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Francis W. M. R. Schwarze - One of the best experts on this subject based on the ideXlab platform.
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using the codit model to explain secondary metabolites of xylem in defence systems of temperate trees against Decay Fungi
Annals of Botany, 2020Co-Authors: Hugh Morris, Ari M Hietala, Steven Jansen, Javier Ribera, Sabine Rosner, Khalifah A Salmeia, Francis W. M. R. SchwarzeAbstract:BACKGROUND In trees, secondary metabolites (SMs) are essential for determining the effectiveness of defence systems against Fungi and why defences are sometimes breached. Using the CODIT model (Compartmentalization of Damage/Dysfunction in Trees), we explain defence processes at the cellular level. CODIT is a highly compartmented defence system that relies on the signalling, synthesis and transport of defence compounds through a three-dimensional lattice of parenchyma against the spread of Decay Fungi in xylem. SCOPE The model conceptualizes 'walls' that are pre-formed, formed during and formed after wounding events. For sapwood, SMs range in molecular size, which directly affects performance and the response times in which they can be produced. When triggered, high-molecular weight SMs such as suberin and lignin are synthesized slowly (phytoalexins), but can also be in place at the time of wounding (phytoanticipins). In contrast, low-molecular weight phenolic compounds such as flavonoids can be manufactured de novo (phytoalexins) rapidly in response to fungal colonization. De novo production of SMs can be regulated in response to fungal pathogenicity levels. The protective nature of heartwood is partly based on the level of accumulated antimicrobial SMs (phytoanticipins) during the transitionary stage into a normally dead substance. Effectiveness against fungal colonization in heartwood is largely determined by the genetics of the host. CONCLUSION Here we review recent advances in our understanding of the role of SMs in trees in the context of CODIT, with emphasis on the relationship between defence, carbohydrate availability and the hydraulic system.We also raise the limitations of the CODIT model and suggest its modification, encompassing other defence theory concepts. We envisage the development of a new defence system that is modular based and incorporates all components (and organs) of the tree from micro- to macro-scales.
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characterization of host fungus interactions among wood Decay Fungi associated with khaya senegalensis desr a juss meliaceae in singapore
Forest Pathology, 2015Co-Authors: Daniel C Burcham, J Y Wong, Mohamed Ismail Mohamed Ali, Nelson V Abarrientos, Yok King Fong, Francis W. M. R. SchwarzeAbstract:Summary Tree pruning creates wounds that are amenable for wood Decay Fungi colonization. To characterize the dynamic host–fungus interactions at this location in Senegal mahogany (Khaya senegalensis), in vitro and in vivo pathogenicity tests were conducted with wood Decay Fungi associated with this tropical tree species. Fomitiporella caryophylii, Hymenochaete murina and Phellinus noxius isolates were included in this experiment following their frequent isolation from Senegal mahogany pruning wounds. The evaluated isolates demonstrated unique host interactions in laboratory tests that suggest equally divergent prognoses for living Senegal mahoganies affected by these Fungi. Although all evaluated fungal isolates successfully breached naturally induced reaction zones, P. noxius alone caused significant mass loss to incubated wood blocks. In addition, P. noxius caused extensive wood Decay after inoculation in living hosts, successfully illustrating Koch's postulates for this host–fungus relationship. The wood Decay ability, invasiveness and facultative parasitism demonstrated by P. noxius suggest its dominant role in wood Decay columns below pruning wounds on living Senegal mahoganies. These results highlight the importance of characterizing specific host–fungus interactions and their implications for wood Decay severity below pruning wounds in living trees.
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Automated quantification of the impact of the wood-Decay fungus Physisporinus vitreus on the cell wall structure of Norway spruce by tomographic microscopy
Wood Science and Technology, 2011Co-Authors: M. J. Fuhr, C. Stührk, B. Münch, Francis W. M. R. Schwarze, Mark SchubertAbstract:The visualization and the quantification of microscopic Decay patterns are important for the study of the impact of wood-Decay Fungi in general, as well as for wood-Decay Fungi and microorganisms with possible applications in biotech- nology. In the present work, a method was developed for the automated localization and quantification of microscopic cell wall elements (CWE) of Norway spruce wood such as bordered pits, intrinsic defects, hyphae or alterations induced by white-rot fungus Physisporinus vitreus using high-resolution X-ray computed tomographic microscopy. In addition to classical destructive wood anatomical methods such as light or laser scanning microscopy, this method allows for the first time to compute the properties (e.g., area, orientation and size distribution) of CWE of the tracheids in a sample. This is essential for modeling the influence of microscopic CWE on macroscopic properties such as wood strength and permeability.
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Automated Quantification of the Impact of the Wood-Decay fungus Physisporinus vitreus on the Cell Wall Structure of Norway spruce by Tomographic Microscopy
arXiv: Quantitative Methods, 2011Co-Authors: M. J. Fuhr, C. Stührk, B. Münch, Francis W. M. R. Schwarze, Mark SchubertAbstract:Wood-Decay Fungi decompose their substrate by extracellular, degradative enzymes and play an important role in natural ecosystems by recycling carbon and minerals fixed in plants. Thereby, they cause significant damage to the wood structure and limit the use of wood as building material. Besides their role as biodeteriorators wood-Decay Fungi can be used for biotechnological purposes, e.g. the white-rot fungus Physisporinus vitreus for improving the uptake of preservatives and wood-modification substances of refractory wood. Therefore, the visualization and the quantification of microscopic Decay patterns are important for the study of the impact of wood-Decay Fungi in general, as well as for wood-Decay Fungi and microorganisms with possible applications in biotechnology. In the present work, we developed a method for the automated localization and quantification of microscopic cell wall elements (CWE) of Norway spruce wood such as bordered pits, intrinsic defects, hyphae or alterations induced by P. vitreus using high resolution X-ray computed tomographic microscopy. In addition to classical destructive wood anatomical methods such as light or laser scanning microscopy, our method allows for the first time to compute the properties (e.g. area, orientation and size-distribution) of CWE of the tracheids in a sample. This is essential for modeling the influence of microscopic CWE to macroscopic properties such as wood strength and permeability.
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resistance of bioincised wood treated with wood preservatives to blue stain and wood Decay Fungi
International Biodeterioration & Biodegradation, 2011Co-Authors: Mark Schube, Thomas Volkme, Christia Lehringe, Francis W. M. R. SchwarzeAbstract:Bioincising is a biotechnological process that aims at the improvement of wood preservative uptake in wood species with a low permeability, such as Norway spruce (Picea abies (L.) Karst). The process is based on a short-term pre-treatment with white-rot fungus Physisporinus vitreus. During incubation the membranes of bordered and half bordered pits are supposed to be degraded by fungal activity resulting in a better treatability of the wood structure for wood preservatives. In the present study, first of all the resistance of bioincised Norway spruce heartwood and untreated controls against blue-stain and wood- Decay Fungi (white- and brown-rot) was determined. Then, bioincised and untreated specimens were dipped or vacuum impregnated with six wood preservatives and substance uptake was assessed gravimetrically. Additionally, the penetration of 3-iodo-2-propynyl butylcarbamate (IPBC) into the wood was analyzed by high-pressure liquid chromatography (HPLC). Finally, wood resistance was assessed according to the European standards EN 152 and EN 113. Results showed no difference between bio- incised wood without preservatives and the untreated wood against blue-stain discolouration. However, a significant (P < 0.05) increase in susceptibility against wood Decay was recorded. In the bioincised wood samples a significantly higher uptake of all the different preservatives was determined and the HPLC-method revealed that IPBC penetrated deeper into bioincised wood than into control samples. The improved uptake of preservatives into bioincised wood resulted in a significantly higher resistance against white- and brown-rot Fungi. However, only a slight protection against wood discolouration by blue-stain Fungi was recorded. The results of this study show for the first time that the biotechnological process with P. vitreus can be used to improve wood durability by increasing the uptake and penetration of wood preservatives.
Shawn D. Mansfield - One of the best experts on this subject based on the ideXlab platform.
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Gene Expression Patterns of Wood Decay Fungi Postia placenta and Phanerochaete chrysosporium Are Influenced by Wood Substrate Composition during Degradation
Applied and environmental microbiology, 2016Co-Authors: Oleksandr Skyba, Carl J. Douglas, Daniel Cullen, Shawn D. MansfieldAbstract:ABSTRACT Identification of the specific genes and enzymes involved in the fungal degradation of lignocellulosic biomass derived from feedstocks with various compositions is essential to the development of improved bioenergy processes. In order to elucidate the effect of substrate composition on gene expression in wood-rotting Fungi, we employed microarrays based on the annotated genomes of the brown- and white-rot Fungi, Rhodonia placenta (formerly Postia placenta) and Phanerochaete chrysosporium, respectively. We monitored the expression of genes involved in the enzymatic deconstruction of the cell walls of three 4-year-old Populus trichocarpa (poplar) trees of genotypes with distinct cell wall chemistries, selected from a population of several hundred trees grown in a common garden. The woody substrates were incubated with wood Decay Fungi for 10, 20, and 30 days. An analysis of transcript abundance in all pairwise comparisons highlighted 64 and 84 differentially expressed genes (>2-fold, P 4-fold, P IMPORTANCE This study describes the variation in expression patterns of two wood-degrading Fungi (brown- and white-rot Fungi) during colonization and incubation on three different naturally occurring poplar substrates of differing chemical compositions, over time. The results clearly show that the two Fungi respond differentially to their substrates and that several known and, more interestingly, currently unknown genes are highly misregulated in response to various substrate compositions. These findings highlight the need to characterize several unknown proteins for catalytic function but also as potential candidate proteins to improve the efficiency of enzymatic cocktails to degrade lignocellulosic substrates in industrial applications, such as in a biochemically based bioenergy platform.
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syringyl rich lignin renders poplars more resistant to degradation by wood Decay Fungi
Applied and Environmental Microbiology, 2013Co-Authors: Oleksandr Skyba, Carl J. Douglas, Shawn D. MansfieldAbstract:In order to elucidate the effects of lignin composition on the resistance of wood to degradation by Decay Fungi, wood specimens from two transgenic poplar lines expressing an Arabidopsis gene encoding ferulate 5-hydroxylase (F5H) driven by the cinnimate-4-hydroxylase promoter (C4H::F5H) that increased syringyl/guaiacyl (S/G) monolignol ratios relative to those in the untransformed control wood were incubated with six different wood Decay Fungi. Alterations in wood weight and chemical composition were monitored over the incubation period. The results showed that transgenic poplar lines extremely rich in syringyl lignin exhibited a drastically improved resistance to degradation by all Decay Fungi evaluated. Lignin monomer composition and its distribution among cell types and within different cell layers were the sole wood chemistry parameters determining wood durability. Since transgenic poplars with exceedingly high syringyl contents were recalcitrant to degradation, where wood durability is a critical factor, these genotypes may offer improved performance.
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significant alteration of gene expression in wood Decay Fungi postia placenta and phanerochaete chrysosporium by plant species
Applied and Environmental Microbiology, 2011Co-Authors: Amber Vanden Wymelenberg, Sandra Splinter Bondurant, Oleksandr Skyba, Shawn D. Mansfield, Jill Gaskell, Michael Mozuch, Grzegorz Sabat, John Ralph, Robert A Blanchette, Igor V GrigorievAbstract:Identification of specific genes and enzymes involved in conversion of lignocellulosics from an expanding number of potential feedstocks is of growing interest to bioenergy process development. The basidiomycetous wood Decay Fungi Phanerochaete chrysosporium and Postia placenta are promising in this regard because they are able to utilize a wide range of simple and complex carbon compounds. However, systematic comparative studies with different woody substrates have not been reported. To address this issue, we examined gene expression of these Fungi colonizing aspen (Populus grandidentata) and pine (Pinus strobus). Transcript levels of genes encoding extracellular glycoside hydrolases, thought to be important for hydrolytic cleavage of hemicelluloses and cellulose, showed little difference for P. placenta colonizing pine versus aspen as the sole carbon source. However, 164 genes exhibited significant differences in transcript accumulation for these substrates. Among these, 15 cytochrome P450s were upregulated in pine relative to aspen. Of 72 P. placenta extracellular proteins identified unambiguously by mass spectrometry, 52 were detected while colonizing both substrates and 10 were identified in pine but not aspen cultures. Most of the 178 P. chrysosporium glycoside hydrolase genes showed similar transcript levels on both substrates, but 13 accumulated >2-fold higher levels on aspen than on pine. Of 118 confidently identified proteins, 31 were identified in both substrates and 57 were identified in pine but not aspen cultures. Thus, P. placenta and P. chrysosporium gene expression patterns are influenced substantially by wood species. Such adaptations to the carbon source may also reflect fundamental differences in the mechanisms by which these Fungi attack plant cell walls.
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comparative transcriptome and secretome analysis of wood Decay Fungi postia placenta and phanerochaete chrysosporium
Applied and Environmental Microbiology, 2010Co-Authors: Amber Vanden Wymelenberg, Oleksandr Skyba, Shawn D. Mansfield, Jill Gaskell, Michael Mozuch, Grzegorz Sabat, John Ralph, Robert A Blanchette, Diego Martinez, Igor V GrigorievAbstract: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.
Mark Schubert - One of the best experts on this subject based on the ideXlab platform.
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Automated quantification of the impact of the wood-Decay fungus Physisporinus vitreus on the cell wall structure of Norway spruce by tomographic microscopy
Wood Science and Technology, 2011Co-Authors: M. J. Fuhr, C. Stührk, B. Münch, Francis W. M. R. Schwarze, Mark SchubertAbstract:The visualization and the quantification of microscopic Decay patterns are important for the study of the impact of wood-Decay Fungi in general, as well as for wood-Decay Fungi and microorganisms with possible applications in biotech- nology. In the present work, a method was developed for the automated localization and quantification of microscopic cell wall elements (CWE) of Norway spruce wood such as bordered pits, intrinsic defects, hyphae or alterations induced by white-rot fungus Physisporinus vitreus using high-resolution X-ray computed tomographic microscopy. In addition to classical destructive wood anatomical methods such as light or laser scanning microscopy, this method allows for the first time to compute the properties (e.g., area, orientation and size distribution) of CWE of the tracheids in a sample. This is essential for modeling the influence of microscopic CWE on macroscopic properties such as wood strength and permeability.
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Automated Quantification of the Impact of the Wood-Decay fungus Physisporinus vitreus on the Cell Wall Structure of Norway spruce by Tomographic Microscopy
arXiv: Quantitative Methods, 2011Co-Authors: M. J. Fuhr, C. Stührk, B. Münch, Francis W. M. R. Schwarze, Mark SchubertAbstract:Wood-Decay Fungi decompose their substrate by extracellular, degradative enzymes and play an important role in natural ecosystems by recycling carbon and minerals fixed in plants. Thereby, they cause significant damage to the wood structure and limit the use of wood as building material. Besides their role as biodeteriorators wood-Decay Fungi can be used for biotechnological purposes, e.g. the white-rot fungus Physisporinus vitreus for improving the uptake of preservatives and wood-modification substances of refractory wood. Therefore, the visualization and the quantification of microscopic Decay patterns are important for the study of the impact of wood-Decay Fungi in general, as well as for wood-Decay Fungi and microorganisms with possible applications in biotechnology. In the present work, we developed a method for the automated localization and quantification of microscopic cell wall elements (CWE) of Norway spruce wood such as bordered pits, intrinsic defects, hyphae or alterations induced by P. vitreus using high resolution X-ray computed tomographic microscopy. In addition to classical destructive wood anatomical methods such as light or laser scanning microscopy, our method allows for the first time to compute the properties (e.g. area, orientation and size-distribution) of CWE of the tracheids in a sample. This is essential for modeling the influence of microscopic CWE to macroscopic properties such as wood strength and permeability.
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field experiments to evaluate the application of trichoderma strain t 15603 1 for biological control of wood Decay Fungi in trees
Arboricultural Journal, 2008Co-Authors: Mark Schubert, Siegfried Fink, Francis W. M. R. SchwarzeAbstract:(2008). FIELD EXPERIMENTS TO EVALUATE THE APPLICATION OF TRICHODERMA STRAIN (T-15603.1) FOR BIOLOGICAL CONTROL OF WOOD Decay Fungi IN TREES. Arboricultural Journal: Vol. 31, No. 4, pp. 249-268.
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evaluation of trichoderma spp as a biocontrol agent against wood Decay Fungi in urban trees
Biological Control, 2008Co-Authors: Mark Schubert, Francis W. M. R. Schwarze, Siegfried FinkAbstract:Abstract Laboratory and field tests were performed to establish the potential of Trichoderma spp. as a wound treatment for biological control of wood Decay Fungi in urban trees. A selection of Trichoderma species were tested in dual culture and interaction tests in wood against four basidomycetes Ganoderma adspersum, Ganoderma lipsiense, Inonotus hispidus, Polyporus squamosus and one acomycete Kretzschmaria deusta. Hyphal interactions were observed by scanning electron microscopy (SEM). The effect of Trichoderma spp. on wood colonization and degradation of wood Decay Fungi were quantitatively measured by dry weight loss of wood and qualitatively by histological studies. Trichoderma atroviride (T-15603.1) was consistently and highly competitive against most wood Decay Fungi with the exception of Polyporus squamosus which showed resistance towards antagonism in laboratory tests. Field experiments with T-15603.1 were carried out at different locations and hosts. A total of 159 angiosperm trees and 1431 wounds from six different species (Platanus × hispanica, Acer pseudoplatanus, Tilia platyphyllos, Populus nigra, Quercus rubra, Robinia pseudoacacia) were treated with different conidial suspensions. In comparison to control wounds, T-15603.1 induced a highly significant (P
Igor V Grigoriev - One of the best experts on this subject based on the ideXlab platform.
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significant alteration of gene expression in wood Decay Fungi postia placenta and phanerochaete chrysosporium by plant species
Applied and Environmental Microbiology, 2011Co-Authors: Amber Vanden Wymelenberg, Sandra Splinter Bondurant, Oleksandr Skyba, Shawn D. Mansfield, Jill Gaskell, Michael Mozuch, Grzegorz Sabat, John Ralph, Robert A Blanchette, Igor V GrigorievAbstract:Identification of specific genes and enzymes involved in conversion of lignocellulosics from an expanding number of potential feedstocks is of growing interest to bioenergy process development. The basidiomycetous wood Decay Fungi Phanerochaete chrysosporium and Postia placenta are promising in this regard because they are able to utilize a wide range of simple and complex carbon compounds. However, systematic comparative studies with different woody substrates have not been reported. To address this issue, we examined gene expression of these Fungi colonizing aspen (Populus grandidentata) and pine (Pinus strobus). Transcript levels of genes encoding extracellular glycoside hydrolases, thought to be important for hydrolytic cleavage of hemicelluloses and cellulose, showed little difference for P. placenta colonizing pine versus aspen as the sole carbon source. However, 164 genes exhibited significant differences in transcript accumulation for these substrates. Among these, 15 cytochrome P450s were upregulated in pine relative to aspen. Of 72 P. placenta extracellular proteins identified unambiguously by mass spectrometry, 52 were detected while colonizing both substrates and 10 were identified in pine but not aspen cultures. Most of the 178 P. chrysosporium glycoside hydrolase genes showed similar transcript levels on both substrates, but 13 accumulated >2-fold higher levels on aspen than on pine. Of 118 confidently identified proteins, 31 were identified in both substrates and 57 were identified in pine but not aspen cultures. Thus, P. placenta and P. chrysosporium gene expression patterns are influenced substantially by wood species. Such adaptations to the carbon source may also reflect fundamental differences in the mechanisms by which these Fungi attack plant cell walls.
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comparative transcriptome and secretome analysis of wood Decay Fungi postia placenta and phanerochaete chrysosporium
Applied and Environmental Microbiology, 2010Co-Authors: Amber Vanden Wymelenberg, Oleksandr Skyba, Shawn D. Mansfield, Jill Gaskell, Michael Mozuch, Grzegorz Sabat, John Ralph, Robert A Blanchette, Diego Martinez, Igor V GrigorievAbstract: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.
Oleksandr Skyba - One of the best experts on this subject based on the ideXlab platform.
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Gene Expression Patterns of Wood Decay Fungi Postia placenta and Phanerochaete chrysosporium Are Influenced by Wood Substrate Composition during Degradation
Applied and environmental microbiology, 2016Co-Authors: Oleksandr Skyba, Carl J. Douglas, Daniel Cullen, Shawn D. MansfieldAbstract:ABSTRACT Identification of the specific genes and enzymes involved in the fungal degradation of lignocellulosic biomass derived from feedstocks with various compositions is essential to the development of improved bioenergy processes. In order to elucidate the effect of substrate composition on gene expression in wood-rotting Fungi, we employed microarrays based on the annotated genomes of the brown- and white-rot Fungi, Rhodonia placenta (formerly Postia placenta) and Phanerochaete chrysosporium, respectively. We monitored the expression of genes involved in the enzymatic deconstruction of the cell walls of three 4-year-old Populus trichocarpa (poplar) trees of genotypes with distinct cell wall chemistries, selected from a population of several hundred trees grown in a common garden. The woody substrates were incubated with wood Decay Fungi for 10, 20, and 30 days. An analysis of transcript abundance in all pairwise comparisons highlighted 64 and 84 differentially expressed genes (>2-fold, P 4-fold, P IMPORTANCE This study describes the variation in expression patterns of two wood-degrading Fungi (brown- and white-rot Fungi) during colonization and incubation on three different naturally occurring poplar substrates of differing chemical compositions, over time. The results clearly show that the two Fungi respond differentially to their substrates and that several known and, more interestingly, currently unknown genes are highly misregulated in response to various substrate compositions. These findings highlight the need to characterize several unknown proteins for catalytic function but also as potential candidate proteins to improve the efficiency of enzymatic cocktails to degrade lignocellulosic substrates in industrial applications, such as in a biochemically based bioenergy platform.
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syringyl rich lignin renders poplars more resistant to degradation by wood Decay Fungi
Applied and Environmental Microbiology, 2013Co-Authors: Oleksandr Skyba, Carl J. Douglas, Shawn D. MansfieldAbstract:In order to elucidate the effects of lignin composition on the resistance of wood to degradation by Decay Fungi, wood specimens from two transgenic poplar lines expressing an Arabidopsis gene encoding ferulate 5-hydroxylase (F5H) driven by the cinnimate-4-hydroxylase promoter (C4H::F5H) that increased syringyl/guaiacyl (S/G) monolignol ratios relative to those in the untransformed control wood were incubated with six different wood Decay Fungi. Alterations in wood weight and chemical composition were monitored over the incubation period. The results showed that transgenic poplar lines extremely rich in syringyl lignin exhibited a drastically improved resistance to degradation by all Decay Fungi evaluated. Lignin monomer composition and its distribution among cell types and within different cell layers were the sole wood chemistry parameters determining wood durability. Since transgenic poplars with exceedingly high syringyl contents were recalcitrant to degradation, where wood durability is a critical factor, these genotypes may offer improved performance.
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significant alteration of gene expression in wood Decay Fungi postia placenta and phanerochaete chrysosporium by plant species
Applied and Environmental Microbiology, 2011Co-Authors: Amber Vanden Wymelenberg, Sandra Splinter Bondurant, Oleksandr Skyba, Shawn D. Mansfield, Jill Gaskell, Michael Mozuch, Grzegorz Sabat, John Ralph, Robert A Blanchette, Igor V GrigorievAbstract:Identification of specific genes and enzymes involved in conversion of lignocellulosics from an expanding number of potential feedstocks is of growing interest to bioenergy process development. The basidiomycetous wood Decay Fungi Phanerochaete chrysosporium and Postia placenta are promising in this regard because they are able to utilize a wide range of simple and complex carbon compounds. However, systematic comparative studies with different woody substrates have not been reported. To address this issue, we examined gene expression of these Fungi colonizing aspen (Populus grandidentata) and pine (Pinus strobus). Transcript levels of genes encoding extracellular glycoside hydrolases, thought to be important for hydrolytic cleavage of hemicelluloses and cellulose, showed little difference for P. placenta colonizing pine versus aspen as the sole carbon source. However, 164 genes exhibited significant differences in transcript accumulation for these substrates. Among these, 15 cytochrome P450s were upregulated in pine relative to aspen. Of 72 P. placenta extracellular proteins identified unambiguously by mass spectrometry, 52 were detected while colonizing both substrates and 10 were identified in pine but not aspen cultures. Most of the 178 P. chrysosporium glycoside hydrolase genes showed similar transcript levels on both substrates, but 13 accumulated >2-fold higher levels on aspen than on pine. Of 118 confidently identified proteins, 31 were identified in both substrates and 57 were identified in pine but not aspen cultures. Thus, P. placenta and P. chrysosporium gene expression patterns are influenced substantially by wood species. Such adaptations to the carbon source may also reflect fundamental differences in the mechanisms by which these Fungi attack plant cell walls.
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comparative transcriptome and secretome analysis of wood Decay Fungi postia placenta and phanerochaete chrysosporium
Applied and Environmental Microbiology, 2010Co-Authors: Amber Vanden Wymelenberg, Oleksandr Skyba, Shawn D. Mansfield, Jill Gaskell, Michael Mozuch, Grzegorz Sabat, John Ralph, Robert A Blanchette, Diego Martinez, Igor V GrigorievAbstract: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.
