Special Session: Functional, Evolutionary, and Ecological Diversity of Wood Decay Systems

7-S

Diversification of wood decay systems in early evolution of Agaricomycotina.
L. G. NAGY (1), D. Floudas (1), R. Riley (2), K. Barry (2), I. V. Grigoriev (2), D. S. Hibbett (1)
(1) Biology Department, Clark University, Worcester, MA, U.S.A.; (2) U.S. Department of Energy, Joint Genome Institute, Walnut Creek, CA, U.S.A.

The Agaricomycotina have evolved the most powerful enzymatic apparatus to attack wood. Copy number evolution in gene families encoding enzymes involved in lignocellulose decomposition shows a significant correlation with the evolution of nutritional strategies, with considerable diversification in white rot lineages and gene loss in brown rot lineages. Recent studies suggest that white rot, i.e. the ability to break down both lignin and cellulose, evolved around the same time as the divergence of Agaricomycetes and Dacrymycetes (certain jelly fungi), but detailed genome-based analyses of the early events of the evolution of nutritional strategies have been impaired by the lack of dense sampling of genomes around these nodes of the fungal tree. In current work, we are extending the sampling of genomes, focusing on the earliest-diverging orders. We are presently analyzing whole genome sequences for Exidia glandulosa (Auriculariales), Sistotremastrum suecicum, S. niveo-cremeum (Trechisporales), Calocera viscosa, C. cornea (Dacrymycetales), Daedalea quercina (Polyporales) and Sistotrema brinkmannii (Cantharellales). We will incorporate these species into existing phylogenomic datasets of single-copy genes to infer a species tree, which we will use to reconstruct evolution of the wood-decay apparatus. The goals of our analyses are to refine our understanding of the evolution of the wood-decay system during a period of significant ecological innovation in Agaricomycotina.