Effect of cytokinins on shoots proliferation and rosmarinic and salvianolic acid B production in shoot culture of Dracocephalum forrestii W. W. Smith

TLDR: In this paper, the effect of different cytokinins on shoot proliferation and biosynthesis of caffeic acid derivatives in Dracocephalum forrestii in vitro culture was analyzed using UPLC-PDA-ESI-MS.

Abstract: The current study estimates the effect of different cytokinins on shoot proliferation and biosynthesis of caffeic acid derivatives in Dracocephalum forrestii in vitro culture. The shoots were grown on Murashige and Skoog (MS) agar medium with 1 µM indole-3-acetic acid (IAA) and different content of 6-benzyloaminopurine (BAP), zeatin, kinetin (1, 2, 4, 8, 18 µM) or thidiazuron (TDZ) (0.1, 0.2, 0.5, 1, 2 µM). The highest multiplication rate (about seven shoots and/or buds per explant) was obtained after 4 weeks of culture on MS medium with 1 µM IAA and 8 or 16 µM BAP. Optimal biomass of plant material was also received on the same media. The identity of the compounds present in the hydromethanolic extracts from D. forrestii shoots grown on cytokinin-supplemented media was confirmed using UPLC–PDA–ESI–MS method. The analysis revealed the presence of nine metabolites recognized as caffeic acid derivatives. The content of the predominant phenolic acids in the extracts, i.e. rosmarinic acid (RA) and salvianolic acid B (SAB), was determined with UHPLC. The highest yield of RA was found in shoots cultivated in the medium containing 1 µM IAA and 2 µM BAP (18.7 mg/g DW). The highest level of SAB (5.3–5.9 mg/g DW) was identified in multiple shoots grown in the presence of 1 µM IAA and 0.5–1 µM TDZ or 2 µM BAP.