• The Journal of Traditional Korean Medicine
• /
• v.15 no.1
• /
• pp.83-89
• /
• 2006

Many naturally occurring plant extracts are studied for their beneficial effects for health and particularly on cancer. Apoptosis, or programmed cell death, occurs in both normal and pathological conditions, including cancer. Dysregulation of apoptosis allows transformed cells to continually and uninhibitedly enter the cell cycle, thus perpetuating the sequence of mutation, genomic instability and, finally, oncogenesis. To investigate the apoptosis-Inducing effect of the extract of Fructus Trichosanthis (EFT) on leukemic HL-60 cells and its mechanism, HL-60 cells in vitro in culture medium were given different doses of the extract. The inhibitory rate of cells were measured by microculture tetrazolium assay, cell apoptotic rate was detected by flow cytometry, morphology of cell apoptosis was observed by DAPI fluorescence staining, and the activations of caspases and PARP were detected using Western blotting analysis. The extract could activate the caspase-3 and caspase-8, induce PARP cleavage, inhibit growth of HL-60 cells, and cause apoptosis significantly. The suppression was in dose-dependent manner. Marked morphological changes of cell apoptosis including condensation of chromatin and nuclear fragmentation were observed clearly by DAPI fluorescence staining especially. These results will provide strong laboratory evidence of EFT for clinical treatment of acute leukemia.

• Korean Journal of Plant Tissue Culture
• /
• v.25 no.1
• /
• pp.13-19
• /
• 1998

We have reported previously that intact embryogenic cells can be used instead of protoplasts for electroporation-mediated transformation of zoysiagrass and rice. In this study, conditions of the tissue electroporation were examined to optimize the procedures. Embryogenic cell suspensions were established in liquid MS medium containing 2 mg/L of 2,4-D with embryogenic calluses induced from mature embryos of Z. japonica. The suspension-cultured cell clumps were electroporated with 35S-gusA expression vector DNA, and degrees of DNA introduction into the cells were determined by histological expression rates of the gusA marker gene. DNA transfer into the cell clumps occurred in wide range of voltage (100-400 V) and capacitance (10-1980 $\mu\textrm{F}$), but more in the ranges of 200-300 V and 330-800 $\mu\textrm{F}$ DNA concentrations higher than 6 $\mu\textrm{g}$/mL were adequate for GUS expression of the electroporated cells. DNA transfers were confirmed in all three embryogenic cell lines but only in one out of eleven non-embryogenic lines. Positive GUS expressions occurred with DNAs added even 20-40 h after pulse treatments. As a promoter of gusA, Act1 and Ubi1 were effective 7 and 5 times than 35S respectively in number of GUS expression units on electroporated cell clumps. Embryogenic cell clumps survived and regenerated into plantlets after pulse treatments of wide range of conditions.

• Journal of Plant Biotechnology
• /
• v.7 no.4
• /
• pp.233-240
• /
• 2005

Slices of embryonic axis of mature pea (Pisum sativum L. cv. Green Arrow) seeds were used as explant. Transformation of explants was done via Agrobacterium tumefaciens bearing vector pBI-P5CS construct. The best results for inoculation of explants were obtained when they were immersed for 90 s at a concentration of $6{\times}10^8$ cell $ml^(-1)$ of bacterial suspension. Transformed pea plants were selected on $50\;mg\;l^(-1)$ kanamycin and successful transformants were confirmed by PCR and blotting. Transgenic plants were further analyzed with RT-PCR to confirm the expression of P5CS. Transgenic plants and non-transgenic plants were treated with different concentrations of NaCl 0 (control), 100, 150 and 200 mM in culture medium. Measurement of proline content indicated that transgenic plants produced more amino acid proline in response to salt in comparison with non-transgenic plants. Photosynthetic efficiency in transgenic plants under salt-stress was more than that of non-transgenic plants.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.34 no.s01
• /
• pp.48-54
• /
• 1989

An immunoassay techniques using monoclonal antibodies have been developed of the quantitative analysis of endogenous hormones in plants. In order to be useful for immunoassay, both a high degree of specificity and a high affinity are required. A system is described for production of hybridomas which secrete antibodies against the plant hormone. Using the system we were able to produce hybridmas with the desired antibody specificity by cell fusion and culture method. For a number of obvious reasons, monoclonal antibodies(mAb) were superior to polyclonal antibodies.

• Journal of Life Science
• /
• v.14 no.6 s.67
• /
• pp.1018-1022
• /
• 2004

Optimized conditions for Agrobacterium-mediated lisianthus pollen transformation were adjusted using various factors such as temperature, pH and sucrose concentration. Pollen tube growth was successfully achieved in a medium (pollen germination medium; PGM) containing $7-15\%$ sucrose with pH in the range of 5.5-7.0 at temperature of $20-27^{\circ}C$. Lisianthus pollen was vacuum-infiltrated with Agrobacterium cell suspension for 20 min, and transformed pollen was confirmed by GUS histochemistry and Southern hybridization following RT-PCR. Transgenic pollen system may be utilized for establishing an area of plant transient expression systems based on the convenient pollen transformation procedure presented in here.

• The Plant Pathology Journal
• /
• v.27 no.4
• /
• pp.390-395
• /
• 2011

Fusarium wilt caused by Fusarium oxysporum has become a serious problem world-wide and relies heavily on chemical fungicides. We selected Pseudomonas sp. NJ134 to develop an effective biocontrol strategy. This strain shows strong antagonistic activity against F. oxysporum. Biochemical analyses of ethyl-acetate extracts of NJ134 culture filtrates showed that 2,4-diacetylphloroglucinol (DAPG) was the major compound inhibiting in vitro growth of F. oxysporum. DAPG production was greatly enhanced in the NJ134 strain by adding mannitol to the growth media, and in vitro antagonistic activity against F. oxysporum increased. Bioformulations developed from growth of NJ134 in sterile bean media with mannitol as the carbon source under plastic bags resulted in effective biocontrol efficacy against Fusarium wilt. The efficacy of the bioformulated product depended on the carbon source and dose. Mannitol amendment in the bean-based formulation showed strong effective biocontrol against tomato Fusarium wilt through increased DAPG levels and a higher cell density compared to that in a glucose-amended formulation. These results suggest that this bioformulated product could be a new effective biocontrol system to control Fusarium wilt in the field.

• Molecules and Cells
• /
• v.39 no.6
• /
• pp.484-494
• /
• 2016

Plant cells have a remarkable ability to induce pluripotent cell masses and regenerate whole plant organs under the appropriate culture conditions. Although the in vitro regeneration system is widely applied to manipulate agronomic traits, an understanding of the molecular mechanisms underlying callus formation is starting to emerge. Here, we performed genome-wide transcriptome profiling of wild-type leaves and leaf explant-derived calli for comparison and identified 10,405 differentially expressed genes (> two-fold change). In addition to the well-defined signaling pathways involved in callus formation, we uncovered additional biological processes that may contribute to robust cellular dedifferentiation. Particular emphasis is placed on molecular components involved in leaf development, circadian clock, stress and hormone signaling, carbohydrate metabolism, and chromatin organization. Genetic and pharmacological analyses further supported that homeostasis of clock activity and stress signaling is crucial for proper callus induction. In addition, gibberellic acid (GA) and brassinosteroid (BR) signaling also participates in intricate cellular reprogramming. Collectively, our findings indicate that multiple signaling pathways are intertwined to allow reversible transition of cellular differentiation and dedifferentiation.

• Korean Journal of Plant Tissue Culture
• /
• v.25 no.2
• /
• pp.89-93
• /
• 1998

Tomato phenylalanine ammonia-lyase 5 (tPAL5) was identified that alternate initiation sites were utilized differentially in response to environmental stimuli (Lee et al, 1992b). In this study, we tried to look into tissue -or cell- specific expression pattern of tPAL5 gene by fusing with ${\beta}-glucuronidase$ (GUS) gene in transgenic tobacco plants. In transgenic plants, root and stem extracts contained 8~12 fold higher levels of GUS activity than petiole or leaf tissue while the highest levels of induction was observed from leaf tissue by mechanical wounding (5~11 fold). In trans-sections of stems and petioles, GUS activity was restricted to phloem cells(outer region) of developing vascular bundle and mainly at apical tip region in the root tissues. The levels of GUS activity was drastically reduced (10~12 fold reduction) when the 5'-upstream region of tPAL5 gene (-1151bp from ATG codon) was deleted up to -665. The levels of GUS expression, however, raised up by 6~8 fold when deleted up to -455. Therefore, we conclude that there are positive cis-elements at the region -1151 to -1008 and at -455 to -195 while the negative cis-element is at -1008 to -455.

• Journal of agriculture & life science
• /
• v.43 no.6
• /
• pp.59-65
• /
• 2009

Combinations of plant growth regulators, darkness treatments, and the order of expanding leaves for explants were evaluated for optimizing in vitro shoot regeneration rate of 'Whangkeumbae' pear. In a MS medium, supplemented with $8.88{\mu}M$ 6-benzylaminopurine (BA) and $0.49{\mu}M$ indole-3-butyric acid (IBA), green foci were observed on the surface of the callus 8 days after culture initiation. Some adventitious buds were later induced from those green foci, resulting in the appearance of normal shoots. In a medium containing $22.20{\mu}M\;BA$, the surface of the callus became compact and greenish, and many adventitious buds were formed over the entire area of the callus surface. When comparing BA concentration via histological observation, the section which had been treated with $22.20{\mu}M\;BA$ exhibited closer cell aggregation than those with $8.88{\mu}M\;BA$. The darkness treatment enhanced the formation of adventitious shoots for up to 3 weeks. The youngest two expanding leaves, proximal to the shoot apex, were proved to be the most regenerative, and yielded the highest shoot number per regenerating leaf. A fourth strength MS medium, which was supplemented with $0.54{\mu}M\;NAA$, yielded good quality plantlets, with regard to root number and root length.

• Korean Journal of Pharmacognosy
• /
• v.50 no.1
• /
• pp.1-10
• /
• 2019

Recently, companion animal culture has grown rapidly and mature, raising interest in preventing and treating animal diseases. In particular, viral infection was a serious threat to companion animal health because there was no proper antiviral drugs. Synthetic antiviral drugs have limitations such as low efficiency, toxicity, and occurrence of resistant viruses. Therefore, attempts to find new anti-viral drugs from natural sources have continued. This review focused on the natural products and active substances that exhibit antiviral activity against three viruses: canine distemper virus (CDV), canine parvovirus (CPV), and feline calicivirus (FCV) that cause fatal diseases in dogs and cats. Natural plant extracts, flavonoids, polysaccharides, alkaloids and saponins showed antiviral activity with various mechanisms and differences in activity depending on the structure. Especially, quercetin and epigallocatechin-3-gallate (EGCG) showed antiviral activity through a multi-mechanism that interferes with the attachment and penetration stages of the virus and inhibits the viral polymerase within the cell. Some natural plant extracts showed a virucidal activity and showed the potential effect as a preventative agent to prevent the viral infection. This review is expected to provide research trend on the development of antiviral natural products for companion animals.