ORIGINAL ARTICLE Increasing the synthesis of bioactive abietane diterpenes in Salvia sclarea hairy roots by elicited transcriptional reprogramming M. C. Vaccaro 1 • A. Mariaevelina 1 • N. Malafronte 1 • N. De Tommasi 1 • A. Leone 1 Received: 5 July 2016 / Accepted: 8 November 2016 / Published online: 16 November 2016 Ó Springer-Verlag Berlin Heidelberg 2016 Abstract Key message Transcriptional activation of genes belonging to the plastidial MEP-derived isoprenoid pathway by elicitation with methyl jasmonate and coronatine enhanced the content of bioactive abietane diterpenes in Salvia sclarea hairy roots. Abstract We have shown that aethiopinone, an abietane diterpene synthesized in Salvia sclarea roots is cytotoxic and induces apoptosis in human melanoma cells. To develop a production platform for this compound and other abietane diterpenes, hairy root technology was combined with the elicitation of methyl jasmonate (MeJA) or the phytotoxin coronatine (Cor). Both MeJA and Cor induced a significant accumulation of aethiopinone, but prolonged exposure to MeJA irremediably caused inhibition of hairy root growth, which was unaffected by Cor treatment. Considering toge- ther the fold increase in aethiopinone content and the final hairy root biomass, the best combination was a Cor treat- ment for 28 days, which allowed to obtain up to 105.34 ± 2.30 mg L -1 of this compound to be obtained, corresponding to a 24-fold increase above the basal content in untreated hairy roots. MeJA or Cor elicitation also enhanced the synthesis of other bioactive abietane–quinone diterpenes. The elicitor-dependent steering effect was due to a coordinated transcriptional activation of several biosyn- thetic genes belonging to the plastidial MEP-derived iso- prenoid pathway. High correlations between aethiopinone content and MeJA or Cor-elicited level of gene transcripts were found for DXS2 (r 2 = 0.99), DXR (r 2 = 0.99), and GGPPS (r 2 = 0.98), encoding enzymes acting upstream of GGPP, the common precursor of diterpenes and other plastidial-derived terpenes, as well as CPPS (r 2 = 0.99), encoding the enzyme involved in the first cyclization steps leading to copalyl-diphosphate, the precursor of abietane- like diterpenes. These results point to these genes as possible targets of metabolic engineering approaches to establish a more efficient production platform for such promising anti- proliferative plant-derived compounds. Keywords Bioactive abietane diterpenes  Salvia sclarea hairy roots  Elicitation  Transcriptional reprogramming Introduction Plant diterpenes are one of the largest and most diverse classes of plant metabolites, with more than 10,000 different structures already described. Diterpenes are characterized by a C-20 hydrocarbon backbone and derived from the universal substrate C-20 geranylgeranyl pyrophosphate (GGPP), which is synthesized through the plastidial MEP- derived isoprenoid pathway. Several plant diterpenoids have well-established antitumor activities, such as the most widely used breast cancer drug taxol (Weaver 2014) or ingenol-3-angelate from Euphorbia peplus, a promising skin cancer chemotherapeutic agent, used in a topically applied formulation and evaluated in clinical trials (Song The original version of this article was revised: The second author ‘‘M. E. Alfieri’’ was incorrect. This error has been corrected. Communicated by E. Benvenuto. Electronic supplementary material The online version of this article (doi:10.1007/s00299-016-2076-x) contains supplementary material, which is available to authorized users. & A. Leone aleone@unisa.it 1 Department of Pharmacy, University of Salerno, Via Giovanni Paolo II 134D, 80084 Fisciano, Italy 123 Plant Cell Rep (2017) 36:375–386 DOI 10.1007/s00299-016-2076-x