Fungal diversity from western redcedar fences and their resistance to ?-thujaplicin

Abstract

The work reported here investigated the fungal community inhabiting western redcedar fence material with a focus on species colonizing wood below the surface, of which little is known. From seven pieces of fence material, twenty-three different fungal species were isolated and characterized using both traditional morphology and molecular identification methods. The species identified included thirteen ascomycetous and ten basidiomycetous fungi. Isolates were tested for their resistance to beta-thujaplicin - one of the principle fungicidal agents of western redcedar heartwood extractives. Generally, ascomycetous fungi exhibited greater resistance to beta-thujaplicin than basidiomycetous fungi. Interestingly, three ascomycetous and two basidiomycetous species frequently isolated had high tolerance to this compound. These species could be candidate 'pioneer' species that invade and detoxify western redcedar extractives, paving the way for colonization by decay fungi.

Preferential Inhibition of the Magnesium-Dependent Strand Transfer Reaction of HIV-1 Integrase by α-Hydroxytropolones

“…We report here the structure-activity relationship of tropolones available in the National Cancer Institute compound repository on HIV integrase activities. Tropolone derivatives are present in cupressaceous trees from genus Thuja and are probably responsible for resistance of fungal and insect attack on the heartwood (Baya et al, 2001;Diouf et al, 2002;Lim et al, 2005). Our experiments demonstrate the ability of the monomer 7-hydroxytropolones (␣-hydroxytropolones) to preferentially inhibit the ST reaction by interfering with the enzyme catalytic site.…”

Characterization of a strong CCA-treated wood degrader, unknown Crustoderma species

“…The fungus was grown for 7 days at room temperature on 2% MEA plate with a layer of cellophane sheet. The mycelium was then scraped from the surface of the cellophane sheet with a sterile scalpel, after which the genomic DNA was extracted using the method described by Lim et al (2005). The obtained genomic DNA was then used as a template for PCR amplification of the LSU rDNA regions using the LR0R-LR3 primer set (http://www.…”

Diversity of fungi in creosote-treated crosstie wastes and their resistance to polycyclic aromatic hydrocarbons

“…DNA extraction, PCR and sequencing DNA was extracted from the mycelium following the method described by Lim et al (2005). To achieve PCR amplification of the 28S rDNA and the internal transcribed spacer (ITS) region, two primer sets, LROR/LR3 (Vilgalys and Hester 1990) and ITS4/ ITS5 (White et al 1990), respectively, were used.…”

“…Moreover, although there are no rules for identifying fungi based on the similarity of LSU rDNA sequences, we previously demonstrated that basidiomycete isolates with greater than 98% similarity are conspecific (Kim et al , 2009). ITS sequence comparison is regarded as an excellent tool for assigning unknown fungi to broad species groups or genera (Horton and Bruns 2001;Schmidt and Moreth 2002) and to identify even very closely related zygomycete (Meyer and Gams 2003;Lutzoni et al 2004;Kwasna et al 2006) and ascomycete species (Lutzoni et al 2004;Lim et al 2005;Arenz et al 2006). Although Landeweert et al (2003) suggested that over 95% ITS region sequence identity was enough to confidently group taxa into a genus, some fungi showed higher intraspecific variation in the ITS region sequence.…”