• Korean Journal of Medicinal Crop Science
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• v.17 no.1
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• pp.26-32
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• 2009

The region containing 18S rRNA gene, ITS 1 and part of the 5.8S rRNA gene of the Atractylodes japonica Koidz was amplified by PCR and the product cloned in a pBluescript SK II plasmid. DNA sequence of the cloned DNA was determined and submitted to the GenBank (accession number EU678363). Phylogenetic analysis of the ITS 1 DNA showed close similarity with the other plant species of the family Compositae. The extract of the plant materials of five different members of the family Compositae was analyzed by HPLC to detect atractylon. Extract of the A. japonica Koidz showed presence of significant amount of atractylon. However, noticeable amount of atractylon was not detected by the same analyses from the extracts of the other plants belonging to the family Compositae including Artemisia capillaris, Chrysantemum zawadskii, Eclipta prostrata or Taraxacum platycarpum.

• Journal of Microbiology
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• v.38 no.2
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• pp.66-73
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• 2000

To investigate the genetic relationship among 12 species belonging to the Fusarium section Martiella, Dlaminia, Gibbosum, Arthrosporiella, Liseola and Elegans, the internal transcribed spacer(ITS) regions of ribosomal DNA (rDNA) were amplified with primer pITS1 and pITS4 using the polymerase chain reaction(PCR). After the amplified products were digested with 7 restriction enzymes, restriction fragment length polymorphism (RFLP) patterns were analyzed. The partial nucleotide sequences of the ITS region were determined and compared. Little variation was observed in the size of the amplified product having sizes of 550bp or 570bp. Based on the RFLP analysis, the 12 species studied were divided into 5 RFLP types. In particular, strains belonging to the section Martiella were separated into three RFLP types. Interestingly, the RFLP type of F. solani f. sp. piperis was identical with that of isolates belonging to the section Elegans. In the dendrogram derived from RFLP analysis of the ITS region, the Fusarium spp. examined were divided into two major groups. In general, section Martiella excluding F. solani f. sp. piperis showed relatively low similarity with the other section. The dendrogram based on the sequencing analysis of the ITS2 region also gave the same results as that of the RFLP analysis. As expected, 5.8S, a coding region, was highly conserved, whereas the ITS2 region was more variable and informative. The difference in the ITS2 region between the length of F. solani and its formae speciales excluding F. solani f. sp. piperis and that of other species was caused by the insertion/deletion of nucleotides in positions 143-148 and 179-192.

• Journal of Korean Society of Forest Science
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• v.96 no.4
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• pp.425-431
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• 2007

To investigate genetic diversity and PCR detection of Rhizina undulata, PCR detection and sequence analysis of rDNA ITS region of R. undulata in soil were analyzed and developed. The length of partial 18S rDNA from four R. undulata isolates were 1,375 nt. The sequence similarity of R. undulata isolates was 100%. The rDNA ITS regions of R. undulata isolates were 585 nt long. Nucleotide sequencing of the ITS regions showed that PDK-1, PTT-1 and PDJ-9 isolates had 100% sequence identity. But, PDS-5 isolate differed from the three isolates by two nucleotide substitution. R. undulata-specific primers designed by the sequence of ITS region were used in PCR detection of R. undulata. PCR products about 525 bp size, which is specific to R. undulata, were amplified from total DNAs of R. undulata isolates. To assay the sensitivity of PCR detection by R. undulata ITS-specific primer, purely cultured mycelial suspension of R. undulata was serially diluted and mixed with 100g of sterile sandy loam soil, respectively. And then, PCR products of total DNAs extracted from each mycelium-soil mixtures were analysed. The PCR protocol could detected up to 1ng mycelium of R. undulata within 100g of soil.

• Korean Journal of Microbiology
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• v.55 no.3
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• pp.220-225
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• 2019

Studies based on microbial community analyses have increased in the recent decade since the development of next generation sequencing technology. Associations of gut microbiota with host's health are one of the major outcomes of microbial ecology filed. The major approach for microbial community analysis includes the sequencing of variable regions of 16S rRNA genes, which does not provide the information of bacterial activities. Here, we conducted RNA-based microbial community analysis and compared results obtained from DNA- and its cDNA-based microbial community analyses. Our results indicated that these two approaches differed in the ratio of Firmicutes and Bacteroidetes, known as an obesity indicator, as well as abundance of some key bacteria in gut metabolisms such as butyrate producers and probiotics strains. Therefore, cDNA-based microbial community may provide different insights regarding roles of gut microbiota compared to the previous studies where DNA-based microbial community analyses were performed.

• Journal of Photoscience
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• v.8 no.2
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• pp.55-60
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• 2001

Ginseng (Panax genus) is one of the most medicinally important genera and consists of highly regarded medicines. Among the species of Panax, the ginseng species is widely known to have most medicinal quality. P. ginseng has 3 varieties, Jakyung, Chunggyung and Hwangsook, discovered in nature with different colors of stem and fruit, Jakyung has two cultivars, Yunpoong and Chunpoong. Rigorous phylogenetic analysis of these varieties and cultivars has been conducted with sequencing of rDNA region. The sequences of ITS1, ITS2 of every varieties and cultivars within P. ginseng were identical. The sequence of 5.8S rDNAs of Hwangsook variety were different from the sequences of 5.8S rDNAs of others by only one base pair at nucleotide position 14. In phylogenetic analysis and predicted RNA secondary structure study, it is assumed that evolution has proceeded from Hwangsook to other varieties. recently.

• The Plant Pathology Journal
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• v.26 no.1
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• pp.83-89
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• 2010

Taxonomic position of 46 Korean isolates of Rhizoctonia solani which were classified into nine intraspecific groups by anastomosis and cultural characteristics was analyzed by randomly amplified polymorphic DNA (RAPD) and sequence analyses of the internal transcribed spacer (ITS) regions of ribosomal DNA. All the isolates within each group showed highly similar band patterns in RAPD. The ITS regions of the isolates within the same groups showed a high level of sequence similarity above 96.0% whereas similarities among different groups were below 94.4%. When compared with several reference strains of R. solani from foreign countries, all the Korean isolates were clustered with the foreign isolates belonging to the same groups in the phylogenetic tree. All six Korean strains of AG-4 were identified as HG-1 out of 3 subgroup of AG-4. We discussed taxonomic position of Korean isolates of R. solani and showed that sequence analysis with ITS regions could be a rapid and useful method for identification of intraspecific group of R. solani.

• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.2
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• pp.83-88
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• 2003

A cellulose-producing strain isolated from rotten apples was identified as Gluconacetobacter hansenii based on its physiological properties and the 16S rDNA complete sequencing method, and specifically named Gluconacetobacter hansenii PJK. The amount of bacterial cellulose (BC) produced by G. hansenii PJK in a shaking incubator was 1.5 times higher than that produced in a static culture. The addition of ethanol to the medium during cultivation enhanced the productivity of bacterial cellulose, plus the supplementation of 1% ethanol into the culture medium made the produced BC aggregate into a big lump and thus protected the bacterial-cellulose-producing G. hansenii PJK cells in the shear stress field from being converted into non-cellulose-producing (Cel) mutants. Cells subcultured three times in a medium containing ethanol retained their ability to produce BC without any loss in the production yield.

• Parasites, Hosts and Diseases
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• v.53 no.5
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• pp.641-645
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• 2015

Fascioliasis, a food-borne trematode zoonosis, is a disease primarily in cattle and sheep and occasionally in humans. Water dropwort (Oenanthe javanica), an aquatic perennial herb, is a common second intermediate host of Fasciola, and the fresh stems and leaves are widely used as a seasoning in the Korean diet. However, no information regarding Fasciola species contamination in water dropwort is available. Here, we collected 500 samples of water dropwort in 3 areas in Korea during February and March 2015, and the water dropwort contamination of Fasciola species was monitored by DNA sequencing analysis of the Fasciola hepatica and Fasciola gigantica specific mitochondrial cytochrome c oxidase subunit 1 (cox1) and nuclear ribosomal internal transcribed spacer 2 (ITS-2). Among the 500 samples assessed, the presence of F. hepatica cox1 and 1TS-2 markers were detected in 2 samples, and F. hepatica contamination was confirmed by sequencing analysis. The nucleotide sequences of cox1 PCR products from the 2 F. hepatica-contaminated samples were 96.5% identical to the F. hepatica cox1 sequences in GenBank, whereas F. gigantica cox1 sequences were 46.8% similar with the sequence detected from the cox1 positive samples. However, F. gigantica cox1 and ITS-2 markers were not detected by PCR in the 500 samples of water dropwort. Collectively, in this survey of the water dropwort contamination with Fasciola species, very low prevalence of F. hepatica contamination was detected in the samples.

• Research in Plant Disease
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• v.10 no.1
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• pp.63-68
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• 2004

Twenty-three strains of Serratia sp., isolated from surface-sterilized rice roots collected in Chonbuk and Chungnam province, were identified and characterized. They were Gram-negative, rod shaped and red pigmented typically and their endophytism was confirmed by inoculation and reisolation of the strains in planta. Their antifungal activity against 4 rice pathogenic fungi was compared and ranged from 62.4 to 85.2％ against Rhizoctonia solani and 68.0 to 88.5％ against Pyricularia grisea. Among the 23 strains tested, strain Rsm220 showed the strongest inhibition activity against 4 pathogenic fungi. The strain was, therefore, selected as a biocontrol candidate for both the pathogens and its bacteriological characteristics and 165 rDNA sequences were analyzed. Phenotypic and biochemical characteristics of the selected Rsm220 were highly related to the type strain of S. marcescens and 165 rDNA sequencing of Rsm220 showed a homology of 98.2％ to the type strain of S. marcescens. The strain Rsm220 was identified as S. marcescens and the inhibition result of this endophytic strain indicates that it is a potential biocontrol agent for R. solani and R grisea.

• The Plant Pathology Journal
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• v.40 no.2
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• pp.171-191
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• 2024

Identification of Helicotylenchus species is very challenging due to phenotypic plasticity and existence of cryptic species complexes. Recently, the use of rDNA barcodes has proven to be useful for identification of Helicotylenchus. Molecular markers are a quick diagnostic tool and are crucial for discriminating related species and resolving cryptic species complexes within this speciose genus. However, DNA barcoding is not an error-free approach. The public databases appear to be marred by incorrect sequences, arising from sequencing errors, mislabeling, and misidentifications. Herein, we provide a comprehensive analysis of the newly obtained, and published DNA sequences of Helicotylenchus, revealing the potential faults in the available DNA barcodes. A total of 97 sequences (25 nearly full-length 18S-rRNA, 12 partial 28S-rRNA, 16 partial internal transcribed spacer [ITS]-rRNA, and 44 partial cytochrome c oxidase subunit I [COI] gene sequences) were newly obtained in the present study. Phylogenetic relationships between species are given as inferred from the analyses of 103 sequences of 18S-rRNA, 469 sequences of 28S-rRNA, 183 sequences of ITS-rRNA, and 63 sequences of COI. Remarks on suggested corrections of published accessions in GenBank database are given. Additionally, COI gene sequences of H. dihystera, H. asiaticus and the contentious H. microlobus are provided herein for the first time. Similar to rDNA gene analyses, the COI sequences support the genetic distinctness and validity of H. microlobus. DNA barcodes from type material are needed for resolving the taxonomic status of the unresolved taxonomic groups within the genus.