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Oecologia

Title:		Herbivore specific induction of silica-based plant defences
Author(s):		Massey FP; Ennos AR; Hartley SE;
Address:		"Department of Biology and Environmental Science, University of Sussex, Falmer, Brighton, East Sussex, BN1 9QG, UK. F.P.Massey@sussex.ac.uk"
Journal Title:		Oecologia
Year:		2007
Volume:		20070321
Issue:		4
Page Number:		677 - 683
DOI:		10.1007/s00442-007-0703-5
ISSN/ISBN:		0029-8549 (Print) 0029-8549 (Linking)
Abstract:		"Induced plant responses to herbivory have major impacts on herbivore feeding behaviour, performance and population dynamics. These effects are well established for chemical defences, but induction of physical defences remains far less studied. However, for many plants, it is physical defences that play the major role in regulating the levels of herbivore damage sustained. We provide evidence that, in grasses, induction of physical defences is both specific to herbivore feeding, as opposed to mechanical damage, and may be dependant on the amount of damage imposed. Furthermore, we show that the magnitude of the induction response is sufficient to deter further damage and affect herbivore performance. We compared silica induction in two grass species in response to vertebrate and invertebrate damage, and to mechanical defoliation. Induction was assessed at two levels of damage over 16 months. Foliar silica content did not increase in response to mechanical defoliation, but damage by either voles or locusts resulted in increases in silica content of over 400%. This increase deterred feeding by both voles and locusts. Silica induction in grasses due to repeated damage events over a prolonged period suggests a possible role for silica defence in the cyclical population fluctuations observed in many grass-feeding herbivores"
Keywords:		Animals Arvicolinae/physiology Feeding Behavior/*physiology Festuca/*physiology Food Preferences Grasshoppers/*physiology Lolium/*physiology Silicon Dioxide/*metabolism;
Notes:		"MedlineMassey, Fergus P Ennos, A Roland Hartley, Sue E eng Research Support, Non-U.S. Gov't Germany 2007/03/22 Oecologia. 2007 Jul; 152(4):677-83. doi: 10.1007/s00442-007-0703-5. Epub 2007 Mar 21"