• Korean Journal of Microbiology
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• v.49 no.4
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• pp.398-402
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• 2013

This study was to investigate beneficial effects of microbial mixture on red pepper which was capable of promoting plant growth by solubilizing insoluble phosphate as well as protecting plants from pathogenic attack. Saccharomyces sp. L13 was isolated for phosphate solubilizing activity on aluminium phosphate, tricalcium phosphate, calcium hydrophosphate, and magnesium hydrophosphate. On the other hand, Bacillus sp. L32 was isolated for antagonistic activity against Phytophthora capsisi and Colletotrichum gloeosporioides, causing Phytophthora blight and Anthracnose disease in pepper, respectively. The strain L32 exhibited antagonistic activities both under dual culture assays and detached leaves assays. The each strain under the condition of mixed cultivation exhibited the same growth rates as one under pure cultivation. In greenhouse study, the mixed culture showed the both effect of plant growth promotion and reduction of disease symptom development against P. capsisi and C. gloeosporioides providing a potential as effective microbial agent for plant husbandry.

• The Korean Journal of Pesticide Science
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• v.20 no.1
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• pp.47-55
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• 2016

The purpose of this study was to control root-knot nematode, Meloidogyne incognita on pumpkin seedling with 10%, 20% coffee ground compost and 1% plant velvet bean powder (plain skin bean, leopard skin bean, hole plant, bean pod). Among the root-knot nematode insecticide treatments, the velvet bean plant powder was the highest mortality rate with 83.2% in greenhouse condition. In addition, the root-knot nematode second juvenile mortality significantly increased with the lapse of processing time for each concentration of leopard skin velvet bean extract in vivo. After 24 hours, the mortality rate of root-knot nematode showed the highest at 1.2% and 2.4% of leopard skin velvet bean extract. The growth promoting effect of seedlings pumpkin, 20% of coffee ground compost treatments inhibited the growth of pumpkin seedlings and 1% the tiger pattern velvet beans powder was the most to promote the growth of pumpkin seedlings. However, the results indicated that the organic materials of velvet beans and coffee ground compost are expected to be able to effectively control the root-knot nematode and further studies will be needed for the concentration and application methods.

• Preventive Nutrition and Food Science
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• v.7 no.3
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• pp.332-345
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• 2002

It is a recent observation that about 80 per cent of the body's immune system is localized in the gastrointestinal tract. This explains to a large extent why eating right is important for the modulation the immune response and prevention of disease. In addition it is increasingly recognized that the body has an important digestive system also in the lower gastrointestinal tract where numerous important substances are released by microbial enzymes and absorbed. Among these substances are short chain fatty acids, amino acids, various carbohydrates, poly-amines, growth factors, coagulation factors, and many thousands of antioxidants, not only traditional vitamins but numerous flavonoids, carotenoids and similar plant- and vegetable produced antioxidants. Also consumption of health-promoting bacteria (probiotics) and vegetable fibres (prebiotics) from numerous sources are known to have strong health-promoting influence. It has been calculated that the intestine harbours about 300,000 genes, which is much more than the calculated about 60,000 for the rest of the human body, indicating a till today totally unexpected metabolic activity in this part of the GI tract. There are seemingly several times more active enzymes in the intestine than in the rest of the body, ready to release hundred thousand or more of substances important for our health and well-being. In addition do the microbial cells produce signal molecules similar to cytokines but called bacteriokines and nitric oxide, with provide modulatory effects both on the mucosal cells, the mucosa- associated lymphoid system (MALT) and the rest of the immune system. Identification of various fermentation products, and often referred to as synbiotics, studies of their role in maintaining health and well-being should be a priority issue during the years to come.

• Proceedings of the Korean Society of Food Science and Nutrition Conference
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• 2001.12a
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• pp.187-231
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• 2001

It is a recent observation that about 80 per cent of the body's immune system is localized in the gastrointestinal tract. This explains to a large extent why eating right is important for the modulation the immune response and prevention of disease. I addition it is increasingly recognized that the body has an important digestive system also in the lower gastrointestinal tract where numerous important substances are released by microbial enzymes and absorbed. Among these substances are short chain fatty acids, amino acids, various carbohydrates, polyamines, growth factors, coagulation factors, and many thousands of antioxidants, not only traditional vitamins but numerous flavonoids, carotenoids and similar plant- and vegetable produced antioxidants. Also consumption of health-promoting bacteria (probiotics) and vegetable fibres (prebiotics) from numerous sources are known to have strong health-promoting influence. It has been calculated that the intestine harbours about 300 000 genes, which is much more than the calculated about 60000 for the rest of the human body, indicating a till today totally unexpected metabolic activity in this part of the GI tract. There are seemingly several times more active enzymes in the intestine than in the rest of the body, ready to release hundred thousand or more of substances important for our health and well-being. In addition do the microbial cells produce signal molecules similar to cytokines but called bacteriokines and nitric oxide, with provide modulatory effects both on the mucosal cells, the mucosa-associated lymphoid system (MALT) and the rest of the immune system. Identification of various fermentation products, and often referred to as synbiotics, studies of their role in maintaining health and well-being should be a priority issue during the years to come.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.1
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• pp.51-58
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• 2012

Salinity is one of the most relevant abiotic factor limiting crop yield and its net primary productivity. In addition, salinity induces an increased stress ethylene synthesis in plants which, in turn, exacerbate the responses to the stressor. Bacterial single or co-inoculation effect was tested using previously characterized plant growth promoting (PGP) bacteria Brevibacterium iodinum RS16 and Methylobacterium oryzae CBMB20 on maize and sorghum-sudan grass hybrid under different concentrations of NaCl. Non-inoculated maize and sorghum-sudangrass hybrid showed 33.4% and 20.0% reduction in seed germination under highest NaCl (150 mM) level tested. However, under the same NaCl concentration, co-inoculation with B. iodinum RS16 and M. oryzae CBMB20 PGP strains increased the seed germination in maize (16.7%) and sorghum-sudangrass hybrid (4.4%). In Gnotobiotic growth pouch experiments conducted for maize and sorghum-sudangrass hybrid, co-inoculation of PGP B. iodinum RS16 and M. oryzae CBMB20 mitigated the salinity stress and promoted root length by 22.9% and 29.7%, respectively. Thus the results of this study could help in development of potential bioinoculants that may be suitable for crop production under saline conditions.

• Korean Journal of Environmental Biology
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• v.17 no.1
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• pp.11-15
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• 1999

To investigate the stimulating effects of the low- dose radiation, the seeds of chinese cabbages (Brassica campestris L. cv. Hanyoreum and cv. Tropic emperor) were irradiated at the dose of 0.5 Gy~20 Gy with the ${\gamma}$-ray radition. In case of ‘Hanyoreum’cultivar, there were no significant promoting effects on the germination rate except the 0.5 Gy irradiated group. The increase in seedling height and fresh weight in 8 Gy and 12 Gy irradiated groups was 20% and 40%, respectively, which suggested the stimulating effect of the low-dose radiation on the early growth. In case of‘Tropic emperor’cultivar, the germination rate of 1 Gy irradiated group increased approximately 10% and the seedling height and fresh weight of 1 Gy and 12 Gy irradiated group in the greenhouse 20% on the average, and plant height and fresh weight of 0.5 Gy and 4 Gy irradiated group in the field increased 10% and 20% on the average, respectively.

• Molecules and Cells
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• v.44 no.11
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• pp.830-842
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• 2021

When perceiving microbe-associated molecular patterns (MAMPs) or plant-derived damage-associated molecular patterns (DAMPs), plants alter their root growth and development by displaying a reduction in the root length and the formation of root hairs and lateral roots. The exogenous application of a MAMP peptide, flg22, was shown to affect root growth by suppressing meristem activity. In addition to MAMPs, the DAMP peptide PEP1 suppresses root growth while also promoting root hair formation. However, the question of whether and how these elicitor peptides affect the development of the vascular system in the root has not been explored. The cellular receptors of PEP1, PEPR1 and PEPR2 are highly expressed in the root vascular system, while the receptors of flg22 (FLS2) and elf18 (EFR) are not. Consistent with the expression patterns of PEP1 receptors, we found that exogenously applied PEP1 has a strong impact on the division of stele cells, leading to a reduction of these cells. We also observed the alteration in the number and organization of cells that differentiate into xylem vessels. These PEP1-mediated developmental changes appear to be linked to the blockage of symplastic connections triggered by PEP1. PEP1 dramatically disrupts the symplastic movement of free green fluorescence protein (GFP) from phloem sieve elements to neighboring cells in the root meristem, leading to the deposition of a high level of callose between cells. Taken together, our first survey of PEP1-mediated vascular tissue development provides new insights into the PEP1 function as a regulator of cellular reprogramming in the Arabidopsis root vascular system.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.6
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• pp.447-453
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• 2007

With a broad objective for the development of microbial based fertilizers, a total of 373 strains were isolated from rhizoplane and rhizosphere of pepper, tomato, lettuce, pasture, and grass. The efficacy of the isolates to augument overall plant growth was evaluated. After screening for their plant growth promotion and antagonistic properties in vitro efficient strains were further selected. The most efficient strains was characterized by 16S rRNA gene sequences and biochemical techniques and was designated as Bacillus subtilis S37-2. The strains facilitated plant growth and inhibited the plant phathogenic fungi such as Fusarium oxysporum (KACC 40037, Rhizoctonia solani (KACC 40140), and Sclerotinia sclerotiorum (KACC 40457). Pot based bioassay using lettuce as test plant was conducted by inoculating suspension ($10^5$ to $10^8cells\;mL^{-1}$) of B. subtilis S37-2 to the rhizosphere of lettuce cultivated in soil pots. Compared with non-inoculated pots, marked increase in leaf (42.3%) and root mass (48.7%) was observed in the inoculation group where the 50ml of cell mixture ($8.7{\times}10^8cells\;ml^{-1}$) was applied to the rhizosphere of letuce either once or twice. Antagonistic effects of B. subtilis S37-2 strain on S. sclerotiorum (KACC 40457) were tested. All the tested lettuce plants perished after 9 days in treatment containing only S. sclerotiorum, but only 17% of lettuce was perished in the inoculation plot. B. subtilis grew well in the TSB culture medium. The isolates grew better in yeast extracts than peptone and tryptone as nitrogen source. The growth rate was 2~4 times greater at $37^{\circ}C$ as compared with $30^{\circ}C$ incubation temperature. B. subitlis S37-2 produced $0.1{\mu}g\;ml^{-1}$ of IAA (indole 3-acetic acid) in the TSB medium containing L-tryptophan($20mg\;L^{-1}$) in 24 hours.

• The Korean Journal of Mycology
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• v.44 no.1
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• pp.36-47
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• 2016

This study was conducted to evaluate five different strains of rhizobacterial isolates viz. PA1, PA2, PA4, PA5 and PA12 for biological control against Colletotrichum acutatum, C. coccodes, C. gloeosporioides, C. dematium, Botrytis cinerea, Rhizoctonia solani, Sclerotinia minor and Fusarium sp. In vitro inhibition assay was performed on three different growth mediums, potato dextrose agar (PDA), tryptic soy agar (TSA), and PDA-TSA (1:1 v/v) for the selection of potential antagonistic isolates. According to the result, isolate PA2 showed the highest inhibitory effect with 65.5% against C. coccodes on PDA and with 96.5% against S. minor on TSA. However, the same isolate showed the highest inhibition with 58.5% against C. acutatum on PDA-TSA. In addition, an in vivo experiment was performed to evaluate these bacterial isolates for biological control against fungal pathogens. Plants treated with bacteria were analyzed with phytopathogens and plants inoculated with phytopathogens were treated with isolates to determine the biological control effect against fungi. According to the result, all five isolates tested showed inhibitory effects against phytopathogens at various levels. Mode of action of these rhizobacterial isolates was evaluated with siderophore production, protease assay, chitinase assay and phosphate solubilizing assay. Bacterial isolates were identified by 16S rDNA sequencing, which showed that isolates PA1 and PA2 belong to Bacillus subtilis, whereas, PA4, PA5, and PA12 were identified as Bacilus altitudinis, Paenibacillus polymyxa and Bacillus amyloliquefaciens, respectively. Results of the current study suggest that rhizobacterial isolates can be used for the plant growth promoting rhizobacteria (PGPR) effect as well as for biological control of various phytopathogens.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.2
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• pp.141-148
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• 1992

Field experiment was carried out to investigate the effect of plant growth regulator (PGR); IAA, GA, Kinetin to regrowth of sorghum and pearlmillet according to variety and plant growth stage. Kinetin application after cut increased tiller number and decreased dry weight of regrowth, but its application on sorghum stubble in water stress increased tiller number and leaf elongation rate, consequently increased regrowth dry weight. GA application reduced tiller production in both species, but tiller formation in pearlmillet was decreased more than in sorghum by promoting leaf elongation of old tiller. Nonstructural carbohydrate (NSC) of stubble during regrowth was consumed less at anthesis than at stem elongation stage because of senescence of tiller primordia. GA treatment reduced NSC content more than other PGR in both plant species, by consuming reserve NSC and stimulating rapid elongation of old tiller after cut. Dry matter increase during regrowth had high correlation with tiller number and tiller elongation a week after cut, while it did not have any correlation with NSC at cutting stage or with consumption of NSC during regrowth. Therefore, regrowth in sorghum and pearmillet must depend upon activity of tiller primordia more than upon amount of reserved NSC.