Abstract Detail

Cell Biology/Physiology

Schilling, Jonathan S. [1], Presley, Gerald  [1], Menke, Jon [1], Zhang, Jiwei [1].

Tracking footprints of wood-degrading fungi that do the two-step.

Wood-degrading fungi either remove lignin to access carboydrates in wood (white rot) or circumvent the lignin barrier to selectively release sugars (brown rot). White rot fungi deploy lignin-degrading enzymes to accomplish the former, and their mechanisms have a long history of research. Their enzymes (e.g., peroxidases) also offer an easy target for ecologists measuring lignolytic activity in forest samples. Brown rot fungi, on the other hand, have evolved mechanisms multiple times from their white rot ancestral lineages that appear dependent on early oxidative, non-enzymatic reactions. Their genomes generally lack lignin-degrading enzyme genes, and they have also shed in most lineages the exo-acting cellulases that are central to the mechanisms of most cellulolytic organisms. In short, they break many of the 'rules' that researchers have increasingly prescribed for lignocellulose decomposition. They are also serious pests in building materials and they are the key drivers of wood decomposition in conifer-dominated forests such as those in the Boreal biome. We still do not know how these fungi decompose wood via the brown rot route and in the absence of those enzymes familiar from white rot secretomes. Our goal is to characterize this natural 'upgrade' in degradation efficiency and to work collaboratively to help learn the genetic basis for brown rot and its functional role in forests. Our work is specifically focused on the interplay and spatial segregation of oxidative mechanisms and the subsequent enzymatic step (aka the 'two-step') with the goal of learning more about the underlying adaptations that allowed fungi to simplify their secretomic arsenal and cause brown rot.

1 - University of Minnesota, Bioproducts & Biosystems Engineering; Institute on the Environment, 2004 Folwell Avenue, Saint Paul, MN, 55108, USA

Keywords:
lignocellulose
decomposition
Forest
microscopy.

Presentation Type: Offered Paper - Paper
Session: 6
Location: Room 104 AB/Kellogg Hotel and Conference Center
Date: Monday, June 9th, 2014
Time: 1:00 PM
Number: 6001
Abstract ID:167
Candidate for Awards:None