Capturing an Early Gene Induction Event during Wood Decay by the Brown Rot Fungus Rhodonia placenta

Abstract

Earth’s aboveground terrestrial biomass is primarily wood, and fungi dominate wood decomposition. Here, we studied these fungal pathways in a common “brown rot”-type fungus, Rhodonia placenta , that selectively extracts sugars from carbohydrates embedded within wood lignin.

Functional genomics gives new insights into the ectomycorrhizal degradation of chitin

“…We also noticed that several genes not directly associated with chitin degradation were significantly upregulated in the presence of exogenous chitin, such as genes coding for laccases, GMC oxidases, benzoquinone reductases, and GSTs. Interestingly, these gene families are known to be implicated in the Fenton reaction, a nonenzymatic mechanism leading to the oxidation of organic matter, both for saprotrophic and EcM fungi (Jensen Jr et al ., 2001; Levasseur et al ., 2013; Nicolás et al ., 2018; Sützl et al ., 2018; Da et al ., 2020; Anderson et al ., 2022). Thus, we speculate that efficient degradation of chitin by EcM fungi could require chitin oxidation through the Fenton reaction in combination with the production of chitinases.…”

A Laccase Gene Reporting System That Enables Genetic Manipulations in a Brown Rot Wood Decomposer Fungus Gloeophyllum trabeum

“…First, we found that brown rot fungi can stagger gene expression to first produce ROS for initial decay, and then express glycoside hydrolases for saccharification ( 10 , 18 ). This, combined with cross-species comparisons, has since enabled us to discover the decay-stage-dependent genes and shuffled genetic regulatory system unique to brown rot ( 19 , 20 ). Supporting this, we also discovered that brown rot adopts an attenuated glucose-mediated repression system to boost cellulase production for rapid carbohydrate release ( 21 ).…”