Project description:DNA microarray analysis was employed to investigate the transcriptome response to nitrosative stress in a non-denitrifying facultative photosynthetic bacterium Rhodobacter sphaeroides 2.4.1. We focused on the role played by a nitric oxide-response transcriptional regulator NnrR in the response. The transcriptome profiles of R. sphaeroides 2.4.1 and its nnrR mutant before and after exposure to nitrosating agents S-nitrosoglutathione (GSNO) or sodium nitroprusside (SNP) under semiaerobic conditions were analyzed.