Rhodobacter sphaeroides 2.4.1 pPos19 versus pBBR under singlet oxygen stress

To learn more about the function of Pos19, we constructed an over-expression strain. For this purpose, the Pos19 gene together with its native RpoE promoter was cloned into the middle-copy plasmid pBBR1 and expressed in the R. sphaeroides wild-type 2.4.1 background. The corresponding strain consequently exhibits a singlet oxygen-induced Pos19 over-expression compared to an empty vector control. Total RNA from the over-expression (pPos19) and from the empty vector control (pBBR) strain was extracted after 7 min of singlet oxygen stress and used for microarray analysis to investigate Pos19-induced changes on transcriptome level. RNA samples collected after 7 min of singlet oxygen stress were analyzed by two-color microarrays. Each microarray contains a pool of three independent biological replicates for each sample.