Dissecting functional roles of different chitin synthases in Trichoderma atroviride

The ascomycete Trichoderma is long known for its mycoparasitic behavior towards plant pathogenic fungi and thus biocontrol. It has recently become evident that cell wall turn over might also contribute to the mycoparasitic ability of Trichoderma spp. as these fungi substantially (re)model their cell periphery during the interaction with host fungi. Since information on the mechanisms of cell wall synthesis in filamentous fungi such as in Trichoderma spp. is still scarce, it shall be the primary focus of the proposed project. Chitin and particularly the deacetylated form chitosan are critical components of the fungal cell wall. Since they play a major role in the defense mechanism of various fungi, they might critically account for specific aspects of mycoparasitism. Hence, we will analyze the synergistic behavior of chitin and chitosan remodeling enzymes, during vegetative growth and mycoparasitism. This shall be accomplished by functional characterization (generation of knock-out lines) of genes involved in chitin biosynthesis such as chitin synthases, which determine the degree of polymerization. The required in-depth characterization of fungal chitin and chitosan formation will largely enhance our knowledge on fungal cell wall synthesis, and as such yet remains to be investigated in Trichoderma species. This is of further importance as chitin synthases are attractive therapeutic targets to battle fungal infections. Taken together, the proposal is designed to mine truly novel insights into the principles of enzymatic cell walls synthesis during vegetative growth and host attack in mycoparasitic Trichoderma species and thereby contributes, at least, to improve biological control on field.