• Mycobiology
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• 제51권5호
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• pp.281-287
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• 2023

The symbiotic association between fungus-gardening termites Macrotermes and its fungal symbiont has a moderate degree of specificity-although the symbiotic fungi (Termitomyces) form a monophyletic clade, there is not a one-to-one association between termite species and their fungus-garden associates. Here, we aim to determine the origin and phylogenetic relationships of Termitomyces in Oman. We used sequences of the internal transcribed spacer region (ITS) and the nuclear large subunit ribosomal RNA (LSU rRNA, 25S) gene and analyzed these with sequences of Termitomyces from other geographic areas. We find no evidence for more than a single colonization of Oman by Termitomyces. Unexpectedly, we find Termitomyces in Oman is most closely related to the symbiont of M. subhyalinus in West Africa rather than to those of geographically closer populations in East Africa.

• Mycobiology
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• 제47권4호
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• pp.506-511
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• 2019

We investigated the antifungal activities of an endophytic fungus identified as Acaromyces ingoldii, found on a loblolly (Pinus taeda L.) pine bolt in Louisiana during routine laboratory microbial isolations. The specific objectives were to determine the inhibitory properties of A. ingoldii secondary metabolites (crude extract) on the mycelial growth of a brown-rot fungus Gloeophyllum trabeum and a white-rot fungus Trametes versicolor, and to determine the effective concentration of A. ingoldii crude preparation against the two decay fungi in vitro. Results show the crude preparation of A. ingoldii from liquid culture possesses significant mycelial growth inhibitory properties that are concentration dependent against the brownrot and white-rot fungi evaluated. An increase in the concentration of A. ingoldii secondary metabolites significantly decreased the mycelial growth of both wood decay fungi. G. trabeum was more sensitive to the inhibitory effect of the secondary metabolites than T. versicolor. Identification of specific A. ingoldii secondary metabolites, and analysis of their efficacy/specificity warrants further study. Findings from this work may provide the first indication of useful roles for Acaromyces species in a forest environment, and perhaps a future potential in the development of biocontrol-based wood preservation systems.

• 한국균학회지
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• 제15권1호
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• pp.48-69
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• 1987

외생균근(外生菌根)버섯의 기주범위(寄主範圍)와 기주선택성(寄主選擇注)을 구명(究明)하고 주요(主要) 조림수종(造林樹種)의 균근균(菌根菌) 선택성(選擇性)을 상호비교(相互比較)하기 위하여 1981년(年)부터 1986년(年)까지 전국(全國)의 여러 곳에서 12개수종(個樹種)의 순림(純林)(소나무, 리기다소나무, 잣나무, 종비나무, 일본잎갈나무, 젓나무, 현사시, 밤나무, 갈참나무, 상수리나무, 신갈나무, 자작나무)를 대상(對象)으로 균근(菌根)버섯을 채집(採集)하여 분석(分析)을 비교(比較)하였다. 6년(年)동안 총(總) 48리(履) 196종(種) 8 품종(品種)의 균근(菌根) 버섯을 동정(同定)하였으며 그 중 Russla가 31종(種) 1 품종(品種), Amanita가 22종(種) 5 품종(品種), Lactarius가 18종(種) 1 품종(品種)이었다. 기주범위(寄主範圍)가 넓은 종(種)은 Russula, Amanita, Lactarius, Laccaria, Cantharellus 속(屬)에 속(屬)해 있있다. Laccaria Laccata는 12개조사수종중(個調査樹種中)에서 12개수종전분의 임분(林分)에서, Amanita vaginata group은 11개수종(個樹種)에서, Labtarius gerardii와 Russula sororia는 9 개수종(個樹種)에 서, Amanita agglutinata, Cantharellus cibarius, Russula bella, Russula bella, Russula virescens는 8개수종(個樹種)의 침개엽수임분(針開葉樹林分)에서 채집(採集)되어 기주(寄主)의 범위(範圍)가 넓은 버섯으로 분류(分類)되었다. Amanita citrina, Boletus bicolor, Boletus erythropus, Lactarius piperatus, L. subzonarius, Russula pseudodelica는 침개활수(針葉闊樹)의 $4{\sim}5$개수종(個樹種)에서 채집(採集)되어 기주(寄主)의 범위(範圍)가 중간(中間)정도(程度)인 버섯으로 분류(分類)되었으며 특히 Suillus grevillei는 잎갈나무에서서만 채집(採集)되어 기주(寄主)의 범위(範圍)가 가장 좁은 버섯으로 판명(判明)되었다. 12개수종(個樹種)의 임분중(林分中)에서 균근(菌根)버섯의 종류(種類)가 가장 많은 젓나무림(林)으로써 83종(重)의 균근(菌根)버섯을 채집(採集)했으며, 소나무(赤松)림(林)에서 66종(重)을, 리기다소나무림(林)에서 50종(種)을, 잣나무림(林)에서 49종(重)을, 갈참나무림(林)에서 46종(種)을 채집(採集)했다. 일본잎갈나무림(林)에서는 23종(種)의 균근(菌根)버섯을 채집(採集)했는데 다른 임분(林分)과 달리 Amanita, Lactarius, Russula 는 적고 대신 Laccaria 가 많이 관찰(觀察)되었다. 본(本) 실험(實驗)에서 조사(調査)된 12개수종(個樹種)의 대부분(大部分)은 다양(多樣)한 균근(菌根)버섯과 공생(共生)하는 듯하며 균선택성(菌選擇性)이 적은 것으로 사료(思料)된다.

• The Plant Pathology Journal
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• 제16권1호
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• pp.1-8
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• 2000

Worldwide, rice blast, caused by Magnaporthe grisea (Hebert) Barr. (anamorph, Pyricularia grisea Sacc.), is one of the most economically devastating crop diseases. Management of rice blast through the breeding of blast-resistant varieties has had only limited xuccess due to the frequent breakdown of resistance under field conditions (Bonman etal., 1992; Correa-Victoria and Zeigler, 1991; Kiyosawa, 1982). The frequent variation of race in pathogen populations has been proposed as the principal mechanism involved in the loss of resistance (Ou, 1980). Although it is generally accepted that race change in M. grisea occurs in nature, the degree of its variability has been a controversial subject. A number of studies have reported the appearance of new races at extremely high rates (Giatgong and Frederiksen, 1968; Ou and Ayad, 1968; Ou et al., 1970; Ou et al., 1971). Various potential mechanisms, including heterokaryosis (Suzuki, 1965), parasexual recombination (Genovesi and Magill, 1976), and aneuploidy (Kameswar Row et al., 1985; Ou, 1980), have been proposed to explain frequent race changes. In contrast, other studies have shown that although race change could occur, its frequency was much lower than that predicted by earlier studies (Bonman et al., 1987; Latterell and Rossi, 1986; Marchetti et al., 1976). Although questions about the frequency of race changes in M. grisea remain unanswered, the application of molecular genetic tools to study the fungus, ranging from its genes controlling host specificity to its population sturctures and dynamics, have begun to provide new insights into the potential mechanisms underlying race variation. In this review we aim to provide an overview on (a) the molecular basis of host specificity of M. grisea, (b) the population structure and dynamics of rice pathogens, and (c) the nature and mechanisms of genetic changes underpinning virulence variation in M. grisea.

• The Plant Pathology Journal
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• 제37권4호
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• pp.339-346
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• 2021

Prevalence of tan spot of wheat caused by the fungus Pyrenophora tritici-repentis has become more prevalent in Oklahoma as no-till cultivation in wheat has increased. Hence, developing wheat varieties resistant to tan spot has been emphasized, and selecting pathogen isolates to screen for resistance to this disease is critical. Twelve isolates of P. tritici-repentis were used to inoculate 11 wheat cultivars in a greenhouse study in splitplot experiments. Virulence of isolates and cultivar resistance were measured in percent leaf area infection for all possible isolate x cultivar interactions. Isolates differed significantly (P < 0.01) in virulence on wheat cultivars, and cultivars differed significantly in disease reaction to isolates. Increased virulence of isolates detected increased variability in cultivar response (percent leaf area infection) (r = 0.56, P < 0.05) while increased susceptibility in cultivars detected increased variance in virulence of the isolates (r = 0.76, P < 0.01). A significant isolate × cultivar interaction indicated specificity between isolates and cultivars, however, cluster analysis indicated low to moderate physiological specialization. Similarity in wheat cultivars in response to pathogen isolates also was determined by cluster analysis. The use of diverse isolates of the fungus would facilitate evaluation of resistance in wheat cultivars to tan spot.

• 식물병연구
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• 제25권3호
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• pp.131-135
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• 2019

Cylindrocarpon destructans causes ginseng root rot and produces radicicol that has an antifungal effect. In this study, we developed a method to detect this fungus using enzyme-linked immunosorbent assay (ELISA). Secreted proteins of C. destructans were used as antigens to obtain C. destructans-specific IgG from mouse. Out of 318 monoclonal antibodies generated from mouse, two antibodies (Cd7-2-2 and Cd7-2-10) showed highest specificity and sensitivity. Indirect ELISA using both antigens successfully detected C. destructans in soils, but direct ELISA using IgG conjugated with horseradish peroxidase failed to detect antigens in soils. The indirect ELISA developed here can efficiently detect the fungus and help manage ginseng root rot disease in fields.

• 한국균학회지
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• 제42권3호
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• pp.243-246
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• 2014

The roots of Monotropa uniflora were collected from a forest in Korea. Morphological characteristics of monotropid mycorrhizas of the plants were determined. Thick mantles covered the roots and fungal pegs inside the epidermal cells of the roots were observed. Fungal symbionts were identified by sequence analysis of internal transcribed spacer region. Phylogenetic analysis based on the sequences demonstrated that the fungus was the most closely related to Russula heterophylla. The result support the strong specificity between M. uniflora and Russula species.

• 한국균학회지
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• 제41권1호
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• pp.52-55
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• 2013

Phoma glomerata는 식물 잎이나 열매에 병을 일으키는 식물병원균으로 알려져 있다. 국내에서는 아직 피해사례가 없기 때문에 P. glomerata는 국내의 식물검역균으로 관리되고 있다. 본 연구는 국내에 들어오는 목재나 과일에 P. glomerata를 검출할 수 있는 방법 개발코자 수행되었다. Phoma 균주들의 translation elongation factor 1 alpha 유전자 염기서열에 기초하여 P. glomerata 특이적 PCR 프라이머를 디자인 하였고 그 특이성을 검정하였다. PCR 수행 결과 P. glomerata에서만 170 bp 크기의 밴드가 증폭되었고, 다른 비교 균주에서는 밴드가 증폭되지 않았다. 검출 감도를 평가하기 위해 기존 PCR방법과 real time PCR 방법을 이용하여 실험한 결과 최소 10 pg과 1 pg까지 각각 검출할 수 있었다. 본 연구결과는 디자인된 PCR 프라이머가 P. glomerata를 특이적으로 검출하는데 유용할 것임을 보여준다.

• The Plant Pathology Journal
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• 제29권4호
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• pp.357-363
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• 2013

The fungus Venturia nashicola is the causal agent of scab on Asian pears. For the rapid and reliable identification as well as sensitive detection of V. nashicola, a PCR-based technique was developed. DNA fingerprints of three closely related species, V. nashicola, V. pirina, and V. inaequalis, were obtained by random amplified polymorphic DNA (RAPD) analysis. Two RAPD markers specific to V. nashicola were identified by PCR, after which two pairs of sequence characterized amplified region (SCAR) primers were designed from the nucleotide sequences of the markers. The SCAR primer pairs, designated as D12F/D12R and E11F/E11R, amplified 535-bp and 525-bp DNA fragments, respectively, only from genomic DNA of V. nashicola. The specificity of the primer sets was tested on strains representing three species of Venturia and 20 fungal plant pathogens. The nested PCR primer pair specific to V. nashicola was developed based on the sequence of the species-specific 525-bp DNA fragment amplified by primer set E11F/E11R. The internal primer pair Na11F/Na11R amplified a 235-bp fragment from V. nashicola, but not from any other fungal species tested. The nested PCR assay was sensitive enough to detect the specific fragment in 50 fg of V. nashicola DNA.

• Journal of Microbiology and Biotechnology
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• 제20권12호
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• pp.1653-1663
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• 2010

The first gene (${\alpha}$-gal1) encoding an extracellular ${\alpha}$-Dgalactosidase from the thermophilic fungus Talaromyces emersonii was cloned and characterized. The ${\alpha}$-gal1 gene consisted of an open reading frame of 1,792 base pairs interrupted by six introns that encoded a mature protein of 452 amino acids, including a 24 amino acid secretory signal sequence. The translated protein had highest identity with other fungal ${\alpha}$-galactosidases belonging to glycosyl hydrolase family 27. The ${\alpha}$-gal1 gene was overexpressed as a secretory protein with an N-terminal histidine tag in the methylotrophic yeast Pichia pastoris. Recombinant ${\alpha}$-Gal1 was secreted into the culture medium as a monomeric glycoprotein with a maximal yield of 10.75 mg/l and purified to homogeneity using Hisbinding nickel-agarose affinity chromatography. The purified enzyme was maximally active at $70^{\circ}C$, pH 4.5, and lost no activity over 10 days at $50^{\circ}C$. ${\alpha}$-Gal1 followed Michaelis-Menten kinetics ($V_{max}\;of\;240.3{\mu}M/min/mg,\;K_m\;of\;0.294 mM$) and was inhibited competitively by galactose ($K_m{^{obs}}$ of 0.57 mM, $K_i$ of 2.77 mM). The recombinant T. emersonii ${\alpha}$-galactosidase displayed broad substrate preference, being active on both oligo- and polymeric substrates, yet had strict specificity for the ${\alpha}$-galactosidic linkage. Owing to its substrate preference and noteworthy stability, ${\alpha}$-Gal1 is of particular interest for possible biotechnological applications involving the processing of plant materials.