Biocontrol Efficacy of Bacillus velezensis FXJ Against Fusarium graminearum-Induced Fusarium Head Blight in Wheat

Fusarium head blight (FHB), caused by <i>Fusarium graminearum</i>, poses a serious threat to wheat production and grain security. In this study, a strain of <i>Bacillus velezensis</i> was isolated from the plant <i>Polygonatum sibiricum</i> and designated FXJ. FXJ inhibited the mycelial growth of <i>F. graminearum</i> by 52% and induced hyphal abnormalities including swelling and shrinkage. <i>In vivo</i> experiments demonstrated that FXJ treatment significantly reduced disease severity in wheat coleoptiles and spikes, decreased deoxynivalenol accumulation in grains, and down-regulated the expression. Transcriptomic analysis further revealed that FXJ suppressed fungal growth by interfering with energy metabolism and essential biosynthetic processes, particularly pathways related to fatty acid degradation and sugar metabolism. Overall, <i>B. velezensis</i> FXJ shows strong potential for integrated management of wheat Fusarium head blight through combined mechanisms, including the inhibition of mycelial growth, disruption of hyphal morphology, reduction in pathogen infection, and suppression of toxin synthesis.