Effects of elicitors on secondary metabolite (SM) production and antioxidant activity in sweet basil (Ocimum basilicum L.) cell suspension cultures

Abstract

Elicitor treatments play an important role in inducing some protective signal transmitter enzymes in cells and regulating phenylalanine ammonia-lyase (PAL) activity. The aim of this study was to determine the effects of elicitors [silver nitrate (AgNO3), salicylic acid (SA) and yeast extract (YE)], which were added individually or in combination to Ocimum basilicum L. cell suspension cultures, on the production and antioxidant activity of secondary metabolites (SMs). Calluses were obtained from the leaves of O. basilicum kept on Murashige and Skoog (MS) medium containing 0.5 mg/l kinetin (KIN) + 2.5 mg/l naphthalene-acetic acid (NAA) and cell suspension cultures were initiated. Then elicitors were applied to the cell suspension cultures individually or in combination, and cells were harvested at the end of the second, fourth, and eighth days. Compared with the control culture, the maximum rosmarinic and chicoric acid production was obtained at the end of the 4th day from SA (24 µM) + YE (80 mg/l) treatment as 20.19 mg/g DW (118%) and 7.55 mg/g DW (123%), respectively. The maximum biosynthesis of isoquercetin and rutin compared with the control culture was 3.88 mg/g DW [YE (80 mg/l)] with a 1.6-fold increase and 6.35 mg/g DW [YE (80 mg/l) + AgNO3 (6 µM)] with a 1.76-fold increase, respectively. Estragole and linalool's highest values compared with the control culture were 4.50 μg/g DW [AgNO3 (6µM) + SA (24 µM)] and 3.02 μg/g DW [SA (24 µM)], respectively. Results clearly show that the elicitor treatment could enhance the biosynthesis of phenolic compounds and terpenoid content in cell suspension cultures of O. basilicum and may be used for commercial supply in the future for therapeutic applications.