Project description:Mycosphaerella graminicola is the causal agent of Mycosphaerella graminicola infection (STB) disease of wheat. Wheat genotypes vary in their response to this disease. Cultivar (cv.) Longbow is susceptible and cv. Flame is resistant to STB disease, with cv. Flame possessing the STB resistance locus Stb6 that confers resistance to pathogen strain IPO323. Gene expression profiling (conducted using Affymetrix wheat gene chip) identified transcripts that accumulate in leaves of both these wheat cultivars as an early response to M. graminicola strain IPO323 (at 24h post-treatment). At this initial time point, microscopic analysis verified that fungal spores had germinated, but not penetrated the leaves of both genotypes. Results showed that basal defence genes were activated in both the compatible and incompatible interactions. A subset of genes were identified that were more pathogen-responsive in the cv. Flame v. IPO323 incompatible interaction as compared to the cv. Longbow v. IPO323 compatible interaction, including defence genes such as peroxidases, beta-1,3-glucanase, annexin, chitinases, brassinosteroid-associated kinase 1 and a jasmonate-inducible protein.