Replicon distribution of over-expressed genes following heat and saline shock. Proportions of the up-regulated gene contributions for each replicon. Axis labels correspond to: chromosome (Ch), plasmid pRet42a (pa), plasmid pRet42b (pb), plasmid pRet42c (pc), plasmid pRet42d (pd), plasmid pRet42e (pe), and plasmid pRet42f (pf). The proportions were obtained by normalising the number of up-regulated genes to the number of annotated genes for each replicon. *Indicates significant difference in the proportions of the up-regulated and down-regulated genes between the chromosome and plasmids (Two-sample for equality proportions with 99 percent confidence intervals).