# Comprehensive Genome-Wide Characterization of L-Type Lectin Receptor-like Kinase (L-LecRLK) Genes in Wheat (Triticum aestivum L.) and Their Response to Abiotic Stress

## TL;DR

This study identifies and characterizes 248 L-LecRLK genes in wheat, revealing their roles in stress responses and evolutionary expansion.

## Contribution

The largest reported L-LecRLK gene family in wheat, with insights into their evolution and abiotic stress responses.

## Key findings

- 248 L-LecRLK genes were identified in wheat, the largest number in any species.
- Gene duplication and purifying selection contributed to the expansion of the L-LecRLK family.
- Some TaL-LecRLKs showed stress-specific expression patterns and ABA-independent regulation.

## Abstract

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.