The Abscisic Acid Receptor Gene StPYL8-like from Solanum tuberosum Confers Tolerance to Drought Stress in Transgenic Plants

Pyrabactin resistance 1-like (PYL) proteins are abscisic acid (ABA) receptors that play a crucial role in the plant's response to adverse environmental conditions. However, as of yet, there is limited research on the role of PYL proteins in potato. In this study, a potato <i>PYL</i> gene, <i>StPYL8-like</i>, was identified through transcriptome analysis under drought stress. Molecular characterization revealed that the StPYL8-like protein possesses a highly conserved PYL family domain. Evolutionary analysis demonstrated that StPYL8-like protein clusters with various PYL proteins are involved in stress responses across different species. Functional assays showed that <i>StPYL8-like</i> robustly responds to different abiotic stresses, including drought and ABA treatment. Furthermore, the transient and stable expressions of <i>StPYL8-like</i> in tobacco enhanced their drought resistance, leading to increased plant height, leaf number, and fresh weight, as well as an improved root system. Transgenic tobacco carrying the <i>StPYL8-like</i> gene exhibited lower malondialdehyde (MDA) levels and higher proline accumulation and antioxidant enzyme activity compared to wild-type plants under drought conditions. Moreover, <i>StPYL8-like</i> upregulated the expression of stress-responsive genes (<i>NtRD29A</i>, <i>NtLEA5</i>, <i>NtP5CS</i>, <i>NtPOD</i>, <i>NtSOD</i>, and <i>NtCAT</i>) in transgenic plants subjected to drought stress. Collectively, these findings highlight the positive regulatory role of the <i>StPYL8-like</i> gene in enhancing potato plants' response to drought stress.