• Journal of Life Science
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• v.26 no.10
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• pp.1163-1168
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• 2016

Plant growth-promoting rhizobacteria (PGPR) have gained worldwide importance and acceptance due to their agricultural benefits. These microorganisms are potential tools for sustainable agriculture, with effects on plant growth, biofertilization, induced systemic resistance, and biocontrol of plant pathogens. In this study, four different Pantoea species were isolated from field soil, and their plant growth-promoting characteristics were studied. Based on 16S rDNA gene sequencing analyses, the se were grouped into Pantoea ananatis, Pantoea citrea, Pantoea dispersa, Pantoea vagans and named as Pa1, Pc1, Pd1, Pv1, respectively. All of these strains have their ability for solubilization of insoluble phosphate depending on pH decrease at the range around pH 5 at 1days after inoculation and production of plant hormone indole acetic acid (IAA) with 85.3±16.3 μg/ml of Pa1, 183.9±16.8 μg/ml of Pc1, 28.8±17.3 μg/ml of Pd1 and 114.1±16.5 μg/ml of Pv1, respectively. Pa1, Pc1 and Pd1 also have high activity for production of gibberellin (GA₃) hormone with 331.1±19.2 μg/ml of Pa1, 288.5±16.8 μg/ml of Pc1, 309.2±18.2 μg/ml of Pd1, but Pv1 does not. Furthermore, all these species have significantly promoted the growth of the lettuce seedling plants at the range around 32~37% for fresh weight and 10~15% for shoot length enhancement, so that these microbe could be used as a potential bio-fertilizer agents.

• Applied Biological Chemistry
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• v.47 no.1
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• pp.17-21
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• 2004

This study was investigated the physiological properties of auxin-producing bacteria that have plant growth promoting activity and plant pathogen antagonistic ability. Auxin-producing bacteria were isolated from field soils of Gyeongsan, Korea. Selected strains were identified as a Pseudumonas fulva N21 and a Pantoea agglomerans; K35 by morphological and physiological test, and Biolog (Microlog) system. Auxins were determined by Salkowski in vitro test and mungbean adventitious root induction bioassay. Also produced indole-3-acetic acid (IAA) was identified by TLC. During cell growth, auxin production were highest in their idiophase after log phase and $35^{\circ}C$ at pH 7.5.

• Journal of Life Science
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• v.31 no.7
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• pp.641-653
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• 2021

The purpose of this study was to confirm the antifungal activity, plant growth-promoting activity, and mineral solubilizing activity of 18 types of bacteria isolated purely from rhizosphere soil. The potential of isolates of the genus Bacillus and Pseudomonas as biocontrol agents was confirmed through the antifungal activity of these isolates. This activity has been determined to be due to various hydrolytic enzymes on the cell wall of plant pathogenic fungi and the production of siderophores in isolates. In addition, most of the isolates have been found to have aminocyclopropane-1-carboxylate deaminase production activity, indole-3-acetic acid production activity, and nitrogen fixation activity. These characteristics are believed to have a positive effect on root development, growth, and the productivity of crops via a reduction in the concentration of ethylene under conditions of environmental stress, to which plants are commonly exposed. In addition, on testing for the solubilizing activity of the isolates for phosphoric acid, silicon, calcium carbonate, and zinc, some isolates were found to have mineral solubilizing activities. Inoculation of these isolates during plant growth is expected to assist plant growth by converting nutrients necessary for growth into usable forms that can be absorbed by plants. The 18 isolated strains can be used as biocontrol agents due to their antifungal activity, plant growthpromoting activity, and mineral solubilizing activity.

• Korean Journal of Plant Resources
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• v.14 no.2
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• pp.108-115
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• 2001

For determining the effect of extracts exudated from ten industrial plant resources on germination and early growth of shoot and root of radish the allelopathic compounds screened. Germination rate and seedling growth of radish differed depending on plant species and extract concentration. Lower levels of 1% extracts exudated from industrial plant resources promoted the rate of germination of radish while higher levels of 10% extract inhibited the rate of germination. Germination rate, shoot growth and root growth of radish in higher concentration of extract also differed depending on the plant species exudated and extract concentraton of industrial plant resources. Higher concentration of extracts from Xanthium strutnarium L. Angellica gigas Nakai, and Solanum nigrum L. were completely inhibited the germination while those from Cichorium intybus L., and Polygonatum officinale Allioni were not inhibited. Extracts exudated from Xanthium strutnarium L, Angellica gigas Nakai, and Solanum nigrum L. showed the strong inhibition of shoot and root growth of radish while those from Cichorium intybus L., and Polygonatum officinale Allioni did not show the bioactivity in shoot and root growth of radish..

• Korean Journal of Organic Agriculture
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• v.22 no.2
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• pp.321-334
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• 2014

This study was conducted to identify plant growth promoting effects of native plant resources and medicinal plants. 65 kinds of plant extracts from 64 species were evaluated based on two rice(Oryza sativa) seedling bioassays for gibberellins and gibberellin-like substances. 12 extracts of Artemisia princeps stem and leaf, Cirsium japonicum var. maackii whole plant, Rhododendron mucronulatum branch and leaf, Phragmites communis stem, Coix lacryma-jobi var. mayuen whole plant, Lespedeza bicolor branch and leaf, Hydrangea serrata f. acuminata whole plant, Phlomis umbrosa whole plant, Glycyrrhiza uralensis Rhizome, G. uralensis stem and leaf, Angelica gigas root, and Cnidium officinale rhizome showed growth promotion of rice seedlings. Our results suggested that the parts of these plants could be the potential sources as farm-made liquid fertilizers for plant growth promotion.

• Microbiology and Biotechnology Letters
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• v.36 no.4
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• pp.268-275
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• 2008

In order to develop the multi-functional rhizobacteria that can exert positive effect on the growth of plants growing in the coastal sand dune located along East Coast of Korea, rhizospheral bacteria of 11 different plants from this area were isolated 1,330 rhizobacteria. Among these, 23 strains were able to produce auxin and had spectrum of antagonism toward various phytopathogenic microbes. To know the mechanism of this antifungal activity, these 23 strains were subjected to further analyses; 19 strains of these produced siderophore as determined by color reaction on CAS-blue plate, 4 strains produced antifungal cellulase as judged by color change on CMC-Congo red plate, 17 strains were able to utilized insoluble phosphate salts, also determined by clear zone formation on PVK medium. Identification of the strain was assigned to all 23 strains by l6s rDNA sequence analysed, and all were identified to be in the genus of Bacillus and Pseudomonas. One strain of these, denoted Pseudomonas fluorescens IB4-14, showed ACC deaminase activity which is known to be involved in the resistance of environmental stress such as salt and drought. Also, P. fluorescens IB4-l4 showed the germination stimulation and roots growth promoting activity on the in vivo assay of Lysimachia mauritiana Lam. (spoonleaf yellow loosestrife).

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2002.11a
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• pp.233-240
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• 2002

식물체내에 미량으로 생성되어 식물체내의 생리적인 작용을 크게 변화시켜 식물의 생장과 발육을 촉진 또는 억제하는 생장조절물질의 종류로는 Auxin, Cytokinin, Gibberellin, Abscisic acid, Ethylene, Brassinosteroids, Polyamine, Jasmonates 등이 있다(byun, 1982). Gibberellin은 포도의 경우 씨 없는 포도(무핵과)를 만드는 기술이 델라웨어 품종을 주축으로 실용화 되어있고(Weaver, 1972) 배의 행수와 신고 품종에서는 Gibberelli paste처리에 으해 5∼7일의 숙기 촉진과 함께 과중의 비대에 효과가 있으나 이러한 Gibberellin 계통의 식물생장조절제 사용으로 과실의 경도가 낮아지고 부패과, 밀병 및 분질화 등의 생리장해가 발생하고 보구력이 크게 떨어지는 단점이 있다. (중략)

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.55-55
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• 2018

본 연구는 상추 '피델'을 이용한 완전제어형 식물공장에서의 재배를 하기 위해 기존의 배양액에 생육 촉진용 AMG의 농도를 구명하고 그에 맞는 매뉴얼을 확립하기 위해 실시하였다. 실험은 기존 배양액에 AMG(고활성 칼슘용액+복합 활성 미네랄)를 추가하였으며 '피델'의 생육에 적합한 AMG의 농도는 0, 0.05, 0.1, 0.2%를 양액에 추가하여 5반복 4처리로 진행하였다. 생육 조사 항목은 초폭, 초장, 엽장, 엽폭, 엽록소, 생체중을 조사하였다. '피델'의 생장에서 초폭, 엽폭, 엽장은 3주차부터 생장량이 급증하였으며 AMG 4처리구 5주차 조사에서는 초폭 평균 335g, 357g, 369g, 381g을 나타냈으며 엽폭은 평균 168g, 191g, 202g, 208g, 엽장 평균 129g, 134g, 144g, 144g으로 조사되었다. AMG 농도 0.1~0.2%는 통계적으로 생장 촉진 효과가 나타났으나 유의차가 크지 않아 0.1% AMG가 적정한 것으로 판단되었다. 엽록소 함량의 경우 정식 2주차 이후서부터는 SPAD 평균 29~32로 기록되어 엽록소함량은 크게 변화하지 않았다. 또한 엽수의 증가폭에 비해 생체중의 증가폭이 컸으며 생체중의 경우 정식 3주부터 5주 사이에 생체중이 5배 이상 급증하는 생장 패턴을 나타내었다. 5주차 생체중에서는 0% AMG의 경우 평균 82g, 0.05% AMG는 평균 85g, 0.1% AMG는 평균 115g, 그리고 0.2% AMG는 평균 114g으로 조사되었다. 따라서 0.1~0.2% AMG에서는 차이가 없게 나타남에 따라 생장촉진을 위해서는 0.1% AMG를 추가하는 것이 적정하다고 판단되었다.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.57-57
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• 2018

본 연구는 상추 '피델'을 이용한 완전제어형 식물공장에서의 재배를 하기 위해 기존의 배양액에 생육 촉진용 AMG의 농도를 구명하고 그에 맞는 매뉴얼을 확립하기 위해 실시하였다. 실험은 기존 배양액에 AMG(고활성 칼슘용액+복합 활성 미네랄)를 추가하였으며 '피델'의 생육에 적합한 AMG의 농도는 0, 0.05, 0.1, 0.2%를 양액에 추가하여 5반복 4처리로 진행하였다. 생육 조사 항목은 초폭, 초장, 엽장, 엽폭, 엽록소, 생체중을 조사하였다. '피델'의 생장에서 초폭, 엽폭, 엽장은 3주차부터 생장량이 급증하였으며 AMG 4처리구 5주차 조사에서는 초폭 평균 335g, 357g, 369g, 381g을 나타냈으며 엽폭은 평균 168g, 191g, 202g, 208g, 엽장 평균 129g, 134g, 144g, 144g으로 조사되었다. AMG 농도 0.1~0.2%는 통계적으로 생장 촉진 효과가 나타났으나 유의차가 크지 않아 0.1% AMG가 적정한 것으로 판단되었다. 엽록소함량의 경우 정식 2주차 이후서부터는 SPAD 평균 29~32로 기록되어 엽록소함량은 크게 변화하지 않았다. 또한 엽수의 증가폭에 비해 생체중의 증가폭이 컸으며 생체중의 경우 정식 3주부터 5주 사이에 생체중이 5배 이상 급증하는 생장 패턴을 나타내었다. 5주차 생체중에서는 0% AMG의 경우 평균 82g, 0.05% AMG는 평균 85g, 0.1% AMG는 평균 115g, 그리고 0.2% AMG는 평균 114g으로 조사되었다. 따라서 0.1~0.2% AMG에서는 차이가 없게 나타남에 따라 생장촉진을 위해서는 0.1% AMG를 추가하는 것이 적정하다고 판단되었다.

• Korean Journal of Plant Resources
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• v.1 no.1
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• pp.48-52
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• 1988

In order to examine the effect of growth regulators on flower bud formation and anthesis, various growth regulators were applied during the initiation and growthstages of flower bud development in Camellia. The inhibitor CCC increased flowerbud formation. But gibberellin had a strong suppressing effect of flower budformation while it stimulated elongatien of shoots. On the other hand, gibberellinpromoted the growth of flower buds and hastened anthesis, while other growthregulators had no effect.