Abstract: There are complex chemical interactions between plants and phytophagous insects. On the one hand, when infested by phytophagous insects, plants can recognize herbivore-associated molecular patterns and trigger early signaling events and phytohormone-mediated signaling pathways. The activated signaling pathways thus result in the reconfiguration of transcriptomes and metabolomes as well as the increases in direct and indirect defensive compounds in plants, which in turn enhance the resistance of plants to phytophagous insects. On the other hand, phytophagous insects can recognize defense responses in plants and then inhibit or adapt to plant chemical defenses by secreting effector, sequestrating and detoxifying defensive compounds, and/or reducing sensitivity to defensive compounds. The deep analysis of chemical interactions between plant and phytophagous insects could improve the understanding of the relationship between insects and plants in theory and also provide important theoretical and technical guidance for the development of new technologies for crop pest control in practice.

Key words: plant, phytophagous insect, herbivore-associated molecular pattern, effector, defensive compound