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Study

Mechanisms of plant defense against insect herbivores

War, Abdul Rashid; Paulraj, Michael Gabriel; Ahmad, Tanveer; Buhroo, Abdhul Ahad; Hussain, Barkat; Ignacimuthu, Savarimuthu; Sharma, Hari Chand

Plant Signaling & Behavior, 2012

Peer-reviewednarrative reviewmixed

A review of constitutive and induced plant defences against insect herbivores: physical barriers, secondary metabolites, defensive proteins, and the hormonal signalling — principally jasmonate — that switches induced responses on.

Studied in
Angiospermae, Insecta
Sample size
review of defence mechanisms

Plants combine defences that are always present with defences produced only after damage. Induced responses are triggered by wounding and by chemical cues in insect saliva, are coordinated largely by jasmonic acid, and include compounds that are directly toxic or antinutritive as well as volatiles that attract the herbivore’s own predators and parasitoids.

What it means

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

How the authors put it

Defence is a layered, inducible system rather than a fixed property of a species, and the inducibility is itself an adaptation to the cost of producing defences.

How NatureHQ reads it

The reason induced defence is worth explaining carefully is that it is where anthropomorphism creeps in. A damaged plant releasing volatiles that happen to attract a parasitic wasp is not calling for help; it is emitting a chemical consequence of injury that a wasp has evolved to detect. The outcome benefits both, and no intent is required anywhere.

  • A review dominated by crop species and by laboratory bioassays.
  • The fitness benefit of induced defence in the field is harder to demonstrate than the response itself.
  • Signalling pathways interact in ways this level of summary flattens.

What this study is used for on NatureHQ

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

Published by: Wiley journalsPublished in a Wiley journal.

doi.org/10.4161/psb.21663

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 2026-08-10.