Banner for LabNotes
From Lab Notes
Contact Information
Forest Products Laboratory
One Gifford Pinchot Drive
Madison, WI 53726-2398
Phone: (608) 231-9200
Fax: (608) 231-9592
Email

 

You are here: FPL Home  / Information Products & Services  / Publications

Requested Product

Title: Localizing gene regulation reveals a staggered wood decay mechanism for the brown rot fungus Postia placenta

Source: Proceedings of the National Academy of Sciences. 113(39): 10968-10973.

Author(s)Zhang, Jiwei; Presley, Gerald N.; Hammel, Kenneth E.; Ryu, Jae-San; Menke, Jon R.; Figueroa, Melania; Hu, Dehong; Orr, Galya; Schilling, Jonathan S.

Publication Year: 2016  View PDF »

Category: Journal Articles
Associated Research Project(s):   FPL-4712-2B

Abstract: Wood-degrading brown rot fungi are essential recyclers of plant biomass in forest ecosystems. Their efficient cellulolytic systems, which have potential biotechnological applications, apparently depend on a combination of two mechanisms: lignocellulose oxidation (LOX) by reactive oxygen species (ROS) and polysaccharide hydrolysis by a limited set of glycoside hydrolases (GHs). Given that ROS are strongly oxidizing and nonselective, these two steps are likely segregated. A common hypothesis has been that brown rot fungi use a concentration gradient of chelated metal ions to confine ROS generation inside wood cell walls before enzymes can infiltrate. We examined an alternative: that LOX components involved in ROS production are differentially expressed by brown rot fungi ahead of GH components. We used spatial mapping to resolve a temporal sequence in Postia placenta, sectioning thin wood wafers colonized directionally. Among sections, we measured gene expression by whole-transcriptome shotgun sequencing (RNA-seq) and assayed relevant enzyme activities. We found a marked pattern of LOX up-regulation in a narrow (5-mm, 48-h) zone at the hyphal front, which included many genes likely involved in ROS generation. Up-regulation of GH5 endoglucanases and many other GHs clearly occurred later, behind the hyphal front, with the notable exceptions of two likely expansins and a GH28 pectinase. Our results support a staggered mechanism for brown rot that is controlled by differential expression rather than microenvironmental gradients. This mechanism likely results in an oxidative pretreatment of lignocellulose, possibly facilitated by expansin- and pectinase-assisted cell wall swelling, before cellulases and hemicellulases are deployed for polysaccharide depolymerization.

Keywords: Biodegradation; bioconversion; decomposition; lignocellulose; cellulase

Publication Review Process: Formally Refereed

File size: 936 kb(s)

Date posted: 07/05/2017

This publication is also viewable on Treesearch:  view
RITS Product ID: 85016
Current FPL Scientist associated with this product
Hammel, Kenneth E.
Research Chemist
  

Additional items that might interest you
View the video celebrating FPL's 100 years of public service in 2010, from the producers of the Greatest Good....view

Research Highlights from FPL....view

Termite Eradication: A search for the Holy Grail.... view

Moisture Management in Residential Construction Series videos...view

Wood Floor Systems in Residential Construction Series videos....view
- FPL's Mission and Strategic Plan -

FPL's mission is to identify and conduct innovative wood and fiber utilization research that contributes to conservation and productivity of the forest resource, thereby sustaining forests, the economy, and quality of life. ... ..more »

- FPL Research Emphasis Areas -
Advanced Composites

As an integral part of the FPL mission, we improve the long-term sustainability of our Nation's forests by creating valuable composite products from biobased materials ... ..more »


Advanced Structures

The FPL has been in the forefront of wood-frame housing research since 1910 and has long been recognized as a world leader in such housing-related areas as engineered wood ... ..more »


Forest Biorefinery

We all know the compelling reasons that the United States needs to reduce its dependence on fossil fuels. Historically, the greatest increases in energy demand have been for transportation fuels ... ..more »


Nanotechnology

A leader in wood products research for over a century, the FPL is positioning itself to become the lead Federal research facility for the application of nanotechnology in forest products ... more »


Woody Biomass Utilization

Forests in the United States contain a substantial amount of small-diameter, overstocked, and underutilized material.FPL research projects are exploring the potential of the small-diameter ... ..more »