04 April 2014
Nature: Lignin is an organic polymer that helps gives trees and other plants their structural strength. When trees are to be pulped to make paper or biofuels, the first step involves dissolving lignin, which requires highly concentrated chemicals at high temperatures. Attempts over the past several decades to reduce the amount of lignin in plants, or to engineer the chemical to be easier to dissolve, have not been successful. Now John Ralph of the University of Wisconsin–Madison and his colleagues have succeeded in producing an easier-dissolving lignin in poplar trees. They incorporated a gene that replaces one of the components of lignin with a similar molecule that forms an ester bond, which is much easier to break with milder chemicals at lower temperatures. The trees have undergone field testing in greenhouses, but have yet to be tested in real-world conditions.