B2: Pathogen-induced cell wall remodeling and production of Danger Associated Molecular Patterns

Volker Lipka & Harry Brumer
PhD student: Sina Barghahn

The cell wall represents a structural barrier that controls the entry success of invasive microbial pathogens into host plant tissues. Moreover, cell wall remodeling at sites of attempted fungal invasion has recently been shown to be an important defense mechanism of Arabidopsis leaves challenged by powdery mildew fungi (Collins et al., 2003; Jacobs et al., 2003; Kwon et al., 2008; Lipka et al., 2008). Similarly, Arabidopsis roots and leaf tissues exhibit substantial cellular reorganization patterns upon infection with soil-borne Verticillium fungi (Reusche et al., 2012, 2013, 2014). Intriguingly, however, the cell wall can also serve as a source of so-called Damage- or Danger-Associated Molecular Patterns (DAMPs) that are generated upon enzymatic degradation of wall polysaccharides during infection

The major goals of two very tightly linked PhD projects, one in the Lab of Dr. Lipka (Göttingen), the other in the lab of Dr. Brumer (Vancouver), are

+ to analyze and compare cell wall remodeling patterns induced by adapted/non-adapted powdery mildew and Verticillium fungi on the host/non-host plant Arabidopsis

+ to identify and functionally characterize cell wall hydrolyzing enzymes produced and required by pathogenic powdery mildew and Verticillium fungi

+ to identify and characterize novel plant carbohydrate DAMPs and the corresponding plant perception machinery


This project depends on close collaboration between the lab of Dr. Lipka (Göttingen), who is an expert in plant-microbe interaction cell and molecular biology, and the lab of Dr. Brumer (Vancouver), whose expertise will be instrumental for in vitro functional characterization of the selected cell wall hydrolyzing enzymes as well as for preparative isolation of hydrolysis products.

The projects aims at providing novel insights into pathogen-induced cell wall remodeling in compatible and incompatible plant-fungus interactions, into potential DAMP production capacities of enzymes that are used by two distinct lineages of phytopathogenic fungi to colonize their respective host plants and into the cognate molecular machineries employed by the latter to guarantee efficient DAMP detection.