Membrane trafficking at the host-pathogen interface
Prof. Sophien Kamoun1, Yasin F. Dagdas1, Khaoula Belhaj1, Benjamin Petre1, Joe Win1, and Tolga O. Bozkurt2
1The Sainsbury Laboratory, Norwich Research Park, Norwich, NR4 7UH, UK.
2Imperial College London, Department of Life Sciences, London, UK.
Many plant pathogenic and symbiotic microbes produce specialized structures that invade host cells but remain enveloped by host-derived membranes. The mechanisms underlying the biogenesis and functions of such host–microbe interfaces are poorly understood. The Irish potato famine pathogen Phytophthora infestans is an oomycete hemibiotroph that infects solanaceous plants. During its biotrophic phase, P. infestans forms haustoria. A host-derived membrane, called the extrahaustorial membrane (EHM), separates haustoria from the plant cell and constitutes the haustorial interface. Some P. infestans strains infect Nicotiana benthamiana and develop haustoria in infected leaf cells. We have exploited the N. benthamiana experimental system to perform fast-forward cell biology of the haustorial interface. This revealed dynamic changes in host membrane compartment formation and rerouting in haustoriated cells. In particular, we discovered that selective autophagy and other trafficking pathways are diverted to the pathogen interface. Our working model is that P. infestans RXLR effectors co-opt host membrane trafficking to promote host colonization.
Molecular handshakes in plant/pathogen interactions
Prof. Mark Banfield
Dept. of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich, UK
The ability of plant pathogens to cause disease and the ability of host plants to resist infection are frequently determined by interactions between proteins. In my Lab we study the biochemical and structural basis of how translocated plant pathogen effector proteins promote disease, and how plant cells recognise and respond to the presence of these molecules to deliver immunity. Ultimately we hope these studies will allow informed engineering of plant immunity in important crop species. In my seminar I will give a general overview of this work, with examples of published and unpublished work to highlight recent progress.
1) Maqbool A, Saitoh H, Franceschetti M, Stevenson CEM, Uemura A, Kanzaki H, Kamoun S, Terauchi R & Banfield MJ (2015) Structural basis of pathogen recognition by an integrated HMA domain in a plant NLR immune receptor. eLife 4:e08709.
2) King SR, McLellan H, Boevink PC, Armstrong MR, Bukharova T, Sukarta O, Win J, Kamoun S, Birch PR & Banfield MJ (2014) Phytophthora infestans RXLR effector PexRD2 interacts with host MAPKKK to suppress plant immune signalling. The Plant Cell. 26: 1345-59.
3) Sohn K, Hughes RK, Piquerez SJ, Jones JD & Banfield MJ (2012) Distinct regions of the Pseudomonas syringae coiled-coil effector AvrRps4 are required for activation of immunity. PNAS (USA). 109: 16371-16376.
4) Boutemy LS, King SR, Win J, Hughes RK, Clarke TA, Blumenschein TM, Kamoun S, Banfield MJ (2011) Structure of Phytophthora RXLR effector proteins: a conserved but adaptable fold underpins functional diversity. Journal of Biological Chemistry. 286: 35834-42.