• Journal of Plant Biotechnology
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• v.30 no.2
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• pp.151-154
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• 2003

This study was conducted to determine the optimal concentrations of plant hormones (2,4-D, picloram, dicamba, NAA, kinetin) and the suitable explants among seeds, hypocotyl, and cotyledons on calls formation and plant regeneration of stevia(Stevia rebaudiana Bertoni). The frequency of cellus formation was higher in the young leaf-explants then the older ones, and in the seeds then the hypocotyls and cotyledons on MS medium with 1mg/L 2,4-D. After transfer of seed-derived stevia callus producing embryogenic callus on plant-regeneration medium, the frequency of plant regeneration from callus was 23.8% in MS medium with 1mg/L NAA and 3mg/L kinetin.

• 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.

• Journal of Crop Science and Biotechnology
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• v.11 no.3
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• pp.187-192
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• 2008

The effects of some coumarins(coumarin, 7-hydroxycoumarin, scopoletin and esculetin) were investigated on pumpkin(Cucurbita maxima Duch.) seedlings and on pumpkin glutathione S-transferases(GSTs). Coumarin and esculetin suppressed the growth of seedlings, especially the elongation of roots as well as hypocotyls. Among the compounds tested, only esculetin inhibited the activity of a particular pumpkin GST by 50%, CmGSTU3 toward 1-chloro-2, 4- dinitrobenzene(CDNB) and at a concentration of 22 ${\mu}M$. Both ethylacetae(EtOAc) and water fractions in pumpkin seedlings and different organs of one-month-old pumpkin plants contained esculetin or similar hydrophobic fluorescent substances as well as hydrophilic substances, which showed different degrees of inhibitory effects on CmGSTU3 activity.

• Journal of Plant Biology
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• v.27 no.2
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• pp.43-50
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• 1984

Effects of IAA on the elongation and cell wall hlysocidase activities were investigated in excised rape (Brassica napus L. cv. Yongdang) hypocotyl segments. IAA promoted the elongation of rape hypocotyl segments. In rape hypocotyls, the first 10-mm segments from the hook exhibited maximal elongation and the capacity of elongation was gradually decreased with increasing distance of each 10-mm from the hook. A good correlation has been obtained between the magnitude of endogenous growth and the activities of $\alpha$, $\beta$-glucosidase and $\alpha$, $\beta$-galactosidase. However, exogenous application of IAA did not seem to enhance the tissue with IAA resulted in acidification of the incubation medium. From these data, we can conclude that IAA seems to enhance elongation of the tissue segments, at least in part, by releasing hydrogen ion into cell wall, some of which may participate in the cell wall extension process, but does not seem to trigger the activation of $\alpha$, $\beta$-glucosidase and $\alpha$, $\beta$-galactosidase.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.3
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• pp.220-225
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• 2010

Soybean sprouts produced at optimal temperature are placed or displayed for several days in market shelf of relatively cool temperature (ca. $13^{\circ}C$). During this period a number of changes occur including changes in color, smell, taste, nutritional quality, etc. In order to investigate the changes of these factors, soybean sprouts packed in plastic film bag (OPP+PE) were stored at the two different temperature ($3^{\circ}C$ and $13^{\circ}C$). Morphological characters, physicochemical changes and enzymes activity related to visible quality (color) of soybean sprouts were examined. The numbers of fine roots were greater and hypocotyls were longer in soybean sprouts stored at $13^{\circ}C$, although there was no significant difference in diameter, fresh weight and dry weight of hypocotyls between the two storage temperatures. Browning of hypocotyl, as an indicator of a typical deterioration in sprout quality, was highly dependent on the activity of polyphenol oxidase (PPO). Considering the low level of soluble protein in hypocotyls, the relatively higher activity of PPO suggested a critical role of PPO in stored soybean sprouts. PPO activity of sprouts stored at $13^{\circ}C$ was 2-fold higher than that of sprouts stored at $3^{\circ}C$ after 4 days. In sprouts stored at $13^{\circ}C$, the PPO activity was increased from day 0 until 6 days and since then, it was not detected. Crude protein content was increased to 30.9~35.4% based on dry weight with extended storage period. The change in crude protein was greater in sprouts stored at high temperature ($13^{\circ}C$). Total free amino acid content was increased in both temperatures. However, the changing rate of free amino acid was greater in sprouts stored at $13^{\circ}C$.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.6
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• pp.482-486
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• 2004

Benzyladenopurine (BA), a synthetic chemical commonly used for bean sprout culture, should be minimized for wellbeing foods or not be applied. The study was done to check the effect of different BA concentrations treated during 5 hour imbibition on growth and morphological characters of mungbean sprouts. The mungbean seeds of 3 cultivars (Keumseongnogdu, Owoolnogdu, and Zhong Lu 1) were imbibed for 5 hours in the solutions with different BA concentrations (0, 25, 50, 75, and 100 ppm) before 3 hour aeration. On the 6th day after culture, the mungbean sprouts were classified by 4 categories on the base of hypocotyl length; > 7cm, 4 to 7cm, < 4cm, and non-germination, and their morphological characters, fresh and dry weights were measured. Regardless of cultivars the composition rate of hypocotyls of longer than 7cm was decreased with increased BA concentration over 50 ppm while the reverse result was true in the rate of shorter than 4cm. In the rate of 4 to 7cm. cv. Owoolnogdu showed the highest rate in its 50 ppm concentration although cv. Keumseongnogdu and Zhong Lu 1 showed similar result to the above two rates. Formation rate and its number of lateral roots were largely changed around 50 ppm concentration but the roots was not formed in over its 75 ppm concentration. Hypocotyl and root lengths of all the cultivars were shortened with increased BA concentration. In the diameter of middle part of hypocotyl, 3 cultivars showed nearly the same responses as the rate of 4 to 7cm hypocotyls. Hypocotyl and total fresh weights per sprout were heavier in BA treated sprouts than in no treated ones but the weights of the former sprouts were not influenced by its different concentrations.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.6
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• pp.472-476
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• 2004

Lateral roots formed on mungbean sprouts should lower their quality. The study was carried out to clarify the effects of aeration periods (AP; 1, 2, 3, and 4 hours) and temperature (AT; 20, 30, and $40^{\circ}C$) after 5 hour seed imbibition into 50 ppm benzyladenopurine (BA) solution on growth and morphological characters of mungbean (cv. Keumseongnogdu, Owoolnogdu and Zhong Lu 1) sprouts. On the 6th day, the mungbean sprouts were sorted by 4 categories on the base of hypocotyl lengths; > 7cm, 4 to 7cm, < 4cm, and non-germination to calculate their composition rates, number of lateral roots, lengths of hypocotyl and root, diameters at middle and upper parts of hypocotyl, fraction fresh and dry weights were measured. AP more affected growth of the cultivars than AT showing little effect on them. In the composition rate of the above 4 categories, cv. Zhong Lu 1 had the highest rate in longer than 7cm but nearly the same rate in AP treatments. Rates of longer than 4cm hypocotyls in cv. Keumseongnogdu, Owoolnogdu were increased with longer AP but their rates of shorter than 4cm showed reverse response to the former. Formation rate and number of lateral roots per sprout were decreased with longer AP, showing more severe decrement when delayed 3 to 4 hour AP. Upper part of hypocotyls and roots were more thickened and shortened in longer AP, respectively. Total fresh weights had no significant difference between AP treatments while hypocotyl fresh weights were increased with longer AP. It was concluded that in mungbean sprout culture aeration from BA treatment to the first watering permitted at least 4 hours.

• Journal of Plant Biotechnology
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• v.2 no.2
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• pp.61-71
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• 2000

By screening a cDNA library of auxin-treated mung bean (Vigna radiata L.) hypocotyls, we have isolated two full-length cDNA clones, pVR-ACS6 and pVR-ACS7, for 1-aminocyclopropane-1-carboxylate (ACC) synthase, the rate-limiting enzyme in the ethylene biosynthetic pathway. While PVR-ACS6 corresponds to the previously identified PCR fragment pMBA1, pVR-ACS7 is a new cDNA clone. A comparison of deduced amino acid sequences among auxin-induced ACC synthases reveal that these enzymes share a high degree of homology (65-75%) to VR-ACS6 and VR-ACS7 polypeptides, but only about 50% to VR-ACS1 polypeptide. ACS6 and ACS7 are specifically induced by auxin, while ACS1 is induced by cycloheximide, and to lesser extent by excision and auxin treatment. Results from nuclear run-on transcription assay and RNA gel blot studies revealed that all three genes were transcriptionally active displaying unique patterns of induction by IAA and various hormones in etiolated hypocotyls. Particularly, 24-epibrassinolide (BR), an active brassinosteroid, specifically enhanced the expression of VR-ACS7 by distinct temporal induction mechanism compared to that of IAA. In addition, BR synergistically increased the IAA-induced VR-ACS6 and VR-ACS7 transcript levels, while it effectively abolished both the IAA- and kinetin-induced accumulation of VR-ACS1 mRNA. In light-grown plants, VR-ACS1 was induced by IAA in roots, whereas W-ACS6 in epicotyls. IAA- and BR-treatments were not able to increase the VR-ACS7 transcript in the light-grown tissues. These results indicate that the expression of ACC synthase multigene family is regulated by complex hormonal and developmental networks in a gene- and tissue-specific manner in mung bean plants. The VR-ACS7 gene was isolated, and chimeric fusion between the 2.4 kb 5'-upstream region and the $\beta$-glucuronidase (GUS) reporter gene was constructed and introduced into Nicotiana tobacum. Analysis of transgenic tobacco plants revealed the VR-ACS7 promoter-driven GUS activity at a highly localized region of the hypocotyl-root junction of control seedlings, while a marked induction of GUS activity was detected only in the hypocotyl region of the IAA-treated transgenic seedlings where rapid cell elongation occurs. Although there was a modest synergistic effect of BR on the IAA-induced GUS activity, BR alone failed to increase the GUS activity, suggesting that induction of VR-ACS7 occurs via separate signaling pathways in response to IAA and BR.

• Analytical Science and Technology
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• v.13 no.3
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• pp.346-350
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• 2000

Boiling stable proteins of 53 kDa and 29 kDa existed natively in the cotyledons of Bak Kyoung, fall radish (Raphanus raphanistrodes L.) Boiling stable proteins of 36 kDa and 16.5 kDa were newly induced by cold stress and the proteins of 53 kDa and 29 kDa increased during the cold stress. The proteins of 53 kDa were denatured within 2 hrs after removing cotyledons from plants. Boiling stable proteins of 53 kDa existed natively in the hypocotyls as much as in the cotyledons whereas 24 kDa and 18 kDa proteins were increased by stress. Boiling stable proteins of 53 kDa were induced and those of the 25 kDa and 23 kDa were increased by cold treatment and ABA treatment in the cotyledons of Jangchundaehyung F1 spring white (Raphanus raphanistrodes L.). These results showed the differences of induced boiling stable proteins between fall radishes and spring radishes. Cycloheximide inhibited the induction of 25 kDa and 23 kDa proteins during stress. 22 kDa native protein disappeared during ABA treatment and reappeared by cycloheximide treatments. It may be explained that cycloheximide was responsible for the destruction process of proteins in the living organisms. The profile of boiling stable proteins in hypocotyls of spring radishes during stress was same as that of fall redishes.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.6
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• pp.429-436
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• 2003

The relationship between seeding depth and apical hook opening was investigated in the hypocotyl hook of soybean (Glycine max Merr., cv. Hwanggeum). Seeds were sawn in different depths (2.5, 5.0, 7.5, and 10.0 cm). The hook opening was slowly progressed with seeding depth. Hook angle opening velocity was negatively correlated with hypocotyl growth at the significant level of P<0.01. It was also clearly observed that seeding depth was positively correlated with hypocotyl growth, suggesting the induction of hypocotyl growth by deep sawing. Futhermore, the contents of fructose and glucose in hypocotyls were about higher than in cotyledons. Both sugars in hypocotyls were highest at the emergence stage. After emergence, their levels were obviously reduced. Total soluble sugar contents continuously retained in cotyledons which were grown at 2.5 and 5.0 cm seeding depths whereas the contents in cotyledons of deep sawn soybean were extremely lowered. It seemed that sugars were actively used to cell construction during the hypocotyl elongation. The results demonstrated that apical hook opening is closely related with light signal after emergence. It implied that the delay of hook opening in deep sawn seeds was resulted from hypocotyl growth in darkness. We suggest that apical hook opening is progressed in sucrose catabolism by light.