Genome-Wide Comprehensive Identification and Characterization of Lectin Receptor-Like Kinase Gene Family in Barley ( L.)

Lectin receptor-like kinases (LecRLKs) are a significant subgroup of the receptor-like kinases (RLKs) protein family. They play crucial roles in plant growth, development, immune responses, signal transduction, and stress tolerance. However, the genome-wide identification and characterization of genes and their regulatory elements have not been explored in a major cereal crop, barley ( L.). Therefore, in this study, integrated bioinformatics tools were used to identify and characterize the LecRLK gene family in barley. Based on the phylogenetic tree and domain organization, a total of 113 genes were identified in the barley genome (referred to as ) corresponding to the genes of . These putative genes were classified into three groups: 62 G-type , 1 C-type , and 50 L-type . They were unevenly distributed across eight chromosomes, including one unknown chromosome, and were predominantly located in the plasma membrane (G-type (96.8%), C-type (100%), and L-type (98%)). An analysis of motif composition and exon-intron configuration revealed remarkable homogeneity with the members of . Notably, most of the (27 G-type, 43 L-type) have no intron, suggesting their rapid functionality. The Ka/Ks and syntenic analysis demonstrated that gene pairs evolved through purifying selection and gene duplication was the major factor for the expansion of the HvlecRLK gene family. Exploration of gene ontology (GO) enrichment indicated that the identified genes are associated with various cellular processes, metabolic pathways, defense mechanisms, kinase activity, catalytic activity, ion binding, and other essential pathways. The regulatory network analysis identified 29 transcription factor families (TFFs), with seven major TFFs including bZIP, C2H2, ERF, MIKC_MADS, MYB, NAC, and WRKY participating in the regulation of gene functions. Most notably, eight TFFs were found to be linked to the promoter region of both L-type and . The promoter cis-acting regulatory element (CARE) analysis of barley identified a total of 75 CARE motifs responsive to light responsiveness (LR), tissue-specific (TS), hormone responsiveness (HR), and stress responsiveness (SR). The maximum number of CAREs was identified in (25 for LR), (17 for TS), and (12 for HR). Additionally, were predicted to exhibit higher responses in stress conditions. In addition, 46 putative miRNAs were predicted to target 81 genes and was the most targeted gene by 8 different miRNAs. Protein-protein interaction analysis demonstrated higher functional similarities of 63 HvlecRLKs with 7 STRING proteins. Our overall findings provide valuable information on the LecRLK gene family which might pave the way to advanced research on the functional mechanism of the candidate genes as well as to develop new barley cultivars in breeding programs.