Skip to content
NatureHQ

Study

Within-plant signaling by volatiles leads to induction and priming of an indirect plant defense in nature

Heil, Martin; Silva Bueno, Juan Carlos

Proceedings of the National Academy of Sciences, 2007

Peer-reviewedfield experimentwild

What they did

On wild lima bean plants, air movement between damaged and undamaged parts of the *same* plant was experimentally blocked or permitted, and extrafloral nectar secretion — which recruits defensive ants — was measured.

Studied in
Phaseolus lunatus
Sample size
wild lima bean plants with airflow between leaves manipulated

What they found

Undamaged leaves downwind of damaged ones on the same plant increased nectar secretion and attracted more ants; blocking the airflow abolished the effect even though the leaves remained vascularly connected.

What it means

The authors' reading, and ours. Where they differ, that difference is the point.

How the authors put it

Volatiles serve as a signal within an individual plant, bypassing vascular limits — and communication between plants may be a by-product of this.

How NatureHQ reads it

This reframes the whole question, and it is the most under-appreciated result in the area. If volatiles evolved so that one part of a plant can signal another part it is poorly plumbed to reach, then "plants warning their neighbours" is not an act of altruism needing an evolutionary explanation — it is a leak that neighbours exploit. A cleaner hypothesis that explains the same observations with far less mystery attached.

Limitations

  • One species with an unusually convenient measurable defence.
  • Whether within-plant signalling is the general explanation for volatile communication is not established.
  • Airflow manipulation may affect humidity and temperature as well as volatile transport.

The experiment, explained

  • Blocking the air between two leaves on the same plant

    When a damaged plant defends its undamaged parts, does the message travel inside the plant — or outside it?

What this study is used for on NatureHQ

One study can inform several subjects. Here is everywhere this one is cited.

Finding the paper

Published by: Proceedings of the National Academy of SciencesPublished in PNAS.

doi.org/10.1073/pnas.0610266104

This reference was resolved automatically against Crossref on 2026-08-11.

NatureHQ summarises research in its own words and does not reproduce published text. Reviewed 2026-08-09.