• Journal of Plant Biotechnology
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• v.36 no.2
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• pp.124-129
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• 2009

In general, the root color of Codonopsis lanceolata is white, but red or blue-colored root is found at a low frequency in nature. Red or blue-colored roots have scarcity value, thus farmers wish to produce colored roots. The factors for determining the color of roots are unclear whether the color is controlled by genetically or simply by environmentally such as soil environment. Using in vitro culture system which is advantageous for setting of the same culture condition, we analyzed the physiological and morphological characteristics and genetic differences among red-, blue- and white lines of C. lanceolata. In the red colored roots, stems of in vitro cultured plantlet were colored in dark red pigment. Histological analysis revealed that the red pigment was accumulated in the outer cortex layer of the stem and determined as anthocyanin. Chlorophyll contents in red root lines were higher than those in white- and blue root lines. Plantlets from red roots were smaller in both shoot length and total leaf area than those from white- and blue roots. Genetic differences among the three different colored C. lanceolata were determined by RAPD (Randomly Amplified Polymorphic DNA) analysis. Each line of colored roots had clear DNA polymorphism. These results indicate that the occurrence of red- and blue colored roots in nature was determined by genetic factors rather than soil enviromental conditions.

• Microbiology and Biotechnology Letters
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• v.43 no.1
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• pp.65-78
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• 2015

The bacterial diversity of the rhizosphere soil of S. japonica native to Suncheon bay was analyzed. Ninety two strains showing different morphological characteristics were isolated from the soils around the community of S. japonica. Bacterial diversity and distributions were studied by phylogenetic analysis of the partial 16S rDNA sequences. Ninety two strains were partially sequenced and analyzed phylogenetically. These strains were composed of 5 phyla firmicutes (56.5%), gamma-proteobacteria (29.3%), alpha-proteobacteria (5.4%), actinobacteria (5.4%), bacteroidetes (3.3%) and Shannon’s diversity index (H') were different from each of sampling sites (1.675, 1.924 and 2.04). Eleven isolates were presumed to be novel species candidates based on similarity analysis of the 16s rRNA gene sequences. Overall, Firmicutes and gamma-proteobacteria of the rhizosphere soil of S. japonica showed a high diversity.

• Korean Journal of Microbiology
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• v.44 no.2
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• pp.156-163
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• 2008

In this study, we isolated 32 strains of kerosene degrading bacteria from oil contaminated soil by enrichment culture. Isolates were screened for kerosene degradation efficiencies and K14 were selected which had the highest removal efficiency for 1,000 mg/L of kerosene. K14 were identified as Pseudomonas aeruginosa by morphological, biochemical test and 16S rDNA analysis. The optimal culture condition were determined as initial inoculated cell concentration, 1.0 g/L; substrate concentration, 1,000 mg/L; temperature $30^{\circ}C$; pH 7. When we enforced batch test in this condition, K14 degraded 72% of kerosene with 1,000 mg/L during 72 hr. And, at low concentration (200 mg/L), K14 degraded 95.8% of kerosene during 48 hr. As a result, kerosene biodegradation by Pseudomonas aeruginosa K14 could be useful for clean up of groundwater and soil contaminated with crude oil.

• Journal of Life Science
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• v.21 no.11
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• pp.1511-1517
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• 2011

We isolated a potent phenanthrene-degrading bacterium from oil-contaminated soils of Suzhou, China, and assessed the potential use of these bacteria for bioremediation of soils contaminated by polycyclic aromatic hydrocarbons (PAHs) in a microcosm. Based on 16S rDNA sequencing, we identified this bacteria as Sphigobacterium sp. SW-09. By PCR amplification, we also identified catechol 2,3-dioxygenase genes (nahH genes) mediating PAH degradation. Staphylococcus sp. KW-07, which has been identified in our previous study, showed potential for use in bioremediation of oil-contaminated soils. In this experiment, we compared the rate of phenanthrene-degradation between Staphylococcus sp. KW-07 and Sphingobacterium sp. SW-09 in a microcosm condition. Newly isolated Sphingobacterium sp. SW-09 showed a higher phenanthrene-degradation rate than that of Staphylococcus sp. KW-07 in soil microcosms. Together, our results suggest that the Sphingobacterim sp. SW-09 strain isolated from the Suzhou area may also be useful in bioremediation of PAH-contaminated soils.

• Research in Plant Disease
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• v.11 no.1
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• pp.48-55
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• 2005

Cylindrocarpon destructans is a soil-borne plant pathogenic fungus causing root rot on ginseng and trees. Rapid and exact detection of this pathogen was practiced on ginseng seedlings by nested PCR using speciesspecific primer set. The second round of PCR amplification by Dest 1 and Dest 4 primer set formed 400 bp of species-specific fragment of C. destructans from the product of first round of amplification by ITS 1 and ITS 4 primer set. In the PCR sensitivity test based on DNA density, nested PCR detected to the limit of one fg and it meant the nested PCR could detect up to a few spores of C. destructans. Also, nested PCR made it possible to detect the pathogen from ginseng seedlings infected by replantation on artificial infested soil. Our nested PCR results using species-specific primer set could be utilized for diagnosis of root rot disease in ginseng cultivation.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.259-259
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• 2022

Soil salinity is a major factor that reduces crop yields. The amount of soil affected by salinity is about 83 million hectares (FAO 2000), which is increasing due to the effects of climate change. In soybean [Glycine max (L.) Merr.], nutritional properties such as protein, starch, and sucrose content together with biomass and yield tends to reduce due to excessive salt. As a result of QTL mapping using the 169 F_2:3 population from the KA-1285 (salt-tolerant) × Daepung (salt-sensitive) in a previous study, two major QTLs (Gm03_39796778 and Gm03_40600088) related to salt tolerance were found on chromosome 3. In this study, the CDS region of the Gmsalt3 gene was analyzed using the ABI 3730x1 DNA Analyzer (Macrogen, Korea). The sequence of Gmsalt3 gene in KA-1285 was compared with Williams 82.a4.vl and PI483463 (Glycine soja). Two transversions were found at exon6 in KA-1285 and PI483463. Currently, whole genome sequencing and variation analysis using the Illumine Novaseq 6000 machine (Illumina, USA) are in progress. The results of this study can provide useful molecular markers for the selection of salt-tolerant soybeans and can be used as basic data for future salt-tolerant gene research.

• Research in Plant Disease
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• v.29 no.4
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• pp.433-439
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• 2023

Bacterial leaf blight in carrot is one of the most important diseases in the worldwide. In the past decade, its introduction into Korea is causing great concern due to the potential damage to carrot crops domestically. This bacterial disease is caused by Xanthomonas hortorum pv. carotae (Xhc). This study aimed to isolate and identify bacterial strains from the soil of carrot farms in Jeju Island. The bacterial isolates showing characteristics similar with those of Xhc were selected when cultured on artificial media. Through DNA sequencing and analysis based on NCBI data, some of the selected bacterial strains were identified as Xhc. Furthermore, the bacterial strains caused the typical symptom of bacterial leaf blight after inoculation on carrot leaves. The results of this study showed the potential establishment of Xhc in the soil of Jeju Island and it may be valuable data for establish a strategy preventing the domestic spread of carrot bacterial leaf blight in the future.

• Korean Journal of Environmental Agriculture
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• v.39 no.1
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• pp.65-74
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• 2020

BACKGROUND: Soil carbon sequestration has been investigated for a long time because of its potential to mitigate the greenhouse effect. No- or reduced tillage, crop rotations, or cover crops have been investigated and practiced to sequester carbon in soils but the roles of soil biota, particularly microorganisms, have been mostly ignored although they affect the amount and stability of soil organic matters. METHODS AND RESULTS: In this study we analyzed the organic matter and microbial community in organically cultivated corn field soils where no-tillage (NT) or conventional tillage (CT) had been practiced for about three years. The amounts of organic matter and recalcitrant carbon pool were 18.3 g/kg dry soil and 4.1 g C/kg dry soil, respectively in NT soils, while they were 12.4 and 2.5, respectively in CT soils. The amounts of RNA and DNA, and the copy numbers of bacterial 16S rRNA genes and fungal ITS sequences were higher in NT soils than in CT soils. No-tillage treatment increased the diversities of soil bacterial and fungal communities and clearly shifted the bacterial and fungal community structures. In NT soils the relative abundances of bacterial phyla known as copiotrophs, Betaproteobacteria and Bacteroidetes, increased while those known as oligotrophs, Acidobacteria and Verrucomicrobia, decreased compared to CT soils. The relative abundance of a fungal phylum, Glomeromycota, whose members are known as arbuscular mycorrhizal fungi, was about two time higher in NT soils than in CT soils, suggesting that the higher amount of organic matter in NT soils is related to its abundance. CONCLUSION: This study shows that no-tillage treatment greatly affects soil microbial abundance and community structure, which may affect the amount and stability of soil organic matter.

• The Plant Pathology Journal
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• v.25 no.1
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• pp.70-76
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• 2009

The rhizobacteria of Panax notoginseng were isolated from six sites in Yanshan, Maguan and Wenshan Counties, Yunnan Province of China, and their antagonistic activity against P. notoginseng root-rot fungal pathogens was determined. Of the 574 rhizobacteria isolated, 5.8% isolates were antagonistic in vitro to at least one of the five pathogens, Cylindrocarpon didynum, Fusarium solani, Phytophthora cactorum, Phoma herbarum, and Rhizoctonia solani. The number of rhizo bacteria and the number that inhibited fungi differed depending on sampling sites and isolation methods. Rhizobacteria isolated from the site in Yanshan and Maguan showed more antagonistic effect than them in Wenshan. Heat treatment of rhizosphere soil at $80^{\circ}C$ for 20 min scaled the antagonists up to 14.0%. Antagonistic bacteria in the roots proportioned 3.9% of the total isolates. The most antagonistic isolates 79-9 and 81-4 are Bacillus subtilis based on their 168 rDNA sequence and biochemical and physiological characteristics. Identification and evaluation of antagonistic bacteria against P. notoginseng root-rot pathogens in the main planting areas improved our understanding of their distribution in rhizosphere soil. Furthermore these results indicated that the interactions between biocontrol agent and soil microbes should be seriously considered for the successful survival and biocontrol efficacy of the agents in soil.

• BMB Reports
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• v.45 no.2
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• pp.96-101
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• 2012

Urea-based nitrogen fertilizer was widely utilized in maize production, but transporters involved in urea uptake, translocation and cellular homeostasis have not been identified. Here, we isolated three maize aquapoin genes, ZmNIP2;1, ZmNIP2;4 and ZmTIP4;4, from a cDNA library by heterogous complementation of a urea uptake-defective yeast. ZmNIP2;1 and ZmNIP2;4 belonged to the nodulin 26-like intrinsic proteins (NIPs) localized at plasma membrane, and ZmTIP4;4 belonged to the tonoplast intrinsic protein (TIPs) at vacuolar membrane. Quantitative RT-PCR revealed that ZmNIP2;1 was expressed constitutively in various organs while ZmNIP2;4 and ZmTIP4;4 transcripts were abundant in reproductive organs and roots. Expression of ZmTIP4;4 was significantly increased in roots and expanded leaves under nitrogen starvation, while those of ZmNIP2;1 and ZmNIP2;4 remained unaffected. Functions of maize aquapoin genes in urea transport together with their distinct expression manners suggested that they might play diverse roles on urea uptake and translocation, or equilibrating urea concentration across tonoplast.