Genome-Wide Identification and Expression Analysis of Tubby-like Proteins (TLPs) in Fragaria × ananassa Reveals Their Role in Abiotic Stress Responses

Background: Cultivated strawberry (Fragaria × ananassa) is one of the most valuable horticultural crops worldwide. Nevertheless, its productivity is increasingly constrained by high susceptibility to adverse environmental conditions, which are intensified by climate change. Drought represents a major limitation, often accompanied by water deficiency and elevated soil salinity. Plants counteract such abiotic stresses through complex molecular defense mechanisms involving transcription factors that regulate stress-responsive gene expression. Methods: In this study, we conducted a systematic bioinformatic analysis of the Tubby-like protein (TLP) transcription factor family in Fragaria × ananassa. RT-qPCR was used to analyze the expression patterns of FaTLP genes under different conditions to elucidate their potential roles in stress adaptation. Results: Eight FaTLP genes were identified in each of the four subgenomes, most of which retained the characteristic TUBBY and F-box domains. Gene expression profiling revealed that several FaTLP genes were differentially expressed in leaves under drought and salt stress, with FaTLP2 and FaTLP7 exhibiting strong induction. In addition, the expression of FaTLP2 and FaTLP7 under various oxidative and signaling-related treatments, as well as in different tissues of strawberry plants were analyzed. Promoter analysis identified multiple cis-regulatory elements associated with phytohormone signaling and abiotic stress responses, such as ABRE, MYB, and MYC motifs. Phylogenetic analysis showed that FaTLP2 and FaTLP7 share high sequence similarity with orthologous TLPs from other plant species known for enhanced stress tolerance, suggesting that these proteins may play conserved roles in the molecular mechanisms underlying drought and salinity resilience. Conclusions: This study provides valuable insights into the potential roles of FaTLPs in regulating environmental signal transduction and transcriptional control, contributing to abiotic stress tolerance in Fragaria × ananassa.