• Korean Journal of Microbiology
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• v.46 no.1
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• pp.33-37
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• 2010

Rhizobacterial strain isolated from barren soil, Bacillus subtilis RFO41 exhibits a high level of phosphate solubilizing activity and produces some phytohormones. Its promoting effect on the growth of Xanthium italicum Moore, a wild plant growing at lakeside barren land and thus a good candidate plant for revegetation of barren lakeside was evaluated in the in situ test for 19 weeks at Lake Paro, Kangwon-do. Strain RFO41 could enhance the dry weight of X. italicum by 67.7%. It also increased the shoot length of X. italicum plant by 21.1% compared to that of uninoculated control. Both growth enhancements had statistical significance. However, the inoculation did not show any effect on the root growth, which might be due to the breakage of tiny root. Denaturing gradient gel electrophoresis analysis showed that the inoculated bacteria were maintained in the soils, and the indigenous bacterial community did not exhibit any significant change. This plant growth promoting capability may be utilized as an environment-friendly and low cost revegetation method, especially for the sensitive areas such as barren lakeside lands.

• 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.

• Journal of Ginseng Research
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• v.11 no.1
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• pp.77-83
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• 1987

The effects of ginseng saponin on the germination and early growth of rice seeds (Oryza sativa L.) were investigated. The early growth (length) of test rice seeds which were rinsed for 60 hrs in $10^{-4}$% saponin solution prior to transplantation to water agar bed was about 20% faster than that of control seeds, It was also found that the amylase activity of the seeds was most active when the seeds were rinsed in 10-4% saponin solution for 48 hrs. In vitro investigation showed that the amylase activities were stimulated about 30% by the treatment of $10^{-5}$% saponin solution compared with control group. From the above results, it seems that the ginseng saponin might activate amylase of rice seed during germination, resulting in rapid growth of rice.

• 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 Korean Society of Forest Science
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• v.28 no.1
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• pp.21-30
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• 1975

The purpose of this paper is to elucidate physiologically the cause of the hastening germination of dormant Taxus cuspidata seeds by stratification. During the stratification the exchange of chemical substances such as sugar, protein, starch and fat were observed, and growth promoting and inhibiting substances were extracted and seperated from seeds by the conventional chromatographic method with coleoptile straight-growth test. An intensive investigation was made on the balance between the promoters and inhibitors. consequently, it was confirmed that germination of seeds was accelerated with exchange of chemical substances by stratification. The results obtained may be summarized as follows: 1. During the stratification growth promoters were increased and growth inhibitors were decreased rapidly in the endosperm of seeds. Thus, it was presumed that hastening germination was controlled by balace between the promoters and inhibitors from November to next March after a year's stratification. On the other hand growth promoters were almost constant and growth inhibitors were decreased rapidly in the seed coats, and it was presumed that hastening germination was influenced by exchange of inhibitors more than by that of promoters. 2. As a results of germination test of lettuce seeds, it was generalized that hastening germination was controlled by a decreased amount of growth inhibitors more than by an increased amount of promoters. 3. During the stratification sugar and crude protein contents were increased gradully with moisture content, while starch and crude fat were decreased in endosperm of seeds. So it was assumed that the exchange of these chemical substances was closely related to the germination of seeds.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.4
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• pp.506-513
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• 2010

Plant growth promoting ability of Methylobacterium oryzae CBMB20 was evaluated under different levels of organic fertilizer application on red pepper plants in a pot experiment. Oil cake as an organic N fertilizer was applied at the rates of 70, 85, 100 and 120% of the conventional recommended level. Each treatment was further treated with or without M. oryzae CBMB20 inoculation. The recommended amount of compost for red pepper was added in all the treatments. Results revealed that plant height, dry biomass and fruit yield were enhanced in increasing order as the rate of fertilization increased. Overall plant growth was improved due to the inoculation of M. oryzae CBMB20 and red pepper fruit yield was also increased by 10-35% in the plants inoculated with M. oryzae CBMB20 at different rates of organic fert1izer application. Total methylotrophic bacterial population in rhizosphere soil measured at the time of harvest was significantly higher in M. oryzae CBMB20 inoculated treatments. The growth promoting effect of M. oryzae CBMB20 found in red pepper could be due to the effective colonization of the bacteria in the rhizosphere and its ability of enhancing nutrient availability and producing plant growth hormones. With the plant growth promoting effect of M. oryzae CBMB20, the rate of organic fertilizer application can be reduced without any significant decreases in biomass production and yield of red pepper.

• 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.

• Journal of Applied Biological Chemistry
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• v.66
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• pp.394-403
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• 2023

In the pursuit of sustainable and environmentally-friendly agricultural practices, we conducted an extensive study on the rhizosphere bacteria inhabiting soils that have been devoid of chemical fertilizers for an extended period exceeding 40 years. Through this investigation, we isolated a total of 80 species of plant growth-promoting rhizosphere bacteria and assessed their potential to enhance plant growth. Among these isolates, Burkholderia cepacia CD2 displayed remarkable plant growth-promoting activity, making it an optimal candidate for further analysis. Burkholderia cepacia CD2 exhibited a range of beneficial characteristics conducive to plant growth, including phosphate solubilization, siderophore production, denitrification, nitrate utilization, and urease activity. These attributes are well-known to positively influence the growth and development of plants. To validate the taxonomic classification of the strain, 16S rRNA gene sequencing confirmed its placement within the Burkholderia genus, providing further insights into its phylogenetic relationship. To delve deeper into the potential mechanisms underlying its plant growth-promoting properties, we sought to confirm the presence of specific genes associated with plant growth promotion in CD2. To achieve this, whole genome sequencing (WGS) was performed by Plasmidsaurus Inc. (USA) utilizing Oxford Nanopore technology (Abingdon, UK). The WGS analysis of the genome of CD2 revealed the existence of a subsystem function, which is thought to be a pivotal factor contributing to improved plant growth. Based on these findings, it can be concluded that Burkholderia cepacia CD2 has the potential to serve as a microbial fertilizer, offering a sustainable alternative to chemical fertilizers.

• Korean Journal of Microbiology
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• v.43 no.4
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• pp.279-284
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• 2007

Two bacterial strains isolated from soil (Bacillus subtilis strains: PS2 and RFO41) were evaluated to determine their promoting effect on the growth of tomato seedling under axonic and pot conditions. The production of phytohormone, such as indole-3-acetic acid, indole-3-butyric acid, gibberellin and zeatin by these two strains was investigated as possible mechanisms for plant growth stimulation. Both PS2 and RFO41 were shown to produce various phytohormones, and. the production of phytohormones was stimulated by the addition of peptone-rich brain heart broth medium. In addition, these bacteria exhibited high levels of phosphatase activity, which ranged from 2.18 to $2.7\;{\mu}\;{\rho}-nitrophenol/ml/hr$. PS2 and RFO41 were applied to the pot test for growth of tomato seed with phosphate. Root and shoot lengths of germinated tomato after 15 days were 45.5% and 36.5% longer than that of control in RFO41 treated samples, respectively. Baciller sp. PS2 and RFO41 may have a potential for biofertilizer in the agriculture.