Physiological function and mechanism mediated by ntrC in Aeromonas hydrophila

Abstract:

[Objective] NtrC is a DNA-binding transcriptional regulator which plays an important role in activating the transcription of nitrogen assimilation genes and maintaining nitrogen supply. The objectives of this study were to explore its physiological function and mechanism in Aeromonas hydrophila.[Methods] In this study, the homologous recombination method was used to construct the ntrC deletion strain of Aeromonas hydrophila, and the physiological phenotype of the deletion strain was measured and analyzed with the wild strain as the control. A data independent acquisition-based quantitative proteomics method was performed to compare the protein expression differences between the wild-type and ntrC deletion strains.[Results] After the ntrC gene was knocked out, the tolerance of Aeromonas hydrophila to nitrogen deficiency, osmotic pressure, heavy metal ions, oxidation and different antibiotic stress was significantly changed, and these phenotypes could be recovered in its rescued strains. Quantitative proteomics was used to compare the protein expression between the WT and the ntrC deletion strain. Results showed that ntrC may be involved in the regulation of biosynthesis of amino acids, ascorbate and aldose metabolism pathways. [Conclusion] This study elucidated the important role of NtrC in Aeromonas hydrophila and its impact on the biological function of the bacteria. Moreover, the relationship between the proteins directly or indirectly regulated by NtrC and the physiological phenotype was discussed, the results provide valuable information for the prevention and control of aquatic pathogens in the future.