Genome-wide profiling of bZIP transcription factors in Camelina sativa: implications for development and stress response.

Background: The bZIP transcription factor family, characterized by a bZIP domain, plays vital roles in plant stress responses and development. While this family has been extensively studied in various plant species, its specific functions in Camelina sativa (False Flax) remain underexplored.

Methods and results: This study identified 71 bZIP transcription factors in C. sativa, classified into nine distinct groups based on phylogenetic analysis. Subcellular localization predicted a nucleus-specific expression for these bZIPs. Analysis of GRAVY scores revealed a range from 0.469 to -1.256, indicating a spectrum from hydrophobic to hydrophilic properties. Motif analysis uncovered 10 distinct motifs, with one motif being universally present in all CsbZIPs. Conserved domain analysis highlighted several domains beyond the core bZIP domain. Protein-protein interaction predictions suggested a robust network involving CsbZIPs. Moreover, promoter analysis revealed over 60 types of cis-elements, including those responsive to stress. Expression studies through RNA-seq and Real-time RT-qPCR demonstrated high expression of CsbZIPs in roots, leaves, flowers, and stems. Specifically, CsbZIP01, CsbZIP02, CsbZIP44, and CsbZIP60 were consistently up-regulated under cold, salt, and drought stresses, whereas CsbZIP34 and CsbZIP35 were down-regulated.

Conclusion: This study presents the first comprehensive genome-wide profiling of bZIP transcription factors in Camelina sativa, providing novel insights into their roles in plant development and stress response mechanisms. By identifying and characterizing the bZIP gene family in C. sativa, this research offers new opportunities for improving stress tolerance and crop resilience through targeted genetic approaches, addressing key challenges in agriculture under changing environmental conditions.