T-DNA Mutagenesis Reveals FpPer1 as a Dual-Function Regulator of Virulence and Fungicide Resistance in Fusarium pseudograminearum

<i>Fusarium</i> crown rot (FCR), caused by <i>Fusarium pseudograminearum</i>, is a devastating wheat disease leading to significant yield losses worldwide. However, the pathogenic mechanism of <i>F. pseudograminearum</i> and its resistance to fungicides remain poorly understood. In this study, we identified a hypothetical gene encoding GPI-anchored protein, designated FpPer1, by screening a T-DNA insertion mutant library of <i>F. pseudograminearum</i> for tebuconazole resistance. The Δ<i>Fpper1</i> mutant exhibited increased sensitivity to the triazole antifungal drugs and fludioxonil. Additionally, the deletion of <i>FpPER1</i> impaired fungal growth, conidiation, and pathogenicity in barley leaves and wheat coleoptiles. Furthermore, the Δ<i>Fpper1</i> mutant displayed enhanced susceptibility to various environmental stresses, including NaCl, CR, sorbitol, H₂O₂, and SDS. The mutant also showed reduced penetration peg formation and impaired reactive oxygen species (ROS) scavenging ability during infection. Subcellular localization analysis revealed that FpPer1-GFP co-localized with the endoplasmic reticulum (ER) marker RFP-HDEL in both conidia and hyphae, indicating its localization in the ER. In summary, our findings demonstrate that <i>FpPER1</i> plays an important role in pathogenicity and fungicide resistance in <i>F. pseudograminearum</i>. This study not only provides a theoretical foundation for understanding fungal virulence mechanisms but also offers practical insights for developing novel fungicide strategies.