scholarly journals Spatial Patterns in Hyphal Growth and Substrate Exploitation within Norway Spruce Stems Colonized by the Pathogenic White-Rot Fungus Heterobasidion parviporum

2009 ◽  
Vol 75 (12) ◽  
pp. 4069-4078 ◽  
Author(s):  
Ari M. Hietala ◽  
Nina E. Nagy ◽  
Arne Steffenrem ◽  
Harald Kvaalen ◽  
Carl G. Fossdal ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Norway Spruce ◽  
Reaction Zone ◽  
Hyphal Growth ◽  
White Rot ◽  
White Rot Fungus ◽  
Local Concentration ◽  
Enhanced Production ◽  
Hyphal Sheath ◽  
Pathogen Dna

ABSTRACT In Norway spruce, a fungistatic reaction zone with a high pH and enrichment of phenolics is formed in the sapwood facing heartwood colonized by the white-rot fungus Heterobasidion parviporum. Fungal penetration of the reaction zone eventually results in expansion of this xylem defense. To obtain information about mechanisms operating upon heartwood and reaction zone colonization by the pathogen, hyphal growth and wood degradation were investigated using real-time PCR, microscopy, and comparative wood density analysis of naturally colonized trees with extensive stem decay. The hyphae associated with delignified wood at stump level were devoid of any extracellular matrix, whereas incipient decay at the top of decay columns was characterized by a carbohydrate-rich hyphal sheath attaching hyphae to tracheid walls. The amount of pathogen DNA peaked in aniline wood, a narrow darkened tissue at the colony border apparently representing a compromised region of the reaction zone. Vigorous production of pathogen conidiophores occurred in this region. Colonization of aniline wood was characterized by hyphal growth within polyphenolic lumen deposits in tracheids and rays, and the hyphae were fully encased in a carbohydrate-rich extracellular matrix. Together, these data indicate that the interaction of the fungus with the reaction zone involves a local concentration of fungal biomass that forms an efficient translocation channel for nutrients. Finally, the enhanced production of the hyphal sheath may be instrumental in lateral expansion of the decay column beyond the reaction zone boundary.

scholarly journals The Pathogenic White-Rot Fungus Heterobasidion parviporum Responds to Spruce Xylem Defense by Enhanced Production of Oxalic Acid

2012 ◽  
Vol 25 (11) ◽  
pp. 1450-1458 ◽  
Author(s):  
Nina Elisabeth Nagy ◽  
Harald Kvaalen ◽  
Monica Fongen ◽  
Carl Gunnar Fossdal ◽  
Nicholas Clarke ◽  
...  
Keyword(s):  
Oxalic Acid ◽  
Reaction Zone ◽  
Antimicrobial Properties ◽  
White Rot Fungi ◽  
White Rot ◽  
White Rot Fungus ◽  
Lignocellulose Degradation ◽  
Crystal Formation ◽  
Enhanced Production ◽  
Fungal Genes

Pathogen challenge of tree sapwood induces the formation of reaction zones with antimicrobial properties such as elevated pH and cation content. Many fungi lower substrate pH by secreting oxalic acid, its conjugate base oxalate being a reductant as well as a chelating agent for cations. To examine the role of oxalic acid in pathogenicity of white-rot fungi, we conducted spatial quantification of oxalate, transcript levels of related fungal genes, and element concentrations in heartwood of Norway spruce challenged naturally by Heterobasidion parviporum. In the pathogen-compromised reaction zone, upregulation of an oxaloacetase gene generating oxalic acid coincided with oxalate and cation accumulation and presence of calcium oxalate crystals. The colonized inner heartwood showed trace amounts of oxalate. Moreover, fungal exposure to the reaction zone under laboratory conditions induced oxaloacetase and oxalate accumulation, whereas heartwood induced a decarboxylase gene involved in degradation of oxalate. The excess level of cations in defense xylem inactivates pathogen-secreted oxalate through precipitation and, presumably, only after cation neutralization can oxalic acid participate in lignocellulose degradation. This necessitates enhanced production of oxalic acid by H. parviporum. This study is the first to determine the true influence of white-rot fungi on oxalate crystal formation in tree xylem.

Xylem defense wood of Norway spruce compromised by the pathogenic white-rot fungus Heterobasidion parviporum shows a prolonged period of selective decay

Planta ◽  
2012 ◽  
Vol 236 (4) ◽  
pp. 1125-1133 ◽  
Author(s):  
Nina Elisabeth Nagy ◽  
Simon Ballance ◽  
Harald Kvaalen ◽  
Carl Gunnar Fossdal ◽  
Halvor Solheim ◽  
...  
Keyword(s):  
Norway Spruce ◽  
White Rot ◽  
White Rot Fungus ◽  
Selective Decay

Quantification of fungal colonization in modified wood: Quantitative real-time PCR as a tool for studies on Trametes versicolor

Holzforschung ◽  
2010 ◽  
Vol 64 (5) ◽  
Author(s):  
Annica Pilgård ◽  
Gry Alfredsen ◽  
Ari Hietala
Keyword(s):  
Real Time ◽  
Trametes Versicolor ◽  
Growth Period ◽  
Hyphal Growth ◽  
Growth Patterns ◽  
White Rot ◽  
White Rot Fungus ◽  
Fungal Colonization ◽  
Wood Preservatives ◽  
Fungal Dna

Abstract Traditional wood preservatives based on biocides are effective against wood-deteriorating organisms because of their toxicity. By contrast, modified woods are non-toxic by definition. To investigate the efficiency of various wood modifications, quantitative real-time polymerase chain reaction (qPCR) was used to profile the DNA amounts of the white-rot fungus Trametes versicolor (L.) [Lloyd strain CTB 863 A] during an 8-week-long growth period in treated Pinus sylvestris (L.) sapwood. The studied wood was modified by acetylation, furfurylation, and thermal treatment. The traditional wood preservatives bis-(N-cyclohexyldiazeniumdioxy)-copper (Cu-HDO) and chromated copper arsenate (CCA) were used as references, whereas untreated P. sylvestris (L.) sapwood served as a control. The maximum levels of fungal DNA in native wood occurred at the end of the experiment. For all wood treatments, the maximum fungal DNA level was recorded after an incubation period of 2 weeks, followed by a decline until the end of the trial. For the preservative-treated woods, Cu-HDO showed the lowest level of fungal DNA throughout the experiment, indicating that exploratory hyphal growth is limited owing to the phytotoxicity of the treatment. The other treatments did not inhibit the exploratory hyphal growth phase. We conclude that qPCR studies of hyphal growth patterns within wood should provide a powerful tool for evaluating and further optimizing new wood protection systems.

scholarly journals Effect of Physisporinus vitreus on wood properties of Norway spruce. Part 2: Aspects of microtensile strength and chemical changes

Holzforschung ◽  
2011 ◽  
Vol 65 (5) ◽  
Author(s):  
Christian Lehringer ◽  
Bodo Saake ◽  
Vjekoslav Živković ◽  
Klaus Richter ◽  
Holger Militz
Keyword(s):  
Norway Spruce ◽  
Lignin Content ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
White Rot ◽  
White Rot Fungus ◽  
Wall Structure ◽  
Fungal Activity ◽  
Selective Delignification ◽  
Simultaneous Degradation

AbstractThe biotechnological application of the white rot fungusPhysisporinus vitreusnamed “bioincising” is currently being investigated for permeability improvement of Norway spruce (Picea abies(L.) Karst.) wood. During short-term (<9 weeks) incubation, fungal activity induces degradation of pit membranes and a simultaneous alteration of the tracheid cell wall structure. In Part 1 of this article series, the occurrence of selective delignification and simultaneous degradation was shown by UV-microspectrophotometry (UMSP). Moreover, significant reduction of Brinell hardness was recorded after 7 and 9 weeks incubation. For a better understanding of the chemical alterations in the wood constituents and the corresponding changes of mechanical properties due to fungal activity, we applied microtensile tests on thin strips that were prepared from the surface of incubated Norway spruce wood. Indications for the occurrence of selective delignification and simultaneous degradation were evident. Determination of lignin content and carbohydrate analysis by borate anion exchange chromatography confirmed the results. The present study verifies the findings from Part 1 of this article series and from previously conducted microscopic investigations. Now, the degradation characteristics ofP. vitreusare established and the bioincising process can be further optimized with higher reliability.

scholarly journals The pathogenic white-rot fungus Heterobasidion parviporum triggers non-specific defence responses in the bark of Norway spruce

2011 ◽  
Vol 31 (11) ◽  
pp. 1262-1272 ◽  
Author(s):  
J. Arnerup ◽  
M. Lind ◽  
A. Olson ◽  
J. Stenlid ◽  
M. Elfstrand
Keyword(s):  
Norway Spruce ◽  
White Rot ◽  
White Rot Fungus ◽  
Defence Responses

scholarly journals Ras GTPase-Activating Protein Gap1 of the Homobasidiomycete Schizophyllum commune Regulates Hyphal Growth Orientation and Sexual Development

2006 ◽  
Vol 5 (4) ◽  
pp. 683-695 ◽  
Author(s):  
Daniela Schubert ◽  
Marjatta Raudaskoski ◽  
Nicole Knabe ◽  
Erika Kothe
Keyword(s):  
Sexual Development ◽  
Schizophyllum Commune ◽  
Type System ◽  
Hyphal Growth ◽  
Bound State ◽  
White Rot ◽  
White Rot Fungus ◽  
Ras Signaling ◽  
No Production ◽  
Gtpase Activating Protein

ABSTRACT The white rot fungus Schizophyllum commune is used for the analysis of mating and sexual development in homobasidiomycete fungi. In this study, we isolated the gene gap1 encoding a GTPase-activating protein for Ras. Disruption of gap1 should therefore lead to strains accumulating Ras in its activated, GTP-bound state and to constitutive Ras signaling. Haploid Δgap1 monokaryons of different mating types did not show alterations in mating behavior in the four different mating interactions possible in fungi expressing a tetrapolar mating type system. Instead, the growth rate in Δgap1 monokaryons was reduced by ca. 25% and ca. 50% in homozygous Δgap1/Δgap1 dikaryons. Monokaryons, as well as homozygous dikaryons, carrying the disrupted gap1 alleles exhibited a disorientated growth pattern. Dikaryons showed a strong phenotype during clamp formation since hook cells failed to fuse with the peg beside them. Instead, the dikaryotic character of the hyphae was rescued by fusion of the hooks with nearby developing branches. Δgap1/Δgap1 dikaryons formed increased numbers of fruitbody primordia, whereas the amount of fruitbodies was not raised. Mature fruitbodies formed no or abnormal gills. No production of spores could be observed. The results suggest Ras involvement in growth, clamp formation, and fruitbody development.

Calcium translocation, calcium oxalate accumulation, and hyphal sheath morphology in the white-rot fungus Resinicium bicolor

1995 ◽  
Vol 73 (6) ◽  
pp. 927-936 ◽  
Author(s):  
Jon H. Connolly ◽  
Jody Jellison
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
Environmental Scanning Electron Microscopy ◽  
White Rot ◽  
White Rot Fungus ◽  
Environmental Scanning ◽  
Resinicium Bicolor ◽  
Hyphal Sheath ◽  
Scanning Electron

The white-rot fungus Resinicium bicolor was cultured on wood blocks in a modified soil block assay and was observed by environmental scanning electron microscopy and scanning electron microscopy. Resinicium bicolor was found to translocate calcium in mycelial cords in quantities greater than that found in the wood blocks and accumulated this calcium in the form of calcium oxalate. Calcium oxalate crystal clusters of mycelial cords were 3 × larger and far more numerous than the crystal clusters produced by the same fungus within the wood. Environmental scanning electron microscopy technology allowed for the examination of the hyphal sheath in a hydrated state. The hydrated hyphal sheath was found to be much thicker than the desiccated sheath observed after standard scanning electron microscope preparations. Calcium oxalate crystals were found to be embedded in the thick hyphal sheath, suggesting that previous observations of within-wall calcium oxalate precipitation may perhaps be better interpreted as artifacts generated during sample preparation. Key words: calcium oxalate, hyphal sheath, environmental scanning electron microscopy.

Two antagonistic fungi, "D 37" and Scytalidium album, reduce the formation of bore holes by Heterobasidion annosum in Norway spruce (Picea abies)

1987 ◽  
Vol 65 (5) ◽  
pp. 916-920 ◽  
Author(s):  
Anna Lundborg
Keyword(s):  
Picea Abies ◽  
Norway Spruce ◽  
White Rot ◽  
Heterobasidion Annosum ◽  
White Rot Fungus ◽  
Antagonistic Fungi

The white-rot fungus Heterobasidion annosum was inoculated into stem discs of Norway spruce together with the antagonistic fungi "D 37" or Scytalidium album. When H. annosum grew alone in the wood, many bore holes were formed through the tracheid walls. The antagonists allowed growth of H. annosum in the wood to the same extent as in wood with H. annosum alone, but there were few bore holes when an antagonist was present. It is suggested that the antagonists decreased the ability of H. annosum to form bore holes.

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