Effects of five allelochemicals on enzyme activity in Panax ginseng roots

Objective To study the effect and action rules of five allelochemicals on protective enzyme activity of Panax ginseng roots.Methods By the method of solution culture, the effects of benzoic acid,diisobutyl phthalate, diisobutyl succinate,palmitic acid,and 2,2-bis(4-hydroxyphenyl) propane on the activity of peroxidase(POD),catalase(CAT),and phenylalanine ammonia-lyase(PAL) of P.ginseng roots at seedling stage were studied.Results Benzoic acid inhibited POD activity at three concentration tested,diisobutyl phthalate and diisobutyl succinate inhibited POD activity at low concentration only,palmitic acid,and 2,2-bis(4-hydroxyphenyl) propane enhanced POD activity at three concentration tested,which was positively correlated to alle-lochemical concentration.Except for diisobutyl succinate and palmitic acid,the other allelochemicals enhanced CAT activity,and their concentration was positively correlated to the activity.Benzoic acid and diisobutyl succinate inhibited PAL activity at low concentration,and the enhancement of PAL activity at middle concentration was higher than that at high concentration.Palmitic acid at low concentration and 2,2-bis(4-hydroxyphenyl) propane at high concentration enhanced the PAL activity most,and the PAL activity was positively correlated to concentration for 2-benzenedicarboxylic acid bis(2-methylpropyl) ester.Furthermore,the activities of POD,CAT,and PAL fluctuated with time at both control and five allelochemical treatments,but no significant correlation among them.ConclusionFive allelochemicals identified from of P.ginseng roots could significantly influence the activities of POD,CAT,and PAL.