qRT-PCR-based Expression Profiling of Selected Drought-Responsive Genes in Chickpea (Cicer arietinum L.) Genotypes under Moisture Stress

Abstract

Background: Gene expression studies have gained prominence as they enable the identification of key regulatory genes and pathways involved in stress response and adaptation. Quantitative Real-Time PCR (qPCR) has emerged as a widely accepted and reliable technique for gene expression analysis due to its high sensitivity, specificity and reproducibility. Aims: The study aims to evaluate the expression patterns of selected drought-responsive genes in chickpea (Cicer arietinum L.) genotypes under well-watered, moisture stress conditions, and to identify candidate genes associated with drought tolerance. Study design: Experimental study using a randomised complete block design. Place and Duration of Study: The study was conducted at the Regional Agricultural Research Station, Vijaypur, during the cropping season of Rabi 2018. Methodology: Eight chickpea genotypes, including MAGIC lines, were evaluated under well-watered and moisture stress conditions. Total RNA was extracted from plant samples and converted into cDNA. Gene expression analysis was performed using quantitative real-time PCR (qPCR) for selected drought-responsive genes, including DREB, AMADH and DHN. The relative expression levels were calculated using the 2^−ΔΔCt method, with Actin being used as the reference gene for normalization. All reactions were carried out with appropriate technical replicates and expression patterns were analyzed across treatments and genotypes. Results: The gene expression analysis revealed relatively stable expression patterns across most genotypes under both conditions. However, genes such as DREB, AMADH and DHN showed comparatively higher expression under moisture stress in certain MAGIC genotypes. The reference gene Actin exhibited consistent expression across all samples, confirming its suitability for normalization. Although no significant fold changes were observed, minor variations in gene expression indicated coordinated transcriptional responses to drought stress among the evaluated genotypes. Conclusion: The results suggest that drought tolerance in chickpea is governed by subtle and coordinated regulation of multiple genes rather than large expression shifts. DREB, CAP2, AMADH, and DHN showed relative expression trends under drought stress; however, these genes should be considered as potential candidates requiring further validation.