Sang-Sun Lee

Mycorrhizal symbioses found in roots of fern and its relatives in Korea

Mycorrhizal symbioses were found in the roots of 45 out of 59 species of pteridophytes collected in Korea. The mycorrhizal fungi were colonized in the root cortical cells, primarily in terrestrial species, but rarely in epiphytic or aquatic pteridophytes. Mycorrhizae that are typically found in orchid colonized the roots of the epiphytic pteridophytes, but not in other species. These were the first observations of orchid mycorrhizae in pteridophytes. Arbuscular mycorrhizal fungi were examined after staining, then confirmed with PCR, using a specific primer. This is the first report of arbuscular mycorrhizal colonization in the roots of pteridophyte species in Asia.

Transformation of Chlorophenols by White-Rot Fungi and their Laccase

Summary The effects of pentachlorophenol (PCP) and 2-chlorophenol (2CP) on white rot fungi, Abortiporus biennis, Cerrena unicolor, Gloeophyllum odoratum, and Trametes versicolor were investigated. With the exception of C. unicolor and A. biennis, concentrations of PCP higher than 50 ppm inhibited fungal growth completely. However, extreme concentrations of PCP (500 ppm) caused a 61% increase in growth of C. unicolor compared to the control culture within 14 days. When initial PCP concentrations were 50 ppm A. biennis and C. unicolor achieved, respectively, 87% and 78% of chlorophenol transformation within 3 days. However, when 2,5-dimethylaniline (0.2mM) was added to the C. unicolor culture, 98% of PCP transformation was achieved after one hour. Under the same conditions, A. biennis transformed 44% of PCP. Both chlorophenols are completely removed, when laccase activity reaches its maximum. In conclusion, among the four fungi investigated, C. unicolor and A. Biennis were very effective in transforming PCP and 2-CP. This biotransformation was greatly intensified by 2,5-dimethylaniline and accompanied by an increase in laccase activity.

Mycorrhizal Formations and Seedling Growth of Pinus desiflora by in vitro Synthesis with the Inoculation of Ectomycorrhizal Fungi

Abstract The mycelia were directly isolated from eight species of fungal basidiocarps, confirmed to the ectomycorrhiza in the roots from the fields (forestry); Suillus bovinus, Paxillus involutus, Lactarius hysginus, Russula fragilis, Lepista nuda, Lyophyllum shimeji, Tricholoma matsutake, and Russula integra. The mycelia were pure-cultured with several transferring in various agars, and inoculated to the roots of pine (Pinus densiflora) seedling by in vitro method. After ten months growth under artificially aseptic conditions, all pine seedlings inoculated were stimulated at the growth-height, whereas those not inoculated were nearly dead. Also, the ramifications of ectomycorrhizal pine roots formed in the synthetic in vitro systems and were various according to the different mycelia. Synthesis of ectomycorrhiza were clearly confirmed in ten months growth, but not distinguished at this moment. It was clearly proved that the mycelia isolated caused the ectomycorrhizae in the roots of pine seedlings.

Ectomycorrhizal Roots Collected from the Bases of the four Edible Basidiocarps Around Mt. Wol Ak

The ectomycorrhizal roots were collected from the soils around the bases of basidiocarps of the four edible mushrooms in the stands of Pinus densiflora or Querns acutissima communities (Mt. Wol-Ak in Eastern Chung-Puk): The basidiocarps of Tricholoma matsutake (TM), Sarcodon asparatus (SA), S. imbricatum (SI), and Polyozellus multiplex (PM) are usually collected. The ectomycorrhizal roots of TM, PM and SI were related to the roots of P. densiflora, but the other to the roots of Q. acutissima in Korea. Particularly, the basidiocarps of PM were collected in the mixed stand of both P. densiflora and Q. acutissima. The morphologies of the ectomycorrhizal roots were observed to be the yellowish brown coral (dichromatous) or pyramid types in the roots of the pine, but dark brown un-branched sticks (roots) in the ends of ectomycorrhizal roots of Querus plants. The un-branched roots were covered with the dark mycelia (rhizomorph) around them. Therefore, the ectomyorrhizal roots of PM were observed to have two kinds of types; The single blackish un-branched roots were observed to be attached to the yellowish coral type roots. The bundles of TM mycelia were filled with cortical cells (in the roots of P densiflora), hut the mycelia of the other fungi (Aphylloporales) were massed between the cortical cells of P densiflora or Q. acutissima. Their anatomical and gross features were considered to be simailar but very important in the ectomycorrhizal roots for these edible mushrooms.

Multiple Symbiotic Associations Found in the Roots of Botrychium ternatum

Abstract Two types of mycorrhizae, orchid (OM) and arbuscular mycorrhizae (AM), were observed in the cortical cells of Botrychium ternatum roots. The vesicles or arbuscules of AM fungi were examined and the fresh or digestive pelotons by other species of basidiomycetes were also observed in the roots under light microscope. These symbioses were, as the genomic DNAs extracted from roots of B. ternatum reacted with the specific primers, confirmed with PCR technique, being added to more strong evidences. These discoveries were rarely happened in the roots, especially a fern in nature. OM was observed in the roots of B. ternatum collected from the nationwide areas, whereas AM was only in the roots of B. ternatum collected from Chung-Buk areas. It is speculated that OM are associated with the nitrogen cycle in Islands and the growth of B. ternatum in the inland of Central Korea is related to both the phosphate and nitrogen cycle in the nature. The results suggest that B. ternatum is a typical species with two types of mycorrhizae under various growing conditions.

Sclerotial Development of Grifola umbellata

Abstract Sclerotial development of Grifola umbellata (Pers. : Fr.) Donk was investigated through microscopic examinations. The sclerotium of G. umbellata was bumpy and rugged, multi-branched, and dark-brown to black in color. The sclerotial development of G. umbellata was categorized into three stages such as sclerotial initial, development and maturation. Sclerotium development was initiated as the white fungal mass. The superficial part of white sclerotium changed into gray, light brown and then black as its development proceeded further. As a distinctive characteristic of this fungus, a large number of crystals were observed in the medulla layer of sclerotium during its maturation. For development of new sclerotium, G. umbellata formed a white sclerotial primordium on the matured sclerotium. Development of sclerotium in G. umbellata was intimately associated with rhizomorphs of Armillariella mellea and the developing sclerotia were often penetrated by rhizomorphs of A. mellea into medulla layer.

Observations on the Ectomycorrhizal Roots Collected from the Bases of the Basiodiocarps in Chungbuk

Various types of ectomycorrihzal root were observed from the bases of the basidiocarps collected from the four different soils of WalAk Mt., JoRyeong Mt., MinJuJi Mt. and hills near Korea National University of Education; The dichotomous ectomycorrihzal roots were mainly found to be from the interactions of the Pinus roots with the basidiocarps of Boletus and Amanita species. The black single bat-like ectomycorrihzal roots with the darken rhizomorphic mycelia were mainly found to be from the interactions of the Quercus roots with the basidiocarps of Russula species. The pyramid and the monopodial-pinnate ectomycorrihzal roots were also found to be from the interactions of the Pinus and deciduous tree roots with the basidiocarps of Russula and Boletus species. The distinguished structures of the mantle and Hartig net in the cortex layers were observed to be from the roots related to the genus of Pinus in the anatomical sections. However, the aggregated (premeated) structures of mantle and Hartig net in the cortex layer were found to be in the black and bat-like ectomycorrihzal roots. The structures of cross section in the ectomycorrihzal roots, especially the roots related to the host-plants of Pinus, were observed to be different from those according to the fungal species of the basidiocarps collected. The ectomycorrihzal root not reported or confirmed by the anatomical sections were newly found to be from the bases of the basidocarps of Amanita castanopsidis, Boletus laetissimus, B. violaceofuscus, B. speciosus, Clitopilus prunulus, Leccinum rugosiceps, Russula, alboareolata, R. bella, Strobilomyces confusus, Tylropilus neofelleus, and T. plumbeoviolaceus. From the observations mentioned above, the various types of ectomycorrihzal roots were speculated to be formed between the different host plants and the different species of basidiocarps.

Melanogenesis Inhibitory and Antioxidant Activities of Phellinus baumii Methanol Extract

Phellinus baumii is a medicinal mushroom used in Asian countries for a long period of time. The purpose of this study was to investigate the skin whitening activities of methanol extracts from fruiting bodies of P. baumii. To evaluate the antioxidant activities of the extract, polyphenol and flavonoid contents, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity and chelating activity on ferrous ions were studied. For assay of skin whitening activities, tyrosinase and DOPA inhibitory activities, and tyrosinase and melanin synthesis inhibitory activities of B16/F10 melanoma cells treated with the methanol extract were investigated. The total polyphenol content of P. baumii methanol extract was 4.19. DPPH scavenging ability of P. baumii methanol extract was 88.26% in concentration. We tested tyrosinase inhibitory activity and melanin contents in melanoma cells. The tyrosinase activity was inhibited to 65.17% at the concentration of and melanin synthesis was inhibited to 57.61% at the concentration of . Overall, the experimental results showed that P. baumii methanol extract had inhibitory activities of tyrosinase and melanin synthesis by dose dependent manner in B16/F10 melanoma cells. Strong ultra-violet absorption spectra in the range of 270~370 nm indicated that ethanol extract of P. baumii could protect the skin from UV. Therefore, P. baumii methanol extract might be used for development of skin whitening, anti-UV and skin care agents.

ITS Primers with Enhanced Specificity to Detect the Ectomycorrhizal Fungi in the Roots of Wood Plants

With universal primer ITS1-F, the specific DHJ2 primer was developed to detect the Ectomycorrhizal (ECM) root tips in soil and to identify the species of ECM fungi, as based on DNA sequences of rDNA stored in GeneBank of NCBI This primer was designed with the common sites of rDNA of Amanita and Boletus, and was also designed with several DNA programs provided by NCBI. The DNA fragments synthesized by PCR were calculated to be 1,000 to 1,200 bps of DNA located to 18s to 28s rDNA to contain two variable sites of ITS, indicating much diversities for specific species or ecotypes of ECM fungi. The primer DHJ2 reacted with the genomic DNA’s extracted from the tissues of basidiocarp at the rate of 73 of 80 fungi collected produced single bands with a 1,100 bps length. The DNA fragment synthesized with the genomic DNA that extracted from eight ECM tips of Pinus densiflora was confirmed and analysized to the rDNAs of ECM in full sequences, and informed to be a ECM fungal species in the forest.

Identification of Arbuscular Mycorrhizal Fungi from Botrychium ternatum Native in Korea

Abstract Arbuscular mycorrhizal fungi were observed in Botrychium ternatum native in Korea. The partial small subunit (SSU) of ribosomal DNA gene from the fern roots was amplified with primers AM1/NS31. Nucleotides sequence analysis of the clones revealed that two fragments were close to Glomus proliferum and G. sinuosum. The other three DNA fragments were close to those of G. proliferum with the relatively low similarities (92~95%) and speculated to be originated from three different species of Glomus (GLA006, GLA016, and GLA032). Five different nucleotide sequences close to three AM fungal species were found in the roots of B. ternatum native in Korea.