Differential Gene Expression in Fusarium Head Blight Pathogens Facilitates Root Infection of Wheat, Maize, and Soybean

Global food security relies on wheat, maize, and soybean, yet their cultivation faces escalating threats from Fusarium head blight (FHB) pathogens. We demonstrate that agricultural intensification enables cross-kingdom root infections by Fusarium graminearum and F. asiaticum across these crops. Screening of 180 Fusarium strains revealed tripartite host infectivity, with transcriptomics uncovering host-adapted virulence strategies. Transcriptome analysis identified distinct gene expression patterns during the infection of each crop, with F. graminearum employing host-specific genes, such as FgPPDT1 (a pyridoxal phosphate-dependent transferase), for maize root infection. The FgPPDT1 knockout mutant (Δfgppdt1) exhibited severely impaired root colonization. Our findings establish differential gene expression as a regulatory axis for cross-host adaptation, directly linking FHB transmission risks to wheat–maize intercropping and wheat-soybean rotations.