Genome-wide identification of ATP-binding cassette (ABC) transporters and functional characterization of FpYOR1 in multidrug sensitivity and virulence of Fusarium pseudograminearum.

ATP-binding cassette (ABC) transporters hydrolyze ATP to drive the transmembrane transport of diverse substrates and thereby participate in a wide range of biological processes. However, the genome-wide landscape and functional contributions of ABC transporters in Fusarium pseudograminearum remain insufficiently characterized. Here, we systematically identified 61 putative ABC transporters and classified them into nine subfamily groups, with ABCB and ABCG subfamily genes representing the major expansions. We further functionally characterized an ABCC transporter gene, named FpYOR1 in this study, which was strongly induced under multiple fungicide stresses and predicted as a potential interacting partner of the ABCG transporter gene FpZRA1. Molecular docking and dynamics simulations further supported the stability and binding affinity of the modeled complexes with four common fungicides. Targeted gene deletion revealed that FpYOR1 is required for hyphal growth, conidial germination, and tolerance to multiple fungicides and abiotic stresses. Moreover, loss of FpYOR1 markedly impaired DON production and virulence on wheat coleoptiles, accompanied by the downregulation of several TRI cluster related genes and impaired toxisome formation. RNA-seq analysis further revealed that ΔFpYOR1 significantly suppressed the peroxisome and MAPK signaling pathways, accompanied by increased oxidative stress indicators, including ROS, GSSG, and MDA levels. Collectively, these results indicate that FpYOR1 functions as a pleiotropic determinant linking multidrug response with redox homeostasis and pathogenicity, and highlight FpYOR1-centered transport module as a potential target for resistance management and antifungal development.