Dinner for two - how does a pathogen access host resources? (FAULKNER_J17DTP)

Pathogens rely on host resources to grow and reproduce. During the infection process, biotrophic pathogens manipulate host cells in order to optimize host cellular processes to their benefit and access resources. In plants, the cytoplasm is connected between cells forming a multicellular entity known as the symplast and this allows direct exchange of nutrients and sugars between cells. Membrane-line pores called plasmodesmata connect the symplast from cell to cell and pathogens can access resources in non-infected cells and tissues through these connections. The regulation of plasmodesmata (whether they are open or closed) can define the transport and distribution of small molecules like sugars between cells and tissues. Current data suggests that while the host tries to close plasmodesmata to cut off the pathogen, the pathogen can override this and access non-infected cells.

Some pathogens produce effector proteins that can move from infected cells into the surrounding non-infected cells via plasmodesmata. This enables pathogens to invade and influence cells that they haven't yet infected. This project will examine how the biotrophic pathogen Hyaloperonospora arabidopsidis manipulates cells around infection sites, and which effectors it deploys to do so. In parallel, the project will assess how plasmodesmal function can affect infection success with the aim of determining if the host can cut off the supply of resources to the host to enhance resistance. The project will employ a combination of molecular biology, live-cell imaging and gene expression analysis to address this element of plant-pathogen interactions.