Metabolites of Ammopiptanthus mongolicus induced by Orgyia ericae attack and mechanical wounding.

In plants attacked by insects, metabolic changes can reflect the direct and indirect ability of those plants to resist infestation. However, the metabolic pathways involved in this process remain unclear, especially for plants which belong to ancient Tertiary relict taxon. To analyze the changes in metabolites and identify specific metabolic patterns induced by herbivorous and continuous mechanical wounding, the metabolism of Ammopiptanthus mongolicus seedlings damaged by Orgyia ericae Germar or continuous mechanical wounding were analyzed using nuclear magnetic resonance (NMR) combined with multivariate data analysis (MVDA). Principal component analysis (PCA) and orthogonal signal correction projections to latent structure discriminate analysis (OPLS-DA) showed that O. ericae feeding and mechanical wounding induced different changes in the metabolic profile of A. mongolicus both in local and systemic leaves. O. ericae feeding was associated with higher concentrations of many primary and secondary metabolites in local and systemic leaves than continuous mechanical wounding. In this way, the response of A. mongolicus to wounding was shown to be both specific to the metabolism, systemic, and to involve both primary and secondary metabolic pathways.