NEW GMC OXIDOREDUCTASES FROM CLONOSTACHYS ROSEA

Enzymes from the glucose-methanol-choline structural family of flavoproteins (GMC oxidoreductases) are often linked to lignin and lignocellulose degradation. Such mechanisms are well known and described in basidiomycetes, mainly for white rot, but also for brown rot fungi, but are largely absent in Ascomycota, which are generally non-ligninolytic. Clonostachys rosea is a filamentous ascomycete that colonizes living plants, digests material in soil and is known as a parasite of other fungi and of nematodes. In the genome of C. rosea, the gene family of GMC oxidoreductases was found to be significantly expanded, with a particularly large number of genes encoding aryl alcohol and glucose oxidases. Ecologically similar fungi like the saprotrophs Neurospora and the mycoparasitic Trichoderma exhibit a reduced content of such genes, suggesting that the respective enzymes are not essential for these fungal life-styles. This poses the question why C. rosea contains this many paralogs in its genome, and what is their function, as this fungus is neither a prominent lignocellulose decomposer nor a plant pathogen, that would demand such an arsenal of genes for (ligno)cellulose degradation. Using transcriptomic, molecular and biochemical techniques the aim of our project is to elucidate the functionality and role of C. rosea GMC oxidoreductases, and identify the nutritional strategies they are involved in. Our large-scale approach will provide important insights in the regulation of gene families supporting different life-styles in C. rosea and highlight mechanisms of mycoparasitism and fungus- plant interactions.