Multivariate analysis of volatile profiles in tea plant infested by tea green leafhopper Empoasca onukii Matsuda

Abstract

The tea green leafhopper (Empoasca onukii Matsuda) is a severe pest for the tea plant (Camellia sinensis (L.) O. Ktze), which significantly reduces the tea yields and quality. Herbivore feeding events lead to the emission of herbivore-induced plant volatiles (HIPVs) to elicit plant defense. To examine the volatile release profiles of tea shoots infested by leafhoppers, gas chromatography-mass spectrometry (GC–MS) analysis was performed. 23 volatiles were emitted in healthy tea shoots whereas 29 volatiles were identified from infested ones. The relative contents of volatiles were significantly increased during infestation. The volatile profiles from healthy and infested tea shoots could be well clustered into two groups by unsupervised clustering analysis and principal component analysis (PCA). Furthermore, a partial least square discriminant analysis (PLS-DA) model can differentiate volatile profiles between healthy and infested tea shoots with a predictive power of 91.8%. From the variable importance for the projection (VIP), eight critical volatiles were identified. Collectively, we have identified a novel volatile release profile after leafhopper infestation in tea plant and provide clues for defensive strategies against herbivores.