A Class II Glutamine Amidotransferase FgDUG3 Is Involved in the Differentiation and Full Virulence of Fusarium graminearum

<i>Fusarium</i> head blight caused by <i>Fusarium graminearum</i> is a serious fungal disease on wheat and maize worldwide, resulting in a significant economic loss. DUG3-mediated glutathione utilization has been revealed to play important roles in fungal differentiation, metabolism, stress adaptation, and plant infection. However, functional roles of the DUG3 homolog in <i>F. graminearum</i> remain uncharacterized. In the present study, <i>FgDUG3</i> was knocked-out via homologous recombination to investigate functions of this gene. The deletion mutant (Δ<i>FgDUG3</i>) was normal in mycelial growth, but showed impairments in conidiation, conidial germination, and plant infection, compared to the wild-type strain. The defects of Δ<i>FgDUG3</i> were recovered in the complemented strain (Δ<i>FgDUG3-C).</i> Transcriptomic analysis revealed that deletion of <i>FgDUG3</i> caused significantly differential expression of genes, mainly related to metabolism, catabolism, cellular structure organization, and signal transduction. Taken together, these results suggest that <i>FgDUG3</i> plays important roles in the differentiation and pathogenicity of <i>F. graminearum</i>.