Phytochemical analysis and enhanced production of alkaloids in non-dormant corm-derived callus of Gloriosa superba (L.) using plant growth regulators and abiotic elicitors

This study focuses on investigating the elicitation of non-embryogenic calli derived from non-dormant corm buds of the endangered medicinal plant Gloriosa superba L., renowned for its role as a primary natural source of the crucial alkaloid—colchicine. Various Murashige and Skoog (MS) based liquid media treatments, incorporating diverse combinations and concentrations of additives, abiotic elicitors, and plant growth regulators, were employed to explore their impact on calli biomass proliferation, phytochemical composition, and alkaloid content. Qualitative phytochemical screening identified major chemical constituents, and quantitative analysis revealed that elicitation with varied abiotic elicitors increased biomass and metabolite content in liquid callus cultures. The most significant outcomes, including the highest average total alkaloid content (0.425 mg (colchicine equivalent)/g dry weight), colchicine content (0.212 mg/g dry weight), and callus biomass (259 mg fresh weight and 32.5 mg dry weight), were achieved with specific MS media supplementation [1.5 mg/L benzylaminopurine (BAP) + 0.5 mg/L 1-naphthalene acetic acid (NAA) + 3% sucrose (w/v) + 1.0 mg/L coumaric acid + 1.5 mg/L phenylalanine + 5 mg/L casein hydrolysate (CH) + 20% coconut water (CW)] and a 4/20-h photoperiod. Notably, the seeds of Gloriosa superba L. exhibited the highest content of total alkaloids (0.283 mg (colchicine equivalent)/g dry weight) and colchicine (0.167 mg/g dry weight) among various plant parts. Our study conclusively demonstrates that the developed in vitro elicitation protocol significantly enhances colchicine and alkaloid production in the liquid callus culture compared to wild plant components. This promising approach holds potential for the sustainable production of this valuable alkaloid, addressing high demand and the challenges associated with the conservation of this endangered medicinal plant.