Genome sequencing of Tulsi – a medicinally important herb

Abstract : Tulsi or Ocimum tenuiflorum, is an Indian herb and has been under cultivation for almost 3000 years now. It has a variety of medicinal properties -- anti-bacterial, anti-fungal, anti-pyretic and anti-cancer, to name a few. It is rightly referred as ‘Queen of Herbs’. The herb has been widely used in the Ayurvedic system of medicine. Despite its historical importance and extensive use in traditional Indian medicine, there is very poor understanding of the bioactive compounds produced by Tulsi. There are more than 40 secondary metabolites in Ocimum species, which are exploited by humans to treat diseases, including Apigenin, Citral, Eugenol, Taxol and Urosolic acid. Apigenin, Taxol and Urosolic acid are implicated in anti-cancer properties of the plant, Citral for its anti-septic nature and Eugenol for its anti-infective properties. We have now produced the first draft genome of O. tenuiflorum Krishna subtype at 64% coverage, which is helpful in understanding and identifying the genes responsible for production of metabolites with medicinal properties. Enzymes, involved in the synthesis of 14 of the metabolites could be identified in Tulsi genome and few of them, for instance in the urosolic acid pathway, have been confirmed using RT-PCR techniques.