herbivore-defense
Herbivore defense refers to the suite of physical, chemical, and molecular strategies plants employ to deter or tolerate damage from insects, mammals, and other plant-eating organisms. Understanding these mechanisms is central to plant biology because they reveal how plants perceive threats, activate signaling pathways, and allocate resources to survival under biotic stress. This research informs efforts to develop crops with enhanced natural resistance, reducing reliance on synthetic pesticides.
open_in_new WikipediaPubMed · 2026-05-01
Corn plants respond to caterpillar saliva by ramping up chemical defenses, but the type of response varies by species — even among closely related armyworms. The fall armyworm, a corn specialist, suppresses the plant's airborne distress signals while still triggering strong internal defense changes.
All three Spodoptera armyworm species triggered significant increases in phytohormone levels and defense gene expression in maize, indicating a broadly conserved plant immune response.
Despite similar internal hormone and gene responses, volatile emissions (airborne defense signals) were considerably lower when plants were treated with fall armyworm (S. frugiperda) secretions compared to beet armyworm and cotton leafworm.
The fall armyworm, a maize specialist, induced greater transcriptome-wide changes than the other two species, suggesting deeper co-evolutionary manipulation of the host plant's signaling pathways.
