P-587 - Investigating mycotoxin biosynthesis and infection strategies in Fusarium graminearum with proteomic approaches

Fusarium graminearum causes Fusarium head blight in cereal crops and contaminates grain with trichothecene mycotoxins like deoxynivalenol (DON), which the FDA strictly regulates. We are applying proteomics to identify protein-protein interactions (PPI) that regulate DON biosynthesis and infection-related processes in F. graminearum. DON production is controlled by the trichothecene (TRI) biosynthetic gene cluster, with many of the TRI enzymes localizing to a reorganized endoplasmic reticulum membrane called the “toxisome”. To understand the PPIs that regulate TRI enzyme dynamics, we are utlizing a proximity labeling approach. We have generated several F. graminearum strains expressing TRI proteins fused to the biotin ligase ultraID. Interacting proteins are biotinylated, isolated using streptavidin enrichment, and identified using LC-MS/MS. Novel TRI-interacting proteins will be functionally characterized for their role in mycotoxin production and could lead to new strategies to inhibit DON biosynthesis. We are also investigating detached leaves as a model for understanding infection-related processes. Lesions were isolated from inoculated leaves over a time course and LC-MS/MS was used to quantify global and phospho-proteome dynamics in Fusarium. Various secreted proteins and transcription factors were differentially expressed at distinct stages, suggesting specific roles during early and late infection. Together, these projects will characterize the strategies that this cereal killer uses to attack its hosts.