Rice blast disease is one of the most serious diseases affecting rice cultivation around the world, detroying enough rice each year to feed 60 million people. The disease is caused by the fungus Magnaporthe (Syn. Pyricularia) oryzae, which also threatens wheat and millet production, affecting Asia and Africa in particular.
To cause plant infection, the rice blast fungus develops a specialised infection structure called an appressorium, which develops enormous pressure that is applied at the leaf surface as physical force to rupture the rice cuticle and allow the fungus to infect leaf tissue. Understanding how appressoria develop and function provides a potential means to combat rice blast disease by preventing initial infection. Appressorium development requires programmed cell death of the fungal spore and recycling of its contents into the infection cell. This process requires autophagy and is tightly coupled to cell cycle control.
This project will investigate the control of plant infection by TOR kinase, a nutrient-sensitive central controller of cell growth. TOR is implicated in many human diseases and is the target of rapamycin, a drug with many therapeutic uses. Its role in fungal pathogenesis is, however, not well understood. The project will characterise TOR kinase in M. oryzae, investigate its activation and regulatory control, identify its downstream phosphorylated protein targets, as well as its ability to control infection-associated autophagy, which is essential for rice blast disease.
The project will provide broad training in molecular genetics, genomics, cell biology, phosphoproteomics, and plantmicrobe interactions. Intellectually, the project provides a challenge in understanding how a global regulator of growth is required for a specific cellular differentiation process, associated with fungal pathogenesis.
Ryder LS, Dagdas YF, Kershaw MJ, Venkataraman, C, Madzvamuse, A., Yan, X., Cruz-Mireles, N., Soanes, DM, Osés-Ruiz, M, Styles, V, Menke, FLH, Talbot, NJ. (2019) A sensor kinase controls turgor-driven plant infection by the rice blast fungus. Nature. 574:423-427
Sakulkoo W, Osés-Ruiz M, Oliveira Garcia E, Soanes DM, Littlejohn, GL, Hacker, C., Correia, A., Valent B, Talbot NJ (2018). A single fungal MAP kinase controls plant cell-to-cell invasion by the rice blast fungus. Science. 359:1399-1403
Osés-Ruiz M, Sakulkoo W, Littlejohn GR, Martin-Urdiroz M, Talbot NJ. (2017) Two independent S-phase checkpoints regulate appressorium-mediated plant infection by the rice blast fungus Magnaporthe oryzae. Proc Natl Acad Sci U S A. 114: E237-E244