Genome-wide identification and characterization of the WRKY gene family in lentil (Lens culinaris Medikus)

The WRKY gene family plays a very important role in plant growth, development, and response to both biotic and abiotic stresses. Despite its importance, WRKY gene family is yet to be explored in lentil (Lentil culinaris Medikus), an important legume cultivated worldwide. This study presents the first in-depth analysis of WRKY genes in lentil with respect to their genomic organization, evolution, and expression patterns. A total of 105 LcWRKY genes were identified, distributed across seven chromosomes, and classified into six subgroups based on conserved motifs and phylogenetic relationships. Promoter analysis revealed cis-regulatory elements associated with hormone signalling and stress responses underscoring the role of LcWRKY genes in stress adaptation. Chromosome mapping showed uneven LcWRKY gene distribution, with chromosome 5 hosting the most, indicating gene duplication's events might have played role in their evolution. Synteny analysis with Arabidopsis further confirmed the evolutionary conservation of this gene family. In silico gene expression profiling revealed 16 LcWRKY genes that were significantly upregulated under both salt and drought stress conditions, supporting their involvement in stress tolerance. Notably, LcWRKY46 and LcWRKY73 showed significant upregulation in response to salt stress, whereas LcWRKY22 and LcWRKY47 were significantly upregulated under drought conditions, indicating their critical roles in enhancing stress tolerance in lentil. This study not only advances our understanding of the organization and evolution of the LcWRKY gene family but also provides insights into its potential role in stress adaptation, which can be utilized by lentil researchers to design stress-tolerant varieties.