Effect of the Nitrogen Source on the Synthesis of Secondary Metabolites by Suspension Culture of Medicinal Asparagus Asparagus officinalis L.

Abstract

Medicinal asparagus contains unique compounds that can stop the development of cancerous tumors and even destroy cancer cells. However, there is still insufficient information about the features of the biosynthesis of these compounds and the conditions for their production. In this paper, the influence of an inorganic nitrogen source on the growth of a suspended culture of medicinal asparagus, the accumulation of phenolic compounds in the culture and culture liquid, and the synthesis of saponins is studied. A callus and suspension culture of medicinal asparagus Asparagus officinalis L. were obtained under in vitro conditions. For further research, concentrations of growth regulators 1 mg/L kinetin and 1.5 mg/L 2,4-D were selected. The fastest growth of the suspension culture was established on the medium with a concentration of potassium nitrate of 1900 mg/L and ammonium sulfate of 250 mg/L. Individual explants demonstrated spontaneous differentiation of callus tissue that affected the increase in callus mass and the ratio of the concentration of exophenols to the total mass of the explant. The highest concentrations of endo- and exophenols were obtained on a medium without ammonium nitrogen sources. A positive effect of the medium with a concentration of ammonium sulfate of 500 mg/L on the synthesis of the main steroidal saponins of Asparagus officinalis L. was determined. As a result of the study, a modified MS medium was developed that promotes the accumulation of steroid saponins in a suspension culture of medicinal asparagus.