Comprehensive Analysis of the OASTL Gene Family in Potato (Solanum tuberosum L.) and Its Expression Under Abiotic Stress

O-acetylserine (thiol) lyase is a pivotal enzyme in plant cysteine biosynthesis, which is crucial for promoting plant growth, development, and resisting abiotic stress. However, the related studies on the potato OASTL gene family (StOASTL) have not been reported. In the present study, we identified 11 members of the StOASTL gene family, conducting a thorough analysis encompassing chromosome distribution, protein physicochemical properties, gene structure, protein-conserved motifs, and gene replication events. Phylogenetic scrutiny delineated these 11 StOASTLs into five distinct subfamilies. Using RNA-seq from the Potato Genome Sequencing Consortium (PGSC), we investigated the expression profile of <i>StOASTLs</i> in different tissues of DM (double-monoploid) potato and under abiotic/biotic stress, hormone treatment, and biostimulant treatment. The results showed that one of the StOASTLs (<i>Soltu09G024390</i>) was differentially expressed under different abiotic stresses and hormone treatments. Our findings showcased the differential response of one <i>StOASTL</i> (<i>Soltu09G024390</i>) to a spectrum of abiotic stresses and hormone treatments. <i>Soltu09G024390</i> was earmarked as a candidate gene and successfully cloned. Functional validation through yeast stress assays demonstrated that the heterologous expression of <i>Soltu09G024390</i> bolstered yeast tolerance to salt and cadmium stresses. This study provides a theoretical basis for revealing the role of the StOASTL family in potato response to abiotic stress and valuable insights for further study of the biological functions of StOASTL.