• 한국약용작물학회지
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• 제25권2호
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• pp.95-101
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• 2017

Background: Callus cultivation has the advantage of producing a large amount of tissue of a plant in a laboratory regardless of the environment, for extracting an active substance. In the present study, callus formation was induced in the leaves of the succulent plant Adenium obesum (Forssk.) Roem & Schult. After callus cultivation, anti-inflammatory activity tests were conducted, because leaves and stems of A. obesum have been reported to possess biological activity. Methods and Results: In order to induce callus formation, various concentrations of plant growth factors, such as kinetin, naphtha-leneacetic acid (NAA), 6-benzyladenine (BA), and indole-3-acetic acid (IAA) were added to MS solid medium. The maximum callus proliferation was induced by mixed medium consisting of NAA ($2mg/{\ell}$) and BA ($1mg/{\ell}$). In addition, an elicitor was added to the medium under optimal conditions for initiating suspension culture. After suspension culturing, the activities of the callus extracts were compared and analyzed. The cytotoxicity and anti-inflammatory activity tests revealed that the anti-inflammatory activity of the callus extract and the content of phenolic compounds were elevated after treatment of the callus culture with the elicitior. Conclusions: A. obesum callus might be considered as potential source of biologically active anti-inflammatory material.

• Journal of Microbiology and Biotechnology
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• 제20권11호
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• pp.1577-1584
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• 2010

In total, 140 halotolerant bacterial strains were isolated from both the soil of barren fields and the rhizosphere of six naturally growing halophytic plants in the vicinity of the Yellow Sea, near the city of Incheon in the Republic of Korea. All of these strains were characterized for multiple plant growth promoting traits, such as the production of indole acetic acid (IAA), nitrogen fixation, phosphorus (P) and zinc (Zn) solubilization, thiosulfate ($S_2O_3$) oxidation, the production of ammonia ($NH_3$), and the production of extracellular hydrolytic enzymes such as protease, chitinase, pectinase, cellulase, and lipase under in vitro conditions. From the original 140 strains tested, on the basis of the latter tests for plant growth promotional activity, 36 were selected for further examination. These 36 halotolerant bacterial strains were then tested for 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity. Twenty-five of these were found to be positive, and to be exhibiting significantly varying levels of activity. 16S rRNA gene sequencing analyses of the 36 halotolerant strains showed that they belong to 10 different bacterial genera: Bacillus, Brevibacterium, Planococcus, Zhihengliuella, Halomonas, Exiguobacterium, Oceanimonas, Corynebacterium, Arthrobacter, and Micrococcus. Inoculation of the 14 halotolerant bacterial strains to ameliorate salt stress (150 mM NaCl) in canola plants produced an increase in root length of between 5.2% and 47.8%, and dry weight of between 16.2% and 43%, in comparison with the uninoculated positive controls. In particular, three of the bacteria, Brevibacterium epidermidis RS15, Micrococcus yunnanensis RS222, and Bacillus aryabhattai RS341, all showed more than 40% increase in root elongation and dry weight when compared with uninoculated salt-stressed canola seedlings. These results indicate that certain halotolerant bacteria, isolated from coastal soils, have a real potential to enhance plant growth under saline stress, through the reduction of ethylene production via ACC deaminase activity.

• 한국작물학회지
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• 제48권1호
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• pp.38-43
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• 2003

Immature and mature embryos of 18 Korean wheat genotypes were cultured in vitro to develop an efficient method of callus formation and plant regeneration, and to compare the responses of both embryo cultures. Immature and mature embryos were placed on a solid agar medium containing the MS salts and vitamins, 30g/l maltose, 2 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D), and amino acids. The developed calli were maintained on regeneration medium containing MS salts and B5 vitamins, 20 g/l sucrose, and the combination of two plant growth regulators, 6-benzylaminopurine (BAP) and indole-3-acetic acid (IAA). Immature embryos in most genotypes showed high efficiency of callus induction except three genotypes; Eunpamil, Chunggemil, and Namhaemil, and significant differences among the genotypes. Plant regeneration of calli induced from immature embryos showed high efficiency in Geurumil (56.5%), Tapdongmil (50.5%), Gobunmil (45.5%), and Urimil(42.2%). The analysis of variance showed significant differences for regeneration frequency among the genotypes. Mature embryos showed low callus induction frequency compared with that in immature embryos, and significant differences among the genotypes. Plant regeneration of calli induced from mature embryos showed high efficiency in Keumkangmil (33.33%), Tapdongmil(28.13%), and Geurumil (27.78%). The analysis of variance showed significant differences for plant regeneration frequency among the genotypes.

• 환경생물
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• 제39권3호
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• pp.354-361
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• 2021

본 연구는 식물검역 분야에서 주요하게 사용되고 있는 메틸브로마이드 훈증제로 인해 발생하는 약해를 저감하기 위한 물질을 모델식물인 애기장대를 이용하여 스크리닝하였다. 사전연구를 통하여 메틸브로마이드 훈증제의 식물 독성 메커니즘으로 활성산소발생와 식물 성장 호르몬인 옥신의 식물체 내 분배억제효과가 발생하는 것을 바탕으로 하여, 약해 저감물질후보군으로 활성산소를 제거하는 역할을 하는 ROS scavenger 2종(NAC, GSH)과 옥신을 훈증제 처리 전 애기장대에 처리한 후 약해의 저감 정도를 육안평가와 더불어 관련 유전자의 발현을 확인하였다. 연구 결과 메틸브로마이드에 의해 유도된 약해는 옥신보다는 활성산소를 저감시키는 물질후보군들에서 약해 저감효과가 나타났다. 이 중 GSH을 이용하여 농도구배하여 전처리하였을 때, 5 mM GSH 전처리 후 메틸브로마이드 훈증시 약해 저감효과가 두드러졌다. GSH 전처리 시 식물체 내에 MBF1c와 HSP70 유전자 발현이 증가하는 것을 확인하였으며, 이는 메틸브로마이드 훈증으로 유도되는 약해를 방어하는 역할을 담당하였을 것이라고 평가된다. 따라서, 식물검역 훈증제 메틸브로마이드에 의해 발생하는 약해를 저감하는 데 GSH의 사용가능성을 평가하였으며, 이를 기반으로 다양한 식물체에 적용하여 수출입 시 약해로 인한 경제적 손실을 감소시킬 수 있기를 기대한다.

• 환경생물
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• 제29권2호
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• pp.92-97
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• 2011

수경재배와 토양재배를 통해 키운 토란이 생리 형태학적으로 어떤 차이가 나는지 조사하였다. Hoa.+IAA를 처리한 수경재배는 질석, Hoa., 토양, 물에서 키운 토란보다 약 9%, 32%, 38% 및 60% 생장이 각각 촉진되었다. 물에서 재배한 토란은 5~6주 생장한 후의 $F_v/F_m$값이 0.54와 0.55를 나타내어 $F_v/F_m$값이 0.8 이상을 보인 Hoa.+IAA, 질석과 토양에 비해 약 32.5% 낮았다. Hoa.+IAA 처리구에서는 가장 낮은 확산저항이 나타났으며 5주와 6주 때는 물로 수경재배한 것에 비해 45~35% 낮았다. 이는 기공 열림이 물로 재배한 것에 비해 45~35% 크게 열렸다고 추측할 수 있다. 질석과 토양에서 자란 토란도 물로 재배한 것에 비해 39~31%와 27~35% 확산저항이 낮았다. 따라서 생장률의 크기, 광합성 활성 및 기공열림은 Hoa.+IAA, 질석, Hoagland 용액, 토양과 물 순으로 낮게 나타났다. IAA를 Hoagland 용액에 넣어 수경재배한 실험 결과에서 생장률과 형광 활성도가 가장 높았으며 확산저항 또한 가장 낮게 나타났다. 토양재배에서 점토와 상토를 포함하는 흙은 질석에서 키운 토란에 비해 뿌리 발달이 저조하였다. 화분 속의 흙은 중력에 의해 시간이 지날수록 단단해졌으나 질석은 흙과의 마찰이 비교적 적기 때문에 수염뿌리와 실뿌리가 잘 생장하였다. 화분에서 키운 토란은 종아와 뿌리가 같이 발달하였으나 종아는 하나만 관찰되었다. 반면에, 야외에서 키운 토란은 30~40개의 종아가 뚜렷하게 발달하여 작물로서의 가치가 충분하였으나 수경재배한 토란은 종아가 분해되어 사라지고 수염뿌리가 발달하였다.

• Journal of Microbiology and Biotechnology
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• 제30권5호
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• pp.668-680
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• 2020

Bacillus velezensis is an important plant growth-promoting rhizobacterium with immense potential in agriculture development. In the present study, Bacillus velezensis Lle-9 was isolated from the bulbs of Lilium leucanthum. The isolated strain showed antifungal activities against plant pathogens like Botryosphaeria dothidea, Fusarium oxysporum, Botrytis cinerea and Fusarium fujikuroi. The highest percentage of growth inhibition i.e., 68.56±2.35% was observed against Fusarium oxysporum followed by 63.12 ± 2.83%, 61.67 ± 3.39% and 55.82 ± 2.76% against Botrytis cinerea, Botryosphaeria dothidea, and Fusarium fujikuroi, respectively. The ethyl acetate fraction revealed a number of bioactive compounds and several were identified as antimicrobial agents such as diketopiperazines, cyclo-peptides, linear peptides, latrunculin A, 5α-hydroxy-6-ketocholesterol, (R)-S-lactoylglutathione, triamterene, rubiadin, moxifloxacin, 9-hydroxy-5Z,7E,11Z,14Z-eicosatetraenoic acid, D-erythro-C18-Sphingosine, citrinin, and 2-arachidonoyllysophosphatidylcholine. The presence of these antimicrobial compounds in the bacterial culture might have contributed to the antifungal activities of the isolated B. velezensis Lle-9. The strain showed plant growth-promoting traits such as production of organic acids, ACC deaminase, indole-3-acetic acid (IAA), siderophores, and nitrogen fixation and phosphate solubilization. IAA production was accelerated with application of exogenous tryptophan concentrations in the medium. Further, the lily plants upon inoculation with Lle-9 exhibited improved vegetative growth, more flowering shoots and longer roots than control plants under greenhouse condition. The isolated B. velezensis strain Lle-9 possessed broad-spectrum antifungal activities and multiple plant growth-promoting traits and thus may play an important role in promoting sustainable agriculture. This strain could be developed and applied in field experiments in order to promote plant growth and control disease pathogens.

• 식물병연구
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• 제24권3호
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• pp.221-232
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• 2018

근권세균은 식물 생육과 건강 증진에 중요한 역할을 하며 생물학적 스트레스뿐만 아니라 저온, 고온, 건조 및 염과 같은 비생물적 스트레스에도 내성을 부여한다. 본 연구는 토마토에 생물적 및 비생물적 스트레스를 완화시키는 기능을 가진 식물생장촉진 근권세균(plant growth promoting rhizobacteria, PGPR)을 선발하는 것을 목표로 하였으며 토마토 근권에서 Variovorax sp. PMC12균주를 분리하였다. PMC12균주는 in vitro에서 PGPR의 특성으로 알려진 암모니아, IAA, 시드로포아 및 ACC 탈아민효소를 생성하였다. PMC12 균주를 처리한 토마토는 대조구에 비해 염, 저온 및 건조 스트레스 조건에서 지상부 생체중이 유의적으로 높았다. 또한 PMC12 균주를 처리한 토마토는 Ralstonia solanacearum에 의한 세균성 시들음병에 대한 저항성이 증가되었다. 결과적으로 PMC12 균주는 식물의 비생물적 스트레스 및 생물적 스트레스에 대한 감수성을 감소시키는 유망한 생물학적 방제제 및 생물활성제로 사용될 수 있을 것으로 전망된다.

• 한국미생물·생명공학회지
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• 제49권3호
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• pp.391-402
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• 2021

Earthworms play an important role in soil fertilization, interacting continually with microorganisms. This study aims to demonstrate the existence of beneficial microorganisms living in the earthworm's immune system, the coelomic fluid. To achieve this goal, a molecular identification technique was performed, using cytochrome c oxidase I (COI) barcoding to identify abundant endogenic earthworms inhabiting the temperate zone of Rabat, Morocco. Then, 16S rDNA and ITS sequencing techniques were adopted for bacteria and fungi, respectively. Biochemical analysis, showed the ability of bacteria to produce characteristic enzymes and utilize substrates. Qualitative screening of plant growth-promoting traits, including nitrogen fixation, phosphate and potassium solubilization, and indole acetic acid (IAA) production, was also performed. The result of mitochondrial COI barcoding allowed the identification of the earthworm species Aporrectodea molleri. Phenotypic and genotypic studies of the sixteen isolated bacteria and the two isolated fungi showed that they belong to the Pseudomonas, Aeromonas, Bacillus, Buttiauxella, Enterobacter, Pantoea, and Raoultella, and the Penicillium genera, respectively. Most of the isolated bacteria in the coelomic fluid showed the ability to produce β-glucosidase, β-glucosaminidase, Glutamyl-β-naphthylamidase, and aminopeptidase enzymes, utilizing substrates like aliphatic thiol, sorbitol, and fatty acid ester. Furthermore, three bacteria were able to fix nitrogen, solubilize phosphate and potassium, and produce IAA. This initial study demonstrated that despite the immune property of earthworms' coelomic fluid, it harbors beneficial microorganisms. Thus, the presence of resistant microorganisms in the earthworm's immune system highlights a possible selection process at the coelomic fluid level.

• Journal of Microbiology and Biotechnology
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• 제17권8호
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• pp.1361-1368
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• 2007

Endophytic bacteria associated with the roots of coastal sand dune plants were isolated, taxonomically characterized, and tested for their plant growth-promoting activities. Ninety-one endophytic bacterial isolates were collected and assigned to 17 different genera of 6 major bacterial phyla based on partial 16S rDNA sequence analyses. Gammaproteobacteria represented the majority of the isolates (65.9%), and members of Pseudomonas constituted 49.5% of the total isolates. When testing for antagonism towards plant pathogenic fungi, 25 strains were antagonistic towards Rhizoctonia solani, 57 strains were antagonistic towards Pythium ultimum, 53 strains were antagonistic towards Fusarium oxysporum, and 41 strains were antagonistic towards Botrytis cinerea. Seven strains were shown to produce indole acetic acid (IAA), 33 to produce siderophores, 23 to produce protease, 37 to produce pectinase, and 38 to produce chitinase. The broadest spectra of activities were observed among the Pseudomonas strains, indicating outstanding plant growth-promoting potential. The isolates from C. kobomugi and M. sibirica also exhibited good plant growth-promoting potential. The correlations among individual plant growth-promoting activities were examined using phi coefficients, and the resulting data indicated that the production of protease, pectinase, chitinase, and siderophores was highly related.

• Journal of Plant Biology
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• 제36권4호
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• pp.391-398
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• 1993

식물에서도 동물에서와 같이 RGD(Arg-Gly-Asp) sequence를 매개로 원형질막과 extracellular matrix(ECM)가 연결되어 있다는 사실이 알려지고 있으므로 RGD sequence가 식물세포의 생장, 분화 등의 여러 가지 생리적인 현상에 관여하리라는 가능성을 생각할 수 있다. 그래서 RGD sequence가 당근(Daucus carota L.) 배양세포에서 에틸렌 생성에 미치는 영향을 조사하였다. RGD sequence를 포함하는 합성 peptide는 당근 배양세포에서 에틸렌의 생성을 촉진시켰다. RGD peptide는 Indole-3-acetic acid(IAA)와 함께 처리한 경우 에틸렌 생성을 더욱 촉진시켰으며, ACC synthase의 활성도 증가시켰다. RGD sequence가 에틸렌 생성을 촉진시킬 때 어떠한 특이성이 있는가를 확인하기 위해 이와 유사한 RGE(Arg-Gly-Glu) peptide, RGK(Arg-Gly-Lys) peptide를 각각 처리하여 보았다. RGE peptide는 RGD peptide와 마찬가지로 에틸렌 생성을 촉진시켰으나 RGK peptide는 에틸렌 생성에 영향을 미치지 않았다. 따라서 RGD peptide의 에틸렌 생성 촉진작용은 RGD dequence를 포함하는 RGD peptide가 ACC synthase의 활성을 증가시켜서 일어나는 현상이라 생각되며, 또한 특정한 아미노산 서열을 요구하는 특이적 반응이라고 생각된다.