Genome-Wide Identification and Characterization of <i>FAR1</i> in <i>Phaseolus vulgaris</i> under Salt and Drought Stress Conditions

The FAR1-related sequence (FAR1) gene family consists of transcription factors that originated from transposases and is crucial for light signaling and stress adaptation in plants. Despite the recognized importance of FAR1 genes in model organisms, their genomic architecture, structural variability, and expression patterns in Phaseolus vulgaris have yet to be investigated. This study offers the inaugural comprehensive genome-wide identification and characterization of the FAR1 gene family in P. vulgaris. A total of 27 PvulFAR1 genes were identified, and their chromosomal distribution, gene structures, conserved domains, and phylogenetic relationships were analyzed systematically. The promoter regions of these genes were discovered to encompass a diverse range of cis-regulatory elements that respond to light, phytohormones, and abiotic stressors, highlighting their regulatory complexity. In silico expression analysis and quantitative real-time PCR (qRT-PCR) experiments demonstrated differential expression patterns of specific PvulFAR1 genes under salt and drought stress in two commercial bean cultivars. PvulFAR1-10 demonstrated consistent upregulation under both stress conditions, especially in the stress-tolerant cultivar Elkoca-05, indicating its potential role in broad-spectrum stress responsiveness. Gene ontology and protein–protein interaction network analyses revealed that PvulFAR1 proteins are predominantly nuclear-localized transcription factors, enriched in zinc ion binding activity, and associated with transcriptional regulation and nucleobase metabolic processes. The results offer novel perspectives on the evolution, structural complexity, and stress-responsive regulatory functions of the FAR1 gene family in common bean. This fundamental knowledge provides significant candidate genes for additional validation and for developing of genetically improved cultivars with enhanced tolerance to abiotic stresses. Future research should focus on clarifying the downstream targets of essential FAR1 members and their integrative function in plant developmental and stress response networks.