Effect Of Elicitors On Effective Compound Content In Adventitious Roots And Antioxidant Activity Of Oplopanax Elatus

Oplopanax elatus Nakai is a perennial woody medicine plant,which contains various bioactive compounds such as polysaccharides,phenolics,and flavonoids.However,the industrial production of products in this species has been limited due to the shortage of the resource.Therefore,this study attempted to improve the effective compound accumulation by the treatment of several elicitors during adventitious root(AR)culture and the antioxidant activity in ARs was also evaluated.In the present study,methyl jasmonate(MeJA),salicylic acid(SA),and pulullan(PA)were used as the elicitors to conduct AR suspension culture.The effective compound(polysaccharides,phenolics,and flavonoids)production was better when ARs were treated with MeJA or SA after 40 d of culture than at initial culture.The MeJA of 200?M was optimal for polysaccharide,phenolic,and flavonoid accumulation.100 ?M SA promoted phenolic and flavonoid production but was not beneficial for polysaccharide accumulation.The suitable concentration of PA was different according to the treatment time,the effective compound production was favorable when adventitious roots were treated with 150 mg·L-1 PA at initial culture and 200 mg·L-1 PA after 40 d of culture for 10 days.Elicitor treatment days affected effective compound accumulation.The contents of polysaccharides,phenolics,and flavonoids were significantly enhanced when adventitious roots were treated with 200?M MeJA and 100 pM SA for 4 d after 40 d of AR culture.The finding of the comparasion among the different elicitors and their combination indicated that MeJA was the optimal elicitor for production of effective compounds in O.elatus during AR suspension culture.To mass production of O.elatus effective compounds,bioreacrtor systems were used to culture ARs.During bioreactor culture,the maximum contents of effective compounds were determined on day 30 but the yield on day 40.Therefore,ARs were treated with different concentrations of MeJA for different days after 30 d and 40 d of culture,respectively.The maximum productivities of effective compounds were found when ARs were treated with 200?M MeJA for 8 days after 30 d of AR bioreactor culture,3135.35 mg·L-1 of polysaccharides,573.76 mg·L-1 of phenolics,and 1868.93 mg-L-1 of flavonoids were obtained.Effective compound accumulation among the different sources of O.elatus were compared.The contents of the effective compounds(polysaccharides,phenolics,and flavonoids)in ARs were significantly higher than those in roots of field-grown 3-year-old plants.Polysaccharide,phenolic,and flavonoid contents in ARs were 1.8-fold,2.5-fold,and 5.0-fold more than in field-grown roots,respectively.Finally,the antioxidant activity of O.elatus was studied by evaluating the DPPH scavenging ability,chelating ability,and reducing power.The antioxidant activity in the extract of bioreactor-cultured ARs was significantly higher than that in the extract of field-grown 3-year-old roots.