Obtaining and Investigation of Callus and Suspension Plant Cell Cultures of Tribulus terrestris L., a Producer of Steroidal Glycosides

Abstract

Callus and suspension plant cell cultures of Tribulus terrestris L, a valuable medicinal plant producing steroidal glycosides, have been obtained. The seeds of T. terrestris from an American population were used as explants. The regulation of cell cultures obtaining and growth, as well as the biosynthetic characteristics of the cell lines were studied. The combination of phytohormones of 2,4-D (2.0 mg/L) and BAP (1.0 mg/L) was found to be optimal for the callus induction and cultivation. The suspension cell culture obtained in the liquid medium of the same composition showed such high growth characteristics during the prolonged cultivation (more than 2 years), as maximum accumulation of dry biomass of 13 g/L, specific growth rate at exponential phase of 0.25 day -1 , and economical coefficient of 0.39. A semi-continuous mode of cultivation was used to grow the plant cell suspension in a lab-scale bioreactor. The screening of steroidal glycosides in the obtained cell cultures was carried out. In the callus cultures, steroidal glycosides were not found. However, it was established by TLC and UPLC ESI MS that the suspension culture contained furostanol glycosides, and their amount increased during the cultivation process. These results support the hypothesis of the autoselection of cultivated cells that contain compounds promoting their proliferation in vitro.