Integrative expression profiling and comparative bioinformatics analysis of ALDH7A1 in chickpea (Cicer arietinum L.) under salt and ABA treatments

BACKGROUND: Soil salinity and abscisic acid (ABA)-related signaling are major constraints affecting chickpea (Cicer arietinum L.) productivity by promoting oxidative stress and aldehyde accumulation. Aldehyde dehydrogenases (ALDHs), particularly members of the ALDH7 family, are involved in aldehyde detoxification and redox homeostasis under adverse conditions. However, the molecular characteristics, expression behavior, and structural features of ALDH7A1 in chickpea under salt and ABA treatments remain insufficiently understood. Therefore, this study aimed to provide an integrative characterization of CaALDH7A1 through expression profiling, oxidative stress assays, comparative structural analyses, evolutionary assessment, and molecular docking. RESULTS: Quantitative real-time PCR analyses showed that CaALDH7A1 was induced in both chickpea genotypes under salt and ABA treatments, with a markedly stronger response in the tolerant genotype (Aksu) than in the susceptible genotype (Uzunlu). In Aksu, transcript accumulation peaked at approximately 4.0-fold under 100 mM NaCl, whereas Uzunlu showed a more gradual increase, reaching a maximum of about 2.4-fold under 150 mM NaCl. Overall, salinity was the primary driver of CaALDH7A1 induction, while ABA alone caused comparatively limited variation under non-saline conditions. This transcriptional pattern was accompanied by lower H₂O₂ accumulation and approximately 30-35% lower MDA levels in the tolerant genotype, indicating an association between stronger CaALDH7A1 responsiveness and reduced oxidative damage. Comparative analyses further showed that CaALDH7A1 retains conserved catalytic domains, motifs, and active-site residues across representative orthologs, while molecular docking with MDA and NAD⁺ revealed favorable predicted binding energies and conserved interaction profiles. CONCLUSIONS: Together, these findings indicate that CaALDH7A1 is a salt- and ABA-responsive gene in chickpea, with its induction being driven mainly by salinity and more strongly expressed in the tolerant genotype. The association of higher CaALDH7A1 expression with lower H₂O₂ and MDA levels supports a stress-related role for this gene in aldehyde metabolism and redox-associated responses. The integration of expression, physiological, structural, evolutionary, and docking analyses further suggests that CaALDH7A1 is a conserved stress-associated candidate that may contribute to salinity-related adaptation in chickpea.