Mots-Clés
metabolic modeling
systems biology
plant pathogens
Description
# Title
Deciphering metabolic trade-offs between growth, survival and virulence in the plant pathogen Ralstonia solanacearum
Short description
Ralstonia solanacearum is a major bacterial plant pathogen responsible for bacterial wilt, a devastating disease affecting a wide range of economically important crops and posing a significant threat to global agricultural production and food security. Ralstonia solanacearum must continuously allocate its limited cellular resources between growth, survival and the expression of virulence functions. These competing demands are expected to generate important trade-offs, particularly under the changing environmental conditions encountered during host colonization.This project will build on an existing genome-scale metabolic model of R. solanacearum and extend it to account for the costs associated with the different components of the cellular machinery, including enzymes, ribosomes and other protein resources required for cellular processes. Quantitative proteomics datasets available in the laboratory will be used to parameterize and constrain the model, providing a quantitative description of cellular resource allocation.The student will use and develop constraint-based and resource allocation modelling approaches to investigate how these constraints affect bacterial physiology under different environmental conditions. In particular, the project will aim to identify how R. solanacearum balances investment in biomass production, maintenance and survival with the production of virulence-associated functions, and to determine the metabolic constraints that drive shifts between these different cellular priorities.The project will combine genome-scale metabolic modelling, quantitative proteomics and computational data analysis, providing an opportunity to develop skills in systems biology and biological modelling while addressing a fundamental question in bacterial pathophysiology.
Concrete objectives
The student will have four main objectives:
• Curate and refine the existing genome-scale metabolic model of R. solanacearum, with particular attention to the representation of cellular processes and the identification of the protein machinery associated with metabolic reactions.
• Extend the model to account for cellular resource costs, including enzyme synthesis and other major components of the cellular machinery, in order to obtain a more realistic representation of the constraints on bacterial growth and survival.
• Integrate quantitative proteomics data available for R. solanacearum to parameterize and constrain the model, and assess whether the resulting model can reproduce experimentally observed physiological phenotypes.
• Use the model to investigate trade-offs between growth, survival and virulence, by simulating different environmental and physiological conditions and identifying the metabolic and resource constraints that determine how the bacterium allocates its cellular resources between these competing functions.
Required skills/background
- Programming in Python for scientific computing and data analysis is a plus
- Knowledge of constraint-based metabolic modelling, including Flux Balance Analysis (FBA), or a strong interest in developing these skills is a plus.
- Background in systems biology, computational biology, bioinformatics or mathematical modelling.
- Ability to analyse and interpret quantitative biological data.
- Good scientific communication skills in English.
Work environment
The internship will take place in a multidisciplinary research environment at the interface of systems biology, metabolic modelling and plant pathology. The student will work within a collaborative team combining computational approaches and experimental data to investigate the molecular mechanisms underlying bacterial physiology and virulence.
Starting date and salary
The internship is expected to start between February and March 2027, with the exact starting date to be agreed upon with the successful candidate. The internship stipend will follow the standard rate applicable to internships in the French public sector, approximately €660 per month.
Application
Send CV + few sentences motivating application to caroline.baroukh@inrae.fr