Skip to main content
ISMPMI Congress 2025 Main banner
Icon Legend
This session is not in your schedule.
This session is in your schedule. Click again to remove it.

Poster

Session: Session 1 Presenting Authors at Posters (Odds)

P-209 - Regulation and Function of the acdS Gene Encoding an ACC Deaminase in Dickeya dadantii

Monday, July 14, 2025
13:30 - 15:15  
Location: Confex Hall 3
Microbial infection strategies (pathogens & non-pathogens)

Dickeya dadantii is a phytopathogenic bacterium responsible for soft rot of many plants. Its success in infection depends on a complex interaction with the host, orchestrated by a dynamic exchange of signals between the two partners. Molecules secreted by D. dadantii play a crucial role in its virulence, while plant-derived compounds are involved in recognising the pathogen and triggering defence mechanisms. The plant's early response involves the synthesis of phytohormones such as ethylene. ACC deaminase (AcdS), an enzyme that degrades the precursor of ethylene synthesis (1-aminocyclopropane-1-carboxylate, ACC), is well studied in plant growth-promoting rhizobacteria, but its role in D. dadantii remains unknown. This work explores the function of acdS in D. dadantii, the mechanisms regulating its expression and its conservation within the Dickeya species. To do this, we combined phenotypic, molecular and comparative genomics approaches. Our results show that AcdS allows ACC to be used as a source of nitrogen and is involved in modulating root elongation in plants. Its expression is upregulated by ACC and controlled by two local regulators, AcdR and LysR. Although acdS is conserved among Dickeya species, its locus shows variability between strains, potentially driven by horizontal gene transfer. This work provides new insights into the regulation and function of acdS in D. dadantii, while offering a perspective on its conservation and evolution at the genus level.