Integrative Analysis of the Transcriptome and Metabolome of Poplar, Populus deltoides 'Shalinyang'. (Salicaceae), Reveals Responses to Attack by Anoplophora glabripennis (Coleoptera).

Anoplophora glabripennis is one of the most devastating wood-boring beetles that attacks poplars. However, one poplar species, Populus deltoides, has strong resistance to Anoplophora glabripennis infestation, the underlying defense mechanisms against Anoplophora glabripennis are poorly understood. Secondary metabolites play a crucial role in plants to combat biological stress. Here, based on transcriptome and metabolome, we demonstrated that the mechanisms for responses to mechanical damage and insect infestation were different. The degree of reactions to adult groove production, larval incubation, and larval frass production was not identical. In addition, the potential genes with insect resistance activity were identified. Predominant differentially expressed genes (DEGs) found in the phloem of Populus deltoides include anthocyanidin 3-O-glucosyltransferase5 (PdUGT72E), peroxidase 73 (PdPod73), peroxidase A2 (PdPodA2) and macrophage migration inhibitory factor (PdMIF) responded to stress caused by Anoplophora glabripennis, which further resulted in activation of the plant defense system against insects via changes in regulation of metabolic pathways, such as tyrosine metabolism pathway, phenylpropanoid biosynthesis pathway and flavonoid biosynthesis pathway. Therefore, this work has laid a foundation for further unraveling the mechanisms involved in this interaction. [ABSTRACT FROM AUTHOR]