Genome-scale transcriptomic insights into molecular aspects of abiotic stress responses in chickpea

Abstract

Chickpea is an important legume crop plant and various abiotic stresses are the major constraints affecting its overall productivity. For discovery of candidate genes involved in abiotic stress responses, we employed RNA sequencing for transcriptome profiling of roots and shoots of chickpea seedlings subjected to desiccation, salinity, and cold stresses. In total, we generated more than 250 million high-quality reads from non-stressed and stressed tissue samples. Data analyses provided a comprehensive view of the dynamic transcriptional response of chickpea tissues to different abiotic stresses. Differential expression analysis identified a total of 11,640 chickpea transcripts showing response to at least one of the stress conditions. The reference-based transcriptome assembly was generated and at least 3,536 previously unannotated gene loci differentially expressed under abiotic stress conditions were identified. We observed extensive transcriptional reprogramming of genes involved in transcription regulation, energy metabolism, photosynthesis, hormonal responses, secondary metabolite biosynthesis and osmoprotectant metabolism under stress conditions. In addition, genes involved in post-translational modifications, RNA metabolic processes, and epigenetic regulation were also significantly highlighted. The comprehensive transcriptome analyses presented in this study revealed several potential key regulators of plant response to abiotic stresses and open avenues to carry out functional and applied genomic studies for improving abiotic stress tolerance in chickpea.