• Korean Journal of Plant Tissue Culture
• /
• v.25 no.2
• /
• pp.81-88
• /
• 1998

The Southeast Asian javanica rice variety Tinawen was investigated for efficient protoplast culture and plant regeneration from cell suspension-derived protoplasts using a feeder cell culture method. Feeder cells of both Lolium multiflorum and Oryza ridleyi, either alone, or in combination, were employed and plants were regenerated from protoplast-derived colonies on several plant regeneration media. Dehydration of protoplast-derived colonies was also investigated as a means of enhancing plant regeneration. In the presence of L. multiflorum or O. ridleyi feeder cells, the protoplast plating efficiency ranged from 0.09% to 1.48%, depending on the feeder cell type and the age of the cell suspension. L. multiflorum feeder cells induced approximately 6-fold higher plating efficiency compared with those of O. ridleyi. The plant regeneration frequencies were 19.3-31.7% with L. multiflorum, 13.0-18.0% with O. ridleyi and 18.0-22.0% with a mixture of both in various plant regeneration media when protoplast-derived colonies were dehydrated, while for the non-dehydrated colonies, the values were 2.0-7.0%, 3.0-5.0% and 0-4.0%, respectively. Flow cytometric analysis of 34 protoplast-derived plants showed that the majority of plants were diploids and only 2 plants were tetraploids. The plants which were transferred to glasshouse were fertile.

• Journal of Veterinary Science
• /
• v.21 no.5
• /
• pp.64.1-64.14
• /
• 2020

Background: Canine distemper virus (CDV) infection results in high morbidity and mortality in dogs. There has been no report about Isolation of Korean CDV since 1980 in Korea. Objectives: To investigate the biological properties and the genetic characterization of Korean CDV. Methods: Vero cells expressing dog signaling lymphocyte activation molecule (dSLAM) gene named as Vero/dSLAM were used to isolate CDV using 17 samples. Diagnostic methods such as cytopathic effects, immunofluorescence assay, peroxidase linked assay, electron microscopy, rapid immunodiagnostic assay, and reverse transcription polymerase chain reaction were used to confirm the Korean CDV isolate as a CDV. The genetic analysis was performed through cloning and sequencing of hemagglutinin gene of CDV isolate. Results: A virus propagated in Vero/dSLAM cell was confirmed as CDV (CD1901 strain) based on the above methods. The CD1901 strain showed the highest viral titer (10^5.5 50% tissue culture infectious dose [TCID₅₀]/mL) in the Vero/dSLAM cells at 4 days post inoculation, but did not form a fork on chorioallantoic membrane of 7-day-old egg. Ribavirin, a nucleotide analogue anti-viral agent, inhibits moderately the Korean CDV propagation in the Vero/dSLAM cells. The nucleotide and amino acid sequences of the H gene of CD1901 strain were compared with those of other CDV strains. The CD1901 strain belonged to Asia 1 group and had the highest similarity (99.9%) with the BA134 strain, which was isolated in China in 2008. Conclusions: We constructed successfully Vero/dSLAM and isolated one Korean CDV isolate (CD1901 strain) from a naturally infected dog. The CD1901 strain belonged to Asia 1 genotype.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2022.09a
• /
• pp.89-89
• /
• 2022

Paeonia lactiflora (P. lactiflora) is a medicinal plant widely used for treating inflammatory diseases. However, P. lactiflora has been recently reported to increase the production of proinflammatory mediators and activates phagocytosis in macrophages. Thus, in this study, we tried to verify the macrophage activation of Paeoniae Radix Alba (PRR, also known as red peony root) and elucidate its mechanism of action. PRR upregulated the production of proinflammatory mediators and activated phagocytosis in RAW264.7 cells. However, these effects were reversed by inhibition of TLR2/4. In addition, the inhibition of p38, JNK, and ERK1/2 reduced the PRR-mediated production of proinflammatory mediators, and the SPL-mediated activation of p38, JNK, and ERK1/2 was blocked by the TLR4 inhibition. These findings indicate that PRR may activate macrophages through TLR4-dependent activation of p38, JNK, and ERK1/2. These indicate that PRR has immunostimulatory activity. Thus, it is believed that PRR can be used as a functional food agent that enhances the immune system.

• Molecules and Cells
• /
• v.27 no.1
• /
• pp.67-74
• /
• 2009

Autophagy degrades toxic materials and old organelles, and recycles nutrients in eukaryotic cells. Whereas the studies on autophagy have been reported in other eukaryotic cells, its functioning in plants has not been well elucidated. We analyzed the roles of OsATG10 genes, which are autophagy-related. Two rice ATG10 genes - OsATG10a and OsATG10b - share significant sequence homology (about 75%), and were ubiquitously expressed in all organs examined here. GUS assay indicated that OsATG10b was highly expressed in the mesophyll cells and vascular tissue of younger leaves, but its level of expression decreased in older leaves. We identified T-DNA insertional mutants in that gene. Those osatg10b mutants were sensitive to treatments with high salt and methyl viologen (MV). Monodansylcadaverine-staining experiments showed that the number of autophagosomes was significantly decreased in the mutants compared with the WT. Furthermore, the amount of oxidized proteins increased in MV-treated mutant seedlings. These results demonstrate that OsATG10b plays an important role in the survival of rice cells against oxidative stresses.

• The Plant Pathology Journal
• /
• v.23 no.3
• /
• pp.203-209
• /
• 2007

Infection structures were observed using a fluorescence microscope at the penetration sites on the leaves of potato plants pre-inoculated with the bacterial strains Pseudomonas putida TRL2-3, Micrococcus luteus TRK2-2, and Flexibacteraceae bacterium MRL412, which mediated an induced systemic resistance on potato plants against late blight disease caused by Phytophthora infestans. In order to compare the infection structures on the leaves expressing systemic acquired resistance, the leaves of potato plants pre-treated with DL-3-amino butyric acid (BABA) were also observed after challenge inoculation with the same pathogen. The infection structures were investigated. The total number of germination and appressorium formation of P. infestans were counted. Furthermore, the frequencies of fluorescent epidermal cells at the penetration sites, which indicate a defense response of plant cell, were estimated. There were no differences on the germination rates of the fungal cysts among the untreated control, BABA pre-treated, and bacterial strains pre-inoculated plants. However, appressorium formation was slightly decreased on the leaves of BABA pre-treated plants compared to those of untreated as well as bacterial strains pre-inoculated plants. Furthermore, the frequencies of fluorescent cells of BABA pre-treated and bacterial strains pre-inoculated were higher than that of untreated plants, indicating an active defense reaction of the host cells against the fungal attack. On the other hand, the pre-treatment with BABA caused a stronger fluorescent of epidermal cells at the penetration sites compared to the pre-inoculation with the bacterial strains. Interestingly, the frequency of fluorescent cells by BABA, however, was lower than that by the bacterial strains. Based on the results it is suggested that the infection structures showing resistance reaction on the leaves of potato plants were different between by pre-inoculation with bacterial strains and by pre-treatment with BABA against the late blight pathogen.

• Molecules and Cells
• /
• v.39 no.10
• /
• pp.768-775
• /
• 2016

The Arabidopsis female gametophyte contains seven cells with eight haploid nuclei buried within layers of sporophytic tissue. Following double fertilization, the egg and central cells of the gametophyte develop into the embryo and endosperm of the seed, respectively. The epigenetic status of the central cell has long presented an enigma due both to its inaccessibility, and the fascinating epigenome of the endosperm, thought to have been inherited from the central cell following activity of the DEMETER demethylase enzyme, prior to fertilization. Here, we present for the first time, a method to isolate pure populations of Arabidopsis central cell nuclei. Utilizing a protocol designed to isolate leaf mesophyll protoplasts, we systematically optimized each step in order to efficiently separate central cells from the female gametophyte. We use initial manual pistil dissection followed by the derivation of central cell protoplasts, during which process the central cell emerges from the micropylar pole of the embryo sac. Then, we use a modified version of the Isolation of Nuclei TAgged in specific Cell Types (INTACT) protocol to purify central cell nuclei, resulting in a purity of 75-90% and a yield sufficient to undertake downstream molecular analyses. We find that the process is highly dependent on the health of the original plant tissue used, and the efficiency of protoplasting solution infiltration into the gametophyte. By isolating pure central cell populations, we have enabled elucidation of the physiology of this rare cell type, which in the future will provide novel insights into Arabidopsis reproduction.

• Journal of Plant Biology
• /
• v.30 no.2
• /
• pp.79-94
• /
• 1987

This study was carried out to investigate the epidermal structure, the stomatal types, the ontogeny of stomara in various parts of each organ of K. blossfeldiana, K. kewensis, and K. tometosa belonging to Kalanchoe. The epidermal cells were polygonal or isodiametric ones in the leaves, and mostly rectangular, tetragonal, and elongated ones in the leaves, and mostly rectangular, tetragonal, and elongated ones in the other organs. The candelabrum-like, triradiate stellete trichomes in the aerial parts of all organs of K. tomentosa were found. The cuticular striations and square crystals of calcium oxalate in the epidermal cells of petals of K. blossfeldiana were observed. The great majority of the mature stomata in various parts of all the organs were commonly helicocytic types. This type was subdivided into three subtypes such as parahelicocytic, anomohelicocytic, and dianisocytic stomata on the basis of the division angle of the guard mother cells. Somethies, the anisocytic type was found in most organs. This type was subdivided into three subtyes such as paranisocytic, nomoanisocytic, and dianisocytic stomata in the same way as the helicocytic type. A new stomataltype with anisocytic stoma within a girdle of four subsidiary cells of tetracytic type in the leaf of K. kewensis was firstly observed in the vascular plants. This type was termed the coaniso-tetracytic type. The anomomeristic pattern in the mesogenous category of stomatal types was found in various organs of all the material plants. Developmental mode of stomata was constant in all the parts of each organ within the same plant. The stomata was observed to be a few similar stomatal types in various parts of each organ within the same plant. The ontogeny of all the types is eumesogenous or mesogenous type. The ontogenetic type of stomata was mostly helico-eumesogenous type in all the organs of all the material plants. The mature stoma varied from organ to in regard of the number and arrangement of subsidiary cells.

• Proceedings of the Korean Society of Plant Pathology Conference
• /
• 2003.10a
• /
• pp.100.1-100
• /
• 2003

A dctA gene encoding a protein with identity to a C4-dicarboxylate/H+ was cloned from a beneficial biocontrol bacterium, P. chororaphis O6. Expression of the dctA was induced in minimal medium by several organic acids and was repressed by glucose. Highest expression was observed in early-log cells grown on fumarate and succinate with decline as cells approached late-log phase. The dctA transcript accumulated weakly when cells were grown on malate but strong expression was observed with benzoate. Expression of the dctA transcript was repressed in early-log cells upon addition of glucose to fumarate, but was detected as the cell culture aged. A dctA-deficient mutant of O6, constructed by marker exchange mutagenesis, did not grow on minimal medium containing succinate, benzoate, or fumarate, and growth on malate was delayed. The dctA mutant and wild type grew equally on glucose. The dctA mutant on cucumber roots in sterilized potting soil was colonized at levels comparable to those of the wild type, but induction level of disease resistance by the mutant against target leaf spot disease was decreased. These results may indicate that the dctA is essential for utilization of certain organic acids and its expression is controlled by the availability of sugars. In addition, the dctA is not essenitial for cucumber root colonization, but important for induction of disease resistance.

• Korean Journal of Plant Resources
• /
• v.36 no.1
• /
• pp.26-31
• /
• 2023

In this study, we investigated in vitro inhibitory activity of wild-simulated ginseng (WSG) against non-alcoholic fatty liver disease using HepG-2 cells. T0901317 treatment increased the lipid accumulation in HepG-2 cells, but WSG treatment inhibited T0901317-mediated lipid accumulation. In addition, WSG downregulated T0901317-mediated expression of SREBP-1c, ACC, FAS and SCD-1 protein. In addition, WSG increased the phosphorylation level of LKB1 and AMPK. Compound C treatment blocked WSG-mediated downregulation of SREBP-1c protein. In conclusion, WSG is considered to inhibit the accumulation of lipids and triglycerides in HepG-2 cells by inducing the activation of LKB1 and AMPK successively, thereby reducing the expression of FAS, ACC, and SCD-1 through suppression of SREBP-1c expression.

• Journal of Plant Biotechnology
• /
• v.6 no.1
• /
• pp.9-13
• /
• 2004

Transient uidA expression was used to optimize parameters required for biolistic transformation of suspension cells of Easter lily, Lilium longiflourm. Maximum uidA expression occurred following bombardment with gold particles as compared to tungsten. A 3hr pre-treatment of suspension cells with 0.125M osmoticum resulted in a 1.5X increase in uidA expression. A helium pressure of 1550 psi combined with a particle travelling distance of 6cm resulted in maximum uidA expression as compared to either 1100, 1200, or 1800 psi. Transient transformation resulted in up to 493 uidA expressing cells/Petri plate. For stable transformation suspension cells of Lilium longiflorum, were co-bombarded with plasmid DNA containing cucumber mosaic virus (CMV) replicase under the rice actin (Act1) promoter and either the bar or PAT genes under the cauliflower mosaic virus (CaMV 355) promoter. Ten regenerated plants contained the transgene as analyzed by PCR, and two of the ten plants were confirmed to contain the transgene by Southern hybridization. The two transgenic plants were independent transformants, one containing the bar gene and the other both the CMV replicase and bar genes. Plants were sprayed at the rosette stage and found to be resistant to 1000 mg/L of phosphinothricin (Trade name-Ignite) indicating expression of the bar gene throughout the leaves when bar was under control of the CaMV 35S promoter.