Micropropagation and Molecular Characterization of Picrorhiza Kurroa Chemotypes for Picroside-i Production

Abstract

Picrorhiza kurroa is a medicinally important perennial herb found at an altitude of 3000-5000 m commonly known as “Kutki” or “Kutaki” from Scrophulariaceae plant family located in the Himalayan region. Plant is now listed as endangered species. It has many valuable compounds which offer many uses of Picrorhiza kurroa such as hepatoprotective, antioxidant, anti-inflammatory, antiallergic, antiasthmatic, anti-oxidant, anticancerous, anti-bacterial, anti-anaphylactic, anti-malarial, cardioprotective and immune-modulating and potential for treatment of vitiligo. The two main iridoid compounds present in Picrorhiza kurroa are Picroside-I and Picroside-II which are used in many herbal drugs commercially available in different combinations. P. kurroa plant chemotypes have varied amount of P-I when grown in field conditions. Two chemotypes of high Picroside-I content PKS-1 and PKS-21 and two of low Picroside-I content PKS-4 and PKS-5 of P. kurroa were selected. The Micropropagation in multiple shoot induction medium showed 21.33 as highest no of shoots, 5.98 cm as highest shoot length and 35.60 g highest number of shoot biomass in PKS-4 followed by PKS-1, PKS-5 and least in PKS-21. The highest P-I content 0.1961mg/g was observed in PKS-21 followed by PKS-1, PKS-5 and least in PKS-4. The gene expression analysis showed expression levels of G10H, PAL, ISPE, HMGR, DXPS, GS, PMK in accordance with levels of P-I which was found to be highest in PKS-21 which proved the association of these genes to P-I synthesis. So the interventions in these genes can be done to increase the P-I content in P. kurroa.