Fossil resources are deeply embedded into our current economic system. However, the large scale use of fossil resources is taxing for the environment due to the emission of greenhouse gasses, which are considered to be causative agents for climate change. Plant cell walls offer an abundant and renewable resource for energy as well as materials. These cell walls contain sugars in the form of polymers. These can be degraded to simple sugars that subsequently can be fermented into valuable products such as bio-fuels. Unfortunately, the aromatic polymer lignin hinders the access to these sugars. Poplar is a potent biomass crop that can grow efficiently in temperate climates and only requires marginal soils. In order to increase the sugar yield of poplar, we aim to reduce the amount of lignin through genetic engineering. A gene (CSE) in the lignin biosynthesis pathway
will be knocked out by the efficient CRISPR/Cas9 technique. The knocked out gene will be complemented in vessels only, to restore lignin biosynthesis in vessels. This is required for mechanical support and water transport and normal development of the poplars. This objective will be supported by studying the lignin biosynthetic pathway more in depth. Research towards the altered metabolism of these transgenic poplars will be performed to gain more insight in the function of the knocked out gene and the properties of these trees. The project will deliver poplar trees with improved sugar yields and normal development.