Comparative transcriptomic analysis of the chickpea glutaredoxin ( CaGrx ) gene over-expressed in Arabidopsis thaliana is associated with drought tolerance by modulating the plant defense system

Glutaredoxins (Grxs) are glutathione (GSH)-mediated, small (10–15 kDa) oxidoreductases. In the present investigation, transgenic Arabidopsis thaliana over - expressing a glutaredoxin gene [ LOC101493651 ( CaGrx )] of chickpea ( Cicer arietinum L.) has been evaluated against drought, and further transcriptomic studies were performed to know the effect of the CaGrx gene in transgenic Arabidopsis in drought tolerance along with wild-type (WT) and control © plants. A total of 1070 (transgenic) and 1423 (wild-type) significant differentially expressed genes (DEGs) were identified from the comparative analysis with control. Out of significant DEGs, 530 and 567 were up-regulated, and 540 and 856 were down-regulated in transgenic and wild-type (WT) plants, respectively. The Kyoto Encyclopedia of Genes and Genomes database (KEGG) identified 32 (Transgenic) and 20 (WT) metabolic pathways from the obtained unigenes. Tolerance against drought in the transgenics over-expressing CaGrx gene was by elevating the expression of genes involved in the plant defense system. This CaGrx administered tolerance in transgenics against drought by elevating glutaredoxin enzyme activity that induced various antioxidant enzymes antioxidants and reduced the level of stress markers. Leaf staining showed less H 2 O 2 accumulation in transgenics as compared to higher accumulation in WT which shows a less stressful environment in transgenics under drought stress. Vast numbers of drought-responsive genes were retrieved, and among them, 28 differentially expressed genes (DEGs) were selected for quantitative real-time PCR that affirmed the reproducibility of the RNA-seq data.