Genetic editing of wood for sustainability

Trees engineered to have less lignin could make paper production less polluting Lignin, a polymer formed by phenylpropanoid units, is responsible for the rigidity and resistance of the lignocellulosic cells in wood ( 1 ). In conventional pulp production, lignin must be cleaved and dissolved under alkaline conditions or first sulfonated to make it soluble so that fiber separation can take place. Delignification processes are reagent and energy intensive, leading to costly chemical recovery ( 2 ). Pulp treatment methods to remove wood extractives such as lignin have been developed, but they are not yet economically viable at an industrial scale ( 3 ). On page 216 of this issue, Sulis et al . ( 4 ) present a multiplex CRISPR genome editing strategy to modify lignin biosynthesis genes and reduce the lignin content of Populus trichocarpa , a species of poplar. This approach could provide a solution to a key operational constraint in the paper and pulp industry.