Effect Of Alternaria Panax Elicitor On Ginsenoside Accumulation And Related Signal Molecules In Adventitious Roots Of Panax Ginseng

At present Methyl jasmonate(abiotic elicitor)is mainly used as elicitor to treat adventitious roots in the process of adventitious root culture of Panax ginseng.However,due to the high price of methyl jasmonate,large-scale production has been greatly burdened So,it is of great significance to select a cheap,easily accessible and efficient inducer to replace methyl jasmonate.In addition,when elicitors induce the accumulation of ginsenosides in adventitious roots of Panax ginseng,the identification of signal molecule transduction is of positive significance to the regulation of saponins,but there is still no research report in this regard.In this study,adventitious roots of ginseng cultured in a reactor for 30 days were used as experimental materials,Alternaria panax was used as biotic elicitor.The effects of different concentration and treatment time of using methods(polysaccharide extract,homogenate and mycelium)on ginsenoside synthesis in adventitious roots of Panax ginseng were studied.It was found that the optimum using method of Alternaria panax was homogenate.When treated with 200 mg·L-1 homogenate for 8 days,the content of ginsenoside adventitious roots of Panax ginseng was the highest It is 3.78 time than control group).In the aspect of signal transduction,NO level,NOS activity and ginsenosides content in adventitious roots of Panax ginseng treated with Alternaria panax increased significantly.On this basis,the effect of SNP,NO inhibitor c-PTIO,NOS inhibitors L-NAME and PBITU on NOS activity,NO level and ginsenoside content in adventitious roots of Panax ginseng induced by Alternoria panax were studied The results show that Alternaria panax rely on NOS-mediated NO signaling pathway to induce the accumulation of ginsenosides in adventitious roots of Panax ginseng.When the adventitious roots of Panax ginseng were treated with Alternaria panax,the content of H2O2 was also significantly increased.But when the adventitious roots were treated with CAT and Alternaria panax,the contents of H2O2 and ginsenosides in the adventitious roots of Panax ginseng decreased significantly.It showed that H2O2 mediates the accumulation of ginsenosides in adventitious roots of Panax ginseng induced by Alternaria panax.Meanwhile,the peak time of H2O2 is later than that of NO burst,so it can be inferred that H2O2 is located downstream of NO.Besides,in this experiment,it was also found that Alternaria panax could increase the content of polyamines in adventitious roots of ginseng.When Alternaria panax were added to the adventitious roots of ginseng,it was found that Alternaria panax promoted the increase of polyamine.And the content of ginsenosides and polyamines in adventitious roots treated with Put alone also increased significantly,but the content of ginsenosides were still lower than those treated with elicitor alone.Polyamines inhibitor D-Arg was used to treat adventitious roots of Panax ginseng with Alternaia panax.The results showed that the amount of polyamines in adventitious roots decreased significantly,and the content of ginsenosides had no significant difference compared with the control group.These results suggest that Polyamines participated in the accumulation of ginsenosides in adventitious roots ofPanax ginseng induced by Alternaria panax.