Genome wide identification of SCL transcription factors in potato (Solanum tuberosum L.) and expression analyses under phytohormones, drought and salt stress

Background Abiotic stresses, such as drought and salinity, severely limit the yield and quality of potato. As a pivotal subfamily of GRAS transcription factors, SCARECROW-like (SCL) proteins play essential roles in phytohormone signaling and stress adaptation; however, their systematic characterization and functional mechanisms in potato remain largely unexplored. Results In this study, we conducted a genome-wide identification of the SCL family, identifying 71 StSCL genes in potato. Phylogenetic analysis revealed that potato StSCL proteins exhibit the closest evolutionary relationship with their counterparts in tomato. Structural and promoter analyses demonstrated that StSCL members possess conserved GRAS and DELLA domains and are enriched with cis -acting elements responsive to ABA, SA, JA, GA, and various abiotic stresses. Protein-protein interaction (PPI) network analysis identified StSCL13 , StSCL24 , and StSCL66 as potential hub genes. Expression profiling revealed tissue-specific patterns and broad responsiveness to hormonal and stress treatments. The StSCL3 was localized to the nucleus and was significantly induced by ABA, GA, SA, JA, and drought stress, but suppressed under salt stress. This divergent regulation suggests that StSCL3 functions as a complex signal "integrator" that integrates multiple hormonal pathways to modulate stress adaptation and growth. Conclusions Collectively, this study elucidates the evolutionary characteristics and regulatory mechanisms of the potato SCL family, highlighting the pivotal role of StSCL3 in hormone signaling and abiotic stress responses, and providing a theoretical foundation for improving stress resistance in potato.