Gene-edited poplar trees that produce less lignin could improve the efficiency and environmental impact of wood processing.

Lignin is one of wood’s three main components, but it is left over as a by-product during processing. Lowering wood’s lignin content would reduce the waste generated during pulping, as well as the energy used in the process.

Red and green stems tied together in bundles

Source: © Daniel B. Sulis et al, Science 2023

Stem segments from the Crispr-edited and wild-type poplars

Now researchers from the US and China have used gene-editing tools to grow 174 poplar variants with increased carbohydrate-to-lignin ratios.

By using a predictive model to explore nearly 70,000 multigenic editing strategies for 21 lignin biosynthesis genes, the researchers created Crispr-edited poplars with higher carbohydrate-to-lignin ratios than has previously been achieved by editing single genes or gene families. The technique could reduce the trees’ lignin content by almost 50%, with carbohydrate-to-lignin ratios increased up to 228% that of non-edited trees. The researchers observed no off-target edits.

The team estimates that using gene-edited wood in pulp production could decrease the global warming impact of the process by up to 20%.