In silico Identification and Functional Characterization of Conserved miRNAs in Fibre Biogenesis Crop Corchorus capsularis

Corchorus capsularis, commonly known as jute occupies the leading position in the production of natural fibre and fibre based products alongside lower environmental threat. Nowadays, the study of lignin biosynthesis pathways with other molecular basis of fibres formation are being more focused for its economic perspective. Small noncoding ∼21 to 24 nt nucleotides long microRNAs play significant roles in regulating the gene expression as well as different functions in cellular growth and development. Here, the study adopted a comprehensive in silico approach to identify and characterize the conserved miRNAs in the genome of C. capsularis including specific gene targets involved in the crucial cellular process. Expressed Sequence Tags (ESTs) based homology search of 3350 known miRNAs of dicotyledons were allowed against 763 non-redundant ESTs of jute genome resulted in the prediction of 5 potential miRNA candidates belonging five different miRNA families (miR1536, miR9567-3p, miR4391, miR11300, and miR8689). The putative miRNAs were 18 nucleotide length, within a range of -0.49 to -1.56 MFEI values and 55% to 61% of (A+U) content of their correspondence pre-miRNAs. A total of 1052 gene targets of putative miRNAs were identified and their functions were extensively analyzed. Most of the gene targets were involved in plant growth, cell cycle regulation, organelle synthesis, developmental process and environmental responses. The five gene targets, namely, NAC Domain Containing Protein, WRKY DNA binding protein, 3-dehydroquinate synthase, S-adenosyl-L-Met–dependent methyl transferase and Vascular-related NAC-Domain were found to be involved in the lignin biosynthesis, phenylpropanoid pathways and secondary wall formation which could play significant roles in the overall fibre biogenesis. The characterization of conserved miRNAs and their functional annotation of specific gene targets might enhance the more miRNA discovery, strengthening the complete understanding of miRNAs association in the cellular basis of lignin biosynthesis towards the production of high standard jute products.