Bacterial gene expression changes in response to nutrient stresses

Sinorhizobia are soil bacteria that can fix nitrogen in symbiosis with legumes. For symbiotic relationships to form, the bacteria need to persist in the rhizosphere which often has nutrient limitations. Understanding how individual stress responses change in the face of a second stress will provide insight into bacterial stress responses at the systems level in conditions that may reflect the natural environment where phosphate and nitrogen are the most commonly limited nutrients. Our goal was to obtain gene expression information from Sinorhizobium meliloti in media that was complete, deficient in either nitrogen or phosphate, and deficient in both nitrogen and phosphate. This data allows for comparison of nitrogen stress and phosphate stress responses as a function of either one or two variables.