| Jasmonic acid,as a new class of plant hormones,can improve the resistance response of plants under the conditions of mechanical damage,pests and diseases,and be used as signaling molecules that pathogen elicitor and trauma induced gene expression of plant defense.Consequently,jasmonic acid’s role in plant defense responses caused widespread concern.This paper seted with2concentrations of jasmonic acid,sprayed leaves of populus cathayana after1d,5d,10d,determinted the activity change of protease inhibitors, phenylalanine ammonialyase,polyphenol oxidase and peroxidase.Contemporary,the developmental duration of gypsy moth larvae feed on leaves of populus cathayana by sprayed jasmonic acid were observed and record every day.The results showed:1The activity of protease inhibitors in the leaves of populus cathayana increase dramaticlly after exogenous jasmonic acid induced.0.1mmol/L jasmonic acid treatme induced the strongest response on the activity of trypsin inhibitor and the maximum appeared on the5th day,increased by54.4%.0.1mmol/L jasmonic acid treatment induced the strongest response on the activity of chymotrypsin inhibitor and the maximum appeared on the10th day,increased by116%.2The activity of phenylalaninammonialyase and polyphenoloxidase in the leaves of populus cathayana increased dramaticlly after exogenous jasmonic acid treatment.0.1mmol/L jasmonic acid treatment after5days,The activity of phenylalanine mmonial-yase in the leaves of populus cathayana increased significantly,increased by19.4%; the activity of polyphenoloxidase in the leaves of populus cathayana increased dramaticlly, increased by80.9%.3The activity of peroxidase in the leaves of populus cathayana increased dramaticlly after exogenous jasmonic acid treatment.0.001mmol/L jasmonic acid treatment induced the strongest response on the activity of peroxidase and the maximum appeared on the5th day,increased by64.7%.4Jasmonic acid treatment affect the developmental duration of the gypsy moth. Jasmonic acid treatment after5days,the developmental duration of2nd instar larvae,three instar larvae,4th instar larvae feeding on populus cathayana were dramaticlly extend.The developmental duration of2nd instar larvae feeding on populus cathayana by0.1mmol/L jasmonic acid treatment was1.25d extender than that of control.The developmental duration of3nd instar larvae feeding on populus cathayana by0.001mmol/L jasmonic acid treatment was3d extender than that of control. The developmental duration of4th instar larvae feeding on populus cathayana by0.1mmol/L jasmonic acid treatment was2.5d extender than that of control. |
