ABSTRACT The relative frequency of Therrya fuckelii and T. pini fruiting on dead branches of Scot... more ABSTRACT The relative frequency of Therrya fuckelii and T. pini fruiting on dead branches of Scots pine was investigated in southern Norway by examining lightning-damaged and wind-fallen trees, randomly collected branches and Nordic herbarium collections of these ascomycetes representing the order Rhytismatales. Ascus, ascospore, and subhymenium characteristics were used as criteria for species identification, while a sequence analysis of ITS rDNA gene cluster was performed to compare the relatedness of the species to each other and to corresponding fungal sequences available at the NCBI GenBank Sequence Database. In a few cases, the two Therrya species co-occurred on the same branch, but in general, whether field or herbarium material, T. fuckelii was clearly more common than T. pini. Within the Nordic countries, both species occurred throughout the natural distribution area of Scots pine. The ITS rDNA sequence of T. pini strains was 91% similar to T. fuckelii strains, the differences locating both within the internal transcribed spacers ITS1 and ITS2 and the 5.8 S rDNA gene. More variation in the ITS1-5.8S-ITS2 sequence was observed among T. pini than T. fuckelii samples; genetic implications of this finding are discussed. Upon sequence analysis, we discovered that a T. pini sequence has been deposited in the NCBI GenBank under a false identity. We emphasize the importance of co-examining strains that originate from mature fruit bodies with fully developed morphologic features as reference samples.
The area of wood protection is in a period of change. New wood protection systems have been devel... more The area of wood protection is in a period of change. New wood protection systems have been developed while their mode of action remains insufficiently understood. The development of molecular methods provides potential tools to investigate the interaction between modified wood and decay fungi. One small step to tackle some of the unsolved questions about the mode of action of modified wood is taken in this study. A specific and quantitative real-time PCR (QRT-PCR) assay was now established for identifying and quantifying early stages of fungal colonisation in modified wood and for profiling growth dynamics of the white-rot fungus Trametes versicolor through different stages of decay. QRT-PCR of colonisation of three different wood modification systems (acetylation, furfurylation, thermal modification), two reference treatments (Cu-HDO, CCA) and Scots pine sapwood as control was performed. Incubation time was 2, 4, 6, 8 and 10 weeks. While the fungal colonisation in untreated contro...
Stilbene synthases make the backbone of stilbenes in a single enzymatic step. Many stilbenes are ... more Stilbene synthases make the backbone of stilbenes in a single enzymatic step. Many stilbenes are stress- induced antimicrobial phenolics, believed to work in disease resistance. In conifers, stilbenes are found in pine (Pinus), spruce (Picea) and a few other genera. Stilbene synthase isoforms in pine use cinnamyl-CoA to form pinosylvin, these are termed pinosylvin synthases, whereas stilbene synthases in spruce use p- coumaryl-CoA to form resveratrol and are sometimes termed resveratrol synthases. Pinosylvin has been found to be more effective than resveratrol in inhibiting fungal growth and wood decay (Seppänen et al. 2004), and pathogens of non-pinosylvin producing species have been found to be less tolerant of pinosylvin than pine pathogens (Seppänen et al. 2004).
In spring 2002, an unusual disease outburst was recorded on Norway spruce seedlings in southeast ... more In spring 2002, an unusual disease outburst was recorded on Norway spruce seedlings in southeast Norway. Extensive damage was recorded on 1- and 2-year-old Norway spruce seedlings that either had wintered in nursery cold storage or had been planted out in autumn 2001. The damage was characterized by leader shoot dieback and stem necroses on the upper or lower part of the shoot from 2001. Gremmeniella abietina and a Phomopsis sp. frequently were isolated from the diseased seedlings. Internal transcribed spacer (ITS) ribosomal (r)DNA sequence analysis and random amplified microsatellites profiling indicated that the G. abietina strains associated with diseased nursery seedlings belonged to the large-tree type (LTT) ecotype of the European race of G. abietina var. abietina, and inoculation tests confirmed their pathogenicity on Norway spruce. Based on ITS rDNA sequence analysis, the Phomopsis strains associated with diseased seedlings did not represent any characterized Phomopsis spp. ...
We studied the defense reactions of 33-year-old susceptible and resistant clones of Norway spruce... more We studied the defense reactions of 33-year-old susceptible and resistant clones of Norway spruce (Picea abies (L.) Karst.) to the major root-rot fungus Heterobasidion annosum (Fr.) Bref. and determined if tissue cultures can be used as a model system for studying defense responses of mature trees at the molecular level. Quantitative PCR analysis of genomic DNA obtained from samples taken at different times along the lesion length in living bark indicated that the fungus was present in higher amounts and extended further into the host tissue in the susceptible clone than in the resistant clone. In protein extracts from the same lesion samples, there were differences in temporal and spatial changes in host chitinase isoform profiles between the resistant and susceptible clones. Host chitinase isoforms with pI values approximately 4.8, 4.4 and 3.7 increased more during the first 7 days after wounding and inoculation and extended further along the lesion length in the resistant clone t...
The area of wood protection is in a period of change. New wood protection systems have been devel... more The area of wood protection is in a period of change. New wood protection systems have been developed while their mode of action remains insufficiently understood. The development of molecular methods provides potential tools to investigate the interaction between modified wood and decay fungi. One small step to tackle some of the unsolved questions about the mode of action of
Stilbene synthases make the backbone of stilbenes in a single enzymatic step. Many stilbenes are ... more Stilbene synthases make the backbone of stilbenes in a single enzymatic step. Many stilbenes are stress- induced antimicrobial phenolics, believed to work in disease resistance. In conifers, stilbenes are found in pine (Pinus), spruce (Picea) and a few other genera. Stilbene synthase isoforms in pine use cinnamyl-CoA to form pinosylvin, these are termed pinosylvin synthases, whereas stilbene synthases in spruce
ABSTRACT The relative frequency of Therrya fuckelii and T. pini fruiting on dead branches of Scot... more ABSTRACT The relative frequency of Therrya fuckelii and T. pini fruiting on dead branches of Scots pine was investigated in southern Norway by examining lightning-damaged and wind-fallen trees, randomly collected branches and Nordic herbarium collections of these ascomycetes representing the order Rhytismatales. Ascus, ascospore, and subhymenium characteristics were used as criteria for species identification, while a sequence analysis of ITS rDNA gene cluster was performed to compare the relatedness of the species to each other and to corresponding fungal sequences available at the NCBI GenBank Sequence Database. In a few cases, the two Therrya species co-occurred on the same branch, but in general, whether field or herbarium material, T. fuckelii was clearly more common than T. pini. Within the Nordic countries, both species occurred throughout the natural distribution area of Scots pine. The ITS rDNA sequence of T. pini strains was 91% similar to T. fuckelii strains, the differences locating both within the internal transcribed spacers ITS1 and ITS2 and the 5.8 S rDNA gene. More variation in the ITS1-5.8S-ITS2 sequence was observed among T. pini than T. fuckelii samples; genetic implications of this finding are discussed. Upon sequence analysis, we discovered that a T. pini sequence has been deposited in the NCBI GenBank under a false identity. We emphasize the importance of co-examining strains that originate from mature fruit bodies with fully developed morphologic features as reference samples.
The area of wood protection is in a period of change. New wood protection systems have been devel... more The area of wood protection is in a period of change. New wood protection systems have been developed while their mode of action remains insufficiently understood. The development of molecular methods provides potential tools to investigate the interaction between modified wood and decay fungi. One small step to tackle some of the unsolved questions about the mode of action of modified wood is taken in this study. A specific and quantitative real-time PCR (QRT-PCR) assay was now established for identifying and quantifying early stages of fungal colonisation in modified wood and for profiling growth dynamics of the white-rot fungus Trametes versicolor through different stages of decay. QRT-PCR of colonisation of three different wood modification systems (acetylation, furfurylation, thermal modification), two reference treatments (Cu-HDO, CCA) and Scots pine sapwood as control was performed. Incubation time was 2, 4, 6, 8 and 10 weeks. While the fungal colonisation in untreated contro...
Stilbene synthases make the backbone of stilbenes in a single enzymatic step. Many stilbenes are ... more Stilbene synthases make the backbone of stilbenes in a single enzymatic step. Many stilbenes are stress- induced antimicrobial phenolics, believed to work in disease resistance. In conifers, stilbenes are found in pine (Pinus), spruce (Picea) and a few other genera. Stilbene synthase isoforms in pine use cinnamyl-CoA to form pinosylvin, these are termed pinosylvin synthases, whereas stilbene synthases in spruce use p- coumaryl-CoA to form resveratrol and are sometimes termed resveratrol synthases. Pinosylvin has been found to be more effective than resveratrol in inhibiting fungal growth and wood decay (Seppänen et al. 2004), and pathogens of non-pinosylvin producing species have been found to be less tolerant of pinosylvin than pine pathogens (Seppänen et al. 2004).
In spring 2002, an unusual disease outburst was recorded on Norway spruce seedlings in southeast ... more In spring 2002, an unusual disease outburst was recorded on Norway spruce seedlings in southeast Norway. Extensive damage was recorded on 1- and 2-year-old Norway spruce seedlings that either had wintered in nursery cold storage or had been planted out in autumn 2001. The damage was characterized by leader shoot dieback and stem necroses on the upper or lower part of the shoot from 2001. Gremmeniella abietina and a Phomopsis sp. frequently were isolated from the diseased seedlings. Internal transcribed spacer (ITS) ribosomal (r)DNA sequence analysis and random amplified microsatellites profiling indicated that the G. abietina strains associated with diseased nursery seedlings belonged to the large-tree type (LTT) ecotype of the European race of G. abietina var. abietina, and inoculation tests confirmed their pathogenicity on Norway spruce. Based on ITS rDNA sequence analysis, the Phomopsis strains associated with diseased seedlings did not represent any characterized Phomopsis spp. ...
We studied the defense reactions of 33-year-old susceptible and resistant clones of Norway spruce... more We studied the defense reactions of 33-year-old susceptible and resistant clones of Norway spruce (Picea abies (L.) Karst.) to the major root-rot fungus Heterobasidion annosum (Fr.) Bref. and determined if tissue cultures can be used as a model system for studying defense responses of mature trees at the molecular level. Quantitative PCR analysis of genomic DNA obtained from samples taken at different times along the lesion length in living bark indicated that the fungus was present in higher amounts and extended further into the host tissue in the susceptible clone than in the resistant clone. In protein extracts from the same lesion samples, there were differences in temporal and spatial changes in host chitinase isoform profiles between the resistant and susceptible clones. Host chitinase isoforms with pI values approximately 4.8, 4.4 and 3.7 increased more during the first 7 days after wounding and inoculation and extended further along the lesion length in the resistant clone t...
The area of wood protection is in a period of change. New wood protection systems have been devel... more The area of wood protection is in a period of change. New wood protection systems have been developed while their mode of action remains insufficiently understood. The development of molecular methods provides potential tools to investigate the interaction between modified wood and decay fungi. One small step to tackle some of the unsolved questions about the mode of action of
Stilbene synthases make the backbone of stilbenes in a single enzymatic step. Many stilbenes are ... more Stilbene synthases make the backbone of stilbenes in a single enzymatic step. Many stilbenes are stress- induced antimicrobial phenolics, believed to work in disease resistance. In conifers, stilbenes are found in pine (Pinus), spruce (Picea) and a few other genera. Stilbene synthase isoforms in pine use cinnamyl-CoA to form pinosylvin, these are termed pinosylvin synthases, whereas stilbene synthases in spruce
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