• Applied Biological Chemistry
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• v.11
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• pp.67-76
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• 1969

The reduced pressure storage of apple, American Summer Pairman, was investigated comparing with the other storage methods and the following results were obtained. 1. The reduced pressure storage was better to extend the storage life and freshness of apples than the controlled atomoshere storage. 2. Decreasing the pressure of chamber atmosphere to about 20 cmHg showed the best result among several pressure conditions. 3. As for the surface treatment of the apples, poly-ethylene film wrapping showed to be the most favorable method in a short-term experiment. In a long-term experiment, however, poly-ethylene film wrapping seemed to cause apples rot. Poly-vinyl acetate coating seemed to keep the apples from color changing, but it caused an unpleasant odor and a peculiar taste. No significant effect was observed in Gibberellin. 4. Total sugar and reduced sugar of apples were decreased after a certain period of increasing. Acid and Vitamin C, however, gradually decreased from the beginning of storage.

• The Korean Journal of Mycology
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• v.11 no.2
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• pp.79-84
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• 1983

To study physiological and ecological characters of the secondary mycelia of Armillariella mellea, it was cultivated on the various media. It was grown very well on the malt extract medium compared with its growth on yeast extract medium, potato dextrose medium and Hamada medium. The temperature of $27^{\circ}C$ gave the best condition for it to grow. The highest rate of growth was shown in medium of pH 6. Heteroauxin of 5 ppm concentration showed a increase as 26.2% in growth in compared with the control group. Gibberelline 10ppm, Tomatoton of 10,000 dilution and Adoton of 5,000 dilution showed positive effect. It was shown that the use of above hormones in appropriate concentration brought the effect of growth, but overuse of them brought inhibitory effect. Under the same condition of 200ppm concentration, vitamin A gave the highest growth of 18.2% than that of the control used.

• Korean Journal of Plant Resources
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• v.28 no.2
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• pp.253-258
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• 2015

In South Korea, Pinus pumila (Pall.) Regel (dwarf stone pine) has been designated as a critically endangered species by the Korea Forest Service. We have difficulties in obtaining the seeds of P. pumila because P. pumila grows only in the Daecheongbong area (1550–1700 m above sea level) of Mt. Seorak and almost all of its cones are damaged by birds and rodents. For establishing an ex situ conservation stand of P. pumila, this study was conducted to figure out the effects of wet cold (cold stratification, prechilling) and GA₃ treatment on the germination of P. pumila seeds. After cold stratification (1, 2, 3, 4, 5 months), prechilling (1, 2, 3, 4, 5 months) and GA₃ treatment (0, 100, 500, 1,000, 2,000, 3,000 ㎎/L), seeds were placed on petri-dishes at 25℃ under light condition. The percentage of germination, mean germination time and the germination rate were investigated. The results showed that both of the cold stratification and prechilling were effective in improving germination performances. However, there were no significant differences in performances between the two cold treatments. Within each treatment, the germination performances improved with the period of treatment. However, after three months of treatment, the performances showed no significant improvement. The gibberellin treatment was also effective in improving seed germination of P. pumila. The percentage of germination reached 79.0% in the seeds treated with 100 ㎎/L of GA₃. However, the germination performances decreased at high concentration of GA₃ treatments (over 2000 ㎎/L). In conclusion, cold stratification (over 3 months) or 100 ㎎/L of GA₃ treatment was considered to be the appropriate method for seedling production of P. pumila.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.3 no.4
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• pp.212-220
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• 2022

DNA markers have been studied and used intensively to identify plant species based on molecular approaches. The genus Medicago belongs to the family Fabaceae and contains 87 species distributed from the Mediterranean to central Asia. Five species of Medicago are known to be distributed in South Korea; however, their morphological characteristics alone cannot distinguish the species. In this study, we analyzed the phylogenetic relationships using collected five species of Medicago from South Korea and 44 taxa nucleotide information from NCBI. The constructed phylogenetic tree using gibberellin 3-oxidase 1 and tRNA^Lys (UUU) to maturase K gene sequences showed the monophyly of the genus Medicago, with five species each forming a single clade. These results suggest that there are five species of Medicago distributed in South Korea. In addition, we designed polymerase chain reaction primers for species-specific detection of Medicago by comparing the plastid sequences. The accuracy of the designed primer pairs was confirmed for each Medicago species. The findings of this study provide efficient and novel species identification methods for Medicago, which will assist in the identification of wild plants for the management of alien species and living modified organisms.

• Horticultural Science & Technology
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• v.16 no.1
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• pp.27-29
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• 1998

Artificial pollination (AP) and gibberellin A4+7 plus benzyladenine (promalin) were applied alone and together. AP was applied at 10% flowering time with 'Senshu' pollen (Malus domestica cv. Senshu). 12mg/L promalin was applied at 0, 10 and 20 days after falling of central flowers, respectively. In promalin treatment with or without AP application methods, fruit length, weight and length/diameter (L/D) were higher than those of control and AP. However, in AP and AP+ promalin application, the number of seeds and seed weight were higher than those of control and promalin. In AP+ promalin treatment, 78.6% fruits showed their uniform fruit shape and so significantly enhanced fruit uniformity compared to other treatments. Also cortex and core thickness of fruits were greater at the apex than that of other treatment. Fruit with L/D ratio over 0.87 were highly produced by applications of AP+promalin and promalin than control and AP only. 'Fuji' apples in good shape can be produced by using of AP + promalin together.

• Applied Biological Chemistry
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• v.40 no.6
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• pp.501-507
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• 1997

Chloroplasts isolated from Stevia rebaudiana Bertoni leaves contained an enzyme activity which catalyzed hydroxylation of ent-kaurenoic acid (ent-kaur-16-en-19-oic acid; ent-KA) to steviol (ent-13-hydroxy kaur-16-en-19-oic acid), the diterpenoid carboxylic alcohol which is the aglycone of sweet stevioside-related glycosides. $[^(14)C]-methylated$ ent-KA was used to localize ent-KA hydroxylase. $[^(14)C]-methyl-KA$ was most actively was transformed into methyl-steviol in chloroplast. The enzymatic activity was found in stroma fraction but not in thylakoid membrane in Stevia rebaudiana Bertoni. However, ent-KA 13-hydroxylase activity was not detected in stroma fraction of either Spinacia oleracea and Solidago altissima. The reaction products using $[^(14)C]-methyl-KA$ were purified and identified on TLC autoradiogram. The hydroxylation of ent-KA from stromal protein to form steviol required NADPH and oxygen. FAD and riboflavin stimulated the enzyme activity 1.5-and 1.7-fold, respectively. It also turned out that the activity of this enzyme using methyl-KA as a substrate was 16.7% that of ent-KA. The purified ent-KA 13-hydroxylase did not act on t-cinnamic acid, 4-hydroxyphenyl acetic acid, choline and resorcinol, known as monooxygenase and hydroxylase substrates.

• FLOWER RESEARCH JOURNAL
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• v.18 no.4
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• pp.256-260
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• 2010

This study was carried out to investigate effects of stock plant management and foliar spray of GA on the flower quality in hydroponically grown chrysanthemum 'Shinma'. In the growth and development as affected by stock plant management, cut flower length, petal number and cut flower weight were the best in the plot of long day and chilling treatment showed 114 cm, 298 and 102 g, respectively. Chlorophyll content(SPAD-value) was the highest in the plot of foliar spray of diluted Molbia(1 : 500). Flower quality according to concentration and spray time of gibberellin showed a different pattern. Cut flower length was the longest in the plot of solution diluted to 1 : 1,000 spraying before flowering at 60 days, petal number was the most in 1 : 500 at 60 days, and cut flower weight was the heaviest in 1 : 2,000 at 60 days, respectively. However, peduncle length was tended to be elongated with foliar spray of gibberellin solution diluted to 1 : 500 or 1 : 1,000 before flowering at 45 days.

• Journal of Plant Biology
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• v.21 no.1_4
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• pp.13-21
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• 1978

The effect of cyclic-AMP on the induction of acid phosphatase activity in barley aleurone layers was examined. Tannic acid was used as a inhibitor. Decursinol and coumarin were also used as a comparison. Maxiumu promotion of the enzyme activity was obtained with 10-5M cyclic-AMP, but this promotion was lower than that of 10-5M GAS induced enzyme activity in incubation medium. The inhibition rate in the addition of tannic acid was shown 17% and 63% at a ratio to GAs (by weight) of 10 : 1, and 58% and 94% at a ratio of 100 : 1 treated with GAs, and cyclic-AMP, respectively. The most potentiation of 10-6M GAS effect was induced by the additiion of suboptimal concentration (10-6M) of cyclic-AMP. Additional GAs and cyclic-AMP were shown the recovery of the enzyme activity inhibited by tannic acid. The combination with cyclic-AMP and theophylline enhanced the enzyme activity, too. Any other nucleotides tested except cyclic-AMP didn't show the action. There were no differences in acid phosphatase isozyme patterns by polyacrylamide disc electrophoresis, in conjunction with the different additions but the size of bands showed great differences. Especially, the 3rd band and the 5th band group were remarkable.

• Journal of Plant Biotechnology
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• v.48 no.3
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• pp.186-192
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• 2021

The roots of Korean ginseng (Panax ginseng) have a long history of usage as a medicinal drug. Ginsenosides, a group of triterpenioid saponins in ginseng, have been reported to show important pharmacological effects. Many studies have attempted to identify the ginsenoside synthesis pathways of P. ginseng and to increase crop productivity. Recent studies have shown that exogenous gibberellin (GA) treatments promote storage root secondary growth by integration of the modulating cambium stem cell homeostasis with a secondary cell wall-related gene network. However, the dynamic regulation of ginsenoside synthesis-related genes and their contents by external signaling cues has been rarely evaluated. In this study, we confirmed that GA treatment not only enhanced the secondary growth of P. ginseng storage roots, but also significantly enriched the terpenoid biosynthesis process in RNA-seq analysis. Consistently, we also found that the expression of most genes involved in the ginsenoside synthesis pathways, including those encoding methylerythritol-4-phosphate (MEP) and mevalonate (MVA), and the saponin content in both leaves and roots was increased by exogenous GA application. These results can be used in future development of biotechnology for ginseng breeding and enhancement of saponin content.

• Journal of Microbiology and Biotechnology
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• v.31 no.3
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• pp.408-418
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• 2021

The diversity and plant growth-promoting ability of fungal endophytes that are associated with five halophytic plant species (Phragmites australis, Suaeda australis, Limonium tetragonum, Suaeda glauca Bunge, and Suaeda maritima) growing in the Buan salt marsh on the west coast of South Korea have been explored. About 188 fungal strains were isolated from these plant samples' roots and were then studied with the use of the internal transcribed spacer (ITS) region (ITS1-5.8S-ITS2). The endophytic fungal strains belonged to 33 genera. Alternaria (18%) and Fusarium (12.8%), of the classes Dothideomycetes and Sordariomycetes, were most rampant in the coastal salt marsh plants. There was a higher diversity in fungal endophytes that are isolated from S. glauca Bunge than in isolates from other coastal salt marsh plants. Plant growth-promoting experiments with the use of Waito-C rice seedlings show that some of the fungal strains could encourage a more efficient growth than others. Furthermore, gibberellins (GAs) GA1, GA3, and GA9 were seen in the Sa-1-4-3 isolate (Acrostalagmus luteoalbus) culture filtrate with a gas chromatography/mass spectrometry.