Interaction between MdMYB63 and MdERF106 enhances salt tolerance in apple by mediating Na⁺/H⁺ transport

Salt stress is an important environmental factor affecting the growth and production of agricultural crops and fruits worldwide, including apple (Malus × domestica). In this study, we demonstrate that a salt-responsive MYB transcription factor (TF), designated as MdMYB63, promotes survival under salt stress. Overexpression of MdMYB63 in apple calli significantly enhanced salt tolerance. Screening of the AP2/ERF family of TFs identified MdERF106 as an interaction partner of MdMYB63. Further analyses showed that the MdMYB63-MdERF106 complex significantly promotes the expression of downstream MdSOS1, thereby improving the Na⁺ expulsion and salt tolerance of apple. These functional analyses of MdMYB63 have provided valuable insights into the regulatory network of salt tolerance, and lay a theoretical foundation for the cultivation of new salt-tolerant apple varieties.