Regulation of fungicide resistance

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Mechanisms underlying the emergence of resistance to fungicides

Plant diseases are a major concern for global food security worldwide. Most crops are attacked by pathogens that severely challenge currently available control measures. One of the major concerns comes from the pathogens’ ability to continuously overcome pesticide treatments. Predicting the emergence of pesticide resistance in populations of the pathogen is therefore crucial for the development of sustainable control strategies. However, if multiple mechanisms of pesticide resistance have been reported, we still lack a global view of how these mechanisms connect to favor the emergence of resistance in natural populations. The diversity of resistance mechanisms reported so far suggests that complex molecular networks are at play. Indeed, protein mutations, gene duplications and changes in gene expression have all been associated with pesticide resistance.

Of the many disease-causing microorganisms, fungi alone are responsible for massive fungicide applications worldwide. In fungi as in all living organisms, individual fitness is tied to the ability to exploit environmental resources i.e the metabolism. Metabolism is one of the major targets for many fungicides and is notorious to harbor network scale properties defining its ability to sustain activity in changing environments (i.e robustness). Ultimately, fungicide resistance is therefore determined by the metabolic capacity of the pathogen at maintaining growth. Genetic and functional redundancy at metabolic pathways can therefore provide increased robustness and plasticity to the metabolic network that will favor growth in challenging conditions. Identifying the metabolic reactions that sustain robustness and plasticity of the global network represent a route to predict the risk of resistance to emerge and design novel control strategies. In this project I propose to combine genome-scale metabolic network modelling and comparative genomics studies to better understand the emergence of fungicide resistance in Zymoseptoria tritici, an important pathogen of wheat.



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