Identifying the Fusarium effector proteases that play a role in pathogenesis in wheat

IS-MPMI XIV Congress Abstract of Poster Presentations

FHB disease in cereal crops occurs just after crop anthesis and goes on to reduce grain yield, quality and safety. Current FHB control measures are complex but inadequate, involving deploying partially resistant cultivars, using partially effective fungicides and altering agricultural
practices. Therefore, there is an urgent need to develop alternate, more robust strategies to control the infection. Plants can detect disease-causing pathogens and then activate robust and highly coordinated defense responses that ultimately lead to localized cell death to stop the invader. To detect pathogens, plants use sensor proteins that are modified by enzymes that pathogens secrete during the infection process. If the enzymes secreted by the pathogens are identified, the sensor proteins in the plants can be engineered to activate the defense responses. Here we identify two target enzymes secreted by the fungal pathogen Fusarium graminearum that are serine-type endoproteases. We identify these proteases [Trypsin Precursor Protein 1 (FgTPP1) and extracellular metalloproteinase 1 (FgMEP1)] are likely to be critical for virulence as the loss of
function for each gene in Fusarium graminearum cause delayed infection/reduced fungal biomass in wheat spikes. The identification of these proteases offers the first insights on the significance of secreted proteins in F. graminearum infection and can be used to engineer the sensor proteins in plants to trigger the defense responses in wheat.