• Journal of Plant Biology
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• v.33 no.2
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• pp.87-96
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• 1990

The role of S-adenosylmethionine (SAM) as an intermediate in interrelation between polyamine and ethylene biosynthesis was studied in suspension cultures of Nicotiana tabacum L. Exogenous SAM stimulated the polyamine and ethylene biosynthesis in 4 day-cultured cells, which were in active cell divisions, and 10 day cultured cells, which went on with active cell elongation and senescence. SAM-induced ethylene production was more effective in 10 day-cultured cells than in 4 day-cultured cells, but SAM-induced polyamine biosynthesis was more effective in 4 day-cultured cells than in 10 day-cultured cells. Polyamine contents were increased by the blockage of ethylene biosynthetic pathway in the conversion of SAM to ethylene via 1-aminocyclopropane-1-carboxylinc acid (ACC) with aminooxyacetic acid (AOA). Also, ethylene production was increased by the inhibitors of polyamine biosynthesis such as methylglyoxal bis-(guanylhydrazone) (MGBG), dicyclohexylamine (DCHA), $\alpha$-difluoromethylarginine (DFMA) and $\alpha$-difluoromethylorinithine (DFMO). These results suggest that there may be interrelations between polyamine and ethylene biosynthesis for the competition of SAM and the inherent mechanism of switch on-off in polyamine and ethylene biosynthetic activity with the progress of cell growth and senescence.

• Plant Biotechnology Reports
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• v.3 no.4
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• pp.347-353
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• 2009

Procedures that induce microspore embryogenesis have been described for a range of Brassica species, but embryo yield remains low for a number of genotypes. We have carried out experiments with the microspores from a weakly responsive line of B. napus to determine the culture conditions that optimize their in vitro embryogenesis by treating them with effectors of ethylene synthesis and action. The results revealed that isolated microspores subjected to an initial heat stress in a medium supplemented with inhibitors of ethylene synthesis such as AVG and $CoCl_2$ exhibited significantly increased embryo yields. This suggested that regulatory effects are exerted by the ethylene produced by the isolated microspores on the early processes of gametogenesis. As a consequence, treatment of microspores with SAM, an ethylene synthesis precursor, or with the ethylene-releasing agent ethephon, led to decreases in embryo yield. A special response to ethylene during the early stages of microspore development was finally shown to occur through experiments where isolated microspores were treated for increasing periods of time with $CoCl_2$. Collectively, our data demonstrated that the induction of embryogenesis induced by heat stress can be enhanced by inhibitors of ethylene 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.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.4
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• pp.300-304
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• 2004

Gibberellic acid did not affect ethylene production, whereas gibberellin biosynthesis inhibitors triggered ethylene production in dormant tubers. Gibberellic acid did not induce sprouting of dormant tubers, however, treatment of gibberellin biosynthesis retardants enhanced sprouting rates. Sprouting rate in ancymidol-treated tubers was highest among gibberellin biosynthesis retardants. Sprouting rate of tubers treated with ancymidol increased to $91.4\%$. Batatasin-III content in $GA_3$ treated tuber was increased in the highest concentration $(30{\mu}g\;I^{-1})$. Tubers treated with mepiquat chloride, Batatasin-I was increased steadily, but contents of Batatasin-III and V showed dramatic decrease at the $ 1,000{\mu}g\;I^{-1})$ concentration. This infers that gibberellin biosynthesis retardants play key roles in promoting breaking dormancy on dormant tubers of Chinese yam.

• Korean Journal of Weed Science
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• v.12 no.1
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• pp.39-45
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• 1992

This experiment was conducted to evaluate the effect of gibberellin biosynthesis retardants as used by rice lodging inhibitors on the gibberellin antagonism, auxin interation, ethylene evolution and growth of second crops. Results obtained can be summarized as follows. Inabenfide, paclobutrazol and uniconazole markedly inhibited the epicotyl elongation of mung bean. Inhibiting effect of epicotyl by these chemicals was markedly stimulated by gibberellic acid, thus showing clear antagonism between these chemicals and gibberellic acid. Significantly large number of roots were formed in the mung bean cuttings which were rooted in the paclobutrazol and uniconazol of 1 ppm. The higher the concentration, the more the number of roots forms. It was guessed that these effect was closely related with auxin. Ethylene evolution was a little stimulated in the leaf of rice under the treatment of inabenfide, paclobutrazol and uniconazole at earlier stage(5 DAT), however it was suppressed at later stage(10, 30 DAT) at higher concentration. The effect of gibberllin biosynthesis inhibitors to second crops retarded tomato plants without influencing the height of barley. The treatment of paclobutrazol and uniconazol which is triazole-type more severely inhibited than that of inabenfide which is isonicotinanilide-type. The more the concentration, the less the height of tomato plants.

• Plant Breeding and Biotechnology
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• v.5 no.3
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• pp.204-212
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• 2017

There is a growing preference for using doubled haploids (DHs) in maize breeding programs because they reduce the time required to generate and evaluate new lines to 2 years or less. However, there is an urgent need for efficient techniques that accurately discriminate between haploid and diploid maize kernels. Here, we investigate the effects of several hormones and chemicals on the germination of haploid and diploid maize kernels, including auxin, cytokinin, ethylene, abscisic acid (ABA) biosynthesis inhibitor (fluridone), ABA catabolism inhibitor (diniconazole), methyl jasmonate (MeJA), and NaCl. Ethylene effectively stimulated the germination of both haploid and diploid maize kernels. The ABA biosynthesis inhibitor fluridone, the ABA catabolism inhibitor diniconazole, and MeJA selectively stimulated the germination of haploid maize kernels. By contrast, gibberellin, 1-naphthaleneacetic acid (NAA), kinetin, and NaCl inhibited the germination of both haploid and diploid maize kernels. These results indicate that the germination of haploid maize kernels is selectively stimulated by fluridone and diniconazole, and suggest that ABA-mediated germination of haploid maize kernels differs from that of diploid maize kernels and other plant seeds.

• 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.

• Korean Journal of Plant Tissue Culture
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• v.22 no.6
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• pp.345-350
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• 1995

Root gravitropism was investigated in the pea (Pisum sativum L.) mutant ageotropum lacking normal gravitropic response. Exogenous ethylene treatment inhibited gravitropic response in the normal (wild type) pea rook, but had no significant effect to restore the unresponsiveness in the mutant Neither inhibitors of ethylene biosynthesis nor antagonists of ethylene action were able to bring about the development of gravioopic curvature in the ageotropum roots. Auxin action seems to be normal since asymmetric application of agar blocks containing auxin to the mutant roots caused normal gravitropic response to occur. Endogenous as well as auxin-induced ethylene production in tissue segments of the mutant root was about equal to that of the wild type. However no appreciable lateral transport of labeled auxin was observed in glavistimulated mutant roots whereas typical auxin asymetry was apparent in the wild type roots under the same conditions. It is concluded that the mutant has a defect in either gravity perception or its transduction, but not in the effector system involving auxin action.

• FLOWER RESEARCH JOURNAL
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• v.19 no.3
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• pp.139-143
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• 2011

This research was conducted to figure out the effect of 1-methylcyclopropene, one of inhibitors of ethylene on the vase life of cut alstroemeria 'Alpine', snapdragon 'Fuji no Yuki', dahlia 'Toast, and lily 'Georgia'. Four kinds of cut flowers were treated with 250, 500, and 750 ppb of 1-MCP respectively for 12 hours. In case of cut alstroemeria, no significant difference was found between the untreated control and the treated ones in the days to flowering. The vase life in the treated ones, however, was extended for over two days, and the treated one with 250 ppb had the longest record with 17.1 days. In every treated ones of cut snapdragon, the remaining florets was more than that of the untreated control. The vase life showed, however, no difference. With the 1-MCP treatment, the vase life of cut dahlia was longer about two days than that of the untreated control. However, water uptake showed the opposite result. The vase life of cut lily showed no significant differences in all treatments. In case of water absorption, the treated one with 750 ppb uptaken more water by 3 ml.