• Journal of Life Science
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• v.19 no.8
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• pp.1139-1144
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• 2009

It has been known that brassiolide (BL) increased the positive gravitropic response and ethylene production in maize roots. This study examined the relationship between the BL-induced gravitropic response and ethylene Production. The ethylene production was inhibited to about 90% of the control by the treatment of $10^{-4}$ M aminoethoxyvinylglycine (AVG), the ethylene synthesis inhibitor. However, the gravitropic response did not show any significant changes compared to the control at $10^{-4}$ M AVG. In the case of treatment of AVG with BL, the ethylene production decreased to 60% of the control. However, the gravitropic response increased to the level which was induced by BL. Cobalt ions, another ethylene biosynthesis inhibitor, inhibited ethylene production, but not gravitropic response. When roots were treated with BL and cobalt ions, they showed the inhibition of ethylene production and promotion of gravitropic response. To elucidate the possibility that the effect of BL is related to auxin transport, roots were treated with TIBA (2,3,5-triiodobenzoic acid), an auxin transport inhibitor. Both treatment of TIBA alone and TIBA with BL stimulated ethylene production to about 96% and 132%, respectively. However, gravitropic response was completely inhibited in both treatments. Further, roots treated with BL in the presence of TIBA and IAA showed a negative gravitropic response, which means that IAA accumulates in the upper side of horizontal roots. Root elongation was also stimulated in this treatment. Taken together, these results suggest that BL might affect the differential distribution of internal IAA on roots, causing the regulation of positive gravitropic response.

• Journal of Korean Society for Atmospheric Environment
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• v.12 no.3
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• pp.333-340
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• 1996

The relationship between ozone-induced damages and ethylend evolution was examined in tomato plants fumigated with ozone of 0.2 $\mu\ell/\ell$. The rate of evolution of ethylent by tomato plants was enhanced by ozone fumigation. Pretreatment of leaves with aminoethoxyvinylglycine (AVG), an inhibitor of ethylene evolution, significantly inhibited the evolution of ethylene that was induced by ozone and concomitantly reduced the extent of ozone-induced visible damage to leaves. Treatment with 2,5-norbonadiene (NBD), and inhibitor of the action of ethylene, strongly reduced the extent of visible damage caused by ozone, even though it did not suppress the evolution of ethylene. These results indicated that ethylene might play an important role in ozone-induced plant injuries at relatively short terms of ozone fumigation. Next, we examined the effect of tiron, a scanvenger of the free-radical, on evolution of ethylene and leaf injury caused by ozone. Tiron treatment strongly reduced the extent of ozone-induced injury, but had not inhibitory effect on the evolution of ethylene from tomato leaves. This result suggests the involvement of free-radical, such as superoxide radicals, in induction of injuries caused by ozone.

• Journal of Plant Biology
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• v.34 no.4
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• pp.325-330
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• 1991

The ability of several auxin analogs to induce ethylene production was tested in the corn coleoptile. The synthetic auxins 1-naphthaleneacetic acid (1-NAA) and 2, 4-dichlorophenoxyacetic acid (2, 4-D) had strong stimulatory effects on ethylene induction surpassing that of IAA. Both 2-naphthalaneacetic acid (2-NAA) and 2, 6-dichlorophenoxy acetic acid (2, 6-D), structural analogs of these auxins, respectively, were found to be inactive. Treatment with NPA, a strong inhibitor of polar auxin transport, led to drastic increase in IAA-induced ethylene production while it has bo effect on ethylene production induced by 1-NAA. A positive correlative existed between intracellular auxin level and ethylene production.

• Journal of Korean Society for Atmospheric Environment
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• v.12 no.3
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• pp.307-314
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• 1996

The rate of evolution of ethylent by tomato plants was rapidly increased by ozone fumigation. In the present study, the mechanism of ethylent evolution by ozone was investigated in experiments with aminoethoxyvinylglycine (AVG) and tiron, which inhibit the formation of ethylene and peroxidation of lipids, respectively. Pretreatment with AVG significantly inhibited the ozone-induced ethylent evolution, but the treatment of plants with tiron did not inhibit. These results indicate that the induction of the evolution of ethylene by ozone involves the pathway via aminocyclopropane-1-carboxylate (ACC), while not released as a result of the peroxidation of lipids. Ozone-induced ethylent evolution was greater in dar- than light-incubated, intact tomato plants. The difference between dark- and light-ethylene evolution was examined with diuron, an inhibitor of photosynthetic electron transport. The inhibitor treatment promoted ethylent evolution. These results suggest that ethylent retention and metabolism in plants were regulated by internal $CO_2$ levels which, in turn, were controlled in large part by photosynthesis. Thus, ethylene was retained in illuminated leaf tissue under low intenal $CO_2$ concentration which may develop in a sealed container without exogenously supplied $CO_2$.

• Journal of Plant Biology
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• v.32 no.4
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• pp.343-350
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• 1989

Calcium promoted ethylene production from mungbean hypocotyl segments incubated in the presence of either auxin or cytokinin (kinetin). Time course studies indicated that the calcium effect on ethylene production had a longer latent period (about 6 h) in combination with kinetin than with auxin. Studies on the effects of agents that are known to interfere with either action or transport (uptake) of calcium on ethylene biosynthesis indicated different patterns between auxin- and kinetin-treated tissues. Auxin-induced ethylene production was inhibited by the calmodulin inhibitor, trifluoperazine (TFP), and this inhibition was overcome by high concentrations of calcium applied, but TFP had no significant effect on kinetin-induced ethylene production regardless of calcium in the medium. The calcium channel blocker, verapamil, inhibited auxin-induced, but had little effect on kinetin-induced, ethylene producton. In vivo activity of "ethylene forming enzyme (EFE)" was found to be substantially promoted by calcium treatment. The enzyme activity was further increased by kinetin when segments were simultaneously treated with calcium, but auxin did not have such an effect.an effect.

• Corrosion Science and Technology
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• v.22 no.5
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• pp.305-313
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• 2023

The objective of this study was to investigate the effectiveness of sodium dodecyl benzene sulfonate (SDBS) as a corrosion inhibitor on the pitting corrosion behavior of aluminum alloys used in electric vehicle battery cooling systems within a mixture of ethylene glycol and water (EG-W) coolant. Potentiodynamic polarization testing revealed unstable passive film formation on the aluminum alloys in the absence of SDBS. However, the addition of SDBS resulted in a robust passive film, enhancing the pitting corrosion resistance across all examined alloys. Pitting corrosion was predominantly observed near intermetallic compounds in the presence of Cl? ions, which was attributed to galvanic interactions. Among tested alloys, A1040 demonstrated superior resistance due to its lower areal fraction of precipitates and donor density. The incorporation of SDBS inhibitors mitigated the overall pitting corrosion process by hindering Cl? ion penetration. These findings suggest that SDBS can significantly improve pitting corrosion resistance in aluminum alloys employed in battery coolant environments.

• YAKHAK HOEJI
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• v.37 no.1
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• pp.100-106
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• 1993

Designed system, in which the $\beta$-hydroxy-$\delta$-lactone moiety is connected to benzimdazole ring by ethylene bridge, was propared from 2-sustd. benzimidazole as a potential HMG-CoA reductase inhibitor.

• Journal of Plant Biology
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• v.39 no.4
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• pp.295-300
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• 1996

The physiological effects of oligogalacturonic acid (OGA:D. P. 6-7), a product of acid hydrolysis of polygalacturonic acid (PGA), on ethylene biosynthesis in mung bean (Vigna radiata W.) hypocotyl segments was studied. Among PGA, OGA and monogalacturomic acid (MGA), only OGA stimulated ethylene production in mung bean hypocotyl segments, and the most effective concentraton of OGA was 50$\mu\textrm{g}$/mL. Time course data indicated that this stimulatiion effect of OGA appeared after 90 min incubation period and continued until 24 h. When indol-3-acetic acid (IAA) and 1-aminocyclopropane-1-carboxylic acid (ACC) were treated with OGA to investigate the mechanism of OGA on ethylene production, they did not show synergistic effects on ethylene production. The stimulation of ethylene production by OGA was due to the increase of in vivo ACC synthase activity, but OGA treatment had no effect of in vivo ACC oxidase activity. The effect of aminoethoxy vinyl glycine (AVG) and Co2+, the inhibitor of ethylene synthesis, was siminished a little by the OGA, but the treatment of Ca2+, known to increase ACC, with OGA did not increase the ethylene production, this effect seems to be specific for Ca2+ because other divalent cation, Mg2+, did not show the inhibition of OGA-indyuced ethylene production. It is possible that the OGA adopts a different signal transduction pathway to the ethylene bioxynthesis.

• Journal of Plant Biology
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• v.37 no.3
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• pp.271-276
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• 1994

The possibility that 1-aminocyclopropane-1-carboxylic acid (ACC)-uptake may be dependent on the H+-gradient established across the plsma membrane was tested in protoplasts isolated from 2.5 day old mungbean hypocotyls. The ACC-induced ethylene production was inhibited when the H+-gradient was collapsed by the treatment with carbonycyamide-p-trifluro-methoxy-phenylhydrazone (FCCP). Moreover, the treatment with o-vanadate, a specific inhibitor of plasma membrane H+-ATPase, caused the inhibition of ethylene production. The ACC-induced ethylene production was inhibited by the treatemnt with verapamil (Ca2+-channel blocker), or ethylene glycol-bis($\beta$-aminoethyl ether) N, N, N', N'-tetraacetic acid (EGTA) (Ca2+-chelator). In contrast, the ehtylene production was stimulated by the application of A23187 (Ca2+ ionophore). The inhibitory effect of EGTA in the ethylene producton was magnified in the presence of A23187. From these results, we suggest that the external Ca2+ influx to the cytosol resulted in the stimulatin of ACC oxidase activity after ACC-uptake resulting from a H+-gradient across the plasma membrane.

• Microbiology and Biotechnology Letters
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• v.18 no.1
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• pp.35-38
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• 1990

$\alpha$-D-Glucosidase inhibitor purified in a pure form was amorphous powder which gave a single spot at Rf value 0.12-0.71 with various developing solvent systems on silica gel thin layer chromatography, and melting point was 154.3-155.3$^{\circ}C$. It was disolved in water, formic acid and ethylene glycol monoethyl ether, and was very high hygroscopic substance. Biochemical reaction of the substance was positive to phenol sulfuric acid, ninhydrin, silver nitrate-sodium hydroxide, but negative to DNS reagent. Acid hydrolysis gave fructose and acid as sole sugar and amino acid constituents respectively. Moelcular weight of the inhibitor was estimated to be 1,050 by Shphadex G-25 column chromatography.