Comprehensive Genome-Wide Characterization of L-Type Lectin Receptor-like Kinase (L-LecRLK) Genes in Wheat (Triticum...

L-type lectin receptor-like kinases (L-LecRLKs) play key roles in plant responses to environmental stresses and the regulation of growth and development. However, comprehensive studies of the L-LecRLK gene family in wheat (Triticum aestivum L.) are still limited. In this study, 248 L-LecRLK candidate genes were identified in wheat, which is the largest number reported in any species to date. Phylogenetic analysis grouped these genes into four clades (I-IV), with Group IV exhibiting significant monocot-specific expansion. Gene duplication analysis revealed that both whole-genome/segmental and tandem duplications contributed to family expansion, while Ka/Ks ratio analysis suggested that the genes have undergone strong purifying selection. The TaL-LecRLK genes displayed diverse exon-intron structures and conserved motif compositions. Promoter analysis revealed a cis-element associated with hormone signaling and abiotic stress responses. Transcriptome profiling showed that TaL-LecRLKs exhibit tissue- and stage-specific expression patterns. RNA-Seq data revealed that, under drought and heat stress conditions, TaL-LecRLK35-3D and TaL-LecRLK67-6B exhibited synergistic expression patterns, whereas TaL-LecRLK67-6A demonstrated antagonistic expression. A qRT-PCR further demonstrated that six TaL-LecRLKs may function through ABA-independent regulatory mechanisms. These findings provide valuable gene candidates for stress-resistant wheat breeding and shed light on the evolution and functional diversity of L-LecRLKs in plants.