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About Heidi Widmer and her project

Functional characterization of core effector proteins in the Sebacinales

Serendipita indica and S. vermifera belong to the ecologically widely distributed order Sebacinales. These root endophytes display wide-host spectrum beneficial effects such as growth promotion and increased pathogen resistance. The ability to colonize various hosts requires adaptation and specific responses to different plant signals. Effector proteins are proposed to have a key role in these processes. With respect to insights into how sebacinoid fungi establish themselves in metabolically active root cells of different hosts and how the plants are reprogrammed for enhanced performance, Heidi functionally characterized fungal effector proteins to find answers to the following questions:

How do sebacinoid effector proteins mediate symbiosis? Are there conserved effectors used by more than one host and by more than one Sebacinales species?

After an initial biotrophic phase S. indica triggers cell death in different plant hosts during compatible root colonization. The fungal effectors that initiate this process and the host biochemical pathway that underpins the execution of this cellular program remain largely unknown. Heidi functionally characterized a fungal secreted endonuclease which was found in the apoplastic fluid of colonized barley roots. She assessed the role of this endonuclease in interaction with the plant host and its involvement in fungal triggered root cell death.

Fig. S. indica colonizing an Arabidopsis root. Cell wall of extracellular hyphae stained with WGA-AF 594 and the S. indica effector FGB1 fused to GFP localising to the fungal cell wall.