Several Green Fluorescent Protein (GFP) tagged strains of C. graminicola were prepared in my laboratory and used to study the plant root colonization process. We have shown that the leaf pathogen C. graminicola is also able to infect and colonize corn roots but the infection process is significantly different than the infection process of leaves. Structures typically formed by root pathogens but not previously reported for C. graminicola on roots, including runner hyphae, hyphopodia and microsclerotia were observed. Microsclerotia produced in culture were able to infect plant roots. Importance of direct infection of roots from infested, buried plant debris has not been previously considered in the life cycle of C. graminicola.The root infection cycle may represent a prolonged biotrophic interaction and may be useful for the study of biotrophic pathogens.
There are a very limited number of studies about the factors that condition the ability for pathogens to colonize different plant tissues . Continued study of tissue-specific infection processes by C. graminicola will help to reveal the molecular nature of tissue specificity, resistance and susceptibility.