Development of a Polygonum minus cell suspension culture system and analysis of secondary metabolites enhanced by elicitation

Polygonum minus has been reported to contain valuable metabolites and to date, there is no report on using cell culture technique for metabolite production in P. minus. Naphthalene acetic acid (NAA) concentrations in the range of 2-6 mg L-1 were used in a matrix of combinations with dichlorophenoxyacetic acid (2,4-D) concentrations in the range of 2-10 mg L-1 as plant growth regulators (PGRs) to induce callus cultures. Media that were supplemented with 2 mg L-1 2,4-D + 4 mg L-1 NAA, 2 mg L-1 2,4-D + 6 mg L-1 NAA and 6 mg L-1 2,4-D + 8 mg L-1 NAA were effective for callus induction (93.3 % of the explants produced callus). To establish cell culture, the best growth was obtained from medium that was supplemented with 1 mg L-1 2,4-D + 2 mg L-1 NAA. From a 1-g inoculum size, the fresh weight increases exponentially after 5-10 days of culture, and a 26.71 g maximum fresh weight was obtained after 25 days of culture. The cell culture medium was then analyzed using gas chromatography-mass spectrometry (GC-MS). Jasmonic acid (100, 50, 25 and 5 mu M), salicylic acid (100, 50, 25 and 5 mu M), yeast extract (500, 250 and 100 mg L-1) and glass beads were used in this research as elicitors. The cell cultures were then incubated with the different elicitors for 1, 2, 3 and 4 days. Several compounds with high peak area percentages were detected, including 2-furancarboxaldehyde, 5-hydroxymethyl, furfural, and 2-cyclopenten-1-one, 2-hydroxy. These results show the diversity of metabolites released by P. minus cell into the culture medium under control conditions.