P. indica impairs hubs of innate immunity to gain root accessibility - MAMP signaling and ER integrity

• Applicant: Professor Dr. Patrick Schäfer
• Subject Area: Organismic Interactions, Chemical Ecology and Microbiomes of Plant Systems ; Plant Cell and Developmental Biology
• Term: from 2007 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 39358904

Arabidopsis root colonization by the mutualistic fungus Piriformospora indica is separated into a biotrophic followed by cell death-associated colonization phase. Our studies indicated the presence of a functional root innate immune system. Biotrophic colonization is dependent on P. indica’s ability to efficiently suppress root immunity. At later interaction stages, P. indica induces an ER stress-initiated caspase-dependent cell death, which is essential for root colonization. Based on our studies, we hypothesize that root and leaf MAMP-triggered immunity (MTI) are highly overlapping and that the MTI suppressing capacities of microbes primarily determine root colonization. However, we do not know which MTI pathways define MTI efficiency and sustainability. The significance of the ER machinery in MTI signaling was just recently demonstrated. Because P. indica was shown to disturb early MTI signaling and ER integrity it is the aim of the 3. project phase to define their contribution to sustainability of root MTI. Furthermore we aim at identifying and investigating the role of cell death regulators on root MTI and root compatibility. Here, special emphasis will be given to ER stress sensors as they represent central regulators of ER stress signaling and of ER-induced cell death as demonstrated in mammals.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1212: Microbial Reprogramming of Plant Cell Development
• International Connection: United Kingdom
• Participating Person: Professor Dr. Karl-Heinz Kogel