• The Plant Pathology Journal
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• v.34 no.3
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• pp.250-255
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• 2018

Pine wilt disease, caused by the nematode Bursaphelenchus xylophilus, is one of the most devastating conifer diseases decimating several species of pine trees on a global scale. Here, we report the draft genome of Raoultella ornithinolytica MG, which is isolated from mountain-cultivated ginseng plant as an bacterial endophyte and shows nematicidal activity against B. xylophilus. Our analysis of R. ornithinolytica MG genome showed that it possesses many genes encoding potential nematicidal factors in addition to some secondary metabolite biosynthetic gene clusters that may contribute to the observed nematicidal activity of the strain. Furthermore, the genome was lacking key components of avermectin gene cluster, suggesting that nematicidal activity of the bacterium is not likely due to the famous anthelmintic agent of wide-spread use, avermectin. This genomic information of R. ornithinolytica will provide basis for identification and engineering of genes and their products toward control of pine wilt disease.

• Korean Journal of Plant Tissue Culture
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• v.24 no.4
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• pp.233-238
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• 1997

Salicylic acid (SA) is involved in the establishment of systemic acquired resistance (SAR) in many plant including tobacco. Considering the important role of SA in disease resistance, biosynthetic and metabolic pathways of SA in tobacco have been studied extensively: The initial step for biosynthetic pathway of SA is conversion of phenylalanine to trans-cinnamic acid, followed by decarboxylation of trans-cinnamic acid to benzoic acid and ie subsequent ring hydroxylation at the C-2 position to form SA. In TMV inoculated tobacco, most of the newly synthesized SA is glucosylated or methylated. Methyl salicylate has been identified as a biologically active, volatile signal. In contrast, the two glucosylated forms accumulate in the vicinity of lesions and consist of SA glucoside, a major metabolite, and SA glucose ester, a relatively minor from. Two enzymes involved in SA biosynthesis and metabolism have been purified and characterized : benzoic acid 2-hydroxylase which catalyzes conversion of benzoic acid to SA; UDP-Glucose: SA 1-O-D glucosyltransferase which converts SA to SA glucose ester. Further studies of the biosynthetic and metabolic pathways of SA will help to elucidate the SAR signal transduction pathway and provide potential tools for the manipulation of disease resistance.

• Journal of Plant Biotechnology
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• v.43 no.2
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• pp.189-203
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• 2016

Brassica oleraceae var capitata is a member of the Brassicaceae family and is widely used as an horticultural crop. In the present study, transcriptome analysis of B. oleraceae L. var capitata was done for the first time using eight-week old seedlings treated with $50{\mu}m$ MeJA, versus mock-treated samples. The complete transcripts for both samples were obtained using the GS-FLX sequencer. Overall, we obtained 275,570 and 266,457 reads from seedlings treated with or without $50{\mu}m$ MeJA, respectively. All the obtained reads were annotated using biological databases and functionally classified using gene ontology (GO), the Kyoto Encyclopedia of Genes and Genomics (KEGG). By using GO analyses, putative transcripts were examined in terms of biotic and abiotic stresses, cellular component organization, biogenesis, and secondary metabolic processes. The KEGG pathways for most of the transcripts were involved in carbohydrate metabolism, energy metabolism, and secondary metabolite synthesis. In order to double the sequenced data, we randomly chose two putative genes involved in terpene biosynthetic pathways and studied their transcript patterns under MeJA treatment. This study will provide us a platform to further characterize the genes in B. oleracea var capitata.

• Korean Journal of Medicinal Crop Science
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• v.20 no.6
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• pp.440-446
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• 2012

Gastrodia elata, an achlorophyllous orchid plant, is rare medicinal plant. We investigated the genetic diversity in G. elata from 4 locations by using Inter-Simple Sequence Repeats (ISSR) markers. Shannon's information Index (S.I.) indicating genetic diversity ranged from 0.255 (Pocheon) to 0.322 (Muju) with the mean of 0.29. The level of genetic diversity was lower than other plant and most genetic diversity was allocated among individuals within populations (26.81%). The UPGMA dendrogram based on genetic distance failed in showing decisive geographic relationship. In the case of gastrodin (GA), the major components in G. elata, Sangju was highest. The ergothionine (ERG) was detected a lot of contents in Muju and Pocheon. In conclusion, our results is very important information for explaining relationship of genetic variation and functional substances without the effects of environment factors and developing genetic marker by ISSR in G. elata, which may be responsible for the development of breeds with a lot of functional substance in G. elata.

• Journal of Plant Biotechnology
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• v.46 no.3
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• pp.143-157
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• 2019

Medicinal plants are high-value natural resources that have been used as precautionary drugs by many people globally. The increasing global demand for bioactive compounds from medicinal plants has led to the overexploitation of many valuable species. One widely used approach to overcome this problem is the use of adventitious root cultures as a propagation strategy. This review examines the scientific research published globally on the application of adventitious root cultures for many medicinal plants. Adventitious roots generated under aseptic environments in suitable phytohormone-augmented medium exhibit high growth rates and production of important secondary metabolites. Parameters such as medium properties and composition, growth hormone type, and elicitation strategies for in vitro grown adventitious roots of medicinal plants, are the main topics discussed in this review. We also examine current developments in bioreactor system cultivation for plant bioactive compounds using adventitious root cultures, a technology with possible commercial applications, via several studies on adventitious root culture of medicinal plants in which bioreactor systems play a role. In conclusion, the development of adventitious root cultures for medicinal plants is highly useful because of their capability for vegetative propagation and germplasm preservation.

• Mass Spectrometry Letters
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• v.14 no.1
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• pp.9-23
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• 2023

Plants are able to produce a large number of diverse bioactive compounds. Solvent extraction is used for isolation of plant metabolites. The extract yield for plant metabolite extraction strongly depends on the nature of solvent. A review showed the methanol can yield more bioactive compounds. Drying of the sample material is also important for the extraction of plant material. The present study was carried out to analyze the phytocomponents of 5 different latex producing plants. The plants like Calotropis gigantea, Carica papaya, Nerium oleander, Ficus benghalensis and Plumeria alba leaves and latex. The GC-MS analysis of the metabolites revealed phytocomponents. Calotropis gigantea leaves showed 14 compounds and latex produced 5 compounds out of this 4,4,6A,6B,8A,11,11,14B-Octamethyl-1,4,4A,5,6,6A,6B,7,8,8A,9,10,11,12,12A,14,14A,14B-Octadeca-hydro-2 and 2R- Acetoxymethyl-1,3,3-trimethyl-4T-(3-Methyl-2-Buten-1-Yl)-1T-Cyclohexanol compound was present in both latex and leaf extraction. Beta. -carotene compound was present in both latex and leaf of Carica papaya. It was observed that Ficus benghalensis contained 2R-Acetoxymethyl-1,3,3-trimethyl-4T-(3-Methyl-2-Buten-1-Yl)-1T-Cyclohexanol was same in latex and leaf extraction.

• Journal of Ginseng Research
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• v.43 no.4
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• pp.645-653
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• 2019

Background: Cytochrome P450 enzymes catalyze a wide range of reactions in plant metabolism. Besides their physiological functions on primary and secondary metabolites, P450s are also involved in herbicide detoxification via hydroxylation or dealkylation. Ginseng as a perennial plant offers more sustainable solutions to herbicide resistance. Methods: Tissue-specific gene expression and differentially modulated transcripts were monitored by quantitative real-time polymerase chain reaction. As a tool to evaluate the function of PgCYP736A12, the 35S promoter was used to overexpress the gene in Arabidopsis. Protein localization was visualized using confocal microscopy by tagging the fluorescent protein. Tolerance to herbicides was analyzed by growing seeds and seedlings on Murashige and Skoog medium containing chlorotoluron. Results: The expression of PgCYP736A12 was three-fold more in leaves compared with other tissues from two-year-old ginseng plants. Transcript levels were similarly upregulated by treatment with abscisic acid, hydrogen peroxide, and NaCl, the highest being with salicylic acid. Jasmonic acid treatment did not alter the mRNA levels of PgCYP736A12. Transgenic lines displayed slightly reduced plant height and were able to tolerate the herbicide chlorotoluron. Reduced stem elongation might be correlated with increased expression of genes involved in bioconversion of gibberellin to inactive forms. PgCYP736A12 protein localized to the cytoplasm and nucleus. Conclusion: PgCYP736A12 does not respond to the well-known secondary metabolite elicitor jasmonic acid, which suggests that it may not function in ginsenoside biosynthesis. Heterologous overexpression of PgCYP736A12 reveals that this gene is actually involved in herbicide metabolism.

• Research in Plant Disease
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• v.19 no.3
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• pp.208-215
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• 2013

3-(4-Hydroxyphenyl)-propionic acid (HPP) is a bacterial metabolite synthesized and released by an entomopathogenic bacterium Xenorhabdus nematophila K1. In this study, the control efficacy of HPP was tested against Phytophthora blight and anthracnose of red pepper plants. HPP suppressed mycelial growth of Phytophthora blight and anthracnose pathogens. Under natural sunlight condition, HPP maintained the antifungal activity on the diseases for at least twenty five days. The antifungal activity was not decreased even in the condition of soil-water. It was proved that HPP was able to penetrate the roots and travel upward of the red pepper plants. When HPP suspension was applied to soil rhizosphere before transplanting the red pepper seedlings or was regularly sprayed to the foliage of the plants with ten days interval, it resulted in significant reduction of the disease occurrences (Phytophthora blight and anthracnose) without any phytotoxicity. These results suggested that HPP can be developed to a systemic agrochemical against Phytophthora blight and anthracnose of red pepper plants.

• The Plant Pathology Journal
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• v.34 no.2
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• pp.126-138
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• 2018

Rice blast caused by Magnaporthe oryzae is a major disease. In the present study, we aimed to identify and evaluate the novel bacterial isolates from rice rhizosphere for biocontrol of M. oryzae pathogen. Sixty bacterial strains from the rice plant's rhizosphere were tested for their biocontrol activity against M. oryzae under in vitro and in vivo. Among them, B. amyloliquefaciens had significant high activity against the pathogen. The least disease severity and highest germination were recorded in seeds treated with B. amyloliquefaciens UASBR9 (0.96 and 98.00%) compared to untreated control (3.43 and 95.00%, respectively) under in vivo condition. These isolates had high activity of enzymes in relation to growth promoting activity upon challenge inoculation of the pathogen. The potential strains were identified based on 16S rRNA gene sequencing and dominance of these particular genes were associated in Bacillus strains. These strains were also confirmed for the presence of antimicrobial peptide biosynthetic genes viz., srfAA (surfactin), fenD (fengycin), spaS (subtilin), and ituC (iturin) related to secondary metabolite production (e.g., AMPs). Overall, the results suggested that application of potential bacterial strains like B. amyloliquefaciens UASBR9 not only helps in control of the biological suppression of one of the most devastating rice pathogens, M. grisea but also increases plant growth along with a reduction in application of toxic chemical pesticides.

• Journal of Ginseng Research
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• v.43 no.1
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• pp.95-104
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• 2019

Background: Oxidized low-density lipoprotein (ox-LDL) causes vascular endothelial cell inflammatory response and apoptosis and plays an important role in the development and progression of atherosclerosis. Ginsenoside compound K (CK), a metabolite produced by the hydrolysis of ginsenoside Rb1, possesses strong anti-inflammatory effects. However, whether or not CK protects ox-LDL-damaged endothelial cells and the potential mechanisms have not been elucidated. Methods: In our study, cell viability was tested using a 3-(4, 5-dimethylthiazol-2yl-)-2,5-diphenyl tetrazolium bromide (MTT) assay. Expression levels of interleukin-6, monocyte chemoattractant protein-1, tumor necrosis factor-${\alpha}$, intercellular adhesion molecule-1, and vascular cell adhesion molecule-1 were determined by enzyme-linked immunosorbent assay and Western blotting. Mitochondrial membrane potential (${\Delta}{\Psi}m$) was detected using JC-1. The cell apoptotic percentage was measured by the Annexin V/ propidium iodide (PI) assay, lactate dehydrogenase, and caspase-3 expression. Apoptosis-related proteins, nuclear factor $(NF)-{\kappa}B$, and mitogen-activated protein kinases (MAPK) signaling pathways protein expression were quantified by Western blotting. Results: Our results demonstrated that CK could ameliorate ox-LDL-induced human umbilical vein endothelial cells (HUVECs) inflammation and apoptosis, $NF-{\kappa}B$ nuclear translocation, and the phosphorylation of p38 and c-Jun N-terminal kinase (JNK). Moreover, anisomycin, an activator of p38 and JNK, significantly abolished the anti-apoptotic effects of CK. Conclusion: These results demonstrate that CK prevents ox-LDL-induced HUVECs inflammation and apoptosis through inhibiting the $NF-{\kappa}B$, p38, and JNK MAPK signaling pathways. Thus, CK is a candidate drug for atherosclerosis treatment.