Ph.D. - University of New Hampshire, 1973
Director and Professor
Center for Agricultural Biotechnology
Plant Sciences Building
University of Maryland
College Park, MD. 20742
Phone: (301)-405-0334
E-mail: nuss@umbi.umd.edu
Research Interests: Engineering viruses to understand and control fungal pathogenesis
Our laboratory has exploited RNA viruses of the genus, Hypovirus, to 1) demonstrate the feasibility of genetically engineering fungal virus for enhanced biocontrol potential, and 2) to identify and dissect signal transduction pathways involved in fungal pathogenesis.
Hypoviruses initially received considerable attention because of their potential utility for biological control by virtue of an ability to reduce virulence (hypovirulence) of the fungal host, Cryphonectria parasitica, the causal agent of chestnut blight. Several years ago, we were able to develop an infectious full-length cDNA clone for the prototypic hypovirus, providing the first and only example of an infectious viral cDNA for an entire taxonomic kingdom (Fungi) of eukaryotic organisms. This development has allowed the construction of "engineered" hypoviruses with enhanced biocontrol potential and the extension of virus host range to include several other pathogenic fungi. Field studies designed to test the dissemination and persistence properties of our first-generation engineered hypovirulent C. parasitica strains are in progress in Connecticut and West Virginia. More aggressive field trials designed to examine the efficacy of second-generation engineered strains in control of chestnut blight are in the planning stages.
A long-standing attraction of the hypovirus/C. parasitica experimental system has been the anticipation that novel insights into the nature and regulation of fungal pathogenesis would derive from an understanding of the mechanism whereby a resident virus attenuates fungal virulence. Our recent observations linking virus-mediated disruption of cellular G-protein signal transduction processes and hypovirulence are beginning to validate this prediction.
We believe that the concept of engineering mycoviruses for purposes of understanding and controlling fungal pathogenesis, as has been demonstrated with hypoviruses, will find application with a broad range of pathogenic fungi, either by direct introduction of hypoviruses or manipulation of endogenous mycoviruses.
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