• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제2권2호
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• pp.159-168
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• 1998

Effect of plant growth regulators and end-product on the enzyme activities in cotyledons of Vigna angularis during germination was investigated by measuring the changes of $\alpha-amylase$ activities in attached and detached cotyledons applied growth regulators and sugars. The higher levels of $\alpha-amylase$ in detached cotyledons than those in cotyledons attached to the embryonic axis were due to both faster synthesis and slower degradation of the enzyme in the detached cotyledons than in the attached cotyledons. Levels of $\alpha-amylase$ activity were reduced by high concentrations of glucose and sucrose, and it is suggested that this effect was caused mostly by osmotic stress and partly by end-product repression. In detached cotyledons exogenously supplied $GA_3,$ IAA, kinetin, or their combinations has a small promotive effect on the developmental patterns of $\alpha-amylase$ activity ABA and uniconazole both prevented the synthesis of $\alpha-amylase$. Glucose inhibition of enzyme activity was partly reversed by the application of $GA_3,$ and CAMP. $GA_3,$ and cAMP seemed to act through a similar mechanism. The addition of inhibitors of protein and RNA synthesis largely prevented the increase of enzyme activity in the presence or absence of exogenous $GA_3,$. The pretreatment experiments with canavanine indicated that the earlier the time of addition was, the lower the amylase activity was.

• 한국환경보건학회지
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• 제33권3호
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• pp.195-201
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• 2007

The objective of present study was to examine the composition of functional components (isoflavones, phytic acid, and saponin) in hypocotyls and cotyledons of six traditional Korean soybeans, namely Cheongtae, Seoritae, Jinjoori, Subaktae, Yutae, and Huktae. Three 'family' of isoflavones, as four chemical structures were present in hypocotyls and cotyledons of six soybean cultivars: the aglycones genistein, daidzein, and glycitein; the glycosides genistin, daidzin, and glycitin; the acetylglycosides 6"-O-acetylgenistin, 6"-O-acetyldaidzin, and 6"-O-acetylglycitin; and the malonylglycosides 6"-O-malonylgenistin, 6"-O-malonyldaidzin, and 6"-O-malonylglycitin. Isoflavone contents of hypocotyls and cotyledons differed among the cultivars, and glucosides and malonylglucosides accounted for more than 90% of the total phytoestrogens, with the remaining $1\sim7%$ taken up by aglycones. Concentrations of isoflavones in cotyledons were approximately about $10\sim20%$ of respective hypocotyls. Contents of phytic acids in hypocotyls and cotyledons of the selected soybean cultivars were $1.21\sim1.70%$ and $2.59\sim3.01%$, respectively. Hypocotyls of Seoritae showed the lowest content of phytic acid with 1.21%, while cotyledons of Cheongtae showed the highest content with 3.01%. The sapogenol concentrations ranged from $13.58mg/100g\sim20.82mg/100g$ for hypocotyls and $0.95mg/100g\sim2.55mg/100g$ for cotyledons showing that concentrations of saponin are $7\sim10$ times higher in hypocotyls than in cotyledons of respective soybeans. For both hypocotyls and cotyledons the sapogenol A were present in higher concentrations than soyasapogenol B.

• Journal of Plant Biology
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• 제28권3호
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• pp.225-232
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• 1985

Intracellular localization and the developmental changes in activities of uricase and allantoinase during germination were investigated with the cotyledons of rape(Brassica napus L.) seedlings. The development anddisappearance of uricase activity took place independently of light, but allantoinase activity was increased by light. The temporal pattern of uricase activity showed that uricolysis was actively taking place in the cotyledons during their early stages of germination. While uricase can be localized in the microbody fraction isolated from crude organelle extracts of the cotyledons by density gradient centrifugation, most of the allantoinase activity found in the microbody fraction did not appear to be an integral part of the microbody.

• 한국초지조사료학회지
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• 제19권4호
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• pp.297-302
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• 1999

알파파의 재분화된 식물체로부터 다량의 이차체세포배를 유도하였으며, 이들 체세포배로부터 재분화되는 식물체의 획득빈도를 향상시키기 위하여, 캘러스에서 유래된 배의 형태 및 형태별 유식물 분화 양상에 관한 실험을 수행하였다. 2,4-D 농도에 따라 체세포배의 형성에 차이를 나타내었는데, 생장조절제가 첨가되지 않았거나, 2,4-D가 $0.1mg/{\ell}$ 첨가된 배지에서 형성된 배는 약 57% 이상이 2개의 자엽을 갖은 정상배였으며, 2,4-D 농도가 증가할수록 정상체세포배의 출현빈도는 감소하였고, 2,4-D $4mg/{\ell}$에서는 10%만이 정상배로 나타났다. 배의 형태에 따른 발아율 및 유식물 분화양상을 조사한 결과, 2개의 자엽을 갖는 정상배의 경우는 발아율이 85%로 가장 높았으며, 정상식물체로 발육되는 비율도 80%로 나타났다. 그러나 자엽이 1개 또는 3~4개인 배는 정상적으로 발육되는 식물체의 비율이 10% 이하로 매우 낮았으며, 자엽이 5개인 배와 나팔모양의 배는 정상적인 식물체로 발달하지 못하였다.

• Journal of Plant Biology
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• 제38권3호
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• pp.227-234
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• 1995

Exogenous putrescine of 0.5 mM or higher concentratons applied during a 16 h inductive dark period could elevate putrescine content in cotyledons of Pharbitis nil Choisy cv. Violet, a short-day plant, resulting in complete blocking of photoperiodic floral induction. Titers of putrescine, spermidine and spermine in the cotyledons were traced throughout a 16 h dark period. While non-induced cotyledons under continous light slightly increased levels of polyamines, induced tissue maintaiend its putrescine, spermidine and spermine levels as low as 66.4%, 60.9% and 84.9% of non-induced levels respecitvely. Endogenous polyamines kept at lower levels in the inductive dark period were found to upsurge by a night break treatment of 10 min light in the middle of the dark and consequently the inductive dark effect was canceled. Elevation of polyamine titers could also be induced by 100 $\mu$L/L ethylene treatment which completely suppressed floral induction. Compared to untreated cotyledons, ehtylene-treated tissues increased putrescine content by as much as 136.5% in 12 h and spermidine level by up to 130.1% in 8 h. Ethylene-treated cotyledons not only increased endogenous polyamine content but also liberate ethylene in the second half of the inductive dark period accumulating up to three to fourfold level supporting a hypothesis that ethylene-treated tissues are stimulated to produce ethylene which in turn accelerates polyamine biosynthesis in the tissues. It is postulated that substantially low polyamine titers in the inductive dark period would be one of the necessary factors controlling photoperiodic induction of flowering in Pharbitis nil and the inhibitory effects of night break and exogenous ethylene treatment may be atributed to their action to stimulate endogenous polyamine production.

• Journal of Plant Biology
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• 제39권1호
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• pp.71-77
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• 1996

배발생 캘러스의 선발은 1.0mg/L 2,4-D를 첨가한 MS 기본배지에서 배양한 당근 유식물의 배축절편으로부터 유도된 캘러스에서 이뤄졌다. 체세포배 발생을 유도하기 위해서 배발생 캘러스로부터 얻어진 세포괴는 2,4-D를 제거한 MS 배지에 옮겼다. 세포괴를 1.0mg/L 2,4-D 첨가배지에서 1주간 그리고 2,4-D 제거 배지에서 2주간 배양한 후에 2자엽배의 발생은 63%에 그쳤고 나머지는 1자엽 5%, 3자엽 21%, 4자엽 6%, 5자엽 5%, 6자엽 0.2% 및 나팔형 자엽 1%의 발생빈도를 나타냈다. 체세포배의 발아율은 다자엽 체세포배에서 보다 2자엽 배에서 높았다. 나팔형 자엽의 체세포배는 경엽부 발생없이 자엽과 뿌리가 다소 신장 확대되는데 그치는 등 정상적으로 발아되지 못했다. 해부학적인 관찰에서 체세포배의 뿌리와 환상 전형성층은 배축의 중간부위에서 분지되기 시작하고 자엽절을 거쳐서 자엽으로 이어지는데 배축에서 전형성층속은 자엽수와 같은 수였다. 1자엽 체세포배는 다자엽 체세포배의 각각의 자엽보다 크고 전형성층과 함께 말굽형 자엽을 가지고 있었다. 따라서 체세포배의 자엽구조는 전형성층 배열상태와 밀접한 관련이 있다는 것을 확인할 수 있었다.

• 분석과학
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• 제9권4호
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• pp.325-330
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• 1996

몸무우의 자엽에 저온과 polyamine(PA)을 처리하면 세포내의 환원당과 설탕의 농도가 증가되었고, 가을무우의 자엽에 저온처리를 하면 환원당과 설탕의 농도가 증가되나, 저온과 PA를 동시에 처리하면 세포내에 당류의 농도가 증가되지 않았다. 몸무우 자엽에서는 저온처리에 의해 총 아미노산의 농도는 증가되나, 가을무우에서는 증가되지 않았다. 이 결과는 저온에 예민한 봄무우는 세포내의 삼투조절에 의하여 적응하며, 봄무우와 가을무우 사이에 생리 및 생화학적인 대사가 다름을 보여 주었다. 저온에 예민한 봄무우에서 PA는 저온처리와 함께 상승효과를 보이나, 저온 스트레스에 강한 가을무우에서는 PA 처리로 상승효과를 나타내지 못함은 처음 보고 하는 결과이다.

• Journal of Plant Biology
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• 제30권2호
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• pp.95-108
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• 1987

Effects of allopurinol (2mM), a specific inhibitor of xanthine oxidase, on the growth and metabolism of llantoin in dark grown Chinese cabbage (Brassica campestris L.) seedlings were investigated. Allopurinol treatment maintained the fresh and dry weights of cotyledons at higher levels, but inhibited the elongation of hypocotyls and roots of the seedlings. Total nitrogen content in the cotyledons decreased at slower rate by allopurinol. Accordingly, the levels of total nitrogen contents in the hypocotyls and roots, were depressed by the inhibitor. In the cotyledons, allopurinol began to elevate RNA levels after day 3, which it did not affect DNA level throughout the experiment. Activities of xanthine oxidase (XO:EC 1.2.3.2), uricase (UO:EC 1.7.3.3) and allantoinase (AL:EC 3.5.2.5) in the cotyledons were examined. The activity of XO was not detected, but the accumulation of xanthine by allopurinol treatment presented an indirect evidence of the existence of XO in the organ. Allopurinol kept UO activity high up to day 2 after sowing and depressed AL activity throughout the experiment. By allopurinol treatment, allantoin content was kept high over the control both in cotyledons and roots, but it was kept low in hypocotyls. The level of allantoic acid in the 3 organs were shown to be depressed by allopurinol. These results suggest that allantoin and allantoic acid produced by the degradation of stored and newly synthesized RNA are transported from the storage tissue to hypocotyls and roots as important nitrogen sources for the development of Chinese cabbage seedlings.

• Journal of Plant Biology
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• 제32권4호
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• pp.293-304
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• 1989

Effects of triacontanol(TRIA) on several parameters of senescence including the changes of related enzyme activities were investigated in radish(Raphanus sativus L._ cotyledons developing in light. In senescing radish cotyledons, 1.0mg TRIA/1 retarded the degradation of chlorophyll content. Moreover, it depressed the increases of malondialdehyde and H2O2 contents compared to the control. Catalase and superoxide dismutase activities were highly maintained but the increase of peroxidase activity was inhibited remarkably under the TRIA application. These results suggested that TRIA participated in the regulation of senescence during the late part of cotyledon development where it delayed senescence through its action on free radical-associated enzymes and consequent metabolic turnover.

• Journal of Plant Biology
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• 제37권2호
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• pp.159-166
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• 1994

Direct current (DC) applied to cotyledons during a 16 h inductive dark period inhibited the flowering in the short-day plant, Pharbitis nil Choisy cv. Violet. The inhibitory effect of DC was more profound when the current flowed from roots to cotyledons, showing its polarity-dependent action. The second half on the inductive dark period was more sensitive to DC stimulus. The flowering was significantly depressed only when DC stimuli were applied to the translocation path of the floral stimulus from the induced cotyledon to the apex, suggesting that the transport of floral stimulus was damaged by the DC treatment. The vegetative apex culture bioassay system showed that a significant level of the floral stimulus activity existed in the phloem exudate from the cotyledons which would fail to form their own floral buds. These results strongly support the hypothesis that DC partially impede, at least temporarily, the transmission path of the floral stimulus from florally-induced cotyledon to the apex, rather than depressing in situ synthesis of the floral stimulus.