Identification and Expression Profiling of LEA Gene Family in Olive (Olea europaea L.)

The olive tree (Olea europaea L.) is a vital crop in Mediterranean agriculture, frequently exposed to harsh drought conditions. Among the molecular mechanisms that confer drought tolerance, Late Embryogenesis Abundant (LEA) proteins play a central role. These hydrophilic proteins function in cellular protection during water deficit, preventing protein denaturation, stabilizing membranes, and scavenging reactive oxygen species. In this study, we performed a comprehensive phylogenetic and gene expression analysis of LEA proteins in olive. We identified LEA genes expressed across different tissues and conducted a differential expression analysis to assess their response to drought stress. A phylogenetic tree was constructed to classify LEA family members, and expression data was mapped onto the tree to link evolutionary conservation with functional responses. LEA proteins were classified into distinct subgroups (LEA_1-5, Dehydrin, SMP) to highlight their functional diversity. Additionally, a tissue-specific expression heatmap was generated to illustrate the spatial dynamics of LEA gene activity. Our results provide valuable insights into the molecular mechanisms of drought tolerance in olive and offer potential targets for genetic improvement to enhance resilience in olive cultivation.