The arms-race of plant-pathogen perception: from structural understanding to disease resistance
J. PAULUS (1), S. Brouwer (1), R. van der Hoorn (1), S. Kumari (2) (1) Department of Plant Sciences, University of Oxford, United Kingdom; (2) Max Planck Institute for Plant Breeding Research, Germany

Tomato secretes three papain-like cysteine proteases during immune responses: Rcr3, Pip1 and C14. Tomato-adapted pathogens secrete small effector proteins to inhibit the defence proteases. Avr2 secreted by the fungal pathogen Cladosporium fulvum inhibits Rcr3 and Pip1, but has a lower affinity to C14. Interestingly, the Avr2-Rcr3 protease-inhibitor complex is detected by plants carrying the Cf-2 resistance gene. Perception triggers a hypersensitive cell death response (HR) to stop invasion and providing resistance against C. fulvum. Despite intensive studies of these proteins, little is known about their molecular interaction, biochemical function and properties. A structural approach will be used to elucidate the molecular interaction between apoplastic proteases of tomato with different pathogen-derived inhibitors and with the Cf-2 immune receptor. In preparation for the crystallization studies, heterologous expression and purification of various proteases and inhibitors has been performed. Maturation of Rcr3 is achieved in vitro. The expression and purification of the glycosylated membrane protein Cf-2 remains the major challenge. The elucidation of structures of protease-inhibitor complexes will increase our understanding of the arms-race between pathogens and their host plants.

Abstract Number: P17-581
Session Type: Poster