• The Plant Pathology Journal
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• 제34권4호
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• pp.286-296
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• 2018

Maintenance of a beneficial microbial community, especially in the rhizosphere, is indispensable for plant growth and agricultural sustainability. In this sense, plant growth-promoting rhizobacteria (PGPR) have been extensively studied for their role in plant growth promotion and disease resistance. However, the impact of introducing PGPR strains into rhizosphere microbial communities is still underexplored. We previously found that the Proteus vulgaris JBLS202 strain (JBLS202) promoted growth of Kimchi cabbage and altered the relative abundance of total bacteria and Pseudomonas spp. in the treated rhizosphere. To extend these findings, we used pyrosequencing to analyze the changes in bacterial communities in the rhizosphere of Kimchi cabbage after introduction of JBLS202. The alterations were also evaluated by taxon-specific realtime PCR (qPCR). The pyrosequencing data revealed an increase in total bacteria abundance, including specific groups such as Proteobacteria, Acidobacteria, and Actinobacteria, in the treated rhizosphere. Time-course qPCR analysis confirmed the increase in the abundance of Acidobacteria, Actinobacteria, Alphaproteobacteria, and Betaproteobacteria. Furthermore, genes involved in nitrogen cycling were upregulated by JBLS202 treatment indicating changes in ecological function of the rhizosphere soil. Overall, these results indicate that introduction of JBLS202 alters both the composition and function of the rhizosphere bacterial community, which can have direct and indirect effects on plant growth. Therefore, we propose that long-term changes in bacterial composition and community-level function need to be considered for practical use of PGPRs.

• Journal of Microbiology and Biotechnology
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• 제29권11호
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• pp.1777-1789
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• 2019

Drought is more concerned to be a huge problem for agriculture as it affects plant growth and yield. Endophytic bacteria act as plant growth promoting bacteria that have roles for improving plant growth under stress conditions. The properties of four strains of endophytic bacteria were determined under water deficit medium with 20% polyethylene glycol. Bacillus aquimaris strain 3.13 showed high 1-aminocyclopropane-1-carboxylate (ACC) deaminase production; Micrococcus luteus strain 4.43 produced indole acetic acid (IAA). Exopolysaccharide production was high in Bacillus methylotrophicus strain 5.18 while Bacillus sp. strain 5.2 did not show major properties for drought response. Inoculation of endophytic bacteria into plants, strain 3.13 and 4.43 increased height, shoot and root weight, root length, root diameter, root volume, root area and root surface of Jerusalem artichoke grown under water limitation, clearly shown in water supply at 1/3 of available water. These increases were caused by bacteria ACC deaminase and IAA production; moreover, strain 4.43 boosted leaf area and chlorophyll levels, leading to increased photosynthesis under drought at 60 days of planting. The harvest index was high in the treatment with strain 4.43 and 3.13 under 1/3 of available water, promoting tuber numbers and tuber weight. Inulin content was unchanged in the control between well-watered and drought conditions. In comparison, inulin levels were higher in the endophytic bacteria treatment under both conditions, although yields dipped under drought. Thus, the endophytic bacteria promoted in plant growth and yield under drought; they had outstanding function in the enhancement of inulin content under well-watered condition.

• 원예과학기술지
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• 제35권1호
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• pp.11-20
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• 2017

The objective of this study was to determine whether inoculation with Bacillus licheniformis MH48 as a plant growth-promoting rhizobacterium (PGPR) could promote nutrient uptake of seedlings of the ornamental plant Camellia japonica in the Saemangeum reclaimed coastal land in Korea. B. licheniformis MH48 inoculation increased total nitrogen and phosphorus content in soils by 2.2 and 20.0 fold, respectively, compared to those without bacterial inoculation. In addition, B. licheniformis MH48 produced auxin, which promoted the formation of lateral roots and root hairs, decreased production of growth-inhibiting ethylene, and alleviated salt stress. Total nitrogen and phosphorus uptake of seedlings subjected to bacterial inoculation was 2.3 and 3.6 fold higher, respectively, than the control. However, B. licheniformis MH48 inoculation had no significant effect on the growth of seedlings. Our results suggest that inoculation with B. licheniformis MH48 can be used as a PGPR bio - enhancer to stimulate fine root development, promote nutrient uptake and alleviate salt stress in ornamental plant seedlings grown in the high-salinity conditions of reclaimed coastal land.

• 한국식품과학회지
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• 제43권3호
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• pp.381-386
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• 2011

실험물질은 두피건강 및 발모에 유용한 소재를 혼합하여 열수 추출한 후 유산균에 발효시킨 2차 발효물질로서 고기능성이 예상되는 물질이다. C57BL/6 마우스의 등을 제모하고 실험물질을 처리하였을 때 암 수 모두에서 양성대조군인 minoxidil과 비교하였을 때 동등이상의 우수한 발모효과가 있음을 확인하였다. 특히 수컷의 경우 200 mg/kg 이하의 농도에서 우수한 효과가 관찰되었고 암컷에서는 고용량인 500 mg/kg까지 현저한 발모효과가 관찰되어 성별 처치 용량에 차이가 있는 것으로 사료되었다. 또한 양성대조군 minoxidil이 신속한 발모효과를 보이는 반면 털의 긁기가 감소하는 현상이 관찰되었으나 실험물질을 처리한 군에서는 제모전과 동등이상의 굵기를 유지하였다. 이러한 발모효과를 확인하기위해 모발성장관련 유전자 발현을 분석한 결과 실험물질이 KGF, VEGF 등의 모발성장촉진인자의 발현을 증가시키는 반면 탈모를 유도하는 $TGF{\beta}1$의 발현에는 반응을 하지 않아 유용한 발모제제로서의 가능성이 입증되었다. 더불어 실험물질에 의한 NO 분비가 두피의 혈류개선을 유도하여 탈모억제효능을 나타낼 것으로 사료되어 발효생약추출물인 MBN이 모발성장 및 탈모예방제제로의 개발이 가능 할 것으로 기대된다.

• 한국작물학회지
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• 제60권3호
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• pp.355-365
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• 2015

Environment-friendly growth enhancers for rice are being promoted to reverse the negative impact of intensive chemical-based and conventional rice farming on yield sustainability and environmental problems. Several rhizosphere microorganisms and pyroligneous acids (PA) had demonstrated beneficial influence on growth, yield and grain quality of rice. Since most of the previous study had evaluated the effect of PGPR and PA on paddy rice singly, the effect of combined application of these on the growth and yield of paddy rice and on some soil chemical properties were determined. A four factorial pot experiment was conducted to evaluate the effect of PGPR, PA in combination with fertilizers and on different soil types. There were 54 treatment combinations including the control with three replications under complete randomized design. Plant growth parameters were evaluated using standard procedures during tillering and heading stages. Rice yield and some soil chemical properties were determined at harvest. Results showed that inoculation of Bacillus licheniformis and Fusarium fujikuroi enhanced plant growth by increasing the plant height which could be ascribe to its ability to promote IAA and GA production in plants. Inoculation of Rhizobium phaseoli enhanced chlorophyll content indicative to its ability to improve the N nutrition. However, these plant growth benefits during the vegetative stage were override by the fertilizer application effect especially during the maturity stage and grain yield. High fertilization rates on coarse-textured soil without nutrient loss resulted to high available nutrients and consequently high yield. Wood vinegar application however improved nutrient availability in soil which could be beneficial for improving soil quality. Further evaluation is necessary to fully assess the potential benefits that could be derived from inoculation of these organisms and wood vinegar application in different soil environment especially under different field conditions.

• Journal of Plant Biotechnology
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• 제7권4호
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• pp.247-257
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• 2005

An efficient, rapid and large-scale in vitro clonal propagation of agronomically important Indian cereal crop genotypes (NSH27 & K5) of Sorghum bicolor (L.) Moench. by enhanced shoot proliferation in shoot tip segments was designed. MS medium fortified with plant growth regulators and coconut water markedly influenced in vitro propagation of Sorghum bicolor. In vitro plantlet production system has been investigated on Murashige and Skoog (MS) medium with the synergistic combination of 6-benzyladenine ($22.2\;{\mu}M$), kinetin ($4.6\;{\mu}M$), adenine sulphate ($2.8\;{\mu}M$), 5% coconut water and 3% sucrose which promoted the maximum number of shoots as well as beneficial shoot length. Subculturing of shoot tip segments on a similar medium enabled continuous production of more than 100 healthy shoots with similar frequency. When the healthy shoot clumps were cultured on MS medium fortified with 6-benzyladenine ($22.2\;{\mu}M$), kinetin ($4.6\;{\mu}M$), adenine sulphate ($2.8\;{\mu}M$), ${\alpha}$-naphthaleneacetic acid ($2.7\;{\mu}M$), ascorbic acid ($30.0\;{\mu}M$) and 5% coconut water, a rapid production of axillary and adventitious buds was developed after 8 wk culture. More than 300 shoots were produced 10 wk after culture. Rooting was highest (100%) on half strength MS medium containing 22.8 mM IAA. Micropropagated plants established in garden soil, farmyard soil and sand (2:1:1) were uniform and identical to the donor plant with respect to growth characteristics. These plants grew normally without showing any traits.

• Journal of Plant Biology
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• 제12권3호
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• pp.15-25
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• 1969

To investigate the radiation effect of P-32 on the soybean plants, the seeds treated with various levels of P-32 solution were sown and cultured in the pots. The growth of the plants and the contents of the macroelements were observed and the following results were obtained. 1) The linear growth of the plants at the early stage seemed to have been promoted by the low-level P-32 treatemnt. At the later growing stage, however, this difference among treatments were less conspicuous. 2) The plants of high level P-32 application showed some growth damaging symptom at the early growing stage. Later this damage was recorded as the time went on and these plants showed even better growth than the control. As a result at the late growing stage, they ensued highest growth. 3) The plants showed in general more growth at the low activity level than at the high-level at the early growing stage. At the late stage, however, the high-level activity promoted more growth than the low-level. 4) At the early growing stage P-32 treatment produced in general significantly more lower than control. At the later stage, however, this difference was not clearly seen. 5) The P-32 treatment seemed to have stimulated earlier florescence and this tendency was more clearly observable eapecially at the high activity level. 6) The weight of the air-dried seeds tended to be increased through P-32 treatment by 10-45%. This tendency was clearly observed especially at the low-level activity. 7) As for the contents of the various macroelements in the leaves, the nitrogen showed significantly larger contents at the middle level(S1) P-32 treatments. The phosphorous contents showed also highest at the middle levels activity and lower both at the high and low-activity levels. The potassium contents was proved, on the contrary, higher at the low-level activity and lower at the high-level. 8) The nitrogen contents in the stems was found significantly higher than control, except at the low-activity level. The phosphorous showed higher contents at the low-activity level and no significant difference at the high-activity level. As for the contents of potassium, calcium and magnesium, three seemed no significant difference among treatments. However, the magnesium showed somewhat higher content at the low-activity level, whereas the calcium was proved high than control. 9) The inorganic contents in the root showed that N and P in the P-32 treated plant were significantly higher than the control and the K-contents was, on the contrary, significantly higher at the control than the rest of the treatments. As for the calcium and magnesium there showed no difference among all treatments.

• Journal of Microbiology and Biotechnology
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• 제17권1호
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• pp.96-103
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• 2007

Plant growth-promoting rhizobacteria (PGPR) have the potential to be used as microbial inoculants to reduce disease incidence and severity and to increase crop yield. Some of the PGPR have been reported to be able to enter plant tissues and establish endophytic populations. Here, we demonstrated an approach to screen bacterial endophytes that have the capacity to promote the growth of pepper seedlings and protect pepper plants against a bacterial pathogen. Initially, out of 150 bacterial isolates collected from healthy stems of peppers cultivated in the Chungcheong and Gyeongsang provinces of Korea, 23 putative endophytic isolates that were considered to be predominating and representative of each pepper sample were selected. By phenotypic characterization and partial 16S rDNA sequence analysis, the isolates were identified as species of Ochrobacterium, Pantoea, Pseudomonas, Sphingomonas, Janthinobacterium, Ralstonia, Arthrobacter, Clavibacter, Sporosarcina, Acidovorax, and Brevundimonas. Among them, two isolates, PS4 and PS27, were selected because they showed consistent colonizing capacity in pepper stems at the levels of $10^6-10^7CFU/g$ tissue, and were found to be most closely related to Pseudomonas rhodesiae and Pantoea ananatis, respectively, by additional analyses of their entire 16S rDNA sequences. Drenching application of the two strains on the pepper seedlings promoted significant growth of peppers, enhancing their root fresh weight by 73.9% and 41.5%, respectively. The two strains also elicited induced systemic resistance of plants against Xanthomonas axonopodis pv. vesicatoria.

• 미생물학회지
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• 제50권4호
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• pp.368-371
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• 2014

염 스트레스를 비롯한 다양한 비생물학적 스트레스는 식물의 생장저해와 작물 생산량을 감소시키는 요인으로 작용한다. 계화도 간척지 토양에서 식물생장 촉진 세균을 분리하여 Pseudomonas sp. G19로 명명하였다. G19 균주는 36시간 배양 후 $7.5{\mu}g/ml$의 indole acetic acid를 생산하고 불용성인산을 25% 가용화시켰으며, 식물의 에틸렌 감소와 관련된 1-aminocyclopropane-1-carboxylate deaminase를 발현하였다. 또한 150 mM NaCl에 침지된 염 조건의 토양에서 재배된 유묘기 배추를 이용한 실증실험에서 G19 균주는 배추의 생체중량을 증가시킴으로써 염 스트레스의 경감 및 생장 촉진에 관여함을 알 수 있었다.

• Journal of Plant Biotechnology
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• 제43권4호
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• pp.438-443
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• 2016

The in vitro propagation of the commercially important Phalaeonopsis hybrid 'Little gem' was achieved by culturing the apical part and axillary buds excised from flower stalks. The explants were cultured on 5 different basal media: $3.0{\cdot}L^{-1}$ Hyponex and $4.0{\cdot}L^{-1}$ peptone ($H_3P_4$) and Murashige & Skoog (MS) media were shown to be suitable for shoot regeneration. The MS medium supplemented with $5.0mg{\cdot}L^{-1}$ 6-benzylaminopurine (BA) was found to be more efficient for shoot regeneration. However, the number of shoots induced by axillary buds was higher than that induced by the apical part. Incubation of the apical part under darkness for one week, as well as of the explants in the same medium with activated charcoal (AC) $0.5g{\cdot}L^{-1}$ promoted shoot regeneration and shoot growth; similar growth was not observed with axillary buds.