Investigating the Pmk1 MAPK cascade in rice blast fungus

The world's food supply is under pressure from climate change, shortages of water as well as agriculture pests and diseases. One of the most devastating diseases of rice is caused by blast fungus (Magnaporthe oryzae), which also is the causal agent of the recent wheat blast outbreak in Asia. Rice blast infections start when spores land on leaf surfaces, attach and germinate. The hydrophobic leaf surface triggers germlings to develop an appressorium, a single celled infection structure that generates enormous turgor pressure required to penetrate the rice leaf surface. Understanding how appressoria develop is important to devise strategies to prevent rice blast disease and other important cereal diseases. This PhD project will investigate the role of the mitogen-activated protein kinase, Pmk1, which plays an essential role in appressorium development. Deletion of the PMK1 gene abolishes pathogenicity of the fungus. Very little is known regarding how upstream components of the Pmk1 MAPK pathway are activated, or how the kinase precisely exerts its activity. This project builds on recent work that has established phosphoproteomic methods for analysing the Pmk1 pathway, revealing its direct targets for the first time (Oses-Ruiz et al., 2021 Nat Microb 6:1383-97).