Transcriptome profiling of the early-response in chickpea to cold stress

In this study, transcriptome responses of cold-tolerant (Sel96Th11439) and cold-sensitive (ILC533) chickpea genotypes were evaluated under short-term cold stress (4˚C). The hydrogen peroxide (H2O2), lipid peroxidation (MDA) and electrolyte leakage content increased significantly under cold stress in sensitive more than tolerant plants. In tolerant genotype, 526 genes showed significant expressions; 261 and 265 genes were up-and down-regulated, respectively, while in sensitive genotype, 901 genes showed significant patterns of expression; 295 and 606 genes showed increases and decreases in their expressions, respectively. In both genotypes and under cold conditions, the down-regulated genes had more frequencies than up-regulated genes. Also, the down-regulated genes in sensitive plants were 2.3-fold compared to tolerant ones. 216 genes, which were up-regulated in tolerant plants, showed decreased expression in sensitive plants under cold stress, among which 15% were transcription factors. Based on identified transcript patterns, those genes involved in biosynthetic pathway of some metabolites were significantly increased in tolerant genotype whereas they were decreased in sensitive genotype. The level of transcript in 31 genes showed significant increase and decrease in sensitive and tolerant genotypes, respectively and10% of these genes were histone producer. Findings indicate the crucial role of early responses, particularly transcription factors and epigenetic changes in cold tolerance in chickpea seedlings.