Abstract:  Tomato is one of the most important horticultural crops, and China is the largest producer of tomato in the world. In recent years, the tomato industry is facing increasingly severe pest threats including the traditional important pests (Bemisi tabaci, Frankliniella occidentalis and Helicoverpa armigera) and the newly emerged invasive pest Tuta absoluta. Elucidating the defensive mechanism of tomato especially wild tomato germplasm resource, which has significantly higher resistance to pests, can provide important genetic resources for breeding process of insect-resistant tomato varieties. Meanwhile, the key insect-resistant metabolites of tomato can also offer valuable insights into the development of new safer and more eco-friendly botanical pesticides. In this article, we summarized the interactions between tomato pests and host plants like tomato across multiple levels of insect resistance mechanisms in plants. Key topics include: (1) the recognition of saliva proteins from piercing-sucking and chewing insects by tomatoes and its impact on anti-insect immunity; (2) the signal transduction networks of insect resistance and the regulatory mechanisms of core defense-related transcription factors in tomato; (3) structural and metabolic bases of insect resistance in plants, such as trichomes, acylsugars, phenolamides, steroidal alkaloids, and volatile compounds, which respond to pest attacks and confer insect resistance through molecular and ecological pathways. Future research should leverage emerging technologies like single-cell transcriptomics and spatial transcriptomics, combined with gene editing and genetic manipulation tools, to further clarify the signaling pathways of insect resistance and the synthesis and regulation of defense compounds in tomato. These efforts will deepen our understanding of plant-insect interactions and lay a theoretical foundation for breeding high-yield, insect-resistant tomato varieties.

Key words: Tomato, plant-insect interaction, insect saliva protein, defense signaling transduction, defensive metabolites