The role of suberin biopolymers for pathogen resistance

Late blight, caused by the oomycete Phytophthora infestans, is a devastating disease of potato
(Solanum tuberosum). Without appropriate control measures, potato fields can be destroyed within a
couple of weeks. Both cost of yield loss and of control measures are reported to be more than 6 billion
dollars annually, making late blight economically the most important foliar disease. P. infestans has a
hemibiotrophic lifestyle, requiring living tissue during the first stages of development and inducing cell
death during the necrotrophic phase. The formation of necrotic lesions of potato leaves correlates with
the deposition of suberin, a lipophilic biopolymer that acts as a transpiration barrier. It is widely accepted
that suberin formation around lesions or wound sites is an important defense response, however,
functional data are missing. In the proposed project, the role of suberin for pathogen defense will be
analyzed by generating and characterizing CRISPR-Cas9-edited potato plants defective in suberin
formation. In addition, pathogen-responsive, TAL-effector-mediated expression of a metabolic pathway
consisting of three suberin biosynthesis enzymes and a suberin transporter will reveal whether
enhanced suberin formation around P. infestans-induced lesions contributes to defense against the
pathogen.