Early signal transduction events in specific plant disease resistance.

Gene-for-gene disease resistance in plants is initiated by highly specific molecular recognition processes, which often lead to a cell-death phenotype termed the hypersensitive response (HR). Recent studies have yielded insight into recognition events, and have begun to explain why the virulence and avirulence activities of pathogen effector molecules often appear to be linked. The nucleotide-binding (NB)-leucine-rich repeat (LRR) proteins appear to be central to both recognition and the activation of defence responses. New structure-function studies suggest that intramolecular interactions are important in the regulation of these proteins.