Analysis of the Role of pH Regulation in the Secretion of Proteins and the Virulence of the Apoplast-Infecting Fungus Mycosphaerella Graminicola

Lawrence Technological University, Southfield MI

Investigators

Abstract

Fungi which infect plants represent both an economic threat and a useful system for the study of fundamental biologic processes. One simple mode of infection used by some fungal plant pathogens is the infection of the space between the cells of the leaf, the apoplast. Even though the infection mechanism is not complex, there are many questions which remain unanswered about how these fungi are able to enter the host, avoid detection, and gain nutrients, events which together comprise pathogenesis. The specific aim of this project is to determine the role that ambient pH signaling plays in the pathogenesis of an apoplast-infecting fungus (Mycosphaerella graminicola) on wheat. M. graminicola is an excellent pathogen for investigation because it exhibits two possible types of growth in culture (single celled and filamentous), two different phases of growth in its plant host (biotrophic (where plant cells are not damaged) and necrotrophic (where plant cells are damaged) and has a sequenced genome. Mutant fungi which lack components of the pH signaling cascade will be created and evaluated with respect to growth under various pH conditions and in plant hosts. The project will rely upon molecular, biochemical and genetic approaches. As a result, the role that pH is playing in influencing the infection process and how pH is sensed by M. graminicola will be understood. The project should provide information about a novel signaling mechanism in this fungus which may be more broadly applicable to other fungal plant pathogens. The broader impacts of this work also include providing research experiences for undergraduate students at Lawrence Technological University.