Résumé
Mycosphaerella fijiensis is a hemibiotrophic ascomycete causing the black leaf streak disease (BLSD) of banana that is commonly called Black Sigatoka disease. BLSD is regarded as the most economically important threat to banana production and affects almost all edible banana cultivars grown worldwide. The M. fijiensis infection cycle goes through a long symptomless phase in the plant, during which the fungus grows in the mesophyll intercellular space, before the appearance of disease symptoms in the form of necrotic areas. Despite the economical importance of the BLSD disease, little is known about the physiological and molecular events occurring during the pathogen life cycle in the plant and on the genetic bases of resistance. To better characterize the interaction, we first established a bioassay based on detached leaves maintained in vitro, associated to phenotyping with an image analysis software package (Visilog® Noesis). This allows higher throughput phenotyping and more precise monitoring of the reaction of banana accessions to M. fijiensis strains. In a preliminary experiment, we also analysed transcriptome changes in three accessions showing contrasted reactions to M. fijiensis, using RNA-Seq. First results of this analysis will be presented. (Texte intégral)