Effect of indole treatment on the resistance to tea tree tea leafhopper Empoasca onukii
In order to clarify the effect of indole treatment on the resistance of tea tree to tea green leaf-hopper Empoasca onukii,the cultivar Longjing 43 was used for indole induction,and the selection of E.onukii for different tea trees was measured in the laboratory.The electrical penetration graph(EPG)technique was used to analyze the feeding behavior of E.onukii.The effects of indole treatment on the volatiles of tea trees were analyzed with gas chromatography-mass spectrometry,and the expression lev-els of defense-related genes were detected by real-time fluorescence quantitative PCR.The results showed that,during all periods,E.onukii adults tended to feed on tea trees in the control group,and the number of adults in the control group was 2.45 times of that in the indole-treated group.The duration of third instar nymph's non-feeding wave(NP wave)on indole-treated tea trees accounted for 72.15%of the total feeding time,and the duration of non-feeding wave(NP wave)in the control group accounted for 33.07%.The duration of main feeding wave E2 in the control group was 3.58 times of that in the in-dole-treated group.Compared with the control group,the total amount of volatiles released by indole-treated tea trees was significantly increased,among which α-farnesene can deter pests but attract natural enemies.Moreover,the expression level of defense genes in indole-treated tea trees was significantly in-creased.The results indicated that the tea trees treated with indoles decreased food intake,increased the amount of volatiles and the expression level of resistance genes,which help to enhance the resistance of tea tree to E.onukii.