016]

Highlight Categories

Program: BER, BRCs, BSSD

Performer/Facility: University, DOE Laboratory

Last modified: 1/17/2014 4:43:20 PM