Improvement of bioactive compound accumulation in adventitious root cultures of an endangered plant species, Oplopanax elatus

Abstract

Efficiently culturing adventitious roots (ARs) has become an alternative route for the protection and utilization of endangered plant resources. In the present study, to improve accumulation of bioactive compounds (polysaccharides, phenolics, and flavonoids) in AR cultures of endangered plant species—Oplopanax elatus—effects of methyl jasmonate (MeJA) and salicylic acid (SA) were investigated. The optimal concentration of MeJA was 200 μM and SA was 100 μM for enhancement of polysaccharide, phenolic, and flavonoid contents. In addition, MeJA (200 μM) was more suitable than SA (100 μM) for polysaccharide and flavonoid production, but both elicitors were equally favorable for phenolic production. During AR bioreactor culture, MeJA was as an elicitor to study the effect of its addition time and contact time. Contents of polysaccharides, phenolics, and flavonoids increased when MeJA was added to culture medium after 40 days of culture, but the increased degree was lower and the AR biomass significantly inhibited. However, when MeJA was added to culture medium after 30 days of culture, polysaccharide, phenolic, and flavonoid contents dramatically increased without AR biomass decrease; the maximum productivity of three bioactive compounds was found on day 8 after the MeJA treatment. Therefore, a novel elicitation method during bioreactor culture of O. elatus ARs was established in the present study, the method could be applied to commercial production of O. elatus products in the future.