A R. solani AG8 Inhibitor I9 domain containing protein induces cell death when transiently expressed in N. benthamiana leaves. (a) Images acquired 5 days after agroinfiltration. (b) Lesion diameter on transiently transformed leaves without R. solani inoculation (light grey), transiently transformed leaves three days following R. solani AG8 inoculation (dark grey). Asterisks indicate values significantly different to the corresponding mock or R. solani inoculated GFP sample according to Dunnett’s test. Average values from three biological replicates is shown with standard error. The experiment was repeated three times with similar results. (c) Number of secreted proteins containing the Inhibitor I9 domain in fungi with different lifestyles. Abbreviations for fungal species names described in Supplementary Data S3b.