Different multicellular trichome types coordinate herbivore mechanosensing and defense in tomato.

Abstract

Herbivore-induced wounding can elicit a defense response in plants. However, whether plants possess a surveillance system capable of detecting herbivore threats and initiating preparatory defenses before wounding occurs remains unclear. In this study, we reveal that tomato (Solanum lycopersicum) trichomes can detect and respond to the mechanical stimuli generated by herbivores. Mechanical stimuli are preferentially perceived by long trichomes, and this mechanosensation is transduced via intra-trichome communication. This communication presumably involves calcium waves, and the transduced signals activate the jasmonic acid (JA) signaling pathway in short glandular trichomes, resulting in the upregulation of the Woolly (Wo)-SlMYC1 regulatory module for terpene biosynthesis. This induced defense mechanism provides plants with an early warning system against the threat of herbivore invasion. Our findings represent a perspective on the role of multicellular trichomes in plant defense and the underlying intra-trichome communication.