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Growth, nutrition and genetic factors that affect pigmentation of wood-sapstain fungi Fleet, Carlos Antonio
Abstract
In this thesis, we examine several factors, including growth, nutrition and genetic identity, which affect pigmentation of sapstain fungi that discolour softwood in Canada from both chemical and molecular approaches. The presented results suggest that there are some chemical and physical factors to living host tissue that may stimulate growth and pigmentation by Ceratocystis resinifera. It was observed that reduced fungal growth on wood with closed border pits was concatenate with reduced consumption of wood nutrients. Nutrients in wood (such as mannose or TG-bound glycerol and fatty acids) play an important role in pigmentation and growth, but it appears that other factors, such as changes to wood ultrastructure or other biochemical factors, are also critical. Thus, some explanation for the differences in fungal distribution between logs and lumber may lie in the access that fungal species have to the host nutrients. Additionally, the presence of the DHN melanin biosynthesis pathway was demonstrated in all tested sapstain fungi using both chemical inhibitors (including tricyclazole, carpropamid and cerulenin) and molecular techniques. Furthermore, since no fungus has ever been found, to our knowledge, to have more than one melanin synthesis pathway, we can speculate with some confidence that the tested species only use the DHN pathway for melanin production. In addition, partial DNA sequences for the genes encoding scytalone dehydratase (SD), 1,3,8-trihyhydroxynaphthalene reductase (3HNR), 1,3,6,8-tetrahydroxynaphthalene reductase (4HNR) and polyketide synthase (PKS) were obtained from species of Ceratocystis and Ophiostoma and found to have homology with known respective DHN biosynthesis gene sequences. Sequence analysis of the partial SD amino acid sequences showed greater than 80% similarity among the sapstain species, and corresponded well with known parsimony analyses of sapstain fungi based on rDNA sequences. Sequence analysis for the genes encoding 3HNR and PKS showed that these sequences had lower interspecies similarities than the gene encoding SD. It is anticipated that this information will contribute to the development of safe and effective means to control sapstain by both researchers and the forest products industry.
Item Metadata
Title |
Growth, nutrition and genetic factors that affect pigmentation of wood-sapstain fungi
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Creator | |
Publisher |
University of British Columbia
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Date Issued |
2001
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Description |
In this thesis, we examine several factors, including growth, nutrition and genetic identity, which
affect pigmentation of sapstain fungi that discolour softwood in Canada from both chemical and
molecular approaches. The presented results suggest that there are some chemical and physical
factors to living host tissue that may stimulate growth and pigmentation by Ceratocystis
resinifera. It was observed that reduced fungal growth on wood with closed border pits was
concatenate with reduced consumption of wood nutrients. Nutrients in wood (such as mannose
or TG-bound glycerol and fatty acids) play an important role in pigmentation and growth, but it
appears that other factors, such as changes to wood ultrastructure or other biochemical factors,
are also critical. Thus, some explanation for the differences in fungal distribution between logs
and lumber may lie in the access that fungal species have to the host nutrients. Additionally, the
presence of the DHN melanin biosynthesis pathway was demonstrated in all tested sapstain fungi
using both chemical inhibitors (including tricyclazole, carpropamid and cerulenin) and molecular
techniques. Furthermore, since no fungus has ever been found, to our knowledge, to have more
than one melanin synthesis pathway, we can speculate with some confidence that the tested
species only use the DHN pathway for melanin production. In addition, partial DNA sequences
for the genes encoding scytalone dehydratase (SD), 1,3,8-trihyhydroxynaphthalene reductase
(3HNR), 1,3,6,8-tetrahydroxynaphthalene reductase (4HNR) and polyketide synthase (PKS) were
obtained from species of Ceratocystis and Ophiostoma and found to have homology with known
respective DHN biosynthesis gene sequences. Sequence analysis of the partial SD amino acid
sequences showed greater than 80% similarity among the sapstain species, and corresponded well
with known parsimony analyses of sapstain fungi based on rDNA sequences. Sequence analysis
for the genes encoding 3HNR and PKS showed that these sequences had lower interspecies
similarities than the gene encoding SD. It is anticipated that this information will contribute to
the development of safe and effective means to control sapstain by both researchers and the forest
products industry.
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Extent |
13301655 bytes
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Genre | |
Type | |
File Format |
application/pdf
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Language |
eng
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Date Available |
2009-08-12
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Provider |
Vancouver : University of British Columbia Library
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Rights |
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
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DOI |
10.14288/1.0090243
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URI | |
Degree | |
Program | |
Affiliation | |
Degree Grantor |
University of British Columbia
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Graduation Date |
2002-05
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Campus | |
Scholarly Level |
Graduate
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Aggregated Source Repository |
DSpace
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Rights
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.