Fusarium oxysporum is the causal agent of the devastating Fusarium wilt by invading and colonizing the vascular system in various plants, resulting in substantial economic losses worldwide. Target of rapamycin (TOR) is a central regulator that controls intracellular metabolism, cell growth, and stress responses in eukaryotes, but little is known about TOR signalling in F. oxysporum. In this study, we identified conserved FoTOR signalling pathway components including FoTORC1 and FoTORC2. Pharmacological assays showed that F. oxysporum is hypersensitive to rapamycin in the presence of FoFKBP12 while the deletion mutant strain ΔFofkbp12 is insensitive to rapamycin. Transcriptomic data indicated that FoTOR signalling controls multiple metabolic processes including ribosome biogenesis and cell wall-degrading enzymes (CWDEs). Genetic analysis revealed that FoTOR1 interacting protein 4 (FoTIP4) acts as a new component of FoTOR signalling to regulate hyphal growth and pathogenicity of F. oxysporum. Importantly, transcript levels of genes associated with ribosome biogenesis and CWDEs were dramatically downregulated in the ΔFotip4 mutant strain. Electrophoretic mobility shift assays showed that FoTIP4 can bind to the promoters of ribosome biogenesis- and CWDE-related genes to positively regulate the expression of these genes. These results suggest that FoTOR signalling plays central roles in regulating hyphal growth and pathogenicity of F. oxysporum and provide new insights into FoTOR1 as a target for controlling and preventing Fusarium wilt in plants.

中文翻译：

---

雷帕霉素靶点通过尖孢镰刀菌FoTIP4控制菌丝生长和致病性

Fusarium oxysporum是破坏性枯萎病的病原体，通过入侵和定植各种植物的维管系统，在全球范围内造成巨大的经济损失。雷帕霉素靶点 (TOR) 是控制真核生物细胞内代谢、细胞生长和应激反应的中枢调节剂，但对尖孢镰刀菌中的 TOR 信号传导知之甚少。在这项研究中，我们确定了保守的 FoTOR 信号通路成分，包括 FoTORC1 和 FoTORC2。药理分析表明，尖孢镰刀菌在存在FoFKBP12的情况下对雷帕霉素过敏，而缺失突变菌株 Δ Fofkbp12对雷帕霉素不敏感。转录组学数据表明，FoTOR 信号控制多种代谢过程，包括核糖体生物发生和细胞壁降解酶 (CWDE)。遗传分析表明，FoTOR1 相互作用蛋白 4 (FoTIP4) 作为 FoTOR 信号传导的新成分，可调节尖孢镰刀菌的菌丝生长和致病性。重要的是，与核糖体生物发生和CWDE相关的基因转录水平在 ΔFotip4 中显着下调突变株。电泳迁移率变动分析表明，FoTIP4 可以与核糖体生物发生和 CWDE 相关基因的启动子结合，从而正向调节这些基因的表达。这些结果表明，FoTOR 信号在调节尖孢镰刀菌的菌丝生长和致病性中起核心作用，并为将 FoTOR1 作为控制和预防植物枯萎病的靶标提供了新的见解。