Biomechanical models applied to the rice blast fungus
Anthony Tongen (Department of Mathematics, University of Arizona)
(March 20, 2008 10:30 AM - 11:30 AM)
The fungus Magnaporthe grisea, commonly referred to as the rice blast fungus, is responsible for destroying from 10% to 30% of the world's rice crop each year. The fungus attaches to the rice leaf and forms a dome-shaped structure, the appressorium, in which enormous pressures are generated that are used to blast a penetration peg through the rice cell walls and infect the plant. We develop models for both the appressorial development and the penetration peg using exact, nonlinear, elasticity theory for shells and membranes. The model for appressorial design explains the shape of the appressorium, and its ability to maintain that shape under enormous increases in turgor pressure that can occur during the penetration phase. The model for the penetration peg provides the means of studying the effects of external surface stresses and the normal motion of material points on the cell surface.