A working model illustrating the role of MdWRKY75-MdERF114-MdMYB8-MdPRX63 in apple response to Fusarium solani. Fusarium solani induces the expression of MdWRKY75, which directly binds to the W-box motif in the promoter of MdERF114. MdERF114 directly binds to the GCC-box motif of the MdPRX63 promoter and activates its expression, resulting in lignin deposition. The expression of MdMYB8 is also induced by F. solani. The interaction between MdMYB8 and MdERF114 enhances the binding of MdERF114 to the MdPRX63 promoter. The deposition of lignin increases the resistance to F. solani in apple roots.