Designing Low Lignin, High Biomass Yielding Plants
The major barrier to the efficient conversion of biomass from plant feedstocks to biofuels is breaking down the plant cell wall so that the sugars locked within can be released. This barrier is due to the presence of lignin, a complex compound that cross links the walls and provides rigidity to the plant. Plants that are genetically modified to have less lignin can be broken down more easily, but often these plants show severely stunted growth. Plants have a stress hormone (salicylic acid (SA)) that is known to impact plant growth and development and whose levels are inversely proportional to lignin levels. Researchers at the DOE BioEnergy Science Center (BESC) have found that genetically removing SA from Arabidopsis plants that were also modified to produce low levels of lignin restores normal growth to these plants while maintaining low lignin content. These results support the hypothesis that low lignin, high biomass yielding plants can be engineered to produce sustainable biofeedstocks for biofuel production.
Gallego-Giraldo, L., L. Escamilla-Trevino, L. A. Jackson, and R. A. Dixon. 2011. “Salicylic Acid Mediates the Reduced Growth of Lignin Down-Regulated Plants,” Proceedings of the National Academy of Sciences of the United States of America 108(51), 20814-19. DOI: 10.1073/pnas.1117873108.