In-silico Genome Wide Identification and Expression Analysis of Wrky Gene Family Members in Chickpea (Cicer Arietinum L.) in Response to Drought Stress

Abstract

The response of drought stress on morpho-physiological and biochemical characters was assessed in chickpea genotypes in a pot culture experiment. Water stress was applied at vegetative stage of the crop and various morpho-physiological and biochemical characters were analyzed under control and drought stress conditions. Based on these studies, genotypes ICC 4958 and ICC 867 identified as tolerant to drought stress conditions. Relative water content, chlorophyll, proline content and peroxidase activity could be useful to screen for drought tolerance in chickpea. An attempt was made to analyze WRKY genes in chickpea using iTak database are used to obtain gene data. This study reported 61 CarWRKY genes, located on the seven main chromosomes of chickpea. Great variations were reported in terms of protein length, molecular weight, grand average of hydropathicity (GRAVY) value and theoretical isoelectric points of CarWRKYs. Gene Structure Display Server (GSDS) demonstrated that the CarWRKY56 gene lack introns. Phylogenetic analysis of CarWRKY proteins divided in three main groups (I, II and III); group II was divided into three subgroups like IIa, IIb, and IIc. Transcription factors have been reported to be the key regulators of drought tolerance. In this study, we analyzed the expression profile of WRKY transcription factor in the leaves of tolerant (ICC 4958; ICC 867) and susceptible (Vishal; DCP-92-3) chickpea genotypes under dehydration period after 40 days of sowing at 3 amplicon cycles (25, 30 and 35 cycles) after irrigation withdrawal to assess the relation between the differential expression levels of this gene and related drought tolerance of these genotypes. Gene expression analysis using semiquantitative PCR indicated that WRKY was significantly induced by drought stress. At the last time point, the expression level of this gene was significantly increased upregulated than control plants under drought condition. The results demonstrated that this TF may play a critical role in drought tolerance.