Identification of Candidate Effector Proteins from Fusarium graminearum during Infection of Arabidopsis thaliana Using Proximity-Dependant Biotin Identification (BioID)

Abstract

Fusarium graminearum is a fungal pathogen that causes Fusarium head blight (FHB) in cereal crops. Identifying proteins that are secreted from pathogens to overcome plant defenses and cause disease, collectively known as effectors, can reveal new targets for fungicides or other control measures. Proximity-dependent biotin identification (BioID) was used to identify potential effector proteins secreted in planta by F. graminearum during the infection of Arabidopsis seedlings. BioID analysis revealed over 300 proteins from F. graminearum, of which 99 were considered to be candidate effector proteins (CEPs). A subset of CEPs was functionally characterized in wheat. Assays examining the ability of a CEP to induce cell death or affect the growth of a bacterial pathogen were performed to determine their role in plant defenses. The expression of four CEPs in wheat were found to alter bacterial growth, supporting their putative role as effector proteins promoting infection by F. graminearum.