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 (Evens)

P-152 - Degradation of aromatic compounds is required for pathogen establishment in the soil and the plant rhizosphere

Tuesday, July 15, 2025
09:55 - 11:30  
Location: Confex Hall 3
Microbial infection strategies (pathogens & non-pathogens)

    Author(s)

  • MR

    Mercedes Rocafort

    Center for research in Agricultural Genomics (CRAG)
    Cerdanyola del Vallès, Catalonia, Spain

  • QZ

    Qingshan Zhang

    Center for research in Agricultural Genomics (CRAG)
    cerdanyola del Vallès, Catalonia, Spain

  • YY

    Yin Yue

    University of Helsinki
    Helsinki, Uusimaa, Finland

  • MR

    Marc Reyes

    Center for research in Agricultural Genomics (CRAG)
    Cerdanyola del Vallès, Catalonia, Spain

  • AD

    Adam Deutschbauer

    UC Berkeley
    Berkeley, California, United States

  • NC

    Núria S. Coll

    Center for research in Agricultural Genomics (CRAG)
    Cerdanyola del Vallès, Catalonia, Spain

  • WZ

    Wei Zhong

    Nanjing Agricultural University
    Nanjing, Jiangsu, China (People's Republic)

  • VF

    Ville-Petri Friman

    University of Helsinki
    Helsinki, Uusimaa, Finland

    • Presenting Author(s)

  • MV

    Marc Valls

    Full Professor in Genetics
    Univ of Barcelona
    Barcelona, Catalonia, Spain

Some plant pathogens show a remarkable ability to thrive in the soil, often in association with the rhizosphere. However, the mechanisms by which pathogens establish in this habitat and manipulate the existing microbiota remain unclear. Ralstonia solanacearum, the causing agent of the devastating bacterial wilt disease, can persist in soil for years and eventually cause disease outbreaks by infecting plants through roots.

Here, we applied for the first time a genome-wide mutant screen to uncover pathogen genes required for colonisation of the rhizosphere-soil environment. We measured survival of >100.000 barcoded R. solanacearum mutants in the tomato rhizosphere using non-destructive sampling and transposon mutant sequencing (TnSeq). Mutants in 103 genes showed a strong fitness loss at 5 and 10 days after rhizosphere inoculation. Motility, chemotaxis and metabolism functional categories were over-represented in these mutants. Two independent genes identified controlled phenylacetate degradation. We demonstrated that R. solanacearum can use phenylacetate very efficiently as the sole carbon source and showed through disruption of each step in this catabolic pathway that it is crucial for survival in the soil-root habitat and under desiccation or oxidative conditions.

We propose that MOTILITY AND the capacity to degrade aromatic compounds enable a plant pathogen to compete with the root and soil microbiota and to cope with environmental stresses to successfully colonise plants.