Rapid adaptation of signaling networks in the fungal Pathogen Magnaporthe oryzae

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The question of how the remarkably diverse array of eukaryotic signaling networks has evolved is of enormous scientific relevance. Evolutionary adaptation of living organisms is commonly thought to be the result of processes that acted over long periods of time. The proposed project is motivated by recent observations that microorganisms are able to rapidly adapt to new environments and establish stable phenotypes by natural selection, even within few generations. We found the filamentous rice blast fungus Magnaporthe oryzae to rapidly rewire signal transduction required for osmoregulation in several independent “loss of function” (lof)-mutants of the High Osmolarity Glycerol (HOG)-pathway upon exposure to salt stress. Adaptation resulted in stable mutants of the model organism being restored in osmoregulation arising as individuals outgrowing from salt-sensitive lof-mutants. The major compatible solute produced upon salt stress by these rapidly “adapted” strains was found to be glycerol whereas it is arabitol in the wildtype strains. These findings lead to the hypothesis that stable adaptation-events under continuously environmental evolutionary pressure enable Magnaporthe oryzae to rapidly restore or modify entire signaling networks. To address this hypothesis, we aim to identify the molecular or biochemical mechanisms of this rapid evolutionary adaption and characterize associated factors and signalling pathways which enable or prevent adaption. Both project partners will interact synergistically to combine expertise of theoretical approaches to integrate sequencing data from genomics and transcriptomics with modern quantitative (phospho)-proteomics techniques. Furthermore, reversed molecular genetics will be used to validate the candidate genes or even other factors (e.g. phosphorylation patterns) found to be putatively promote or constrain rapid evolutionary adaptation. Consequently, the proposed project will open the door to investigate the relationship of phenotypic and genetic evolution in eukaryotic microorganisms.