In Silico Study of bZIP TFs Family Genes for Osmotic Stress Responsive in Genomic Elements Pigeon Pea (Cajanus cajan L.)

The bZIP transcription factor (TF) gene family plays a pivotal role in regulating plant responses to abiotic stresses and developmental processes. In pigeon pea (Cajanus cajan L.), a legume adapted to semi-arid environments, 69 putative bZIP genes (CcbZIP1 to CcbZIP69) were identified through homology-based BLASTP searches and Pfam verification for the bZIP_1 domain (PF00170). These genes exhibit significant structural diversity, with coding sequence lengths ranging from 273 to 2,235 base pairs, encoding proteins of 90 to 744 amino acids. Functional domain analysis confirmed the bZIP_1 domain in 33 proteins, with additional domains suggesting functional diversification. Subcellular localization analysis revealed predominant nuclear localization, consistent with their role in transcriptional regulation. Motif analysis identified conserved patterns critical for DNA binding and dimerization, while physicochemical properties indicated diverse protein architectures suited for stress responses. Phylogenetic analysis grouped the 32 bZIP_1-containing proteins into three clades, reflecting evolutionary divergence. These findings highlight the CcbZIP family’s role in pigeon pea’s stress resilience and provide a foundation for molecular breeding to enhance crop tolerance.