Increase of diosgenin in fenugreek seedlings by cobalt nanoparticles

Diosgenin is the most important steroidal saponin in fenugreek, with multiple medicinal properties. Increasing the production of diosgenin in fenugreek requires stimulating the production of saponins. The production of saponins or secondary metabolites is affected by biological and non-biological elicitors. The main aims of this study were investigate whether cobalt nanoparticles as an abiotic elicitor in Murashige and Skoog (MS) medium affect produced diosgenin in roots and shoots of fenugreek, and comparison of produced diosgenin between the shoots and roots. Experimental treatments were different concentrations of cobalt nanoparticles (0, 100, 200 and 300 μM l−1) in the MS medium in vitro, and the treatments’ effects were examined in a statistical model of a completely randomized design with four replications. Experimental variables included some components of fenugreek vegetative growth, production of diosgenin in shoots and roots, as well as expression of genes involved in diosgenin biosynthesis pathway (Squalene monooxygenase (SQS), Cycloartenol shynthase (CYC), 26_o_beta_glucosidase (BGL). The most important results showed that first the maximum level of produced diosgenin in roots, and later in shoots was obtained in a MS medium without micro cobalt which contain only 300 μM l−1 of cobalt nanoparticles. The results demonstrated that the enhancement of diosgenin was associated with increased expression of the genes related with diosgenin biosynthesis pathway. The diosgenin was elevated in fenugreek following high concentration of cobalt nanoparticles application.