Concurrent Session
Sohini Deb
Postdoc
Department of Plant and Environmental Sciences, University of Copenhagen
Copenhagen, Hovedstaden, Denmark
Jesper Johansen Sølvsten
Department of Plant and Environmental Sciences, University of Copenhagen
Copenhagen, Hovedstaden, Denmark
Paraskevi Doukoudaki
Department of Plant and Environmental Sciences, University of Copenhagen
Copenhagen, Hovedstaden, Denmark
Maj Kamille Møller Nielsen
Department of Plant and Environmental Sciences, University of Copenhagen
Copenhagen, Hovedstaden, Denmark
Ole Reppien Christensen
Department of Plant and Environmental Sciences, University of Copenhagen
Copenhagen, Hovedstaden, Denmark
Björn Sabelleck
Department of Plant and Environmental Sciences, University of Copenhagen
Copenhagen, Hovedstaden, Denmark
Hans Thordal-Christensen
Department of Plant and Environmental Sciences, University of Copenhagen
Copenhagen, Hovedstaden, Denmark
Powdery mildew fungi are serious pathogens on numerous plant species. They are obligate biotroph, and hence requires living host cells for disease establishment and development. Thus, they form a specialized feeding structure, called haustoria inside the plant cell. Haustoria are dependent on and surrounded by a plant cell-generated extra-haustorial membrane (EHM), a unique membrane that separates the fungus from the host cytosol. However, little is known about how the plant cell forms the EHM. In barley attacked by the powdery mildew fungus (Blumeria hordei, Bh), it has been shown that the EHM has endoplasmic reticulum (ER)-like properties. However, different lines of evidence indicate that the EHM forms by a membrane trafficking-independent pathway, which likely includes lipid transfer from the ER, mediated by lipid transfer proteins (LTPs). We show that silencing by RNAi of one such barley LTP, LTP2, but not the related LTP1 and LTP3, results in reduced haustoria formation. Further, bioinformatics analysis indicated that LTP2 has two putative ‘FFAT’ (phenylalanine-phenylalanine-acidic-tract) motifs for interaction with VAP proteins, which are ER membrane-anchored proteins that tether LTPs. We could subsequently show that LTP2 interacts with barley VAP proteins, whereby it localizes to the EHM. In summary, our data suggest that Bh hijacks the host lipid transfer machinery for EHM formation.