show Abstracthide AbstractWe analyzed the transcriptomes of different general stress response key regulator knockout mutants after stress exposure and compared them to the wild-type strain. Thereby we aimed to identify the regulon of the alternative sigma factor EcfG and to find out how the regulators PhyR, SdrG and the seven GSR-activating histidine kinases (Paks) influence transcription. The RNA for transcriptome analyses was prepared from the respective Sphingomonas melonis Fr1 cultures in mid-exponential phase. The cultures were split and were either treated with the appropriate stress stimuli or were left untreated. The cells were harvested 1 h after the beginning of the treatment.