Differential Gene Expression Pattern of Drought Responsive Transcription Factors in Chickpea: An Expressional Analysis

Chickpea ( Cicer arietinum L.) is an important grain crop mainly grown in arid and semi-arid regions of the world. Drought is the major factor limiting chickpea growth and productivity. Transcription factors (TFs) genes have been reported as key regulators of drought tolerance in plants. In this study, we determined the relative gene expression of transcription factors of WRKY , DREB2A , and CarNAC3 in three weeks seedlings of tolerant (MCC537) and susceptible (MCC674) genotypes under progressive water deficit through semi-quantitative reverse transcriptase PCR (SqRT-PCR) method. Furthermore, results of SqRT-PCR were more confirmed by quantitative PCR (qPCR). Relative gene expression analysis of the selected genes using qPCR revealed different dehydration-responsive expression patterns. The expression of WRKY gene was significantly induced in both tolerant and sensitive genotypes under severe drought stress (at the last time point). Also, in tolerant genotype, DREB2A gene was approximately expressed three, five and fourfold higher than control plants at three times points, respectively. Moreover, the expression level of CarNAC3 gene in this genotype increased four and twofold higher compared to the relative control at 2 and 4 days after stress, respectively. However, the expression of these genes in the susceptible genotype was constant or decreased relative to the control. Furthermore, the CarNAC3 and DREB2A genes showed higher and more effective expression than the WRKY gene. Overall, the results demonstrated that these TFs may play an important role to improve drought tolerance and have a potential to facilitate molecular breeding and development of drought-tolerant chickpea varieties.