Genome-Wide Identification and Characterization of Thaumatin-Like Proteins in Potato (Solanum tuberosum L.) and Their Role in Stress Tolerance.

Abstract

Thaumatin-like proteins (TLPs), part of the Pathogenesis-related protein 5 (PR5) family, play key roles in plant defense against biotic and abiotic stresses. In Solanum tuberosum, a crucial global food crop, the functional diversity of TLPs under stress conditions remains poorly understood, hindering efforts to improve stress tolerance. This study aimed to address this gap by performing a genome-wide identification and characterization of the TLP gene family in potato. We identified 34 TLPs (StTLP1 to StTLP34), distributed across 11 chromosomes. Detailed analyses were conducted on their physicochemical properties, gene structures, conserved motifs, and expression patterns. Promoter analysis revealed multiple stress-responsive cis-elements. Differential expression analysis showed that several StTLPs are significantly regulated in response to salinity, heat, and pathogen infection. Protein-protein interaction and miRNA targeting analyses further highlighted the regulatory networks involving StTLPs in stress adaptation. This study advances the theoretical understanding of the roles of StTLPs in stress response. It provides a valuable genetic resource for future efforts to enhance stress resilience in potato, with potential applications in crop improvement strategies. The 0 l expression of three TLP genes under salt and mannitol stress was verified through real-time PCR analysis after the interval of 15 days. Alterations in the expression patterns of StTLPs offered deeper insight into the involvement of this gene family in diverse abiotic stress responses. All three StTLPs were upregulated under both treatments at 400 mM, relative to their expression at 200 mM. The highest level of upregulation was observed in StTLP20, indicating its prominent role in both stress treatments.