Grant: Discovery Grants Program - Individual

Introduction: Confrontation between fungal cells of the same species or different species leads to one of a variety of events including no apparent interaction, avoidance, growth inhibition, death of one or both fungi, or cell fusion (parasitic, vegetative or sexual fusion). Early cellular recognition events are mediated by production and reception of diffusible signals or through direct cell to cell contact mediated by surface ligands and receptors. The proposed research will investigate early molecular events during the interaction between Trichoderma aggressivum, the causative agent of mushroom green mould disease, and Agaricus bisporus, the commercial mushroom. Specific short-term goals of the research are: (1) to determine if differences in inhibition shown by various strains of the commercial mushroom are due to altered N-acetylglucosaminidase production; (2) to determine if differences in inhibition are associated with differential metabolism of Trichoderma toxins; (3) to determine the nature of the signal(s) produced by A. bisporus which lead to increased production of hydrolytic enzymes by T. aggressivum; and (4) to determine if chitinases, glucanases and proteinases produced by T. aggressivum play any role in green mold disease progression. Significance: Longer-term goals include definition of the genetic control of signal production, reception and transduction and determination of the universality of these mechanisms within other fungus-fungus interactions. Work of this nature will give insight into diverse areas such as recognition, attachment and disease progression in plant and animal tissues by parasitic fungi and the use of fungi as biocontrol agents of other fungi. These studies will also provide a basis for understanding the disease relationship between T. aggressivum and A. bisporus. An economically significant long-term goal is to develop procedures that will prevent or disrupt the relationship and thereby result in disease control.