Ascospore Discharge

The drawing below to left illustrates how fruiting bodies of F. graminearum look.  One ascus (water cannon filled with spores) stretches up to the top of the fruiting body (ostiole) and fires its contents into the air.  Eight spores and some fluid are discharged rapidly into the air (See figure above).  Defining the mechanism of dispersal of the primary inoculum will lead to new approaches for disease control for this and other disease-causing organisms that rely similar mechanisms for dispersal of disease-causing propagules. We focus on how the ascus works.  Ultimately we want to know what it responds to in the environment and how it translates this into shooting spores.  We want to understand how the ascus is structured so that it stretches in one direction and moves to the opening of the fruiting body to discharge spores.  We  have now identified more than 10 genes that are involved in the function of the ascus. These genes provide us with still disparate pieces of the puzzle, but the pieces are beginning to be linked.  To read about our current model for ascus function, see our recently published synthesis with biophysicist Dr. Agnese Seminara. (The mechanism of ascus firing – Merging biophysical and mycological viewpoints Frances Trail and Agnese Seminara, Fungal Genetics Reviews, 2014, DOI: 10.1016/j.fbr.2014.07.002).