The chloroplast protein Ferredoxin 1 (FD1), with roles in the chloroplast electron transport chain, is known to interact with the CPs of ToMV and CMV. However, our understanding of the roles of FD1 in virus infection remains limited. Here, we report that the PVX p25 protein interacts with FD1, whose mRNA and protein levels are reduced by PVX infection or by transient expression of p25. Silencing of FD1 by TRV-based VIGS promoted the local and systemic infection of plants by PVX. Use of a drop-and-see assay (DANS) and callose staining revealed that the permeability of plasmodesmata (PD) was increased in FD1-silenced plants together with a consistently reduced level of PD callose deposition. After FD1 silencing, qRT-PCR analysis and LC-MS revealed these plants to have a low accumulation of the phytohormones ABA and SA, which contributed to the decreased callose deposition at PD. Overexpression of FD1 in transgenic plants manifested resistance to PVX infection, but the contents of ABA, SA and the PD callose deposition were not increased in transgenic plants. Overexpression of FD1 interfered with the RNA silencing suppressor function of p25. These results demonstrate that interfering with FD1 function causes abnormal plant hormone-mediated antiviral processes and, thus, enhances PVX infection.