KSEF RDE: Investigating the Role of the Cuticle in Resistance to Foliar Plant Pathogens

The plant cuticle is a hydrophobic layer that covers the aerial surface of plants and forms the first line of contact with the environment. Plant cuticle, which is composed of cutin and cuticular wax, was primarily thought to serve as a physical barrier to pathogen ingress. However, recent studies have demonstrated that cuticle may also playa signaling role and participate in innate immune response. For example, exogenous application of cutin monomers confers enhanced resistance to several fungal pathogens. Furthermore, plants containing defective cuticles show enhanced resistance to fungal pathogens and appear to produce a fungitoxic diffusate, which possibly provides a first powerful line of defense against invasion by fungal pathogens. This proposal aims to analyze biochemical changes in cutin and cuticular wax composition of tobacco during compatible and incompatible interactions with Peronospora, Thanatephorus, and Colletotrichum. Long-term aim of this proposal will be to isolate cuticle-derived compounds that confer broad-spectrum resistance in crop plants. We anticipate that our research findings will help us to develop alternative disease controls that are less costly and less harmful to the environment and human health than the chemical fungicides that are currently used.