An efficient protocol for inoculation of Fusarium graminearum in detached leaves of Arabidopsis

Fusarium graminearum is the main cause of Fusarium head blight, a fungal disease that reduces yield and affects the quality of wheat and other small grains. Genetic resistance is the ideal method for disease control; however, there are not yet cultivars with sufficient resistance levels to withstand an epidemic. Genetic engineering strategies such as gene silencing, host-induced gene silencing (HIGS), overexpression, and genome editing are promising, but many target genes need to be analyzed to find a suitable one. Arabidopsis thaliana is a model plant that is also susceptible to F. graminearum . Although this interaction was reported nearly two decades ago, consistent infection and symptoms are not always obtained. The availability of an efficient inoculation method is essential for studying plant-pathogen interaction. This work aimed at testing protocols for inoculating F. graminearum in detached leaves of A. thaliana which varied in inoculation site (leaf sides), wound (abrasion or hole injury), and inoculum type (mycelium agar disk or spore). We found that a mycelium agar disk placed on an abrasion injury at the adaxial leaf side was the most efficient (highest lesion size, incidence, and easiness to visualize the symptoms caused by the pathogen) method to inoculate F. graminearum in detached leaves of Arabidopsis.