Allocating nitrogen away from a herbivore: a novel compensatory response to root herbivory

Oecologia. 2007 Oct;153(4):913-20. doi: 10.1007/s00442-007-0791-2. Epub 2007 Jul 7.


Centaurea maculosa, an invasive North American plant species, shows a high degree of tolerance to the root-boring biocontrol herbivore, Agapeta zoegana. For example, infested individuals of C. maculosa often exhibit more rigorous growth and reproduction compared with their non-infested counterparts. Compensatory responses to aboveground herbivores often involve increases in leaf area and/or photosynthetic capacity, but considerably less is known about root system compensatory responses to belowground herbivory. We used a (15)N labeling approach to evaluate whether compensatory adjustments in N acquisition via changes in root morphology and/or physiological uptake capacity could explain the ability of C. maculosa to tolerate root herbivory. Root herbivory reduced whole plant N uptake by more than 30% and root uptake capacity by about 50%. Despite a marked reduction in N procurement, herbivory did not affect total biomass or shoot N status. Infested plants maintained shoot N status by shifting more of the acquired N from the root to the shoot. To our knowledge, shifting N allocation away from a root herbivore has not been reported and provides a plausible mechanism for the host plant to overcome an otherwise devastating effect of a root herbivore-induced N deficit.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adaptation, Physiological
  • Animals
  • Asteraceae / growth & development
  • Asteraceae / metabolism*
  • Moths / physiology*
  • Nitrogen / metabolism*
  • Pest Control, Biological
  • Plant Roots / growth & development
  • Plant Roots / metabolism*
  • Soil / analysis


  • Soil
  • Nitrogen