David S. Hibbett
Professor of Biology, Clark University
The Roots of Rot: Evolution of Wood-Decay Mechanisms in Saprotrophic Basidiomycetes
Abstract: Wood is a major pool of terrestrial carbon that is resistant to microbial attack, due largely to the presence of the tough, heterogeneous polymer, lignin. Basidiomycetes (mushroom-forming fungi) have two major mechanisms for digesting wood: white rot and brown rot. White rot fungi decay all components of plant cell walls, including lignin, whereas brown rot fungi employ a non-enzymatic mechanism using hydroxyl radicals to initiate depolymerization of cellulose, while leaving lignin mostly intact. We are using comparative analyses of fungal genomes to understand the evolution of white rot and brown decay modes, and their potential impact on the history of organic carbon sequestration.