Potato blight, caused by the water mould Phytophthora infestans, is the major disease of potatoes worldwide and is thus a threat to food security. New research from the Birch lab in the Division of Plant Sciences based at the James Hutton Institute has discovered a mechanism that could combat late light disease. The findings have been published in Proceedings of the National Academy of Sciences (PNAS).
Professor Paul Birch, Head of the Division of Plant Sciences explained, “To be a successful pathogen, microbes need to suppress or otherwise manipulate host defences. To do this they use virulence determinants called ‘effector’ proteins that are delivered inside plant cells where they re-programme defences and metabolism to the pathogen’s benefit.”
“This latest research, primarily conducted by Dr Qin He and Dr Shaista Naqvi in my lab, found that the infamous potato blight pathogen delivers an effector protein into its host which targets a negative regulator of immunity, NRL1, which is a ubiquitin E3 ligase. The effector promotes the activity of NRL1 in removing the host protein SWAP70, which is a positive regulator of immunity. In effect, the pathogen is using the plant against itself - promoting endogenous processes that negatively regulate immunity in order to create a susceptible environment. This study reveals that protecting SWAP70 by reducing the activity or availability of NRL1 could provide a method to combat late blight disease.”