Experimental evidence that fungal symbionts of beetles suppress wood decay by competing with decay fungi

Throughout forests worldwide, bark and ambrosia beetles inoculate dead and dying trees with symbiotic fungi. We experimentally determined the effects of three common and widely distributed ascomycete symbionts, and one introduced Asian basidiomycete symbiont on the decay of pine sapwood. Ascomycetes caused less than 5% mass loss and no structural degradation, whereas the basidiomycete Flavodon ambrosius caused nearly 15% mass loss and visible degradation of wood structure. In co-inoculation experiments, the beetle symbionts Ophiostoma ips and Raffaelea fusca reduced white and brown rot decay through competition with Ganoderma curtisii and Phaeolus schweinitzii, respectively. The inhibitory effects of O. ips and R. fusca on decay were negated when co-inoculated with F. ambrosius, suggesting that widespread introduction of this beetle symbiont could alter forest carbon fluxes. In contrast to the predominant forest biology narrative, most bark and ambrosia beetles introduce fungi that delay rather than facilitate tree biomass recycling.

Download Full-text

Fungal symbionts of bark and ambrosia beetles can suppress decomposition of pine sapwood by competing with wood-decay fungi

Fungal Ecology ◽

10.1016/j.funeco.2020.100926 ◽

2020 ◽

Vol 45 ◽

pp. 100926 ◽

Cited By ~ 3

Author(s):

James Skelton ◽

Andrew Loyd ◽

Jason A. Smith ◽

Robert A. Blanchette ◽

Benjamin W. Held ◽

...

Keyword(s):

Wood Decay ◽

Ambrosia Beetles ◽

Decay Fungi ◽

Wood Decay Fungi ◽

Bark And Ambrosia Beetles

Download Full-text

Mode of action of brown rot decay resistance in modified wood: a review

Holzforschung ◽

10.1515/hf-2013-0057 ◽

2014 ◽

Vol 68 (2) ◽

pp. 239-246 ◽

Cited By ~ 66

Author(s):

Rebecka Ringman ◽

Annica Pilgård ◽

Christian Brischke ◽

Klaus Richter

Keyword(s):

Cell Wall ◽

Mode Of Action ◽

Wood Decay ◽

Brown Rot ◽

Decay Resistance ◽

Hydroxyl Groups ◽

Decay Fungi ◽

Brown Rot Decay ◽

Thermally Modified Wood ◽

Modified Wood

Abstract Chemically or physically modified wood materials have enhanced resistance to wood decay fungi. In contrast to treatments with traditional wood preservatives, where the resistance is caused mainly by the toxicity of the chemicals added, little is known about the mode of action of nontoxic wood modification methods. This study reviews established theories related to resistance in acetylated, furfurylated, dimethylol dihydroxyethyleneurea-treated, and thermally modified wood. The main conclusion is that only one theory provides a consistent explanation for the initial inhibition of brown rot degradation in modified wood, that is, moisture exclusion via the reduction of cell wall voids. Other proposed mechanisms, such as enzyme nonrecognition, micropore blocking, and reducing the number of free hydroxyl groups, may reduce the degradation rate when cell wall water uptake is no longer impeded.

Download Full-text

Resistance of thermally modified and pressurized hot water extracted Scots pine sapwood against decay by the brown-rot fungus Rhodonia placenta

European Journal of Wood and Wood Products ◽

10.1007/s00107-019-01482-z ◽

2019 ◽

Vol 78 (1) ◽

pp. 161-171 ◽

Cited By ~ 5

Author(s):

Michael Altgen ◽

Suvi Kyyrö ◽

Olli Paajanen ◽

Lauri Rautkari

Keyword(s):

Cell Wall ◽

Mass Loss ◽

Scots Pine ◽

Elevated Temperatures ◽

Brown Rot ◽

Decay Resistance ◽

Hot Water ◽

Decay Fungi ◽

Effective Reduction ◽

Cell Wall Porosity

AbstractThe thermal degradation of wood is affected by a number of process parameters, which may also cause variations in the resistance against decay fungi. This study compares changes in the chemical composition, water-related properties and decay resistance of Scots pine sapwood that was either thermally modified (TM) in dry state at elevated temperatures (≥ 185 °C) or treated in pressurized hot water at mild temperatures (≤ 170 °C). The thermal decomposition of easily degradable hemicelluloses reduced the mass loss caused by Rhodonia placenta, and it was suggested that the cumulative mass loss is a better indicator of an actual decay inhibition. Pressurized hot water extraction (HWE) did not improve the decay resistance to the same extent as TM, which was assigned to differences in the wood-water interactions. Cross-linking reactions during TM caused a swelling restraint and an effective reduction in moisture content. This decreased the water-swollen cell wall porosity, which presumably hindered the transport of degradation agents through the cell wall and/or reduced the accessibility of wood constituents for degradation agents. This effect was absent in hot water-extracted wood and strong decay occurred even when most hemicelluloses were already removed during HWE.

Download Full-text

Variation in germination percentage of basidiospores collected successively from wood decay fungi in culture

Canadian Journal of Botany ◽

10.1139/b83-017 ◽

1983 ◽

Vol 61 (1) ◽

pp. 171-173 ◽

Cited By ~ 3

Author(s):

E. L. Schmidt ◽

D. W. French

Keyword(s):

Spore Germination ◽

White Rot Fungi ◽

Wood Decay ◽

Brown Rot ◽

Germination Percentage ◽

White Rot ◽

Malt Extract ◽

Decay Fungi ◽

Brown Rot Fungi ◽

Wood Decay Fungi

Successive collections of basidiospores, produced in culture from the same hymenial areas of four species of wood decay fungi, were tested for spore germination percentage on malt extract agar under controlled conditions. Spores from white rot fungi retained high germination levels after 5 weeks of spore production, but germination averages for brown rot fungi decreased by more than 50%. Such variation should be considered in wood pathology research using spore germination bioassay.

Download Full-text

Changes in Carbon Sequestration in Wood During Decay by Brown- and White-Rot Fungi

Journal of Biobased Materials and Bioenergy ◽

10.1166/jbmb.2020.1968 ◽

2020 ◽

Vol 14 (3) ◽

pp. 414-419

Author(s):

Huadong Xu ◽

Jiedong Wei ◽

Yanan Di ◽

Ruixia Qin ◽

Zonglin Zhen

Keyword(s):

Carbon Sequestration ◽

Mass Loss ◽

Decay Time ◽

Carbon Emission ◽

Wood Decay ◽

Brown Rot ◽

White Rot ◽

Korean Pine ◽

Decay Test ◽

The Absolute

Wood decay is a releasing process of carbon fixed in the wood. The study on carbon sequestration change caused by decay can provide a theoretical basis for wood preservation and utilization. At present, there are few reports on decay influence on wood carbon emission and no corresponding quantitative data. Therefore, one broad-leaved species, Poplar, and one coniferous species, Korean pine, were selected as the research object, and brown rot fungus (Gloeephyllum trabeum) and white rot fungus (Coriolus versicolor) were used to conduct accelerated decay test on wood samples in the laboratory. During decay, specimens were taken out in different periods to measure chemical properties, mass loss and carbon sequestration. The influence of decay time on carbon sequestration, chemical component and mass loss were then analyzed and the change rule of carbon sequestration were finally studied. The results showed that with increasing decay time, the relative carbon sequestration content of wood affected by different types rot fungi decreased, which was consistent with the change rule of mass loss, indicating that decay would lead to a loss of wood mass and affect its carbon sequestration. However, the absolute carbon sequestration (measured value of carbon sequestration) after brown rot treatment did not decrease but increased slightly, which was different from previous expectation. According to the analysis, with increasing brown rot time, the absolute content and proportion of lignin in wood samples increased slightly, while the corresponding value of holocellulose (including α-cellulose and hemicellulose) decreased significantly. The carbon content of lignin per unit mass is higher than that of holocellulose (Poplar 64.08% > 37.38%; Korean pine 66.37% > 35.94%), resulting in absolute carbon sequestration in wood increases instead of decreases. In conclusion, the change of lignin proportion during the process of brown rot is the decisive factor affecting the change of absolute carbon sequestration. This study focused on two aspects of wood decay and wood carbon sequestration, systematically analyzed the change rule and internal mechanism of wood carbon sequestration with the increase of wood decay degree, and accumulated basic data for wood carbon emission reduction and wood prevention.

Download Full-text

Comparative Transcriptome and Secretome Analysis of Wood Decay Fungi Postia placenta and Phanerochaete chrysosporium

Applied and Environmental Microbiology ◽

10.1128/aem.00058-10 ◽

2010 ◽

Vol 76 (11) ◽

pp. 3599-3610 ◽

Cited By ~ 181

Author(s):

Amber Vanden Wymelenberg ◽

Jill Gaskell ◽

Michael Mozuch ◽

Grzegorz Sabat ◽

John Ralph ◽

...

Keyword(s):

Phanerochaete Chrysosporium ◽

Cellulose Degradation ◽

Expression Patterns ◽

Wood Decay ◽

Brown Rot ◽

White Rot ◽

Glycosyl Hydrolases ◽

Decay Fungi ◽

Postia Placenta ◽

Wood Decay Fungi

ABSTRACT Cellulose degradation by brown rot fungi, such as Postia placenta, is poorly understood relative to the phylogenetically related white rot basidiomycete, Phanerochaete chrysosporium. To elucidate the number, structure, and regulation of genes involved in lignocellulosic cell wall attack, secretome and transcriptome analyses were performed on both wood decay fungi cultured for 5 days in media containing ball-milled aspen or glucose as the sole carbon source. Using liquid chromatography-tandem mass spectrometry (LC-MS/MS), a total of 67 and 79 proteins were identified in the extracellular fluids of P. placenta and P. chrysosporium cultures, respectively. Viewed together with transcript profiles, P. chrysosporium employs an array of extracellular glycosyl hydrolases to simultaneously attack cellulose and hemicelluloses. In contrast, under these same conditions, P. placenta secretes an array of hemicellulases but few potential cellulases. The two species display distinct expression patterns for oxidoreductase-encoding genes. In P. placenta, these patterns are consistent with an extracellular Fenton system and include the upregulation of genes involved in iron acquisition, in the synthesis of low-molecular-weight quinones, and possibly in redox cycling reactions.

Download Full-text

Decay susceptibility of Amazon wood species from Brazil against white rot and brown rot decay fungi 10th EWLP, Stockholm, Sweden, August 25–28, 2008

Holzforschung ◽

10.1515/hf.2009.119 ◽

2009 ◽

Vol 63 (6) ◽

Cited By ~ 2

Author(s):

Jane Silveira Carneiro ◽

Luciano Emmert ◽

Gerson H. Sternadt ◽

Julio César Mendes ◽

Getúlio F. Almeida

Keyword(s):

Wood Species ◽

Wood Decay ◽

Brown Rot ◽

White Rot ◽

Natural Resistance ◽

Decay Fungi ◽

Pycnoporus Sanguineus ◽

Hymenaea Courbaril ◽

Weight Losses ◽

Resistant Species

Abstract A total of 28 tropical Amazon woods – many of them rarely used – from Tapajós National Forest, Pará state, Brazil, were tested for their natural resistance against the decay fungi: Ganoderma applanatum, Trametes versicolor, Pycnoporus sanguineus, Meruliporia incrassata, and Gloeophyllum trabeum. The wood resistance classification was made according to the ASTM D 2017-81 method. High variability on susceptibility to wood decay fungi was found. Their mean weight losses varied from 0.6% to 45.6%. Highly resistant species include: Astronium gracile, Bagassa guianensis, Caryocar villosum, Claricia racemosa, Diplotropis purpurea, Dipteryx odorata, Hymenaea courbaril, Manilkara huberi, Mezilaurus itauba, Sextonia rubra, Tabebuia incana, and Vatairea paraensis. The following wood species are less durable: Brosimum parinarioides, Jacaranda copaia, Laetia procera, Pouteria pachycarpa, Virola caducifolia, and Trattinnickia rhoifolia. Meruliporia incrassata caused extensive weight losses in most of the investigated Amazon wood species.

Download Full-text

A METHOD FOR EVALUATING ERGOSTEROL CONTENT IN WOOD-DECAY FUNGI

Revista Árvore ◽

10.1590/1806-908820200000010 ◽

2020 ◽

Vol 44 ◽

Author(s):

Carlos Garrido Pinheiro ◽

Nadia Helena Bianchini ◽

Alana Silveira Pavlack ◽

Marlove Fátima Brião Muniz ◽

Victor Dos Santos Barboza ◽

...

Keyword(s):

Wood Decay ◽

Brown Rot ◽

White Rot ◽

Uv Spectrophotometry ◽

Decay Fungi ◽

Potato Dextrose Agar Medium ◽

Ergosterol Content ◽

Wood Decay Fungi ◽

Antifungal Action ◽

Wet Weight

ABSTRACT Ergosterol is responsible for important functions in the fungal plasma membrane. The influence of fungitoxic agents on membrane ergosterol content is one of the most important mechanisms of antifungal action and its knowledge allows the generation of products that associate active compounds of different mechanisms, consequently improving the effectiveness of wood preservatives. Therefore, this study optimized a method for quantifying ergosterol in wood-decay fungi. The white-rot species selected were Ganoderma applanatum and Trametes versicolor, while the brown-rot were Gloeophyllum trabeum and Lentinus lepideus. Mycelial discs of each species were transferred to Petri dishes containing a cellophane-covered potato-dextrose-agar medium. Mycelia of each fungus were collected, weighed, and transferred to test tubes with 5 mL of 25% alcoholic potassium hydroxide. The tubes were vortexed for 5 min, subjected to ultrasound for 5 min, incubated at 85 °C for 4 h, followed by the addition of 2 mL of sterile distilled water and 5 mL of n-heptane and subsequent ultrasound shaking for 2 min. The n-heptane layer was analyzed by UV spectrophotometry between 230 and 300 ηm. The blank sample only contained n-heptane. The mycelia wet weight of the fungi ranged from 0.061 to 0.296 g. Ergosterol content was 0.007% for Lentinus lepideus and 0.004% for the other species. The absorbance was higher than the ones observed in the blank for all samples. The adapted method was efficient for ergosterol extraction.

Download Full-text

High-performance liquid chromatographic analysis of soluble and total oxalate in Ca- and Mg-amended liquid cultures of three wood decay fungi

Holzforschung ◽

10.1515/hf.2004.124 ◽

2004 ◽

Vol 58 (6) ◽

pp. 682-687 ◽

Cited By ~ 14

Author(s):

Jonathan S. Schilling ◽

Jody Jellison

Keyword(s):

High Performance ◽

Wood Decay ◽

Brown Rot ◽

High Performance Liquid Chromatographic ◽

White Rot ◽

Fomitopsis Pinicola ◽

Decay Fungi ◽

Postia Placenta ◽

Medium Components ◽

Wood Decay Fungi

AbstractTwo brown-rot wood decay fungi,Fomitopsis pinicolaandMeruliporia incrassata, and the white-rot speciesPhanerochaete chrysosporiumwere grown for 4 weeks in liquid culture at 0.35, 0.70, 1.05, and 5.00 mM calcium (Ca) and 1.35 and 2.70 mM magnesium (Mg) concentrations. Soluble and total oxalate levels were quantified using a revised ion-exchange HPLC protocol developed specifically for resolving oxalate and other organic acid anions from medium components. Total oxalate concentrations in brown-rot filtrate were not significantly different among treatments; however, soluble oxalate decreased significantly with increasing Ca concentration. Higher Mg concentrations increased soluble oxalate levels only slightly. There was a significant decrease in medium pH at 5.00 mM Ca for all species, as well as an apparent increase in decarboxylation activity in brown-rot fungi. Total and soluble oxalate levels in the white-rot cultures were generally below detection for all treatments. The results show a significant influence of Ca on soluble oxalate concentrations not seen previously in the brown-rot speciesPostia placenta.

Download Full-text