Drought is a primary limiting factor for potato growth. PYR/PYL/RCAR (referred to hereafter as PYL) proteins, as receptors for abscisic acid (ABA), play a crucial role in the plant response to drought stress. However, the underlying mechanisms of this control remain largely elusive in potatoes. In this study, a potato StPYL20 gene was identified through genome-wide investigation and transcriptome analysis under drought stress. Molecular feature analysis revealed that the StPYL20 gene exhibits the highest expression level in tubers, and is significantly up-regulated under ABA and drought stress conditions. The StPYL20 protein harbors a conserved domain exclusive to the PYL family. Further functional analysis showed that both transient and stable expressions of StPYL20 in tobacco enhanced the drought resistance of transgenic plants, resulting in increased plant height, leaf number, and fresh weight, and an improved root system. Compared to wild-type plants under drought conditions, transgenic tobacco with the StPYL20 gene exhibited lower levels of malondialdehyde (MDA), higher proline (Pro) accumulation, and increased antioxidant enzyme activity. Moreover, overexpression of the StPYL20 gene heightened the sensitivity of transgenic plants to ABA. Furthermore, StPYL20 up-regulated the expression of stress response and development-related genes in transgenic plants under drought stress. In conclusion, our findings indicated that StPYL20 enhances drought resistance and root development in transgenic plants, and plays a positive regulatory role in the potato's response to drought stress.
Keywords: ABA; PYR/PYL/RCAR; StPYL20; drought stress; potato.