LAUSR

Abstract The roots of Indian ginseng, Withania somnifera (L.) Dunal (Solanaceae) are extensively used in ayurvedic and other traditional medicines. The plant produces a steroidal lactone, withanolide which has multiple health benefits. Squalene synthase plays a central role in regulating the withanolide biosynthetic pathway in W. somnifera. The present approach investigated the up-regulation of squalene synthase in withanolides biosynthesis pathway in hairy roots. The higher expression of squalene synthase was noticed in hairy root line Ws9 which exhibited withanolide A (2.82 mg/g DW), withanolide B (1.34 mg/g DW), withaferin A (1.83 mg/g DW) and withanone (1.97 mg/g DW) on the 40th day of culture with 1.08 to 1.25-times higher, respectively. Semi-quantitative and quantitative polymerase chain reaction confirmed the incorporation and expression of squalene synthase in cultured hairy roots.