Nicholas J. Talbot, School of Biosciences, University of Exeter, presents this Plant and Microbial Sciences Seminar Series on “Investigating the biology of plant infection by the rice blast fungus Magnaporthe oryzae.”
Abstract: Magnaporthe oryzae is the causal agent of rice blast, one of the most devastating diseases of cultivated rice. Each year rice blast disease destroys enough rice to feed 60 million people. The availability of complete genome sequences for M. oryzae and its host rice, Oryza sativa, has provided the means to investigate this fungal-plant interaction in great detail. During plant infection M. oryzae develops a differentiated infection structure called an appressorium. This unicellular, dome-shaped structure generates cellular turgor that is translated into mechanical force to cause rupture of the rice cuticle and entry into plant tissue. My research group is interested in determining the molecular basis of appressorium development and understanding the genetic regulation of the plant infection process by the rice blast fungus. Recently, we have shown that development of a functional appressorium is linked to cell cycle progression and programmed autophagic cell death of the fungal spore. We have shown that non-selective fungal macroautophagy is essential for plant infection. Appressorium formation is also associated with an oxidative burst that requires NADPH oxidases that are virulence determinants of M. oryzae. To study appressorium physiology and function in greater detail we have used high throughput gene functional analysis, proteomics and metabolomics to define the major genetic regulators of infection-related development of turgor generation and the role of glycerol, trehalose and glycogen metabolism in the development of infection-competent apppressoria.