The effect of the two-component system GrtK and GrtR proteins of Burkholderia glumae on the metabolic detoxification of intracellular ammonia.

This study demonstrates that the two-component system, consisting of the sensor kinase GrtK and the response regulator GrtR, plays a crucial role in detecting and neutralizing toxic environmental ammonia produced as waste by Burkholderia glumae, a rice pathogen. The growth of grtK or grtR null mutants was inhibited by ammonia produced as waste in amino acid-rich media, such as Luria-Bertani broth, but no growth inhibition was observed in amino acid-free minimal media, where ammonia production is limited. Transcriptomic analysis of grtK and grtR mutants also indicated that GrtK and GrtR are involved in the metabolic detoxification of intracellular ammonia. These results suggest that GrtK is not a member of the ammonia transporter protein family but acts as an external ammonia sensor, working in conjunction with the response regulator GrtR to respond to the dangers posed by its own metabolism. Overall design: A comparative analysis of RNA-seq profiles was performed on Burkholderia glumae wild-type BGR1 and its grtK and grtR null mutants during 12 hours of growth in amino acid-rich media, such as Luria-Bertani broth.