Blue Light Sensing in Listeria monocytogenes Is Temperature-Dependent and the Transcriptional Response to It Is Predominantly SigB-Dependent

In this study the global transcriptional response of L. monocytogenes to blue light was elucidated using an RNAseq-based approach. A transcriptomic analysis of the response to sub-lethal levels of blue light found that the changes in transcription were almost entirely SigB-dependent. A mutant where the light sensing mechanism of RsbL was inactivated through an amino acid substitution (Cys56Ala) was found to have an attenuated response to blue light, but residual activation of SigB-dependent genes suggested that alternative routes for activation of SigB by light are likely to exist. Overall design: Comparison between wild-type and mutant cells cultured in darkness and in light.