l ‐Arginine Priming Enhances Wheat Seedling Resistance Against Fusarium graminearum Through Reprogramming Nitrogen Me

ABSTRACT

Fusarium graminearum is a major fungal pathogen responsible for Fusarium head blight and crown rot in wheat, posing a serious threat to global wheat yield and grain quality. In this study, combined in vitro antifungal and in vivo inoculation assays revealed that

arginine significantly inhibits the mycelial growth of F. graminearum and reduces infection severity in wheat seedlings. Time‐series transcriptome analysis showed that differentially expressed genes (DEGs) following arginine treatment were mainly enriched in pathways associated with amino acid metabolism, carbon metabolism, plant–pathogen interactions and secondary metabolite biosynthesis. During the defence preparation phase, numerous homologous genes involved in nitrogen turnover and redox processes, such as those related to allantoin transport and polyamine oxidation, were significantly induced. In the infection outbreak phase, candidate genes associated with lignification reinforcement, protease inhibition and hormone signal transduction exhibited more robust responses in the treatment group. These findings provide important insights into the molecular regulatory network underlying arginine‐mediated wheat resistance against F. graminearum and highlight the potential for developing green control strategies based on metabolic regulation.