REVIEW Potential and Prospects of Shikonin Production Enhancement in Medicinal Plants Minakshi Pal 1 • Vinod Kumar 2 • Rakesh Yadav 3 • Deepika Gulati 1 • R. C. Yadav 1 Received: 16 December 2016 / Revised: 26 October 2017 / Accepted: 1 November 2017 Ó The National Academy of Sciences, India 2017 Abstract Plants are a rich source of valuable chemicals that are used as herbal and modern medicines. Shikonin, a naphthoquinone red pigment, produced from roots of Arnebia hispidissima, A. euchroma, Lithospermum ery- throrhizon and other Boraginaceous species was the first phytochemical to be produced on commercial scale using biotechnological approach. Plant cell culture technologies were the only tools employed for secondary metabolites production in other cases in past. Shikonin production and localization is tissue specific with stringent metabolic regulation. Hence, the differentiated cultures such as those of hairy root cultures offer a great promise for secondary metabolite production. A. rhizogenes-mediated transformed roots are characterized by high growth rate, genetic sta- bility and growth in hormone free media. These genetically transformed root cultures can produce larger amounts of secondary metabolites. The present review deliberates upon potential and prospects of diverse physico-chemical factors that affect shikonin production in tissue culture, as well as, the genetic modification for enhancement of shi- konin production. Keywords Arnebia euchroma Á Arnebia hispidissima Á Lithospermum erythrorhizon Á Phytochemicals Á Secondary metabolites Á Shikonin List of symbols ABA Abscisic acid BAP 6-Benzylaminopurine B 5 Gamborg’s medium CaMV35S Cauliflower mosaic virus 35S promoter 2,4-D 2,4-Dichlorophenoxy acetic acid DA Davydenkov arnebia medium DOPA L-3,4-Dihydroxyphenylalanine GA 3 Gibberellic acid GUS b-Glucuronidase HMGR Hydroxymethylglutaryl CoA reductase HPLC High pressure liquid chromatography HPT Hygromycin phosphotransferase IAA Indole acetic acid LS Linsmaier and Skoog’s medium MeJa Methyl jasmonate MS Murashige and Skoog’s medium NAA a-Naphthalene acetic acid PAL Phenylalanine ammonia-lyase PFP P-fluorophenylalanine PVP Polyvynilpirrolidone RC Root culture medium TDZ Thidiazuron TLC Thin layer chromatography Significance statement ‘Shikonin, a naphthoquinone red pigment, produced from roots of A. hispidissima and other Boraginaceous species was first phytochemical produced on commercial scale. This review describes enhanced shikonin production strategies from medicinal plants’. & Minakshi Pal minakshiarnav@gmail.com 1 Centre for Plant Biotechnology, Haryana State Council for Science and Technology, CCSHAU New Campus, Hisar 125001, India 2 Department of Biotechnology, Eternal University, Baru Sahib, Sirmour, Himachal Pradesh 173101, India 3 Department of Bio and Nano Technology, Guru Jambheshwar University of Science and Technology, Hisar 125001, India 123 Proc. Natl. Acad. Sci., India, Sect. B Biol. Sci. https://doi.org/10.1007/s40011-017-0931-3