Ubiquitin-conjugating enzyme StUBC19 regulates osmotic and salt stress in potato transgenic plants.

Potato is an important food and vegetable crop. Along with global climate change and the deepening industrialization of human life, drought and salinity have become important factors threatening potato production. The ubiquitin proteasome system is an important post-translational modification of proteins in eukaryotic organisms and plays an important role in plant resistance to abiotic and biotic stresses. In this study, StUBC19 was cloned from Atlantic and analyzed for tissue expression specificity and molecular characterization. Tissue specificity and molecular characterization were carried out and StUBC19 expression levels were significantly higher in leaves and terminal buds than in stem. histochemical staining showed that β-glucuronidase (GUS) activity driven by the StUBC19 promoter was induced by a variety of abiotic stresses (salt and drought) and phytohormones (abscisic acid, gibberellin, auxin, salicylic acid), which suggests that StUBC19 may be involved in a variety of signal transduction processes. StUBC19 may be involved in multiple signal transduction processes. The results of subcellular localization showed that StUBC19 was localized in the nucleus and plasma membrane. Transgenic plants overexpressing StUBC19 (OEs) showed increased plant height, root length, and biomass accumulation compared to wild-type plant (WT) under drought stress and salt stress. The transgenic lines had higher activities of antioxidant enzymes (superoxide dismutase, catalase, and peroxidase) and lower malondialdehyde levels. Yeast two-hybrid, bimolecular fluorescence complementation and luciferase complementation experiments confirmed the existence of a mutualistic relationship between StUBC19 and StWIN2. In conclusion, our results provide important reference information for the future use of StUBC19 in potato resistance breeding.