StMAPKK5 positively regulates drought and salt stress responses in potato. The study investigated the role of StMAPKK5 in potato stress tolerance by analyzing its expression under drought and NaCl treatments, constructing overexpression and RNA interference lines, and examining physiological and biochemical parameters. StMAPKK5 was found to be upregulated under drought and salt stress, with the highest expression in leaves. The protein was localized in the nucleus, cytoplasm, and cell membrane. Overexpression of StMAPKK5 enhanced drought and salt tolerance by increasing antioxidant enzyme activities (SOD, CAT, POD), proline content, and reducing MDA levels. RNA interference reduced these parameters, indicating StMAPKK5's role in stress resistance. Yeast two-hybrid and bimolecular fluorescence complementation assays identified four interacting proteins: StMYB19, StZFP8, StPUB-like, and StSKIP19. qRT-PCR showed that StMYB19, StZFP8, StPUB-like, and StSKIP19 were differentially expressed in transgenic plants, with StMYB19 and StSKIP19 playing key roles in stress response. The study provides insights into the molecular mechanisms of StMAPKK5 in potato stress tolerance, highlighting its importance in improving drought and salt resistance. The findings contribute to understanding the signaling pathways and biological functions of StMAPKK5 in potato crops.StMAPKK5 positively regulates drought and salt stress responses in potato. The study investigated the role of StMAPKK5 in potato stress tolerance by analyzing its expression under drought and NaCl treatments, constructing overexpression and RNA interference lines, and examining physiological and biochemical parameters. StMAPKK5 was found to be upregulated under drought and salt stress, with the highest expression in leaves. The protein was localized in the nucleus, cytoplasm, and cell membrane. Overexpression of StMAPKK5 enhanced drought and salt tolerance by increasing antioxidant enzyme activities (SOD, CAT, POD), proline content, and reducing MDA levels. RNA interference reduced these parameters, indicating StMAPKK5's role in stress resistance. Yeast two-hybrid and bimolecular fluorescence complementation assays identified four interacting proteins: StMYB19, StZFP8, StPUB-like, and StSKIP19. qRT-PCR showed that StMYB19, StZFP8, StPUB-like, and StSKIP19 were differentially expressed in transgenic plants, with StMYB19 and StSKIP19 playing key roles in stress response. The study provides insights into the molecular mechanisms of StMAPKK5 in potato stress tolerance, highlighting its importance in improving drought and salt resistance. The findings contribute to understanding the signaling pathways and biological functions of StMAPKK5 in potato crops.