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Contacts: E-Mail valentin.fievet@inrae.fr   -   Linkedin 

Background

Interested since college in biology, Valentin continued his studies by joining a school of engineering specialized in Biotechnology, Sup'Biotech. During these 5 years, he was interested in research topics related to the interactions of different microorganisms with their environment, whether to evaluate the effectiveness of biocontrol solutions (Trichoderma spp.), the study of molecules of antifungal interest (extracts of Alliaceae) or the characterization of resistance to fungicides DMI in fungi (Venturia inaequalis).

After obtaining his engineering degree with a specialization in research and environment, Valentin joined the INRAE-MycSA laboratory in 2023 to complete a thesis on the development of the new paradigm of «meta-pathogens». He studies the composition and metabolomic dynamics of a synthetic community, the «Meta-Fusarium» (mixture of 7 Fusarium species), exposed to abiotic and biotic stresses. TeamTox Project

Job description and activities

Thesis subject: Dynamics of the composition of Meta-fusarium (mixture of 7 Fusarium species) and its production of secondary metabolites under abiotic and biotic pressures.

Funding: ARN funding (TeamTox project)

Supervisors: Florence Forget (thesis supervisor); Louis Carles (co-supervisor)

Summary of the thesis project

Fusarium species are causal agents of Fusarium Head Blight (FHB), one of the most devastating fungal diseases affecting cereal crops. In addition to yield losses, some of these fungal species are responsible for grain contamination with mycotoxins including type A and type B trichothecenes, zearalenone, enniatins and beauvericin. FHB and mycotoxin contamination of cereals are not caused by a single species of fungus, but by a mixture of Fusarium species whose representativeness varies according to agricultural practices and climate. A wide range of Fusarium species has been associated with FHB, each producing one or more mycotoxins.

Despite intensive research over the past decades, recommended agronomic practices and current mitigation strategies are not enough to guarantee mycotoxin levels complying with European regulatory limits. Up to now, investigations aiming at providing bases for the development of mycotoxin control strategies were virtually exclusively conducted considering “one species-one disease”, an approach that has proved itself insufficient to reach a comprehensive understanding of the FHB disease process and mycotoxin accumulation in crops. Indeed, the blend of Fusarium species in interaction inside a shared niche is likely to result in a production of mycotoxins having its own regulation.

In this context, the objective of the PhD is to study the regulation of mycotoxin production by a synthetic community, called "Meta-Fusarium", containing the seven main FHB species encountered in Europe. It will be considered in ecophysiological analyses as an individual fungus that functions as a whole. The composition dynamics of Meta-Fusarium and its production of secondary metabolites, including mycotoxins, will be studied under various abiotic (temperature and oxidative stress) and biotic (biocontrol agents, biomolecules, etc.) factors