Rapid green leaf volatile sensing allows intact plants to release induced volatiles earlier than wounded emitters.

Intact maize neighbors exposed to herbivory-induced volatiles begin emitting most induced volatiles 15–80 min earlier than attacked plants themselves.

• Why it matters: The timing of plant neighbor-to-neighbor defense signaling is poorly resolved, limiting understanding of how early cues shape subsequent multitrophic interactions.
• What they did: Maize receivers were monitored in real time after exposure to induced volatiles from herbivory-induced neighbors, including tests with volatile-deficient mutants and measurements of stomatal aperture, hormones, gene expression, and within-leaf volatile accumulation.
• The result: Receiver plants’ rapid responses are triggered by green leaf volatiles released from sender wound sites within minutes, independent of stomatal aperture, enabling “unhindered observers” to activate defenses earlier.