Funding award to fight potato blight

Damage from pests and pathogens causes losses of up to 25% of global production of the five most important food crops, representing a significant threat to food security. For example, the potato and tomato late blight pathogen Phytophthora infestans causes annual global losses estimated to exceed $10 bn. Plant pathogens such as P. infestans cause disease by delivering an arsenal of virulence proteins, called effectors, into plant tissues during infection. Amongst these are hundreds of so-called RXLR effectors that are delivered inside living plant cells where they often target host proteins to suppress immunity. A major scientific challenge in the plant-microbe interaction field is to understand how RXLR effectors are secreted and delivered into plant cells. 

The BBSRC responsive mode grant awarded to Paul Birch (project lead) alongside Dr Steve Whisson and Dr Petra Boevink (co-investigators) from the James Hutton Institute aims to study the RXLR effectors and associated factors in more detail.

Paul Birch, Professor of Plant Pathology, Division of Plant Sciences, School of Life Sciences, based at the James Hutton Institute, said, “We have generated data showing that RXLR effectors are secreted in association with membrane-bound extracellular vesicles (EVs). We have discovered other proteins associated with these EVs, including proteins with MARVEL domains containing multiple transmembrane helices. These MARVEL proteins co-localise with RXLR effectors in vesicles, and we hypothesise that they are novel markers of EVs associated with RXLR effector delivery. 

“In our proposal we aim to confirm whether MARVEL proteins are markers of EVs associated with RXLRs and we will use cutting-edge super-resolution microscopy to provide a detailed and deep investigation of their secretion and delivery at the interface between P. infestans and its hosts. 

“This work will provide a deep understanding of a key fundamental effector delivery mechanism likely to be shared across plant pathogens which can be targeted by agrochemical or biotechnological means to prevent crop disease.”