Genome-wide identification, evolution and expression analysis of the HSP20 gene family in lentil [Lens culinaris (L.) Medikus]

Lentil [Lens culinaris (L.) Medikus, 2n = 2x = 14] is one of the most important legumes around the world. The crop is sensitive to various abiotic stresses, including heat and drought. Among various classes of proteins, heat shock proteins (HSPs), play a vital role in regulating developmental processes and the responses to environmental stresses. Of these, the HSP20 family has gained attention however, its genomic organization and functions are uncharacterized in Lens species. Our study thus identified a total of 47 putative LcHSP20 genes, which were classified into five subfamilies based on predicted subcellular localization and phylogenetic relationships. Sequence analysis revealed that the majority of LcHSP20 genes possess either no introns or only a single short intron, indicating a streamlined gene structure. Phylogenetic clustering further demonstrated that members of the same subfamily exhibit conserved gene structures and motifs, suggesting potential functional similarities. Moreover, expressions analysis revealed that the transcript levels of LcHSP20 genes were significantly induced under salt stress condition. Notably, two genes, LcHSP20-44 and LcHSP20-13, were markedly upregulated in response to these stressors, highlighting their potential roles in enhancing salt stress tolerance in lentil plants. This is the first genome-wide study of the HSP20 gene family in lentils, providing critical insights into their evolutionary and functional roles, laying the groundwork for future research on stress tolerance and improving lentil breeding programs.