Horizon Europe LigMo project: A genetic engineering approach to lignifying moss cell walls to develop a new wood-like biomass.

In the current context of climate change, the transition from an oil-based economy to more sustainable alternatives is a top priority. Wood is one of the most abundant renewable resources and has a consolidated role in the furniture, construction, paper, and energy sectors. Because of this, demand for wood is increasing as policies around the world promote wood-based energy generation, which risks further deforestation and the conversion of diverse forests to monoculture plantations.

The industrial applications of wood depend on its composition, specifically that of lignin in the secondary cell wall (SCW). Although much is known about lignification through extensive research in Arabidopsis thaliana and other vascular plants, there are still gaps in knowledge regarding the initiation and control of lignin polymerization that remain to be addressed in order to delineate the core set of genes associated with lignin formation.

Along these lines, the long-term objective of this proposal is to engineer innovative wood-like biomass by introducing lignin biosynthetic genes into fast-growing mosses to establish new types of biomaterials, potentially reducing the use of wood in certain applications and alleviating growing pressures on forests. Mosses are terrestrial plants that lack lignified vascular tissues but have genes homologous to most steps of lignin biosynthesis.

Our hypothesis is that the lack of lignin in mosses makes them potential model systems for determining how lignin polymerization and SCW formation occur in plants. In this proposal, we will systematically transform the model moss Physcomitrium patens with vascular plant genes until canonical lignin is observed in its cell wall. The results of this work will pave the way for innovative biomass sources and potentially provide insights into how to tailor lignin composition and transfer such knowledge to existing agricultural biomass. This approach also promises to become a powerful tool for basic research in the study of lignin.