FIG 6.

A working model for the physiological roles of RstA/RstB under nitrosative stress of P. fluorescens 2P24. During anaerobic nitrate respiration in P. fluorescens 2P24, RstB is activated by sensing relative signal molecules and activates RstA which upregulates expression of efflux pumps and pyoverdine biosynthesis-related enzymes. This process not only protects cells against nitrosative damage by extruding the nitrosyl-damaged cellular components but increases antibiotic resistance. The solid arrows denote direct regulations while the dashed arrows denote indirect regulations.