Field pathogenomics of Fusarium head blight reveals pathogen transcriptome differences due to host resistance.

Fusarium head blight (FHB), caused by Fusarium graminearum and other Fusarium species, is a detrimental disease that affects small grains such as wheat around the world. Management of FHB is difficult, and surveillance as well as a better understanding of pathogen aggressiveness is needed for improved control. F. graminearum disease severity varies depending on the resistance of the host genotype. In this study, we used the field pathogenomics method to investigate gene expression and population structure of isolates collected from wheat lines of varying resistance levels (susceptible, intermediate, and resistant) as well as an axenic control. Differential gene expression was found among isolates collected from different host genotypes. Candidate gene sets were identified for both F. graminearum infection of specific host genotypes and general infection to wheat. Population structure of isolates from different resistance level sources was the same, with all isolates belonging to the NA1 population.