Deciphering Effector Delivery and Uptake ChannEls (DEDUCE)

Infections by filamentous pathogens pose escalating threats to global food security, over 25% of crops are lost to destructive outbreaks such as potato late blight, caused by Phytophthora infestans. It is critical to understand how such diseases are caused, informing new ways to safeguard food supplies. P. infestans deploys virulence factors called effectors that act either outside (apoplastic) or within (RXLR) host cells to destroy plants.

While we have made strides in understanding how effectors suppress host immunity, how RXLRs are delivered into host cells is largely unknown. In my project, I will focus on two objectives: 1) Characterize effector trafficking pathways within P. infestans; 2) Investigate how RXLR effectors enter plant cells.

The team I aim to join in Dundee is at the forefront of deciphering how P. infestans RXLR effectors are delivered into plant cells. Recent advances include the demonstration that they are taken into host cells by endocytosis, and the unpublished observations that RXLR effectors are secreted via extracellular vesicles (EVs). In this project, using a bespoke super-resolution confocal microscope unique within plant science, I will scrutinize vesicular effector trafficking with unprecedented precision.

Integrating biochemical and proteomic approaches to explore the biogenesis and secretion of EVs and whether they are taken up in entirety by receptor-mediated endocytosis. Additionally, the cutting-edge technology Cryo-transmission electron microscope will be used to precisely dissect how EVs are recognized by host receptors during endocytosis. The availability of these advanced technologies, combined with my extensive expertise in Phytophthora and EV research, holds the potential for groundbreaking steps in understanding how filamentous pathogens secrete and deliver effectors, unlocking further potential to develop targeted chemicals or biotechnological interventions, to combat crop diseases by impeding effector trafficking.