Grazing-induced expression of seaweed genes

The aim of this study was to elucidate which changes in gene expression are related to the induced anti-herbivory response in the brown seaweed Fucus vesiculosus. Microarray hybridizations were used to identify genes differentially expressed in response to grazing by the isopod Idotea baltica. This study shows that modifications in gene expression occur simultaneously to a reduced palatability and that defence induction entails reallocation of resources from primary to secondary metabolism with down-regulation of photosynthesis and degradation of storage compounds. Total RNA of Fucus vesiculosus pieces that were or were not previously grazed by Idotea baltica for 15 and 18 days (3 biological replicates each) was hybridized against pooled RNA from 4 F. vesiculosus pieces that were collected before onset of grazing (day 0).