%0 Journal Article
%T Genotypic variation in genome-wide transcription profiles induced by insect feeding: Brassica oleracea ¨C Pieris rapae interactions
%A Colette Broekgaarden
%A Erik H Poelman
%A Greet Steenhuis
%A Roeland E Voorrips
%A Marcel Dicke
%A Ben Vosman
%J BMC Genomics
%D 2007
%I BioMed Central
%R 10.1186/1471-2164-8-239
%X The transcriptional responses of the two cultivars differed in timing as characterized by changes in their expression pattern after 24, 48 and 72 hours of caterpillar feeding. In addition, they also differed qualitatively. Surprisingly, of all genes induced at any time point, only one third was induced in both cultivars. Analyses of transcriptional responses after jasmonate treatment revealed that the difference in timing did not hold for the response to this phytohormone. Additionally, comparisons between Pieris rapae- and jasmonate-induced transcriptional responses showed that Pieris rapae induced more jasmonate-independent than jasmonate-dependent genes.The present study clearly shows that global transcriptional responses in two cultivars of the same plant species in response to insect feeding can differ dramatically. Several of these differences involve genes that are known to have an impact on Pieris rapae performance and probably underlie different mechanisms of direct defense, present in the cultivars.In nature, plants are constantly surrounded by herbivorous insects that negatively influence plant fitness. To effectively combat them, plants have evolved direct and indirect defense mechanisms [1-3]. Chemical compounds that play a role in direct defense are produced and stored in tissues of the plant that are consumed by herbivores [4,5]. These compounds can alter the physiology of herbivores by reducing their growth rate, adult size, and survival probability [5]. Glucosinolates, for example, are well characterized defense compounds of cruciferous plants that are hydrolyzed by specific thioglucosidases called myrosinases. This reaction results in the release of an array of toxic compounds such as isothiocyanates [6] that reduce herbivore survival, growth, and development rate [7]. In contrast to direct defense mechanisms, indirect defense mechanisms promote the effectiveness of the natural enemies of herbivores e.g. through volatile secondary metabolites [8,9]
%U http://www.biomedcentral.com/1471-2164/8/239