• Journal of Microbiology
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• 제45권1호
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• pp.15-20
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• 2007

The majority of soil microorganisms can derive ethylene from L-methionine (L-MET), while some rhizobacteria can hydrolyze 1-aminocyclopropane-1-carboxylate (ACC) due to their ACC-deaminase activity. In this study, three strains having either ACC-deaminase activity (Pseudomonas putida biotype A, $A_7$), or the ability to produce ethylene from L-MET (Acinetobacter calcoaceticus, $M_9$) or both (Pseudomonas fluorescens, $AM_3$) were used for inoculation. The highly ethylene specific bioassay of a classical 'triple' response in pea seedlings was used to investigate the effect of the inoculation with the rhizobacteria in the presence of 10 mM ACC or L-MET. The exogenous application of ACC had a concentration-dependent effect on the etiolated pea seedlings in creating the classical 'triple' response. The inoculation with P. putida diluted the effect of ACC, which was most likely due to its ACC-deaminase activity. Similarly, the application of $Co^{2+}$ reduced the ACC-imposed effect on etiolated pea seedlings. In contrast, the inoculation of A. calcoaceticus or P. fluorescens in the presence of L-MET caused a stronger classical 'triple' response in etiolated pea seedlings; most likely by producing ethylene from L-MET. This is the first study, to our knowledge, reporting on the comparative effect of rhizobacteria capable of utilizing ACC vs L-MET on etiolated pea seedlings.

• Applied Biological Chemistry
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• 제33권2호
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• pp.125-128
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• 1990

저온에서 완두유묘 줄기의 유리 IAA 수준과 그 전구체인 트립토판 수준이 저하하므로, IAA수준의 조절 메커니즘을 규명하기 위하여 IAA분해효소계에 미치는 저온의 영향을 조사하였다. $25^{\circ}C$에서 키운 백색 관두유표를 $5^{\circ}C$의 저온으로 옮기면 IAA oxidase와 peroxidase의 수준은 증가하였으며 catalase의 수준은 저하되었고 과산화수소는 축적되어, 전체적으로 IAA분해계가 저온에서 강화되었다. 저온에 놓였던 유묘를 상온으로 옮기면 IAA 분해계는 다시 대조구 수준으로 회복하였다.

• Applied Biological Chemistry
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• 제33권1호
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• pp.68-72
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• 1990

저온에서 일어나는 식물생육의 억제와 식물생장조절물질의 하나인 IAA 수준의 조절을 알아보기 위하여 암실재배한 백색 완두유묘를 재료로 저온처리에 따른 생육과 IAA 수준의 변화를 조사하였다. $25^{\circ}C$에서 성장한 백색 완두유묘는 $5^{\circ}C$의 저온에 접하면 생장이 거의 정지하였다. 유리 IAA 수준은 생체중 기준 상온묘의 17.6 ng/g에서 3일간 저온처리시에 4.9 ng/g으로, 총 IAA 수준은 113.2 ng/g에서 60.8 ng/g으로 현저하게 감소하였다. IAA의 전구체인 트립토판 수준은 생체중 기준 상온묘의 583 nmol/g에서 저온처리시에 414 nmol/g으로 약 30 % 감소하였으며, 시킴산경로에 의하여 트립토판과 함께 생합성되는 페닐알라닌과 티로신 수준도 감소하였다. 이 결과는 저온에서 IAA의 전구체인 트립토판 생합성의 억제를 통하여 IAA 수준을 일부 하향조절할 수 있을 것임을 시사한다.

• Journal of Photoscience
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• 제9권2호
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• pp.94-97
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• 2002

Light is one of the most important environmental factors that influence plant growth and development. It does not function independently but exerts its role through coordinated interactions with intrinsic developmental programs, such as hormonal regulation. One typical example is hypocotyl growth in which light signals are modulated through growth hormones. However, the underlying molecular mechanisms are largely unknown. We demonstrated that brassinosteroids play an important role in the light signal transduction in etiolated hypocotyl growth. A light-responsive Ras-like G-protein, Pra2 from pea, physically and functionally interacts with a cytochrome P450 that specifically catalyzes C-2 hydroxylation in brassinosteroid biosynthesis. The cytochrome P450 expression, along with Pra2, is induced in the dark and predominantly localized in the rapidly elongating zone of etiolated pea epicotyls. Transgenic plants with a reduced level of Pra2 exhibit a dark-specific dwarfism, which is completely rescued by brassinosteroid application. On the contrary, overexpression of the cytochrome P450 results in enhanced hypocotyl growth even in the light, which phenocopies the etiolated hypocotyl growth. It is therefore envisioned that Pra2 is a molecular switch that mediates the crosstalk between light and brassinosteroids in the etiolation process.

• 한국환경농학회지
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• 제4권1호
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• pp.43-51
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• 1985

식물체중의 IAA-아미노산 복합체를 확인하기 위하여 23종의 IAA-아미노산 복합체를 합성하여 이들의 UV와 IR spectra, TLC, HPLC 그리고 가수분해등 화학적 증거를 토대로, 암실재배한 완두 유묘의 줄기에서 IAA-Asp와 IAA-Glu를 잠정적으로 동정하였다. IAA-Asp는 식물체에서 IAA의 대사산물로 이미 확인된 화합물(化合物)이지만 IAA-Glu는 아직 확인되지 않고 있다.

• Journal of Photoscience
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• 제4권3호
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• pp.141-145
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• 1997

Polymerase chain reaction(PCR) was conducted with a pea cDNA library using two primers synthesized from homology analysis of amino acid sequences for animal and plant cytosolic FBPases. A PCR product with 650 bp long was cloned into pGEM-T vector and sequenced. The deduced amino acid sequence of the cDNA fragment was 98, 91, and 85% homologous with those of cytosolic FBPases from spinach, sugarbeet, and sugarcane, respectively. It was 51% homologous with amino acid sequence of FBPase from pea chloroplasts. Northern blot analysis was proceeded with the cDNA clone resulting that 1.2 kb transcript was highly expressed in light-grown pea leaves but almost not expressed in dark-grown etiolated pea seedlings. When peas grown in the light for 10 days were transferred to darkness, the transcript was gradually decreased with dark treatment, indicating that the expression of the enzyme was induced by continuous white light but suppressed by dark treatment. Pea cytosolic FBPase was highly expressed in leaves with trace amounts in stems. but almost not expressed in roots.

• BMB Reports
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• 제32권4호
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• pp.393-398
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• 1999

Acetolactate synthase (ALS) catalyzes the first reaction common to the biosynthesis of L-valine, L-leucine, and L-isoleucine. ALS is the target site of several classes of herbicides, including the sulfonylureas, the imidazolinones, and the triazolopyrimidines. Two forms of ALS (ALS I and ALS II) which have different affinity for Heparin have been separated from etiolated pea seedlings. The substrate saturation curves of both ALS I and ALS II were hyperbolic in contrast to previous reports. The two forms of ALS showed significant differences in their physical and kinetic properties. The values of $K_m$ for ALS I and ALS II were 9.0 mM and 4.8 mM, respectively. The pI values for ALS I and ALS II were determined to be 5.3 and 5.75 by isoelectric focusing, respectively. The native molecular weights for ALS I and ALS II obtained by nondenaturing gel electrophoresis and activity staining were 124 and 244 kDa, respectively. They also exhibited different sensitivity to feedback inhibition by end-product amino acids and inhibition by Cadre, an imidazolinone herbicide.

• 한국광과학회:학술대회논문집
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• 한국광과학회 2000년도 학술대회지
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• pp.33-33
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• 2000

• Journal of Plant Biology
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• 제38권4호
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• pp.343-348
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• 1995

Treatment of Pisum sativum tissue with the protein kinase inhibitor staurosphorine resulted in impairment of 3H-indoleacetic acid transport in etiolated stem segments. The transport inhibitiion was accompanied by an increase in net uptake of labeled auxin in the tissue. The magnitude of auxin accumulation in tissue treated with the phytotropin N-1-naphthylphthalaic acid (NPA) which specifically blocks the efflux of auxin in the plasma membrane was reduced by the protein kinase inhibitor, suggesting that inhibition of protein phosphorylation could lead to hindrance of the auxin-exporting function of NPA receptors. The flavonoid genistein which is also known to inhibit protein kinase likewise reduced NPA-induced auxin accumulation. However, the flavonoid did not bring about auxin accumulation by itself, nor did it inhibit auxin transport. In view of the finding that the flavonoid also competes with NPA for a common binding site, a mechanism for the flavonoid effect on the NPA action will be proposed.

• Applied Biological Chemistry
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• 제32권2호
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• pp.162-169
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• 1989

완두(豌豆) 유묘(幼苗)줄기의 추출물(抽出物)에서 silica gel column chromatography, TLC, HPLC 등으로 분리(分離)하고 여러 가지 정색반응(呈色反應)을 행한 결과 tryptophan, indole-3-acetaldehyde, IAA, indole-3-aldehyde를 확인(確認)할 수 있었다. 여기서 확인(確認)된 indole화합물(化合物)들을 근거(根據)로 볼 때 완두유묘(豌豆幼苗)에는 tryptophan${\rightarrow}$(?)${\rightarrow}$indole-3-acetaldehyde${\rightarrow}$IAA${\rightarrow}$indole-3-aldehyde로 이어지는 대사계(代謝系)가 존재(存在)할 수 있음을 추정(推定)할 수 있었다. 한편, IAA-당(糖) 복합체(複合體)로써 IAA-rhamnose와 IAA-glucose가 완두 유묘에 분포함을 잠정적으로 확인하였다.