Comparative Study of Withanolide Biosynthesis-Related miRNAs in Root and Leaf Tissues of Withania somnifera.

Withania somnifera, popularly known as Indian ginseng, is one of the most important medicinal plants. The plant is well studied in terms of its pharmaceutical activities and genes involved in biosynthetic pathways. However, not much is known about the regulatory mechanism of genes responsible for the production of secondary metabolites. The idea was to identify miRNA transcriptome responsible for the regulation of withanolide biosynthesis, specifically of root and leaf tissues individually. The transcriptome data of in vitro culture of root and leaf tissues of the plant was considered for miRNA identification. A total of 24 and 39 miRNA families were identified in root and leaf tissues, respectively. Out of these, 15 and 27 miRNA families have shown their involvement in different biological functions in root and leaf tissues, respectively. We report here, specific miRNAs and their corresponding target genes for corresponding root and leaf tissues. The target genes have also been analyzed for their role in withanolide metabolism. Endogenous root-miR5140, root-miR159, leaf-miR477, and leaf-miR530 were reported for regulation of withanolide biosynthesis.