Enhanced anthraquinone production in presence of silver nitrate in suspension culture of Gynochthodes umbellata (L.) Razafim. & B. Bremer (Rubiaceae), a traditional medicinal plant mentioned in Hortus Malabaricus

Silver nitrate (AgNO3) enhanced production of anthraquinone was standardized in cell suspension cultures of Gynochthodes umbellata, a plant mentioned in the Hortus Malabaricus. The present research investigates the effect of silver nitrate, an abiotic elicitor on production of anthraquinone in in vitro cell suspension cultures of G. umbellata. Friable callus culture was established using in vitro derived leaf segment obtained from the nodal explant culture maintained in Murashige and Skoog (MS) medium containing 2 mg/l benzyl amino purine (BAP) and 3% sucrose. The in vitro derived leaf segments (0.5cm2) were cultured on MS medium containing 1 mg/l 2,4-D and 2% glucose for the production of friable callus. After 30 days of culture, uniform yellow friable callus was inoculated into MS liquid medium containing 1 mg/l 2,4-D and 2 % glucose for raising suspension culture. Uniform cell suspension was transferred to same media constituents and treated with different concentrations of AgNO3 on 25th day of culture. Fresh weight, dry weight and accumulation of anthraquinone content was studied and found that AgNO3 caused a marginal increase in biomass and anthraquinone based on the concentration and duration of AgNO3 treatment. A maximum fresh weight (19.48 g/fwt) dry weight (1.92g/dwt) and highest amount of anthraquinone content (48.62 mg/gdwt) were recorded in MS medium supplemented with 1 mg/l 2,4-D, 2%glucose and 3.5μM AgNO3 after 72 hrs of incubation.