Genome-Wide Identification of the GELP Family in Juglans mandshurica Reveals Their Potential Roles in Seed Development and Stress Responses

GDSL esterase/lipases (GELPs) are important regulators of plant growth and development, lipid metabolism, and stress responses. However, their genomic characteristics and expression patterns have not been systematically characterized for Juglans mandshurica, a woody oil crop species of significant ecological and economic value. Here, we identified 61 JmGELP genes in J. mandshurica through genome-wide analysis. Phylogenetic analysis classified them into seven major clades, and variations in gene structure and conserved motifs suggested potential functional divergence. Promoter cis-acting element analysis revealed widespread enrichment of motifs responsive to light, phytohormones, and abiotic stresses. Transcriptomic sequencing and qRT-PCR validation revealed distinct tissue-specific and seed development stage-specific expression patterns of JmGELP members, as well as their differential responses to various stress and hormone treatments. Gene Ontology (GO) annotation and protein–protein interaction (PPI) network analyses further supported their involvement in lipid metabolism. In silico analyses of transcription factor binding sites, miRNA targets, and molecular docking predicted that JmGELP-3, -38, and -41 have distinct transcriptional and post-transcriptional regulatory networks and potentially divergent substrate preferences. This study provides the first comprehensive characterization of the GELP family in J. mandshurica, identifying candidate genes that may inform future germplasm improvement and stress-resistance breeding in Juglans species.