• Korean Journal of Soil Science and Fertilizer
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• v.37 no.1
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• pp.7-13
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• 2004

Mung beans (Vigna radiata L.) were used to investigate the roles of strontium in hypocolyl elongation under IAA regime during the germination. After imbibition in a medium with or without IAA, $Sr^{2+}$ stimulated IAA oxidation. Three to five fold increasing in IAA oxidase activity seems to be direct evidence of growth inhibition through $Sr^{2+}$. Furthermore, the accumulation of spermidinc and spermine by $Sr^{2+}$ in the range of 1 to 10 mM was observed. Spermidine levels were 2 to 3 fold higher than in control seedling grown without strontium. The increase in polyamine levels was observed on a g fresh weight basis. In conclusion, it was demonstrated that the inhibitory action of $Sr^{2+}$ is closely related with the IAA oxidation and polyamine biosynthesis.

• Journal of Plant Biology
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• v.35 no.4
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• pp.425-429
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• 1992

Cell elongation is known to be promoted by ethylene in petioles of Ranunculus sceleratus. Treatment of petiole segments with spermine resulted in an inhibition of cell elongation and of ethylene biosynthesis in the presence of applied auxin. Dose response curve for the spermine inhibition of auxin-induced ethylene production appeared similar to that of ACC-based ethylene production suggesting that the polyamine inhibits ethylene biosynthesis by blocking the conversion of ACC to etylene. Auxin-induced ethylene production was significantly promoted by treatment of the tissue with either DFMA or DFMO. specific inhibitors of polyamine biosynthesis. Increased level of ethylene production by DFMA was found to be completely abolished by application of exogenous spermine at a high concentration. These results indicate that endogenous spermine plays a regulatory role in the growth response of Ranunculus petioles to auxin and ethylene.hylene.

• Journal of Plant Biology
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• v.34 no.4
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• pp.297-302
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• 1991

The effects of polyamines on auxin polar transport were studied in corn coleoptile segments. Among putresine, spermidine and spermine tested in labelled auxin transport, spermidine inhibited auxin polar transport most strongly. Its inhibitory effect appeared after 1 h of transport period. Spermidine inhibited labelled auxin and 14C-benzoic acid accumulation into the tissue in the various pH range tested (pH 4.0-8.0). These results suggest that the inhibition of auxin transport may not be due to decrease in pH by spermine the effect of decreased pH in the extracellular space.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.6
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• pp.438-441
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• 2003

The present study was carried out to assess the possibility of rapid multiplication of Curcuma longa Linne through in vitro culture of shoot-apex. The factor investigated was effect of various growth regulators on shoot-apex culture. The shoot-apex cultured of MS(Murashige and Skoog) medium developed into plantlet in 16 Weeks. M.S. medium containing NAA at 0.5 ppm and BA 5.0 ppm was found to be optimal for growth of in vitro plantlet

• Journal of Plant Biology
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• v.34 no.4
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• pp.317-323
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• 1991

Partial recovery in auxin transport capacity from inhibition by N-naphthylphthalamic acid (NPA) was observed when corn coleoptile segments were subjected to a prolonged NPA treatment. Kinetic data indicated that the recovery time is a function of the concentration of NPA applied. Desensitization to NPA was also seen in tissue slices where NPA increased net uptake of auxin, indicating that the apparant adaptation in the auxin transport system did not results possibly from auxin accumulated during transport inhibition. Studies on in vitro binding of NPA to membrane vesicles isolated from the coleoptile indicated that preincubation of the tissue with NPA resulted in the reduced binding activity. Scatchard analysis of the data indicated that this was due to decreases in the number of NPA binding sites. The possibility of causal relationship of modified NPA receptors to the sensory adaptation in auxin transport observed in coleoptile segments will be discussed.

• Journal of Plant Biology
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• v.33 no.4
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• pp.309-314
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• 1990

Effect of mannose on auxin-induced ethylene production in corn (Zea mays L.) coleoptiles was studied. Auxin induced ethylene production decreased in proportion to mannose concentrations. The inhibitory effect of mannose appeared after 2 h of incubation. Ethylene production was significantly depressed by mannose at high concentration (10-5M-10-4M) of indole acetic acid (IAA), but not at low concentrations (10-8M-10-6M). The inhibition of auxin-induced ethylene production by mannose was specific, since other sugars such as galactose, glucose, sucrose and mannitol did not have an inhibitory effect. In an effort to elucidate mechanisms of mannose the effect on the auxin induced ethylene production, effect of the sugar on ACC synthase activity and ACC induced ethylene production was studied. Mannose failed to inhibit ACC mediated ethylene production, but decreased both the ACC content and ACC synthase activity in the tissue. These results suggest that the inhibitory effect of mannose on auxin induced ethylene production results from suppression of auxin induction of ACC synthase.

• Korean Journal of Weed Science
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• v.8 no.3
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• pp.244-249
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• 1988

Some experiments were conducted to utilize the raphanus test as a bioassay method for plant growth regulaters and hormonal herbicides. Among seven radish cultivars, the response of Jangbaegminong was the most sensitive and quantitative to ${\alpha}$-NAA and its coefficient of variation value was the lowest. The optimum application time of test compounds was estimated seven to nine days after seeding. After ${\alpha}$-NAA treatment the curvature angle of radish cotyledonary petiols was sharply increased to the maximum value at 24 hours after and was changed by light and temperature conditions. The curvature response was observed by application of ${\alpha}$-NAA, phenoxy and indole compounds but often plant growth regulators, $GA_3$ benzyladenine, ABA and homobrassinolide was not detected by this method. So this bioassay was useful to evaluate the activity of a compound as an auxin or a hormonal herbicide.

• The Korean Journal of Pesticide Science
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• v.15 no.4
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• pp.495-501
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• 2011

Bacterial strains were isolated from forest soils of Halla mountain, Jeju island in Korea. The soil samples were collected at each altitude of 100m from 1,000 m above sea level. Total 398 strains were isolated and tested for their physiological characteristics of antagonistic and proteolytic activities, and auxin production. Among the isolates, 172 strains were selected as antifungal strains showing antagonistic activity against at least one of 8 plant fungal pathogens (Alternaria alternata, Botrytis cinerea, Collectotrichum acutatum, Fusarium oxysporum, Phytophthora capsici, Pythium ultimum and Sclerotinia sclerotiorum). In addition 203 strains for proteolytic activity and 26 strains for auxin production were characterized for further study. Je28-4 (Rhodococcus sp.) were showed 80% of control value against tomato gray mold in vivo. Thus, it is suggested that soil bacteria isolated from forest soils of Halla mountain can be important sources of bioactive compounds for improving plant growth or promising biocontrol agents.

• FLOWER RESEARCH JOURNAL
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• v.18 no.1
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• pp.23-28
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• 2010

This study was conducted to determine the optimal rooting media composition and plant growth regulators for the mass production of new three cultivars in Dendrobium. Rooting medium experiments showed that shooting rate of 'Fizz' was the highest in perlite (Per) and vermiculite (V) mixture (1 : 1, v/v). Rooting rate of 'Prince' was 10% in the same treatment 60 days after cutting, while those of 'Candy' and 'Fizz' showed no shooting. With various kinds of auxin and different levels of concentrations, shooting rate in the other cultivars except 'Candy' increased highly at 60 days after cutting. Whereas, there were no differences between control and treatment except that of 'Fizz' with 200 ppm of IBA treatments showing 86.7%. Rates of cutting with leaves of 'Candy' and 'Fizz' were fairly high with 200 ppm of IBA compared to the control. Rate of rooting of 'Prince' was twice with 200 ppm of IBA or 50 ppm of NAA compared to the control. With various kinds of cytokinin and different concentrations, shooting rate of 'Candy' was 20% with 50 ppm of BA at 60 days after cutting; however, that of 'Fizz' increased in all treatments in 30 days after cutting and reached 100% with 200 ppm of BA compared to the control which was 77% at 60 days after cutting. Kinetin treatment had little effect on shooting rate compared to control at all concentrations. Treatment with 200 ppm of BA had clear effect on the rate of cutting with leaves of 'Fizz' and 'Prince', which was similar to shooting rate. However, the same treatment of BA had no effect on the rooting rate in all cultivars.

• FLOWER RESEARCH JOURNAL
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• v.18 no.1
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• pp.29-32
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• 2010

This study was conducted to determine the effects of cutting position, media, and auxin on rooting of Artemisia keiskeana cuttings. In the cutting positions, the cutting of middle and basal positions had a better growth in the both upper and lower part than the cutting of the top position. Especially, the cutting of the middle position showed the highest rooting rate, at 68.3%. In the media, peatmoss showed the latest date on the rooting initiation. Also, the growth, survival rate and rooting rate of the upper part and lower part were low. However, the cutting in vermiculate showed the fastest date on the rooting initiation, and had a significant effect on the growth of the upper part and lower part, showing the highest rooting rate and survival rate in all tested media. When cuttings were treated by auxin, the rooting rate and growth of cuttings were higher than the control. The control showed the lowest rooting rate, at 41%, while, the auxin treatment showed the highest, rate over 80%. Whereas when treated by NAA, the lower part of cuttings had a better growth than these treated by IBA. Also, the higher the concentration of auxin was, the higher the rooting rate and growth rate of Artemisia keiskeana cuttings were.