Genome-Wide Identification, Characterization, and Expression Profiling of the HvLEA Family Genes Under Salt Stress, and Prediction of Their Protein–Protein Interaction Networks in Barley (Hordeum vulgare L.)

Salt stress is a major abiotic factor that significantly limits crop yields worldwide. Late embryogenesis abundant (LEA) proteins, which are widely present across diverse organisms, play critical and multifaceted roles in plant responses to abiotic stress. However, only a few salt tolerance-related HvLEA genes have been identified in barley. In this study, we characterized 107 HvLEA proteins in barley, which were classified into eight groups and found to be distributed across all seven chromosomes. RNA-Seq analysis of root and leaf tissues from the cultivar “Golden Promise” at 12, 48, and 120 h after salt stress treatment identified 69 differentially expressed HvLEA genes across both tissues. Among these, 41 HvLEA genes were commonly differentially expressed in leaves and roots. Six genes (HvDHN2, HvDHN5, HvDHN10, HvLEA1.1, HvLEA1.6, and HvSMP2) were extremely up-regulated after salt stress in both roots and leaves, with log2FC values exceeding 10, indicating their potential key roles in salt stress response. qPCR validation of selected genes confirmed expression trends consistent with the RNA-Seq data. Database predictions and co-expression network analysis suggested that, in addition to potential protein interactions within the same family, these genes may interact with partners such as cysteine-rich receptor kinases, zinc finger proteins, calcium-binding EF-hand family proteins, NAC domain-containing proteins, and glycosyltransferases. This study identified key HvLEA genes involved in salt stress response and provided valuable genetic resources for improving barley tolerance through molecular breeding.