Specific regulator of choline metabolism, which activates transcription of at least 25 genes from 11 promoters in response to choline metabolites (PubMed:24097953). Required for the induction of plcH, encoding the phospholipase C, and pchP, encoding the phosphorylcholine phosphatase, in response to glycine betaine (GB) and dimethylglycine (DMG) (PubMed:19103776). Also controls the expression of gbcAB and dgcAB, which are required for GB and DMG degradation, respectively, in response to both GB and DMG (PubMed:17951379). The GbdR regulon also includes genes encoding sarcosine, glycine and serine catabolic enzymes, the BetX and CbcXWV quaternary amine transport proteins and the acetylcholine esterase gene, choE (PubMed:24097953). Acts by binding directly to the promoter region of the genes (PubMed:19103776, PubMed:24097953). May play an important role during P.aeruginosa interactions with eukaryotes (PubMed:17951379). Is critical for induction of plcH and pchP in response to bovine surfactant and mouse bronchoalveolar lavage fluid (BALF) (PubMed:19103776). The highest level of transcriptional activity is reached in the presence of choline. Regulated at the transcriptional level by a sigma-54-dependent promoter. Transcription can be activated by NtrC in the absence of a preferential nitrogen source, by CbrB in the absence of a preferential carbon source, and by the integration host factor (IHF), by favouring DNA bending. Negatively regulated by BetI in the absence of choline. Mutant is unable to grow on choline, GB and DMG as sole carbon or nitrogen sources (PubMed:17951379). Mutants that lack this gene are unable to induce plcH and pchP in media containing GB or choline and in phosphatidylcholine-rich environments, such as lung surfactant or mouse lung lavage fluid (PubMed:19103776).