Exploring the drought-responsive miRNAs and their corresponding target genes in chickpea root tissue.

Chickpea is an important pulse crop globally, with major production in Southeast Asia. However, the production of chickpea is hampered due to various biotic and abiotic stressors. In response to such stressors, microRNAs which are small non-coding regulatory RNA molecules have been observed as key players. The present study evaluates the role of drought-responsive microRNAs in the root tissues of chickpea genotypes contrasting for drought tolerance. This study led to the generation of 146.7 million short-read sequences from small RNA libraries constructed from the root tissues of the two genotypes. Upon analysis, 224 conserved and 155 novel miRNA sequences were identified. The miR156 family was found to be the most abundant among the 51 families identified for the conserved miRNAs. Quantitative real-time PCR (qRT-PCR) was used to validate eleven conserved and six novel miRNAs. The identification of drought-induced expression of specific miRNAs and their related target genes suggests miRNA-mediated response mechanisms in chickpea. Furthermore, this research investigated the role of drought-responsive miRNAs, specifically miR171 and miR166 and their target genes, SCL27 (scarecrow-like protein 27) and ATHB15 (Homeobox-leucine zipper family protein), respectively. The study validated the miR171 and miR166 directed cleavage of SCL27 and ATHB15, respectively, in drought-stressed root tissues using 5´RLM-RACE (5' RNA Ligase-Mediated Rapid Amplification of cDNA Ends) analysis. The study highlights the role of diverse miRNAs in chickpea for mitigating drought.