Hairy Root Induction for Production of Bioactive Metabolites from Picrorhiza kurroa Royle ex Benth

Abstract

Picrorhiza kurroa Royle ex Benth (kutki) is a community herb of local tribes of Uttarakhand. This plant is habitant of Himalaya found at the ranges between (3000-5300m) from mean sea level (msl). Significance is undoubtedly proven for various ailments and their care management. An excessive damage from natural habitat threatened the existence of this particular herb by virtue of unsustainable harvesting practices, habitat behavior due to changing climate effect. As a result its natural population is being diminishing upto an extent of its extinction. Our laboratory research data based on various experiments conducted during in vitro growth and development with special reference to hairy roots. Leaf explants were used for initial callus induction on media containing Thidiazuron (TDZ) (2.27 μM). Induced callus(s) on basal Murashige and Skoog (MS) media with desired phytoregulators selected on the basis of required responses include Naphthalene-1-acetic acid (NAA) (2.15µM) and Indole-3-acetic acid (IAA) (2.28µM). Hairy root induction and subsequent proliferation from callus(s) was observed. Indirectly regenerated shoot tips from callus(s) upon sub culturing with NAA (10.74µM) and IAA (11.42µM) showed hairy roots in addition to normal regenerated roots. Indirectly regenerated leaves while inoculated as further explants(s) from indirectly regenerated plantlet with NAA (2.15µM) and IBA (2.95µM) showed hairy root development upto a greater extent compared to various phytoregulator and their combination.NAA (2.15µM) alone showed hairy root induction while nodal regions of regenerated plantlets were used as explants. Picroside-II, the principal iridoid glycoside of Picrorhiza kurroa, was quantitatively analyzed using High-Performance Liquid Chromatography (HPLC), enabling precise determination of this key bioactive compound. This attempt provides an opportunity to generate the desired plant material for further extraction of bioactive metabolites alongwith sustainable conservation strategy for Picrorhiza kurroa.