Recently emerged Fusarium chemotypes reprogram wheat defence and detoxification networks during Fusarium head blight development

Fusarium head blight (FHB) is a major threat to global wheat production and food safety due to contamination with mycotoxins, such as deoxynivalenol (DON). The emergence of new mycotoxin chemotypes, including 7--hydroxy,15-deacetylcalonectrin (3ANX), presents an evolving challenge for disease management and resistance breeding. Here, we performed a field-based, systems-level proteome analysis of wheat infected with Fusarium graminearum strains belonging to the common 15ADON and recently emerged 15ADON/3ANX chemotypes. Across host and pathogen, we quantified more than 9,200 proteins, providing extensive coverage of infection-associated molecular responses. Infection with 15ADON/3ANX strains suppressed canonical wheat detoxification pathways while promoting structural and oxidative defence responses. Concurrently, the fungal proteome of 15ADON/3ANX-producing strains indicated altered mitochondrial ribosome function and alternative virulence strategies. Further investigation of the host-pathogen interface defined hub protein networks negatively regulating classical detoxification markers, suggesting coordinated regulation of host defence responses regardless of chemotype. Molecular responses were linked to field phenotypes by quantification of DON-3-glucoside/DON ratios and disease severity, defining positive correlations in 15ADON infections, which were abolished upon 15ADON/3ANX infection, indicating chemotype-specific evasion or suppression of host defenses. These findings demonstrate reprogramming of host-pathogen interaction networks and reveal molecular targets that may inform chemotype-aware breeding strategies to enhance crop resilience.