Identification of potential stress responsive microRNAs and their targets in Cajanus spp.

Plant under stress exercises a variety of changes at genetic and molecular level, including microRNA (miRNA) mediated post-transcriptional gene silencing. MicroRNA is a small endogenous non-coding RNA, which regulates the target genes post-transcriptionally. In the present study, 9 stress responsive miRNAs was successfully identified from available stress related EST libraries of Cajanus species applying computational approach. Six of them namely., miRNA156, miRNA2924, miRNA6214, miRNA5652, miRNA1862 and miRNA7982 are responsive to heat, drought and flood stresses and 3 miRNAs namely, miRNA395, miRNA417 and miRNA867 are disease responsive in Cajanus spp. Three out of 9 miRNAs namely, miRNA156, miRNA6214 and miRNA1862 identified in heat, drought and flood stress libraries, respectively belonged to Cajanus scarabaeoides, a close wild relative of C. cajan. miRNA156, miRNA1862, miRNA395 and miRNA417 target different transcription factors like wrky, cw-type zing finger protein, b3 domain containing protein and bsd domain-containing transcription factors. The target genes of identified miRNAs are playing crucial role in well defined molecular pathways like., cell division, translation machinery, epigenetic modification and ubiquitin proteasome pathway. The stress responsive miRNAs of Cajanus species identified in the present study provides a better understanding of the regulatory role of miRNAs in biotic and abiotic stresses.