Induction of specialized metabolites in hairy rootS of Scutellaria lateriflora treated with cyclodextrin and methyl jasmonate

Scutellaria lateriflora (American skullcap) is a plant in the mint family (Lamiaceae) which produces biologically active flavonoids exhibiting antioxidant and anticancer properties. In order to develop a bioproduction system to study the biosynthesis of these compounds, hairy root cultures were developed using Agrobacterium rhizogenes and line SL-4 was selected for further studies because of its growth performance in liquid medium. In the present work, we studied the effect of methyl jasmonate and cyclodextrin on production of specialized metabolites in these hairy root cultures. Thirty-day-old hairy root cultures were treated with 0.75, 7.5 or 15 mM of cyclodextrin alone or combined with 100µM of methyl jasmonate (MeJA). As controls ethanol (solvent of MeJA), cyclodextrin and MeJA alone were used. After 24 hours of treatment, the roots and culture medium were collected and the metabolites were extracted with ethyl acetate. The extracts were further analyzed by HPTLC and HPLC. The HPTLC system was developed in order to rapidly detect the presence of known and unknown compounds. The levels of the known Scutellaria flavonoids baicalin, baicalein and wogonin did not vary significantly in the roots or medium upon the above treatments, however at least 10 novel compounds were induced upon treatment with MeJA and cyclodextrin. Our results suggest that this strategy could be used to induce and identify novel bioactive compounds in this medicinal plant.