Fig. 3

Input function of the mar operon with respect to salicylate and cAMP. Two-dimensional input function (promoter activity in steady state) as function of salicylate and cAMP (42 concentration combinations of the two input signals). a Wild-type system. b ∆rob system. Inset figures show model simulations of gene expression levels (MarR) for the corresponding system that anticipate the experimental data. Absence of Rob leads to the appearance of cross talk between signals