Differential expression of genes associated with signalling molecules. Based on curator annotated Gene Ontology categories at TAIR, A. thaliana genes were identified that are (i) involved in the metabolism of, (ii) are part of the signal transduction mediated by, or (iii) are responsive to signalling compounds (i.e., ABA: abscicic acid; AUX: auxin; BS: brassinosteroid; CYT: cytokinin; ETH: ethylene; GA: giberellic acid; JA: jasmonates; SA: salicylic acid). Fractions of genes that are differentially expressed upon DBM herbivory (in % of the genes in each category) in at least one time point (p[t-test] < 0.05, fold-change > 2) are shown. The fraction of down-regulated genes is shown in dark grey, the fraction with mixed expression over the time course in medium grey, and the fraction of up-regulated genes in light grey. Stars indicate that the frequency of differentially expressed genes in the given functional group is significantly higher (p[hyper] < 0.05) than the frequency observed in the set of all genes represented on the microarray.