• Journal of Plant Biotechnology
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• v.40 no.2
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• pp.59-64
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• 2013

Auxin is a key plant hormone which regulates overall plant growth development. A number of researches to investigate auxin signaling identified three major classes of early auxin response genes: AUX/IAA, GH3 and SMALL AUXIN UP RNA (SAUR). Among these genes, in planta functions of SAUR gene family are largely ambiguous, while both AUX/IAA and GH3 genes are analyzed to mediate negative feedback on auxin response. SAUR genes encode small plant-specific proteins. SAUR gene products are highly unstable and transiently expressed in the tissue- and developmental-specific manners in response to auxin and various environmental stimuli. In the decades, molecular and genetic approaches to elucidate in planta functions of SAURs have been hampered by several factors such as the unstable molecular features and functional redundancy among them. However, a series of recent studies focusing on several subgroups of SAUR gene family made significant progress in our understanding of its biochemical and physiological functions. These works suggest that many SAUR proteins mainly regulate auxin-related cell expansion and auxin transport. In this review, the recent progress in SAUR research and prospects for crop improvement through its genetic manipulation are discussed.

• Proceedings of the Botanical Society of Korea Conference
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• 1995.06a
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• pp.67-78
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• 1995

Monoclonal antibodies (MoAbs) are a highly diversified class of proteins with major research and commercial applications such as diagnostics and therapeutics. Currently, the dominant method for producing MoAbs is through the hybridoma technique. However, this technique is slow, tedious, labor intensive, and expensive. The production of MoAbs in cultured transgenic plant cells can offer some advantages over that in the over that in the mammalian systems. The media to cultivate plant cells are well defined and inexpensive. Contamination by bacteria or fungi is easily monitored in plant tissue cultures. Furthermore, these contaminants are usually not potent pathogens to human beings. In our interdisciplinary research efforts, heavy chain monoclonal antibody (HC MAb) was inserted into Ti plasmid vector and transferred into A. tumefaciens for the transformation in tobacco cells. It was found that 76% of the transformants produced HC MAb. The presence of HC MAb in the cell membrane fraction indicated that the signal peptide was functional and efficient. The change of the HC MAb concentration during a batch culture followed a similar trend as dry cell concentration, indicating that the production of HC MAb was growth related. The long-term repeated subcultures of 11 cell lines showed that there was no obvious trend of neither the decrease nor the increase of the productivity with the repeated subcultures.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.62-62
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• 2022

Freesia has been an important worldwide cut flower because of its fragrance, long vase life and the wide color range of the flower. The conventional propagation methods by seeds and corms have many disadvantages such as shorter inflorescences with fewer numbers of florets, a reduction in cut flower quality and the accumulation of plant viruses in corms by successive cultivation. Therefore, the conventional propagation systems in Freesia needs to be replaced with tissue cultures to overcome the disadvantages. This study explored an efficient multiplication protocol using the combination of plant growth regulators (PGRs) for developed cultivar 'Sunny Gold'. The combination between 6-benzylaminopurin (BA) and α-naphthalene acetic acid (NAA) did not produce new shoots but developed enlarged roots. BA only treatments and the combination between BA and kinetin treatments were effective on shoot multiplication. The highest average number of shoots was 5.3 in the presence of 3 mg/L BA and 0.5 mg/L kinetin. To produce corms and cormlets, proliferated shoots were subcultured on 1/2 Murashige and Skoog (MS) medium supplemented with 90 g/L sucrose, 1 g/L charcoal and 7 g/L plant agar and placed at 4℃ in the dark for 6 months. The small size of corms and comlets were produced. The average number of regenerated comlets was 2.75 per shoot. The results showed that shoot multiplication is more efficient than cormlet regeneration for in vitro freesia proliferation.

• The Plant Pathology Journal
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• v.40 no.4
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• pp.358-376
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• 2024

Inoculation of Chinese cabbage leaves with high titer (10⁷ cfu/ml) of the non-adapted bacteria Xanthomonas campestris pv. vesicatoria (Xcv) strain Bv5-4a.1 triggered rapid leaf tissue collapses and hypersensitive cell death (HCD) at 24 h. Electrolyte leakage and lipid peroxidation markedly increased in the Xcv-inoculated leaves. Defence-related gene expressions (BrPR1, BrPR4, BrChi1, BrGST1 and BrAPX1) were preferentially activated in the Xcv-inoculated leaves. The Xcv-triggered HCD was attenuated by continuous light but accelerated by a dark environment, and the prolonged high relative humidity also alleviated the HCD. Constant dark and increased relative humidity provided favorable conditions for the Xcv bacterial growth in the leaves. Pretreated fluridone (biosynthetic inhibitor of endogenous abscisic acid [ABA]) increased the HCD in the Xcv-inoculated leaves, but exogenous ABA attenuated the HCD. The pretreated ABA also reduced the Xcv bacterial growth in the leaves. These results highlight that the onset of HCD in Chinese cabbage leaves initiated by non-adapted pathogen Xcv Bv5-4a.1 and in planta bacterial growth was differently modulated by internal and external conditional changes.

• Journal of Bio-Environment Control
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• v.14 no.2
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• pp.119-127
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• 2005

This study was carried out to investigate the effect of magnesium concentrations in fertilizer solution on growth and cut flower quality of chrysanthemum 'Biarritz'. The nutrient concentrations in plant tissue and soil solution of root media were also determined. Magnesium deficiency appeared on older leaves with interveinal yellow-green chlorosis. Marginal chlorosis and necrosis also developed on some of older leaves. Elevation of Mg concentration in fertilizer solution increased cut flower weight at harvesting stage resulting in the 8.84g in 1.5mM treatment. Dry weight of whole above ground plant tissue increased as Mg concentrations in fertilizer solution were elevated within the range from 0 to 15mM, but that of 20mM decreased compared to 15mM treatment. The dry weight of 0.5, 1.0 and 1.5mM treatments were 8.42, 8.75 and 8.848 and tissue Mg contents of those based on the youngest fully expanded leaves at harvesting stage were 0.34, 0.53 and $0.71\%$, respectively. Based on dry weight and tissue Mg contents, Mg fertilization to maintain tissue contents higher than $0.64\%$ is necessary to ensure flower quality and yield. By considering the concentration in 15mM treatment, Mg concentration in soil solution of root media should be higher than $3.68mg{\cdot}L^{-1}$ at harvesting stage.

• The Plant Pathology Journal
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• v.21 no.2
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• pp.158-163
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• 2005

Virus-induced gene silencing (VIGS) is a recently developed gene transcript suppression technique for characterizing the function of plant genes. However, efficient VIGS has only been studied in a few plant species. In order to extend the application of VIGS, we examined whether a VIGS vector based on TRV would produce recognizable phenotypes in soybean. Here, we report that VIGS using the Tobacco rattle virus (TRV) viral vector can be used in several soybean cultivars employing various agro-inoculation methods including leaf infiltration, spray inoculation, and agrodrench. cDNA fragments of the soybean phytoene desaturase(PDS) was inserted into TRV RNA-2 vector. By agrodrench, we successfully silenced the expression of PDS encoding gene in soybean. The silenced phenotype of PDS was invariably obvious 3 weeks after inoculation with the TRV-based vector. Real-time RT-PCR analyses showed that the endogenous level of GmPDS transcripts was dramatically reduced in the silenced leaf tissues. These observations confirm that the silenced phenotype is closely correlated with the pattern of tissue expression. The TRV-based VIGS using agrodrench can be applied to functional genomics in a soybean plants to study genes involved in a wide range of biological processes. To our knowledge, this is the first high frequency VIGS method in soybean plants.

• Korean Journal of Microbiology
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• v.43 no.3
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• pp.227-231
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• 2007

Many of antimicrobial components used in the mouthwash have disadvantages such as coloring of periodontal tissue and homing sensation. To find the more biocompatible antimicrobial agent, we have screened the 2,125 kinds of natural plant extracts obtained from by the Plant Extract Bank (Daejeon, Korea). The antimicrobial activity was determined by spectrophotometric growth inhibition assay for the major dental pathogens. For the Porphyromonas gingivalis, 19 plant extracts had an antimicrobial activity, 17 plant extracts for the Prevotella intermedia, 45 plant extracts for the Haemophilus actinomycetemcomitans and 85 plant extracts for the Streptococcus mutans. Among these effective extracts, 8 kind of natural plant extracts had an antimicrobial activity for more than 3 species of dental pathogens. In our experiment, Cudrania tricuspidata, Morus bombycis and Mallotus japonicas have antibacterial effects on the all kinds of major dental pathogens. Therefore these plant extracts have a possibility to be a candidate for major antibacterial components in dental products.

• Journal of Veterinary Science
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• v.21 no.5
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• pp.74.1-74.13
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• 2020

Background: The quality of a vaccine depends strongly on the effects of the adjuvants applied simultaneously with the antigen in the vaccine. The adjuvants enhance the protective effect of the vaccine against a viral challenge. Conversely, oil-type adjuvants leave oil residue inside the bodies of the injected animals that can produce a local reaction in the muscle. The long-term immunogenicity of mice after vaccination was examined. ISA206 or ISA15 oil adjuvants maintained the best immunity, protective capability, and safety among the oil adjuvants in the experimental group. Objectives: This study screened the adjuvant composites aimed at enhancing foot-and-mouth disease (FMD) immunity. The C-type lectin or toll-like receptor (TLR) agonist showed the most improved protection rate. Methods: Experimental vaccines were fabricated by mixing various known oil adjuvants and composites that can act as immunogenic adjuvants (gel, saponin, and other components) and examined the enhancement effect on the vaccine. Results: The water in oil (W/O) and water in oil in water (W/O/W) adjuvants showed better immune effects than the oil in water (O/W) adjuvants, which have a small volume of oil component. The W/O type left the largest amount of oil residue, followed by W/O/W and O/W types. In the mouse model, intramuscular inoculation showed a better protection rate than subcutaneous inoculation. Moreover, the protective effect was particularly weak in the case of inoculation in fatty tissue. The initial immune reaction and persistence of long-term immunity were also confirmed in an immune reaction on pigs. Conclusions: The new experimental vaccine with immunostimulants produces improved immune responses and safety in pigs than general oil-adjuvanted vaccines.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.3
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• pp.232-236
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• 2004

In order to optimize tissue culture conditions for genetic transformation of orchardgrass (Dactylis glomerata L.), the effects of culture medium supplements on tissue culture responses were investigated with mature seeds of a cultivar, 'Roughrider', as explant tissues. The optimal concentration of 2,4-D for the induction of embryogenic callus from mature seeds was 3 mg/L. Plant regeneration frequency was 36.3% when embryogenic calli were cultured on the regeneration medium supplemented with 1mg/L 2,4-D and 3mg/L BA. Addition of 1 g/L casein hydrolysate and 300 mg/L L-proline improved frequencies of embryogenic callus induction and plant regeneration up to 57.3 and 60.7%, respectively. Supplementation of the media with 10 mga $\textrm{AgNO}_3$ and 40 mg/L cysteine enhanced frequencies of callus induction and plant regeneration. Efficient regeneration system established in this study will be useful for molecular breeding of orchardgrass through genetic transformation.

• Korean Journal Plant Pathology
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• v.13 no.3
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• pp.172-178
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• 1997

Xanthmonas campestris pv. campestris, causal agent of Black rot of crucifers, were isolated and identified from crucifer host. In order to determine the characters of X. c. pv. campestris associated with pathogenicity, Tn5 mutagenesis was carried out by conjugating with E. coli pJB4J1. Transconjugants were plate- assayed for missing cellulase, protease and amylase activity. A cellulase negative mutant was selected and tested for pathogenicity. Light microscopy and Scanning electron microscopy revealed that substomatal tissues were colonized by mutant, but was far less extensive than those by wild type. Stomatal surface and substomatal tissue appeared to have degraded by only wild type in 24 hrs and progression of pathogenesis was distinct in 48 hrs. In 6 days, wild type proliferated well in the tissue facilitated by cellulase activity. As a result, cellulase was determined as the important factor in pathogenesis.