• The Plant Pathology Journal
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• v.38 no.4
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• pp.403-409
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• 2022

In biological particles such as Fusarium species, ice nucleation activity (INA) has been observed. Fusarium strains isolated from apple declined trees in Korea were identified with a multilocus sequence analysis using the tef1 and rpb1 genes. Droplet-freezing and tube-freezing assays were used to determine the INA of the strains, using Pseudomonas syringae pv. syringae KACC 21200 as a positive control and resulting in seven INA+ fungal strains that were identified as F. tricinctum (KNUF-21-F17, KNUF-21-F18, KNUF-21-F29, KNUF-21-F32, KNUF-21-F38, KNUF-21-F43, and KNUF-21-F44). The effect of Fusarium INA+ KNUF-21-F29 was compared to that of INA- strains on Chrysanthemum morifolium cv. Shinma explants. A higher callus formation and no-shoot formation were observed, suggesting that fungal INA could play a role in cold injuries and be a factor to consider in rapid apple decline. To the best of our knowledge, this is the first report of INA fungal strains isolated in Korea.

• Korean Journal of Plant Tissue Culture
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• v.27 no.2
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• pp.109-115
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• 2000

Effects of the heavy-ion ($^{14}$ N or $^{20}$ Ne) beam irradiation on the response of anthers, growth of calli, germination of seeds, and the early growth after the germination of tobacco (Nicotiana tabacum L. cv. BY-4) were investigated. Anthers precultured for 10 days before the irradiation became brown without callus or shoot induction over 20 Gy of $^{14}$ N and $^{20}$ Ne ion beam irradiation. Relative growth rate of the cultured calli was reduced by the irradiation and became brown significantly 2 weeks after the $^{14}$ N and $^{20}$ Ne ion beam irradiation over 50 Gy. The increased intensity of the heavy-ion ($^{14}$ N, $^{20}$ Ne) beam irradiation resulted in the delay of seed germination and the inhibition of the early growth both in water-treated and non-treated seeds before the irradiation. In addition, the heavy-ion beam irradiation to the imbibed seeds inhibited seed germination more than that to the non-imbibed seeds. The screening approach of non-imbibed seeds with heavy-ion beam irradiation using in vitro culture system was more useful than the filter-paper germination method in investigating the characteristics of heavy-ion beam-irradiated seed population and the screening of morphological variants at the early stage of the plant growth.

• The Journal of Korean Physical Therapy
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• v.6 no.1
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• pp.95-107
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• 1994

This study was performed to identify the effect of constant direct current and to give us methods which can be applied easily in clinic. Six rabbits was used at this experiment. After each animal was fractured at left fibula, divided into experimental group(n=3) and central group(n=3). Experiment duration of electrical stimulation on experimental rabbits was 35 days. Direct current from fifteen microampere to twenty microampere was passed continously through the placed electrode between fracture area and thigh. Negative electrode was placed at fracture area and positive at thigh. Roentgenography was used to observe bone-healing progression wet three times-at 15days, 25days and 35days after electrical stimulation. The results obtained are as followings: 1. Both experimental group and control group do not obtain callus formation on the first roentgenography(15 days after ES). 2. On the second roentgenography(25 days after ES), experimental group achieves above $70\%$ on fracture-healing, but control group achieves about $20-30\%$ on fracture healing. 3. On the third roentgenegraphy(35 nays after ES), experimental group achieves above $85-95\%$ on fracture healing and control group achieves about $60-70\%$ of bone union. Thus, statistically significance(independent t-test) was occured ie the second and third roentgenography between experimental group and control group.

• Plant Biotechnology Reports
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• v.5 no.3
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• pp.265-271
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• 2011

The cultivated potato as well as its tuber-bearing relatives are considered model plants for cell and tissue culture, and therefore for exploiting the genetic variation induced by in vitro culture. The association between molecular stability and tissue culture in different genetic backgrounds and ploidy levels has already been explored. However, it still remains to be ascertained whether somaclonal variation differs between callus-derived chromosome-doubled and undoubled regenerants. Our research aimed at investigating, through amplified fragment length polymorphism (AFLP) markers, the genetic changes in marker-banding patterns of diploid and tetraploid regenerants obtained from one clone each of Solanum bulbocastanum Dunal and S. cardiophyllum Lindl (both 2n = 2x = 24) and tetraploids from cultivated S. tuberosum L. (2n = 4x = 48). Pairwise comparisons between the banding patterns of regenerants and parents allowed detecting considerable changes associated to in vitro culture both at diploid and tetraploid level. The percentages of polymorphic bands between diploid and tetraploid regenerants were, respectively, 57 and 69% in S. bulbocastanum and 58 and 63% in S. cardiophyllum. On average, the frequencies of lost parental fragments in regenerants were significantly higher than novel bands both in S. bulbocastanum (48 vs. 22%) and S. tuberosum (36 vs. 18%) regenerants. By contrast, in S. cardiophyllum, a similar incidence of the two events was detected (32 vs. 29%). Our results revealed that structural changes after tissue culture process strongly affected the genome of the species studied, but diploid and tetraploids regenerated plants responded equally.

• Korean Journal of Plant Resources
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• v.21 no.1
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• pp.60-65
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• 2008

Kalopanax pictus was cultured in vitro to find out optimal condition for embryogenic cells proliferation in liquid media rapidly. Embryogenic cells were induced from leaves and petiols of Kalopanax pictus. Optimum culture medium appeared to be a 1/2MS medium supplemented with 2.0mg/L 2,4-D and 0.1mg/L BA. To find out optimal conditions, embryogenic cells were cultured some condition as different concentrations of 2,4-D, medium and sucrose. There was cultured on 1/2MS liquid medium containing different concentration of 2,4-D. When embryogenic cells were cultured on 1/2MS liquid medium supplemented with 1.0mg/L 2,4-D, cell propagation rate was higher than other concentration of 2,4-D. When embryogenic cells were cultured on different media that MS, Gambols B5, N6, White, SH medium, observed the highest multiplication rate among Gambols B5 and White medium. To find out of effect of sucrose to embryogenic cells propagation, we tested cells under different concentrations. Optimal concentration of sucrose appeared to be a basal medium added 3% sucrose. Above results suggest that optimal conditions for proliferation of embryogenic cells were established Gambols B5 and White medium added 1.0mg/L 2,4-D and 3% sucrose. There is every possibility achieving embryogenic cells proliferation via bioreactor culture system in Kalopanax pictus.

• Korean Journal of Plant Tissue Culture
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• v.22 no.5
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• pp.299-306
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• 1995

The objective of this study is to establish an efficient celll culture system for somatic embryogenesis in Ostericum koreanum and Angelica purpuraefolia. The highest frequency of embryogenic callus on immature seeds of O. konanum and A, purpuraefolia. was obtained when seeds were cultured on MS medium containing 0.1 mg/L 2,4-D and 0.1 mg/L BA. However somatic embryos were formed directly from the edge of cotyledon and hypocotyl of plant which regenerated on medium supplemented with 0.1-3.0 mg/L NAA. Immature seed explane cultured at 25$\pm$2$^{\circ}C$ after 10 days treatment at 5$^{\circ}C$ produced embryogenic callus and somatic embryos, and these differentiated into whole plane. Addition of glutamine and coconut milk to media did not enhance the frequency of somatic embryogenesis in immature seed cultures of A. purpuraefolia. However in immature seed culture of O. koreanum, the frequency of somatic embryogenesis were increased on media supplemented with glutamine and 10% coconut milk. Especially addition of glutamine to the medium substituted effect of NH$_4$N0$_3$ in constast to coconut milk. The highest frequency of conversion somatic embryos into plantlet was 89.1% on MS basal medium Embryogenic calli were grown vigorously when maintained on medium with 0.01 mg/L 2,4-D and 0.01 mg/L BA.

• Molecules and Cells
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• v.25 no.2
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• pp.231-241
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• 2008

Indole glucosinolates (IG) play important roles in plant defense, plant-insect interactions, and stress responses in plants. In an attempt to metabolically engineer the IG pathway flux in Chinese cabbage, three important Arabidopsis cDNAs, CYP79B2, CYP79B3, and CYP83B1, were introduced into Chinese cabbage by Agrobacterium-mediated transformation. Overexpression of CYP79B3 or CYP83B1 did not affect IG accumulation levels, and overexpression of CYP79B2 or CYP79B3 prevented the transformed callus from being regenerated, displaying the phenotype of indole-3-acetic acid (IAA) overproduction. However, when CYP83B1 was overexpressed together with CYP79B2 and/or CYP79B3, the transformed calli were regenerated into whole plants that accumulated higher levels of glucobrassicin, 4-hydroxy glucobrassicin, and 4-methoxy glucobrassicin than wild-type controls. This result suggests that the flux in Chinese cabbage is predominantly channeled into IAA biosynthesis so that coordinate expression of the two consecutive enzymes is needed to divert the flux into IG biosynthesis. With regard to IG accumulation, overexpression of all three cDNAs was no better than overexpression of the two cDNAs. The content of neoglucobrassicin remained unchanged in all transgenic plants. Although glucobrassicin was most directly affected by overexpression of the transgenes, elevated levels of the parent IG, glucobrassicin, were not always accompanied by increases in 4-hydroxy and 4-methoxy glucobrassicin. However, one transgenic line producing about 8-fold increased glucobrassicin also accumulated at least 2.5 fold more 4-hydroxy and 4-methoxy glucobrassicin. This implies that a large glucobrassicin pool exceeding some threshold level drives the flux into the side chain modification pathway. Aliphatic glucosinolate content was not affected in any of the transgenic plants.

• Journal of Plant Biotechnology
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• v.34 no.4
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• pp.355-361
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• 2007

Cotyledons of perilla6 were cultured on MS medium containing 0.5 mg/l NAA and 0.5 mg/l BA for 7 weeks. The activity of perilla peroxidase was observed to increase following culture stages as assessed by peroxidase assay. A peroxidase (POD) was purified from perilla tissue cultured on MS medium for 7 weeks. The peroxidase was purified using ion exchange and gel nitration chromatography. The perilla peroxidase had a molecular mass of 30 kDa by SDS-PAGE. We showed that the N-terminal amino acid sequence of this protein shared 67% identity with the tea peroxidase. As indicated by SDS-PAGE, the banding pattern of the 30 kDa polypeptide present in total soluble protein from perilla tissue was increased following culture stages. Immunoblot analysis indicated that perilla peroxidase protein appeared after 3 weeks of perilla tissue culture, and continued to increase with extended duration of tissue culture for at least 7 weeks.

• Advances in Traditional Medicine
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• v.9 no.2
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• pp.174-181
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• 2009

Pterocarpus marsupium, Clitoria ternatea, and Sanseveiria cylindrica are some of the important and endangered medicinal plant species of India. Despite of medicinal properties, antibacterial potential of the plants have not yet been explored. The present study was designed to optimize the in vitro technique for micropropagation and to screen the extracts from leaves and in vitro raised calli for antibacterial properties. Excised leaf-explants from the parent plants were surface sterilized and cultivated on Murashige & Skoog's (MS) medium containing $N^6$-benzyladenine (BA) in concentrations of 1, 2, 5, and $10{\mu}M$. Optimal growth of calli was noticed at a concentration of $5{\mu}M$, therefore the extracts from calli grown at this concentration were further studied for antibacterial activity. Both alcoholic and aqueous extracts from leaves of respective plants, and their in vitro raised calli were tested for antibacterial activity by agar well diffusion method against a range of Gram-positive and Gram-negative bacteria. Aqueous extracts showed antibacterial activity against limited number of bacterial species; notably the extracts of C. ternatea which showed antibacterial activity against Streptococcus pyogenes, Bacillus subtilis and Bacillus cereus. Alcoholic extracts of all three plants showed antibacterial activity against a wider range of bacteria. Among the Gram-positive bacteria, extracts from C. ternatea showed strong antibacterial activity against Bacillus spp., whereas the extracts of S. cylindrica showed good antibacterial potential for Staphylococcus aureus, S. epidermidis and S. pyogenes. The extracts from all three plants showed antibacterial activity against Gram-negative bacteria, including, Salmonella spp. and Shigella dysenteriae; organisms causing enteric fever and dysentery. In most of the cases, the extracts from respective calli showed comparable, and in some cases better, result in comparison to the extracts from parent leaves. To the best of our knowledge this is the first preliminary report on antibacterial potential, especially through calli extracts, of these plants; and in vitro cultivation of the explants may be used to obtain phytotherapeutic compounds.

• Korean Journal of Plant Tissue Culture
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• v.27 no.3
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• pp.163-167
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• 2000

This study was carried out to identify varietal difference and the inheritance of the ability of plant regeneration in anther culture of rice. The anthers of 33 Japonica, 11 Indica/Japonica, and 3 Indica rice cultivars were culture on $N_6-Y$_1$$ medium with 1 mg/L NAA and 2 mg/L kinetin. The remarkable variability in plant regeneration were observed among the genotypes, ranging from 0.0% to 19.4% Most of Japonica rices were resulted to have better culturability than that of Indica/Japonica and Indica type cultivars. Newly developed Japonica rices, 'Ilmibyeo' and 'Hangnambyeo' showed to have regenerability with the frequency of 19.4% and 18.1% respectively. The segregation mode for callus formation and plant regenerationin anther culture of F$_2$ population of 'Milyang 23/Chucheongbyeo' showed a continuous variation. The variation of plant regeneration frequency in anther culture of F$_2$ plants ranged from 0% to 33.3% with a mean of 6.3% The broad-sense heritability estimated from the ability of plant regeneration was considerably high (82.7%).