Abstract
Background/Objectives: Late embryogenesis abundant (LEA) proteins regulate stress responses and contribute significantly to plant stress tolerance. As a model species for stress resistance studies, foxtail millet (Setaria italica) lacks comprehensive characterization of its LEA gene family. This study aimed to comprehensively identify SiLEA genes in foxtail millet and elucidate their functional roles and tissue-specific expression patterns. Methods: Genome-wide identification of SiLEA genes was conducted, followed by phylogenetic reconstruction, cis-acting element analysis of promoters, synteny analysis, and expression profiling. Results: Ninety-four SiLEA genes were identified and classified into nine structurally distinct subfamilies, which are unevenly distributed across all nine chromosomes. Phylogenetic analysis showed closer clustering of SiLEA genes with sorghum and rice orthologs than with Arabidopsis thaliana AtLEA genes. Synteny analysis indicated the LEA gene family expansion through tandem and segmental duplication. Promoter cis-element analysis linked SiLEA genes to plant growth regulation, stress responses, and hormone signaling. Transcriptome analysis revealed tissue-specific expression patterns among SiLEA members, while RT-qPCR verified ABA-induced transcriptional regulation of SiLEA genes. Conclusions: This study identified 94 SiLEA genes grouped into nine subfamilies with distinct spatial expression profiles. ABA treatment notably upregulated SiASR-2, SiASR-5, and SiASR-6 in both shoots and roots.