• Korean Journal of Microbiology
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• v.50 no.4
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• pp.302-307
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• 2014

Many rhizobacteria can promote plant growth through various direct or indirect mechanisms, and their production of phytohormones such as indole-3-acetic acid (IAA) may have pronounced effects on growth and development of plants. Rhizobacterial strain isolated from rhizosphere of foxtail (Setaria viridis), Acinetobacter sp. SW5 produced 118.1 mg/L of IAA and 4.5 mg/L of gibberellin ($GA_3$) in brain heart broth medium at 2 and 1 day of incubation, respectively. In a pot test the lengths of stem and root and fresh weight of the germinated tomato seedlings treated with Acinetobacter sp. SW5 significantly increased by 26.3, 33.3, and 105.3%, respectively compared to those of the uninoculated control in 12 weeks of cultivation. When the root exudate secreted from tomato seedlings was analyzed by HPLC, 3.75 ng mg tomato $root^{-1}$ of tryptophan which is an IAA precursor was detected. Acinetobacter sp. SW5 could produce $4.06{\mu}M$ of IAA from root exudate from 8 tomato seedlings. Together with the capability of growth of Acinetobacter sp. SW5 in the tomato root exudates, this IAA secreted by bacteria might contribute to enhance the growth of tomato plants.

• Applied Biological Chemistry
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• v.32 no.2
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• pp.162-169
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• 1989

Tryptophan, indole-3-acetaldehyde, indole-3-acetic acid(IAA), and indole-3-aldehyde were identified as endogenous IAA analogues in etiolated pea(Pisum sativum L. var. 'Sparkle') shoots, which suggests a metabolic sequence(s) of tryptophan${\rightarrow}$(?)${\rightarrow}$indole-3-acetaldehyde${\rightarrow}$IAA${\rightarrow}$indole-3-aldehyde occurring in pea plants. IAA-rhamnose and IAA-glucose were tentatively confirmed as IAA conjugates.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.1
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• pp.96-104
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• 2010

A comparative study was performed in gnotobiotic and greenhouse conditions to evaluate the effect of exogenous application of indole-3-acetic acid (IAA) and inoculation of Methylobacterium spp. possessing 1-aminocyclopropane-1-carboxylate deaminase (ACCD) and IAA activity on red pepperand tomato seedling growth and development. Application of 1.0 ${\mu}g\;mL^{-1}$ IAA positively influenced root growth while high concentrations (>10.0 ${\mu}g\;mL^{-1}$) suppressed root growth of red pepper and tomato under gnotobiotic condition. On the other hand, inoculation of Methylobacterium strains with ACCD activity and IAA or without IAA enhanced root growth in both plants. Similarly, under greenhouse condition the inoculation of Methylobacterium sp. with ACCD activity and IAA enhanced plant fitness recorded as average nodal length and specific leaf weight (SLW) but the effect is comparable with the application of low concentrations of IAA. Seedling length was significantly increased by Methylobacterium strains while total biomass was enhanced by Methylobacterium spp. and exogenous applications of < 10.0 ${\mu}g\;mL^{-1}$ IAA. High concentrations of IAA retard biomass accumulation in red pepper and tomato. These results confirm that bacterial strains with plant growth promoting characters such as IAA and ACCD have characteristic effects on different aspects of growth of red pepper and tomato seedlings which is comparable or better than exogenous applications of synthetic IAA.

• Korean Journal of Microbiology
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• v.10 no.3
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• pp.117-127
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• 1972

To study the effect of IAA on the growth of Chlorella, the alage wre cultured on the media for six days by bubbling $_{2}$ enriched air under 10K lux at 20-$25^{\circ}C$. The culture media were made by adding a concentration of $10^{-3}$M, $10^{-4}$M, and 0M(as a control) IAA to the standard media. During the period of culture, Chlorella was smapled for the given time of interval and photosynthetic and respiratory activities were measured by Warburg manometer and change of chemical components of Chlorella was determined by spectrophotometry after the Chlorella cell was fractionated by Schmidt-Thannhauser method. 1) Photosynthetic and respiratory activities were enhanced by IAA ; especially the enhancement of respiratory activity was so remarkable. 2) As to the chemical components of Chlorella, carbohydrates and amino acids were reduced a little but phosphate, RNA, DNA, and protein were increased by $10^{-3}$M IAA ; the increase of RNA, in particular, was noticable. 3) The above results suggest that the enhancement of growth of Chlorella, by IAA and ATP induced by respiratory activity accelerated with IAA enhanced RNA synthesis, resulting in an increase of protein synthesis.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.6
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• pp.386-391
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• 2006

This study was conducted to evaluate the indole acetic acid (IAA) formation in soils as a biological indicator for the health of rice paddy soils with control, nitrogen sole, chemical fertilizer (NPK), and chemical fertilizer plus compost (CNPK) plots. There was a positive relationship between colorimetric method and high performance liquid chromatography for IAA in soils determined, and the values were similar between two methods, as $0.83{\sim}1.23{\mu}g\;IAA\;g^{-1}h^{-1}$ in colorimetric method, $0.80{\sim}1.29{\mu}g\;IAA\;g^{-1}h^{-1}$ in HPLC method. Numbers of dehydrogenase-producing bacteria and the IAA production in soils were high in NPK and CNPK plots comparing with control and nitrogen sole plots. Also there was high correlation between numbers of dehydrogenase-producing bacteria and IAA production in soils.

• Proceedings of the SCSK Conference
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• 2003.09a
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• pp.617-629
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• 2003

A recent development in cosmetics has been the pursuit of wrinkling in the skin. The cosmetics composed of anti-wrinkle agent stand out from the point of view of environmental contamination and pollution. Among them, Indole-3-acetic acid (IAA), studied with wrinkling pigmentation and swelling conditions in the area of the eye, showed clinically significant reduction in depth of lines during one month trial using skin treatment. But, IAA has shown some problems when used in cosmetic formulations, such as stability, permeability and toxicity. The results of the clinical examination were shown that its permeability and toxicity didn't matter. To increase the stability of IAA, antioxidants such as Licorice, ubiquinone, tocopherol, Baicalin, ferulic acid, BHT, ascorbic acid, sodium metabisulfite, and so on were employed in cosmetic formulations. Our main purpose is the study for the stability efficiency and effect of each other of cream formulations containing optimal dosage antioxidants (o/w type emulsion), This study evaluated wrinkle reduction effect of IAA, which is used in cosmetics.

• Journal of Microbiology and Biotechnology
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• v.18 no.7
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• pp.1235-1244
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• 2008

Indole-3-acetic acid (IAA) is produced commonly by plants and many bacteria, however, little is known about the genetic basis involving the key enzymes of IAA biosynthetic pathways from Bacillus spp. IAA intermediates from the Gram-positive spore-forming bacterium Paenibacillus polymyxa E681 were investigated, which showed the existence of only an indole-3-pyruvic acid (IPA) pathway for IAA biosynthesis from the bacterium. Four open reading frames (ORFs) encoding indole-3-pyruvate decarboxylase-like proteins and putative indole-3-pyruvate decarboxylase (IPDC), a key enzyme in the IPA synthetic pathway, were found on the genome sequence database of P. polymyxa and cloned in Escherichia coli DH5$\alpha$. One of the ORFs, PP2_01257, was assigned as probable indole-3-pyruvate decarboxylase. The ORF consisted of 1,743 nucleotides encoding 581 amino acids with a deduced molecular mass of 63,380 Da. Alignment studies of the deduced amino acid sequence of the ORF with known IPDC sequences revealed conservation of several amino acids in PP2_01257, essential for substrate and cofactor binding. Recombinant protein, gene product of the ORF PP2_01257 from P. polymyxa E681, was expressed in E. coli BL21 (DE3) as a glutathione S-transferase (GST)-fusion protein and purified to homogeneity using affinity chromatography. The molecular mass of the purified enzyme showed about 63 kDa, corresponding closely to the expected molecular mass of IPDC. The indole-3-pyruvate decarboxylase activity of the recombinant protein, detected by HPLC, using IPA substrate in the enzyme reaction confirmed the identity and functionality of the enzyme IPDC from the E681 strain.

• Microbiology and Biotechnology Letters
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• v.18 no.4
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• pp.327-330
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• 1990

The effects of various plant growth regulators, both auxins and cytokinins, on cell growth and berberine production were investigated in cell suspension cultures of Thafictrum rugosum. Indole-%-acetic acid (IAA) was found to be the best for berberine production among five examined plant growth regulators and the optimum concentration of IAA was 1 $\mu \textrm M$. The enhancement compared to control 2, 4-dichlorophenoxyacetic acid (2, 4-D) was more than 60%. Simultaneous addition of cytokinins such as kinetin and 6-benzylamiroyurine (BA) was inhibitory.

• Korean Journal of Microbiology
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• v.50 no.1
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• pp.15-21
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• 2014

The promoting effect of Pseudomonas sp. P7014 on the mycelia growth of Pleurotus eryngii was investigated. An ethyl acetate fraction (F5) from the culture supernatant of the bacteria was confirmed to contain the growth promoting compound (GPC). The GPC was identified to be indole acetic acid (IAA) by TLC, HPLC, MS/MS, and NMR analyses. P. eryngii mycelia grew rapidly both on PDA and in PDB after the treatment of GPC. The promoting concentration of GPC was as low as 1.0 nM. Tryptophan, the aminated form of IAA, was confirmed to be the precursor of IAA. These results suggested that bacterial secreted compound was IAA and plays an important role in promoting growth of mushroom mycelia.

• Proceedings of the Botanical Society of Korea Conference
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• 1995.06a
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• pp.12-26
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• 1995