Evolutionary Ecology of Fungi

The EcoFun team investigates the adaptive mechanisms of the fungal pathogen Venturia inaequalis to its hosts. Its research is structured around three complementary axes:

• Epidemiology: evolution of pathogenicity within populations
• Quantitative genomics: genomic architecture underlying virulence traits and evolutionary trade-off
• Interaction mechanisms: molecular processes governing host specificity

Within IRHS, the EcoFun team has established close collaborations with the RESPOM and VADIPOM teams, which focus on apple resistance.

Epidemiology :

Venturia inaequalis is responsible for scab disease on Malus sp, including apple (Malus domestica), the most cultivated fruit tree in temperate areas worldwide. It also causes scab disease on other Rosaceus species, including pyracantha and loquat. The Ecofun team is interested in the pathogenicity of V. inaequalis at different levels:

• Host specificity among Rosaceus species,
• Evolution of pathogenicity during apple domestication,
• Evolution of pathogenicity under the selection pressure exerted by apple genetic resistance based on major genes (R gene), quantitative trait loci (QTL), or plant resistance inducers.

Interaction mechanisms 

The functional biology approaches developed in Venturia inaequalis combine fungal genetic transformation, mutant phenotyping, and the use of heterologous systems.

• Genetic transformation enables the generation of strains expressing proteins of interest or carrying targeted modifications, whose effects can then be assessed in terms of growth, sporulation, virulence, and development during infection.
• Heterologous systems such as yeast and Nicotiana benthamiana are used to characterize the functions of fungal effectors, investigate their molecular interactions, and assess their ability to modulate plant immune responses.

Integrating these complementary approaches makes it possible to link the molecular functions of effectors to their cellular and phenotypic consequences in both the pathogen and its host.