• Korean Journal of Environmental Agriculture
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• v.28 no.4
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• pp.447-452
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• 2009

A bacterium, which was named to be Bacillus cereus A-139, secreting auxin was isolated from the east coast sand dunes in Korea. The secretion of auxin was confirmed by HPLC. When cultured in LB broth, Bacillus cereus A-139 produced $16.12\;{\mu}$g/mL auxin after 8 days in LB broth. Bacillus cereus A-139 produced $49\;{\mu}$g/mL auxin and $162.6\;{\mu}$g/mL by the addition of 2% tryptone and 0.1% tryptophan, respectively. The root growth of Arabidopsis thaliana was retarded by Bacillus cereus A-139 culture broth up to 57% but the formation of lateral roots was increased up to almost twice after 4 days incubation. Also the formation of lateral roots of mung bean was increased up to 57% after 10 days incubation.

• Korean Journal of Plant Tissue Culture
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• v.27 no.6
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• pp.469-474
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• 2000

Effect of the antibiotic carbenicillin on callus and shoot formation from the leaf disc culture of tobacco (Nicotiana tabacum L. cv. BY-4) was examined. The number of shoot induced from the leaf explants was decreased as the amount of carbenicillin increased from 250 mg/L to 2,000 mg/L on MS medium containing 0.5 mg/L of BAP or kinetin. In addition, calli formation from the leaf explants was increased by the treatment of 250 mg/L ∼ 500 mg/L carbenicillin with or without 0.5 mg/L of 2,4-D or NAA. However, the fresh weight of 4-week-cultured explants was decreased with increasing carbenicillin from 250 mg/L to 2,000 mg/L on MS medium containing 0.5 mg/L of 2,4-D or NAA. These results indicate that carbenicillin has an auxin-like effect, such as promoting callus formation and inhibiting shoot induction. It leads to the conclusion that the auxin-like property should be taken into account for the production of transgenic plants via Agrobacterium-mediated transformation.

• Journal of Plant Biotechnology
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• v.29 no.2
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• pp.111-115
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• 2002

Taraxacum platycarpum has been used as a medicinal plant. We investigated optimal condition for efficient plant regeneration through adventitious shoot formation on medium with various kinds of growth regulators. Adventitious shoot formation was achieved when cytokinin was used alone. Shoot formation was higher on MS medium containing 2 mg/L BAP compared to that with 2 mg/L kinetin and 2 mg/L 2-ip. Among root, hypocotyl and cotyledon, roots were the best explant for the adventitious shoot induction. Adventitious shoot formation from roots declined markedly by the combination of both 0.1 mg/L NAA and 2 mg/L BAP, while shoot formation from cotyledons was stimulated by the same combination. Root formation from the regenerated shoots was achieved on 1/3MS medium containing 0.2 mg/L NAA. Regenerated plantlets was acclimatized and transplanted to the soil, showing 100% survival.

• Molecules and Cells
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• v.23 no.1
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• pp.115-121
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• 2007

Root nodule formation is controlled by plant hormones such as auxin. Auxin-repressed protein (ARP) genes have been identified in various plant species but their functions are not clear. We have isolated a full-length cDNA clone (EuNOD-ARP1) showing high sequence homology to previously identified ARP genes from root nodules of Elaeagnus umbellata. Genomic Southern hybridization showed that there are at least four ARP-related genes in the genome of E. umbellata. The cDNA clone encodes a polypeptide of 120 amino acid residues with no signal peptide or organelle-targeting signals, indicating that it is a cytosolic protein. Its cytosolic location was confirmed using Arabidopsis protoplasts expressing a EuNOD-ARP1:smGFP fusion protein. Northern hybridization showed that EuNOD-ARP1 expression was higher in root nodules than in leaves or uninoculated roots. Unlike the ARP genes of strawberry and black locust, which are negatively regulated by exogenous auxin, EuNOD-ARP1 expression is induced by auxin in leaf tissue of E. umbellata. In situ hybridization revealed that EuNOD-ARP1 is mainly expressed in the fixation zone of root nodules.

• Plant Resources
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• v.7 no.1
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• pp.60-64
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• 2004

The establishment of an efficient protocol for plant regeneration and micropropagation from leaf explant cultures of Chicory, Cichorium intybus L. var. sativus. is reported. Callus formation rate appeared 100% from explant in all growth regulators, but calli formed in the prensence of naphthaleneacetic acid (NAA) were appeared very compact and non-embryogenic state. The regenerated shoots were obtained from leaf explant cultures on solid MS medium containing different concentrations of cytokinins and auxin. The highest number of shoots (5.7) per explant and shoot growth (2.8cm) was obtained on MS medium containing 0.1 mg BAP L$^{-1}$ and 0.1 mg NAA L$^{-1}$ . Indole acetic acid was the most suitable auxin for root formation among three auxins tested. 2,4-D had no effect on shoot and root formation.

• Journal of Plant Biotechnology
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• v.4 no.1
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• pp.33-37
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• 2002

Micropropagation and adventitious root production via the culture of Polygonatum odoratum were performed. Stem segments of seedlings of Polygonatum odoratum were the most efficient explants for adventitious shoot formation compared to leaf and root segments. Exogenous cytokinin treatment was required for adventitious shoot formation. Among the cytokinin (BA, Kinetin and Zeatin) tested, BA was most effective for shoot formation from stem segments. Auxin (NAA or IBA) in combination with cytokinin significantly enhanced adventitious shoot formation. Twenty five percent of explants produced adventitious shoots on medium with 2.0 mg/L BAP alone, while 83% of explants produced adventitious shoots on medium with the combination of 2.0 mg/L BAP and 0.1 mg/L IBA. Rooting of adventitious shoots was achieved after transferring to 112 MS medium supplemented with 0.1 mg/L IBA and 0.5 mg/L zeatin. When stem segments were cultured on MS medium with various kinds of auxin (IBA, NAA and 2,4-D), adventitious roots were formed from callus. frequency of adventitious root formation was highest in 2,4-D than NAA and IBA. When roots were in clusters together with parental stem segments, growth of roots actively occurred in hormone-free MS liquid medium. The above results represent that possible application for the mass production of roots and plantlets through in vitro culture system of Polygonatum odoratum.

• Journal of Plant Biotechnology
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• v.47 no.3
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• pp.194-202
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• 2020

The sweetpotatoes (Ipomoea batatas) generate adventitious roots (ARs) from cut stems that develop into storage roots and make for an important means of propagation. However, few studies have investigated the hormones involved in AR development in sweetpotato. In this study, the expression patterns of hormone-related genes involved in AR formation were identified using the transcriptome data. RNA-seq data from stems grown for 0 and 3 days after cutting were analyzed. In addition, hormone-related genes were identified among differentially expressed genes (DEGs) and filtered genes, and cluster analysis was used to characterize expression patterns by function. Most hormone-related regulated genes expressed 3 days after growing the cut stems were abscisic acid (ABA)-related genes, followed by ethylene- and auxin-related genes. For ABA, the biosynthesis genes (including genes annotated to NINE-CIS-EPOXYCAROTENOID DIOXYGENASE 3 (NCED3)) and signal transduction and perception genes (including genes annotated to PROTEIN PHOSPHATASE 2Cs (PP2Cs)) tended to decrease. Expression patterns of auxin- and ethylene-related genes differed by function. These results suggest that ABA, auxin, and ethylene genes are involved in AR formation and that they may be regulated in a hormone function-dependent manner. These results contribute to the identification of hormone functions during AR formation and may contribute to understanding the mechanism of AR formation in the sweetpotato.

• Journal of The Korean Society of Grassland and Forage Science
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• v.15 no.2
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• pp.101-105
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• 1995

This experiment was conducted to determine factors affecting callus formation of some varieties of red clover. Growth regulators. basal medium, medium pH, agar concentration, and plant age for explant were investigated. The result obtained were as follows. As auxin source, 0.1 mg/ l picloram was found to be effective on callus formation. Callus formation was the highest on PC medium among several growth media. The callus produced on PC medium was more friable than those produced on the other media. The medium pH 5.8 gave the best response for callus formation. The effective seedling age for callus formatiom was around 5-7 days old. In agar concentration, 0.5-0.8%(WN) was suitable for callus formation.

• Korean Journal of Agricultural Science
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• v.13 no.2
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• pp.168-175
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• 1986

Leaf segments of tomato (Lycopersicum escullentum Mill) were cultured on the MS medium supplemented with the concentration of 0, 0.2, 0.5, 2.0 or $5.0mg/{\ell}$ NAA, 2,4-D and/or BA. The treatments were able to induced callus, however the best combinations for the induction of callus were $2.0mg/{\ell}$ BA and 2.0 or $0.5mg/{\ell}$ NAA. Shoot formation was stimulated at the treatment of 2.0 or $5.0mg/{\ell}$ BA, and root formation was stimulated on the medium of 0.2, 0.5, 2.0 or $5.0mg/{\ell}$ NAA plus 0, 0.2 or $0.5mg/{\ell}$ BA.

• The Korean Journal of Pesticide Science
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• v.15 no.4
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• pp.495-501
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• 2011

Bacterial strains were isolated from forest soils of Halla mountain, Jeju island in Korea. The soil samples were collected at each altitude of 100m from 1,000 m above sea level. Total 398 strains were isolated and tested for their physiological characteristics of antagonistic and proteolytic activities, and auxin production. Among the isolates, 172 strains were selected as antifungal strains showing antagonistic activity against at least one of 8 plant fungal pathogens (Alternaria alternata, Botrytis cinerea, Collectotrichum acutatum, Fusarium oxysporum, Phytophthora capsici, Pythium ultimum and Sclerotinia sclerotiorum). In addition 203 strains for proteolytic activity and 26 strains for auxin production were characterized for further study. Je28-4 (Rhodococcus sp.) were showed 80% of control value against tomato gray mold in vivo. Thus, it is suggested that soil bacteria isolated from forest soils of Halla mountain can be important sources of bioactive compounds for improving plant growth or promising biocontrol agents.