• Journal of Plant Biology
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• v.39 no.2
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• pp.107-112
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• 1996

To study the compensatory aspect of putrescine biosynthetic enzyme n tobacco suspension cultured cells, we examined the contents of the cellular polyamines and the activities of arginine decarboxylase (ADC, EC 4.1.1.19) and ornithine decarboxylase (ODC, EC 4.1.1.17) in the tobacco suspension cells treated with $\alpha$-difluoromethyl arginine (DFMA) or $\alpha$-difluoromethyl ornithine (DFMO). In the untreated cells, the content of the cellular putrescine was decreased during the first 3 hours and then subsequently increased. However, the content of the cellular spermidine and spermine remained constant during the incubation time. While ADC activity increased after 6 hours, ODC activity decreased following the rapid increase until 6 hours. DFMA induced the decrease in the contents of putrescine and spermidine, and the increase in that of spermine. It also caused the inhibition of ADC and ODC activities throughout the incubation time. DFMO produced the stimulation of ADC activity about 2 times of untreated cells and the decrease in the content of putrescine about 50% of them at 12 hour. The application of putrescine or cycloheximide prevented the increase of ADC activity by DFMO but that of actinomycin-D did not show any detectable effect. The stimulation of ADC activity by DFMO in tobacco suspension cultured cells was probably due to the enhancement of de novo synthesis for ADC protein, which might be regulated in the translation step by the content of the cellular putrescine.

• Journal of Ginseng Research
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• v.13 no.2
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• pp.229-233
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• 1989

The effect of some phytohormones and light on the growth, ADC activity and polyamine content in ginseng was studies. In seedlings, the growth, ADC activity and putrescine content were in creased by Ghs treatment. ADC activity ann putrescine content were slightly slightly derreased by ABA, but not changed by kinetin. Light treatment increased ADC activity and putrescine content greatly. In two year ginseng leaves treated by GA3, the ADC actin$.$its reached maximum and the spermidine content reached maximum 2 days faster than in the control. Thtse results suggest the possibility that these regulators are closely related to growth and polyamine cotent. UeVo'ordsEPanaxgineng C.A. Meyer, Polyamine, Putrescine spermidine, arginine decarboxylose, GA3 kiiletin , ABA.

• Applied Biological Chemistry
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• v.39 no.2
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• pp.112-117
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• 1996

Arginine decarboxylase (ADC) is the first enzyme in one of the two pathways of diamine putrescine biosynthesis in plants. The genes encoding ADC have previously been cloned from Escherichia coli, oat and tomato genome. Two degenerate oligonucleotides (17-mer) corresponding to two conserved regions of ADC were used as primers in polymerase chain reaction of rice (Oryza sativa L.) genomic DNA, and an approximately 1.0 kbp fragment was obtained. This amplified PCR product showed an open reading frame which contains 1,022 bp of nucleotide sequences. This PCR product was cloned into pGEM-originated T vector and the short 500 bp PstI digested fragment was subcloned into pGEM-3zf(+/-) vectors to facilitate sequencing. The nucleotide sequence of this PCR product showed about 74% and 70% identity with the same regions of the oat and tomato ADC cDNA sequences, respectively. The predicted amino acid sequence exhibited 45% and 62% identity with oat and tomato ADC polypeptide fragments, respectively. The sequence similarities of 34%, 47% and 38% were previously reported in oat and E. coli, tomato and oat, and tomato and E. coli ADC amino acids, respectively. Therefore, similarities and identities between rice and oat or tomato are remarkably higher than those others of the previous reports. In the highly conserved regions in both the amino acid sequence and spacing regions among the sequences of these three, rice ADC open reading frame also has the exactly same regions with the striking similarity. RNA blot analysis showed that hnc is expressed as a transcript of approximately 2.5 kbP in the rice seedling leaf tissues.

• Journal of the Korean Society of Tobacco Science
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• v.21 no.1
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• pp.26-35
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• 1999

Effects of $\alpha$-difluoromethylornithine (DFMO) and $\alpha$-difluoromethylarginine (DFMA), inhibitors of polyamine syntheic enzymes (ornithine decarboxylase, arginine decarboxylase), on ovary were investigated during pupal-adult development of Helicoverpa assulta. Two inhibitors (DFMO, DFMA) showed definite inhibition effects on ovarian development. The inhibition effect on ovaries weight was more marked in DFMA-injection than that observed in DFMO-injection. Two inhibitors (DFMO, DFMA) gave rise to a peculiar decrease in ornithine decarboxylase (ODC) or arginine decarboxylase (ADC) activity in ovaries, 72 hrs (5-day old pupa) post injection. However, DFMO clearly exhibited supression of ODC activity after 96 hrs (6-day old pupa). In addition, two inhibitors (DFMO, DFMA) diminished putrescine content in the ovary. The spermidine level was slightly decreased by each injection of the inhibitors. However, two inhibitors (DFMO, DFMA) raised the spermine content at certain developmental stages in the ovary. Although the effect of DFMA was less severe, two inhibitors (DFMO, DFMA) caused not only an overall delay in ovarian development, but also abnormalities in cellular differentiation. Noted effects in the pupal ovary were the appearance of irregular nurse cells and partial destruction of follicle epidermal cells. Adult ovary showed rapid degradation of nurse cells, a reduction in the number of follicle epidermal cells and immature oocytes that had a low yolk content.

• Journal of Ginseng Research
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• v.13 no.1
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• pp.19-23
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• 1989

The polyamine and its biosynthetic enzyme In ginseng has been studied , We have found that putrescine was a major polyamine in ginseng seedling. Putrescine was increased with growth stage , and ADC activity was also increased as putnescine content. But ODC activity was not shown. ADC activity was shown l0% inhibition by spermidine and 20% inhibition by spermine but not affected by putrescine. in contrast to seed, spermidine was a major polyamine in two year old ginseng. The abundance was decreased in order of leaf, petiole, root, and stem. ADC activity seemed to parallel with polyamine content.

• Journal of Plant Biology
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• v.36 no.1
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• pp.1-8
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• 1993

Polyamine contents and the activities of their main biosynthetic enzymes, arginine decarboxylase (ADC) and ornithine decarboxylase(ODC), were investigated in Populus leaf segments during adventitious shoot regeneration with the addition of 1 millimolar polyamine synthesis inhibitors. From the study of polyamine synthesis inhibitors, ODC was found to be the principal route of polyamine biosynthesis in adventitious shoot regeneration of Populus leaf segments. The ADC inhibitor difluoromethyl arginine(DFMA) and ODC inhibitor difluoromethyl ornithine(DFMO) strongly reduced the putrescine content. On the contarary, DCHA, an inhibitor of spermidine synthase, increased it. Spermidine content was decreased with the treatment of each polyamine synthesis inhibitor, but the inhibitory effect of DCHA was stronger than any other polyamine inhibitor. The decreased polyamine level by polyamine synthesis inhibitors was restored with the exogenously applied polyamine. Comparing the polyamine contents with the adventitious shoot regeneration rate, were observed a close correlation between spermidine content and adventitious shoot regeneration of Populus leaf segments.

• Journal of Plant Biology
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• v.33 no.4
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• pp.243-251
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• 1990

Polyamine titers and the activities of arginine decarboxylase(ADC) and ornithine decarboxylase (ODC), enzymes which catalyze rate-limiting steps in polyamine biosynthesis, were investigated during polar regeneration of Populus leaf segments. The polar regeneration occurred at the basal cut end of Populus leaf segments through cell division around the vascular bundle. In the process of polar regeneration, the titers of putrescine and spermidine increased rapidly but the content of spermine remained constant. The leaf segments were then divided into three separte part ; the proximal, middle and distal. Spermidine titers showed an increase mainly in the proximal parts where polar regeneration occurred. On the other hand, putrescine titers showed an increase in the other two parts. In the course of polar regeneration, the activities of ADC and ODC increased, the ADC activities being higher than those of ODC. However, ODC activity was higher in the proximal part. Therefore, the spermidine contents and ODC activities are suggested to be related to polar regeneration in Populus leaf segments.

• Journal of the Korean Society of Tobacco Science
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• v.21 no.1
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• pp.17-25
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• 1999

To elucidate the effect of elevated sublethal temperature ($33\pm1^{\circ}C$) on polyamine metabolism and oogenesis, we investigated alterations in the major polyamines and ornithine decarboxylase (ODC) and arginine decarboxylase (ADC), and ovarian development during the pupal-adult development of the tobacco budworm, Helicoverpa assulta. Ovaries ODC activity under the elevated sublethal temperature ($33\pm1^{\circ}C$) were lower than those of the optimal rearing temperature ($25\pm1^{\circ}C$). whereas ovarian ADC activity was consistently higher than the optimal rearing temperature ($25\pm1^{\circ}C$). When the gonads were exposed to the higher temperature, ovarian putrescine showed somewhat suppressed levels throughout development, indicating a relatively high correlationship with the alteration aspects in ODC or ADC activity under elevated sublethal temperature. A somewhat precocious ovary was observed in an early stage of development at $33\pm1^{\circ}C$, but cellular abnormalities occurred in this ovary. The ovary developed under elevated sublethal temperature was observed the inhibitional effect of polyamine metabolism and the abnormal development of ovariole, which seem to be related to the sterility.

• Journal of Plant Biology
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• v.32 no.4
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• pp.285-292
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• 1989

The intracellular localizations of polyamines and their related enzymes were investigated from young spinach leaves. Polyamines were present in all parts of plant cells, both in the subcellular organelles and in the soluble fraction of cytoplasm, however, polyamines were mainly located in the cytosolic fraction. Most activities of L-arginine decarboxylase(ADC) and L-ornithine decarboxylase(ODC), two important enzymes of putrescine and polyamine biosynthesis, were detected in cytosol fraction, while in subcellular organelles the activities were very low. Activities of diamine oxidase(DAO) and polyamine oxidase(PAO), the catabolic enzyme of diamine and polyamine, were not detected in spinach leaves. It was suggested that polyamines and their related synthetic enzymes were located in the soluble fraction of cytoplasm.