• Bulletin of the Korean Chemical Society
• /
• 제25권9호
• /
• pp.1321-1325
• /
• 2004

Sodium dodecyl sulfate (SDS), an anionic surfactant, can strongly adsorb at the surface of a carbon paste electrode (CPE) via the hydrophobic interaction. In pH 3.0 $Na_2HPO_4$-citric acid buffer (Mcllvaine buffer) and in the presence of SDS, the cationic indole-3-acetic acid (IAA, $pK_a$ = 4.75) was highly accumulated at the CPE surface through the electrostatic interaction between the negative-charged head group of SDS and cationic IAA, compared with that in the absence of SDS. Hence, the oxidation peak current of IAA increases greatly and the oxidation peak potential shifts towards more negative direction. The experimental parameters, such as pH, varieties of surfactants, concentration of SDS, and scan rate were optimized for IAA determination. The oxidation peak current is proportional to the concentration of IAA over the range from $5\;{\times}\;10^{-8}$ mol/L to $2\;{\times}\;10^{-6}$ mol/L. The detection limit is $2\;{\times}\;10^{-8}$ mol/L after 3 min of accumulation. This new voltammetric method was successfully used to detect IAA in some plant leaves.

• 한국환경과학회지
• /
• 제13권6호
• /
• pp.513-518
• /
• 2004

3-weeks old Commelina was transferred to and grown in Hoagland solution (Control, $100\muM$ $Cd^{2+}$, $100\muM$ $Cd^{2+}$+ $100\muM$ IAA, $100\muM$ $Cd^{2+}$+ $100\muM$ IAA + 2 mM sucrose) for 3 weeks and then the effects of indole acetic acid (IAA) on the accumulation of $Cd^{2+}$ and growth of $Cd^{2+}$-treated Commelina were investigated. In the treatment of $Cd^{2+}$, $Cd^{2+}$ was uptaked to 1.74, and 51.36 ${\mu}g/g$ frwt. at the first week, but for three weeks, 0.51 and 34,53 ${\mu}g/g$ frwt, in leaf and stem respectively. When IAA was treated along with $Cd^{2+}$, $Cd^{2+}$ was uptaked to 0.18 and 8.63 ${\mu}g/g$ fiwt, at the first week, and for the incubation of 3 weeks, 0,51 and 45.0 ${\mu}g/g$ fiwt. in leaf and stem. In case of $Cd^{2+}$+IAA+sucrose, $Cd^{2+}$ was uptaked to 1.45 and 18.33 ${\mu}g/g$ frwt. at the first week, but for 3 weeks, 0,51 and 25.45 ${\mu}g/g$ fiwt. in leaf and stem. Likewise $Cd^{2+}$ uptake, the growth was also affected by $Cd^{2+}$ and IAA. During the incubation of 3 weeks, $Cd^{2+}$ reduced the stem growth about 8% in all weeks, but the treatment of IAA recovered the inhibition of stem growth caused by $Cd^{2+}$ to the degree of the control Therefore, it could be concluded that IAA altered the pattern of $Cd^{2+}$ uptake and the growth which were supposed to change $Cd^{2+}$ toxicity.

• Applied Biological Chemistry
• /
• 제15권3호
• /
• pp.181-186
• /
• 1972

소맥 자엽초를 일정한 길이로 절단하여 식물생장 조질제인 교dole acetic acid (IAA)와 abscieic acid (ABA)를 처리하여 아래와 같은 결과를 얻었다. 1. IAA는 고분자 핵산의 F2와 F3을 감소시킨 반면에 ABA는 F4를 증가 시켰다. 2. IAA는 G2 isozyme의 활성도를 증가시켰으나 G3 isogyme의 활성도는 ABA에 의하여 감소되었다. 3. 상기의 결과로 부터 IAA와 ABA는 핵산과 RNase에 대하여 어느정도 공통되는 효과를 갖는다는 것이 암시됨을 알수 있었다. 4. SH group을 저해하는 pb, p-hydroxymercury benfoa 둥에 의해서 발현되는 latent RNase의 활성도는 나타나지 않았다.

• Journal of Microbiology and Biotechnology
• /
• 제20권9호
• /
• pp.1259-1265
• /
• 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.

• Journal of Plant Biotechnology
• /
• 제46권3호
• /
• pp.180-188
• /
• 2019

옥신은 식물의 생장과 발달 과정에서 중요한 조절자로서 기능한다. 옥신 신호전달 과정은 3개의 주요 옥신 반응 전사인자인 Auxin/indole-3-acetic acid (Aux/IAA), Gretchen Hagen 3 (GH3), 그리고 small auxin up RNA (SAUR) 유전자에 의해 조절된다. 특히, Aux/IAA는 옥신 신호에 반응하여 빠르게 축적되는 수명이 짧은 핵 단백질이다. 이 실험에서 우리는 현사시 나무(Populus alba ${\times}$ P. glandulosa)로 부터 PagAux/IAA1 유전자를 분리하고 발현 특성을 분석하였다. PagAux/IAA1 cDNA는 4개의 보존된 도메인과 2개의 nuclear localization sequence (NLS)을 포함한 200개의 아미노산을 암호화하고 있다. Southern blot 분석으로 현사시나무 genome에 PagAux/IAA1 유전자가 single copy로 존재하는 것을 확인하였다. PagAux/IAA1 유전자는 잎과 꽃에서 특이적으로 발현되었다. 그리고 PagAux/IAA1 유전자는 현탁배양세포의 생장 과정에서 초기 지수생장기에 발현되었다. PagAux/IAA1 유전자의 발현을 분석한 결과, 건조와 염 스트레스 및 식물호르몬인 ABA 처리에 의해 발현이 감소된 반면 저온 스트레스, 형성층의 세포 분열 과정 그리고 식물호르몬인 GA와 JA 처리에서 발현이 증가하였다. 따라서 PagAux/IAA1 유전자가 현사시나무에서 저온 스트레스 반응뿐 아니라 생장 과정에 관여할 것으로 판단된다.

• 한국유기농업학회지
• /
• 제14권4호
• /
• pp.411-420
• /
• 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
• /
• 제28권9호
• /
• pp.1511-1516
• /
• 2018

In this study, we investigated Indole-3-acetic acid (IAA) production by a rice phylloplane bacteria, Enterobacter sp. DMKU-RP206, using sweet whey as a feed stock instead of lactose. We succeeded in using sweet whey for Enterobacter sp. DMKU-RP206 to produce 3,963.0 mg IAA/l with the optimal medium containing 1.48% sweet whey, 1.42% yeast extract and 0.88% $\text\tiny{L}$-tryptophan. The medium pH was adjusted to 6 and the culture conditions were shaking at 200 rpm on an orbital shaker at $30^{\circ}C$ for 3 days. We also evaluated the effect of IAA in culture filtrates of Enterobacter sp. DMKU-RP206 on the promotion of jasmine rice growth in a pot experiment. Compared with the negative control (without IAA), the result showed that biosynthetic IAA produced by Enterobacter sp. DMKU-RP206 significantly increased the growth of jasmine rice (Oryza sativa L. cv. KDML105) in terms of length and dry weight of shoot. This work thus reveals the impact of IAA produced by Enterobacter sp. on the promotion of jasmine rice growth.

• 한국토양비료학회지
• /
• 제49권5호
• /
• pp.461-468
• /
• 2016

One of the important phytohormones produced by plant growth promoting bacteria is the auxin; indole-3-acetic acid (IAA), with L-tryptophan as the precursor. In this study, we focused on the investigation of optimal conditions for the production of IAA by Bacillus megaterium BM5. We investigated culturing conditions, such as incubation temperature, pH of the culture medium and incubation period, with varying media components such as inoculation volume, tryptophan concentration and carbon and nitrogen source. Besides, optimization study intended for high IAA production was carried out with fermentation parameters such as rpm and aeration. The initial yield of $42{\mu}g\;IAA\;ml^{-1}$ after 24 hr increased to $85{\mu}g\;ml^{-1}$ when 5% (v/v) of L-tryptophan was used in the culture broth. The maximum yield of $320{\mu}g\;IAA\;ml^{-1}$ was observed in trypticase soy broth (TSB) supplemented with starch and soybean meal as C and N sources with a C/N ratio of 3:1 (v/v) at $30^{\circ}C$, pH 8.0 for 48 hrs with 1.0 vvm and 250 rpm in 5 L working volume using 10 L scale fermenter. The bacterial auxin extracted from the culture broth was confirmed by thin layer chromatography and high-performance liquid chromatography and effect on plant growth was confirmed by root elongation test.

• 미생물학회지
• /
• 제50권4호
• /
• pp.302-307
• /
• 2014

많은 근권세균들이 다양한 직간접적인 방법을 통해 식물생장을 촉진할 수 있으며 indole acetic acid (IAA) 같은 식물호르몬의 생산과 분비는 식물의 생장과 발달에 큰 영향을 미친다. 강아지풀의 근권에서 분리된 Acinetobacter sp. SW5는 BHB 배지에서 각각 2일과 1일 배양 시 118.1 mg/L의 IAA와 4.5 mg/L의 지베렐린을 생성하였다. 소규모 재배실험에서 토마토 유묘에 이 균주를 2주 간격으로 처리하면서 12주 재배 시 토마토 식물의 shoot와 뿌리 길이 및 습윤중량이 비접종 대조군과 비교할 때 통계적으로 유의하게 각각 26.3, 33.3과 105.3% 증가하였다. 토마토 유묘의 뿌리로부터 분비되는 삼출물을 HPLC로 분석한 결과 IAA의 전구물질인 아미노산 트립토판이 3.75 ng/mg tomato root 검출되었으며 Acinetobacter sp. SW5는 8개의 토마토 유묘뿌리 삼출물로부터 $4.06{\mu}M$의 IAA를 생성하였다. 토마토 뿌리 삼출물에서 Acinetobacter sp. SW5의 생장능과 더불어 이 세균에 의해 생성된 IAA가 토마토 식물의 생장을 촉진시키는데 관여했을 것으로 추정된다.

• 미생물학회지
• /
• 제48권1호
• /
• pp.1-7
• /
• 2012

대표적인 식물호르몬인 indole-acetic acid (IAA)를 생성하는 근권세균에서 IAA 생합성 경로와 생성량과의 관계를 파악하기 위해 IAA 생성능이 크게 다른 4개 균주를 선발하고 동정하였다. 특정 경로를 이용한 IAA 생합성능의 조사를 위해 주요 전구물질을 첨가하여 IAA 생성량을 측정하였다. Tryptophan 의존적 경로에 의한 총 IAA 생성량은 Acinetobacter guillouiae SW5가 1.66 mg/ml로 가장 높았으며, indole acetamide (IAM)를 배지에 첨가했을 때 amidase의 활성은 분리균주 중 Rhodococcus equi SW9이 가장 높았다. IAA 생합성을 위한 또 다른 두 가지 경로의 전구물질인 indole acetonitrile (IAN)을 첨가하였을 때 IAA 생합성은 A. guillouiae SW5가 가장 높았으며, 이 때 nitrilase 보다는 nitrile hydratase의 활성이 높았다. 그러나 두 경로 중 IAN을 직접 IAA로 전환시키는 nitrilase의 활성은 Bacillus thuringiensis SW17이 균주들 중 가장 높았다. B. thuringiensis SW17은 4균주 중 IAA생합성능이 가장 낮았으며 tryptophan을 이용하여 생합성하는 IAA 중 상당량을 IAM을 거치는 경로를 통해 생성한다. Lysinibacillus fusiformis SW13은 IAA 생합성에 관여하는 nitrile 전환경로들을 비교적 고르게 이용하여 IAA를 생성하였다. Tryptophan 비의존적 경로를 통한 IAA 생합성은 A. guillouiae SW5에서만 소량 관찰되었다.