• Journal of Microbiology and Biotechnology
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• v.20 no.9
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• pp.1259-1265
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• 2010

The filamentous cyanobacterium Arthrospira platensis strain MMG-9 was isolated from a rice field. The ability of this strain to synthesize the bioactive compound indole-3-acetic acid (IAA) was demonstrated. IAA was extracted from the culture of A. platensis strain MMG-9 and its identity was confirmed by thin-layer chromatography (TLC) as well as by high-performance liquid chromatography (HPLC). The IAA precursor L-tryptophan was required for IAA biosynthesis. Released IAA increased with the increase of the initial concentration of L-tryptophan in the medium and with the incubation time. A. platensis strain MMG-9 accumulated more IAA than it released into the medium. The bioactivity of the secreted IAA was shown by its effect on the formation of roots by Pisum sativum. There was a significant positive effect of the supernatant of cultures of A. platensis strain MMG-9 on the number of lateral roots of P. sativum, whereas a negative effect on root length was observed.

• 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.

• Korean Journal of Environmental Agriculture
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• v.4 no.1
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• pp.43-51
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• 1985

To identify amino acid conjugates of indole-3-acetic acid(IAA) in plants, 23 amino acid conjugates of IAA were synthesized and characterized by UV and IR spectroscopies, and thinlayer and high performance liquid chromatographies. In etiolated pea(Pisum sativum L. var. Sparkle) shoots, aspartic and glutamic acid conjugates of IAA were tentatively identified as metabolites of endogenous IAA by thin-layer and high performance liquid chromatography, and by alkaline hydrolysis of the conjugates.

• Applied Biological Chemistry
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• v.15 no.3
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• pp.181-186
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• 1972

Wheat coleoptile sections were treated with either $1.5{\times}10^{-5}M$ ABA or $5×10^{-5}M$ IAA in vitro, the results may be summarized as follows, 1. The treatmert of IAA decreased the level of high molecular weight RNA F2 and F3 but that with ABA increased the F4 level. 2. IAA caused an increased activity of G2 isozyme, while ABA suppressed the activity of G3 isozyme. 3. The results may suggest that there may exist common effects of IAA and ABA on RNA and RNase. 4. The latent RNase activity caused by SH blocking reagent (p-hydroxymercury benzoate, Pb et al) was not observed.

• Applied Biological Chemistry
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• v.40 no.4
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• pp.357-360
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• 1997

The biological activity of monoglycerides, diglycerides, triglycerides and free fatty acids were investigated by the rice inclination test that is specific bioassay for brassinosteroids. The experimental results revealed that some diglycerides, triglycerides and free fatty acids as well as monoglycerides showed positive response. ${\alpha}-Monoolein$ and diolein as active principles showed higher activity than indole-3-acetic acid at the same concentration. From the results, it can be confirmed that the active principles are related to olein which especially have a high activity.

• 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 Plant Biology
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• v.20 no.2
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• pp.91-101
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• 1977

Using barley seeds (Hordeum sativum Jess, var.), the influences of gibberellic acid (GA) and indole-3-acetic acid(IAA) on the amylase synthesis and that of the nucleic acid metabolism were investigated. 1. With the deembrynized barley seeds, the increase of amylase treated with a $10^{-5}M$ of GA and the decrease of amylase treated with $10^{-5}M$IAA were matched by a proportionate increase and decrease in the amount of RNA. The influence of the hormones on the RNA synthesis has appeared immediately after the treatment but on the amylase synthesis it has appeared 8 hours later. But no influence on the DNA synthesis was observed on both hormones. 2. The amylase from deembryonized barley seeds treated with GA and IAA have been fractionated by gel filteration on Sephadex G-100. The amylase components showed four fractions on both enzymes treated with GA and IAA. Fraction I(FI) was differed from fraction Ⅵ(FIV) in Km value and the effects of temperature, pH and metal ions. On the basis of their emzymatic properties, it was considered that the FI was $\beta$-amylase and FIV was $\alpha$-amylase. The influences of GA and IAA on each fractions appeared to be similar but on the amylase units per souble protein, IAA inhibited the production of amylase FIV while it promoted that of amylase FI. 3. An experiment was conducted to determine whether IAA inhibits GA-promoted amylase synthesis competitively or non-competitively. Using a Lineweaver-Burk plot, it was clear that IAA was acting in a non-competitive fashion. From this, IAA was probably not competing with GA at the same site, but it was acting at some other site which resutled in partial blocking of the action of GA on the amylase synthesis.

• Journal of Plant Biotechnology
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• v.46 no.3
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• pp.180-188
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• 2019

Auxin plays a crucial regulatory role in plant growth and development processes. Three major classes of auxin-responsive transcription factors controlled by the Auxin/indole-3-acetic acid (Aux/IAA), Gretchen Hagen 3 (GH3), and small auxin up RNA (SAUR) genes regulate auxin signaling. Aux/IAA, in particular, encodes short-lived nuclear proteins that accumulate rapidly in response to auxin signaling. In this study, we isolated a PagAux/IAA1 gene from poplar (Populus alba ${\times}$ P. glandulosa) and investigated its expression characteristics. The PagAux/IAA1 cDNA codes for putative 200 amino acids polypeptide containing four conserved domains and two nuclear localization signals (NLSs). Utilizing Southern blot analysis, we confirmed that a single copy of the PagAux/IAA1 gene was present in the poplar genome. The expression of this gene is specific to leaves and flowers of the poplar. PagAux/IAA1 expressed in the early exponential growth phase of cell-cultured in suspension. PagAux/IAA1 expression level reduced in drought and salt stress conditions, and the presence of plant hormones such as abscisic acid. However, expression enhanced in cold stress, cambial cell division, and presence of plant hormones such as gibberellic acid and jasmonic acid. Thus, these results suggest that PagAux/IAA1 participates in cold stress response as well as developmental processes in the poplar.

• Korean Journal of Organic Agriculture
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• v.14 no.4
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• pp.411-420
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• 2006

Indole-3-acetic acid (IAA) biosynthesis by bacteria occurs widely in rhizospheres. Bacterial species able to synthesize IAAmay be exploited for beneficial interactions in crop management systems. The objective of this study was to determine the response of ivyleaf morningglory (Ipomoea hederacea) seedlings to IAA and to an IAA-producing rhizobacterum, Bradyrhizobium japonicum isolate GD3. IAA solution and isolate GD3 suppression of seedling growth measured as radicle length and biomass depended on IAA concentration. Seedling radicle length was significantly reduced by ca. 29% with more than $1.0{\mu}M$ of IAA solution, compared to the control, 48 h after application. The cell concentration at 50% growth reduction ($GR_{50}$) of the seedling radicle was IAA production by isolate GD3 at $10^{4.82}\;cfu$, the cell concentration for 50% growth reduction ($GR_{50}$) of seedling radicle was 0.24 iM, which was much lower than the IAA solution concentration ($117.48{\mu}M$) required for $GR_{50}$. Therefore, excess IAA production by isolate GD3 may be more detrimental to morningglory radicle growth than standard IAA solution. Results confirmed involvement of IAA in suppressive effects of isolate GD3 on morning-glory seedlings grown in a hydroponic system.

• Journal of Microbiology and Biotechnology
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• v.18 no.4
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• pp.773-777
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• 2008

Phosphate solubilizing bacteria (PSB) were isolated from the rhizosphere of Chinese cabbage and screened on the basis of their solubilization of inorganic tricalcium phosphate in liquid cultures. Ten strains that had higher solubilization potential were selected, and they also produced indole-3-acetic acid, 1-aminocyclopropane-1-carboxylate (ACC) deaminase, and siderophores. The strains were identified to be members of Pseudomonas, by 16S rDNA sequence analysis. Seed bacterization with PSB strains increased the root elongation and biomass of Chinese cabbage in seedling culture, although they had no effect on phosphorus uptake of plants. The plant growth promotion by PSB in this study could be due to the production of phytohormones or mechanisms other than phosphate solubilization, since they had no effect on P nutrition.