A Nitrate-Sensing Domain-Containing Chemoreceptor Is Required for Successful Entry and Virulence of Dickeya dadantii 3937 in Potato Plants

Phytopathology. 2023 Mar;113(3):390-399. doi: 10.1094/PHYTO-10-22-0367-R. Epub 2023 Mar 27.

Abstract

Nitrate metabolism plays an important role in bacterial physiology. During the interaction of plant-pathogenic bacteria with their hosts, bacteria face variable conditions with respect to nitrate availability. Perception mechanisms through the chemosensory pathway drive the entry and control the colonization of the plant host in phytopathogenic bacteria. In this work, the identification and characterization of the nitrate- and nitrite-sensing (NIT) domain-containing chemoreceptor of Dickeya dadantii 3937 (Dd3937) allowed us to unveil the key role of nitrate sensing not only for the entry into the plant apoplast through wounds but also for infection success. We determined the specificity of this chemoreceptor to bind nitrate and nitrite, with a slight ligand preference for nitrate. Gene expression analysis showed that nitrate perception controls not only the expression of nitrate reductase genes involved in respiratory and assimilatory metabolic processes but also the expression of gyrA, hrpN, and bgxA, three well-known virulence determinants in Dd3937.

Keywords: Dickeya dadantii; bacterial pathogen; chemoreceptor; chemotaxis; nitrate sensing.

MeSH terms

  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Dickeya
  • Enterobacteriaceae / genetics
  • Enterobacteriaceae / metabolism
  • Gene Expression Regulation, Bacterial
  • Nitrates* / metabolism
  • Nitrites / metabolism
  • Plant Diseases / microbiology
  • Plants
  • Solanum tuberosum* / microbiology
  • Virulence / genetics

Substances

  • Nitrates
  • Nitrites
  • Bacterial Proteins

Supplementary concepts

  • Dickeya dadantii