• Mycobiology
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• 제42권1호
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• pp.34-40
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• 2014

Usnea longissima has a long history of use as a traditional medicine. Several bioactive compounds, primarily belonging to the polyketide family, have been isolated from U. longissima. However, the genes for the biosynthesis of these compounds are yet to be identified. In the present study, three different types of non-reducing polyketide synthases (UlPKS2, UlPKS4, and UlPKS6) were identified from a cultured lichen-forming fungus of U. longissima. Phylogenetic analysis of product template domains showed that UlPKS2 and UlPKS4 belong to group IV, which includes the non-reducing polyketide synthases with an methyltransferase (MeT) domain that are involved in methylorcinol-based compound synthesis; UlPKS6 was found to belong to group I, which includes the non-reducing polyketide synthases that synthesize single aromatic ring polyketides, such as orsellinic acid. Reverse transcriptase-PCR analysis demonstrated that UlPKS2 and UlPKS4 were upregulated by sucrose; UlPKS6 was downregulated by asparagine, glycine, and alanine.

• 식물병연구
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• 제13권3호
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• pp.223-227
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• 2007

지의류는 곰팡이와 광합성을 하는 조류 또는 남조류의 공생체로서 토양, 바위, 나무 등에 아주 널리 분포하는 진핵생명체다. 지의류형성곰팡이는 흔히 죽은 나무나 죽어가는 나무 위에서 부착하여 증식하지만 나무를 직접적으로 죽이지는 않는다. 전남 순천시 매실나무 과수원 포장에 있는 매실나무 수피에 엽상체 지의류 Parmotrema autrosinense를 포함한 몇 가지 가상체 지의류가 심하게 증식하고 있었다. 이러한 지의류 조합의 증식으로 매실나무는 회색으로 흉하게 보이고 정상적인 생장이 억제되었으며, 심각하게 영향을 받은 매실나무 가지의 수피에서 지의체를 제거하지 않으면 낙엽이 지고 가지가 말라 죽었다. 매실나무 수피에 있는 지의체를 제거해주면 매실나무 가지들은 수세를 회복하였으며, 지의체를 제거한 후에 $Twin^{(R)}$ 20 또는 톱신페스트를 발라주면 더욱 수세가 왕성해졌다. 따라서 매실나무에 몇 가지 지의류 조합의 정착 및 증식에 의해 발생하는 낙엽과 가지마름 증상을 '매실나무 지의류병(lichen disease)'이라고 명명할 것을 제안한다.

• Mycobiology
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• 제34권3호
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• pp.148-150
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• 2006

Karoowia saxeti was recorded during the lichen field expedition in southern part of Korea in 2006. The lichen was found on the rock surface along coastal line. This species was easily recognized by chemistry (K+ yellow) and the presence of isidia. Thallus was saxicolous, subcrustose, more or less lobate at the center with clearly lobed margins, $2{\sim}6\;cm$ broad and pale yellowish green. Thalli lobes were irregular, variable, up to 1.0mm wide, not branched, flat to more or less convex and contiguous to subimbricate. Upper surface of the thalli was continuous, emaculate, moderately isidiate. The isidia was subglobose to cynlindrical, darkening at the tips and unbranched. Low surface of the thalii was black with a spongy rhizoidal and lamellar layer. HPLC analysis proved the presence of stictic acid (K+ yellow), norstictic acid and usnic acid. This is the first record of the species in South Korea.

• Journal of Microbiology and Biotechnology
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• 제27권6호
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• pp.1189-1197
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• 2017

Lichen-forming fungi are known to have various biological activities, such as antioxidant, antimicrobial, antitumor, antiviral, anti-inflammation, and anti proliferative effects. However, the immunosuppressive effects of Bryoria sp. extract (BSE) have not previously been investigated. In this study, the inhibitory activity of BSE on the proliferation of $CD8^+$ T cells and the mixed lymphocytes reaction (MLR) was evaluated in vitro. BSE was non-toxic in spleen cells and suppressed the growth of splenocytes induced by anti-CD3. The suppressed cell population in spleen cells consisted of $CD8^+$ T cells and their proliferation was inhibited by the treatment with BSE. This extract significantly suppressed the IL-2 associated with T cell growth and $IFN-{\gamma}$ as the $CD8^+$ T cell marker. Furthermore, BSE reduced the expression of the IL-2 receptor alpha chain ($IL-2R{\alpha}$) on $CD8^+$ T cells and CD86 on dendritic cells by acting as antigen-presenting cells. Finally, the MLR produced by the co-culture of C57BL/6 and MMC-treated BALB/c was suppressed by BSE. IL-2, $IFN-{\gamma}$, and CD69 on $CD8^+$ T cells in MLR condition were inhibited by BSE. These results indicate that BSE inhibits the MLR via the suppression of $IL-2R{\alpha}$ expression in $CD8^+$ T cells. BSE has the potential to be developed as an anti-immunosuppression agent for organ transplants.

• Journal of Microbiology and Biotechnology
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• 제18권6호
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• pp.1016-1023
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• 2008

Lichens are predominant and important components of flora in the terrestrial ecosystem of Antarctica. However, relatively few researches on the phylogenetic position of Antarctic lichen-forming fungi have been accomplished. In this study, partial sequences of nuclear large subunit rDNAs from 50 Antarctic specimens were obtained and the phylogeny was reconstructed. Antarctic lichen species were distributed in 4 orders, including the monophyletic order Agyrales, paraphyletic orders Pertusariales and Teloschistales, and polyphyletic order Lecanorales. Species diversity was highest in the order Lecanorales, followed by Teloschistales and Pertusariales. Based on the phylogeny and sequence similarity analyses, it is proposed that the taxonomy of Stereocaulon alpinum, Physcia caesia, Usnea aurantiacoatra, and Cladonia species should be revised by careful examination of their phenotypic and molecular characteristics. Six species known to be endemic to Antarctica, Catillaria corymbosa, Himantormia lugubris, Leptogium puberulum, Pertusaria pertusa, Rhizoplaca aspidophora, and Umbilicaria antarctica, formed unique lineages, implying independent origins in the Antarctic area.