DNA microarray hybridizations of the C. glutamicum RES167 and the C. glutamicum RES167Δrel mutant strain. (A) and (B) Scatter plots (m/a plots) of the experiments. Shown are all genes whose transcription has been significantly up- (green) or downregulated (red) after induction of the stringent response by DL-serine hydroxamate. Genes which showed the most prominent changes in expression are labelled. (C) Venn diagram of the differentially expressed genes in the C. glutamicum RES 167 and Δrel mutant after treatment with SHX is shown. The numbers of genes which were placed in each of the three classes A, B and C is given. Green numbers represent upregulated genes, red ones represent downregulated genes.