EN
Seedlings of Trigonella foenum-graecum were treated with four heavy metal salts (CdCl₂, CoCl₂, K₂Cr₂O₇ and NiCl₂) to study the effect of heavy metals on growth and diosgenin production. It was found that CdCl₂ increased diosgenin production up to 40-fold and CoCl₂ increased diosgenin production up to 41-fold at concentrations which did not affect growth significantly. But K₂Cr₂O₇ and NiCl₂ were toxic to growth and inhibited diosgenin production. Effect of exogenously applied methyl jasmonate (MeJa) and calcium (Ca²⁺) on diosgenin production in seedlings of T. foenum-graecum was also investigated. MeJa enhanced the production of diosgenin. Maximum increase (10.5-fold) was found at 100 µL L⁻¹ concentration of MeJa. To study the role of Ca²⁺ on diosgenin production, seedlings of T. foenum-graecum were treated with a promoter of Ca²⁺ influx (calcium ionophore A23187), calcium depleted medium, Ca²⁺ channel blocker (verapamil) and antagonist (LaCl₃), a divalent cation chelator (EGTA) and modulator of calcium release (caffeine). All the treatments were compared with a control containing 220 mg L⁻¹ concentration of CaCl₂. The results suggest that the increase in cytosolic Ca²⁺ has an inhibitory role on diosgenin production. However, a calcium chelator or Ca²⁺ channel inhibitors could be used to elicit diosgenin production in this plant.