The rice Magnaporthe grisea pathosystem as a research model

Rice blast caused by Magnaporthe grisea is the most important fungal disease of rice, and greatly limits production, particularly in Latin America. The resistance of a new variety is in general quickly overcome by the pathogen, and the cost of fungicides is prohibitive for most rice growers. Rice blast is a research model for numerous international research teams. A large collection of isolates has been assembled and is used in studies of M. grisea population structures and their evolution. This work has been conducted at different levels: worldwide, European, Chinese and fertile populations of Asia. The mechanisms of interaction have also been studied. New resistance and virulence genes have been mapped. In a collaboration with an Aventis-CNRS (National Centre for Scientific Research) research group, one of the avirulence genes has been cloned, and others are now being studied. The cloning of a resistance gene is currently under way. Genomics is now being used to identify and clone genes involved in the defence mechanisms of rice. (Texte intégral