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.