• Journal of Plant Biotechnology
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• v.44 no.4
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• pp.431-437
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• 2017

Mulberry (Morus sp.) of the family Moraceae is very economically important in Asian countries including Korea, because its leaf and fruit have been commercially used in sericulture and horticultural industries. Therefore it is necessary to develop the optimal production system for rapid and cost-effective propagation of mulberry. Our studies focused on establishing an acclimatization method for the successful plantlet production of new cultivar 'Cheongsu' which was transferred ex vitro after in vitro culture. In particular, effect of abscisic acid (ABA) addition into the last subculture medium on plantlet response to subsequent ex vitro transfer and its growth was investigated. During acclimatization, stomatal conductance and transpiration rate of ABA-pretreated plantlets were significantly lower than those of non-treated plantlets. Net photosynthetic rate of ABA-pretreated plantlets decreased after ex vitro transfer but increased after 14 days, and it was mostly higher than that of non-treated plantlets. Moreover, relative water content as well as chlorophyll contents and its ratio were also higher in ABA-pretreated plantlets. On the other hand, proline was considerably higher than in control plantlets. After 1 month of ex vitro transfer, survival rate of ABA-pretreated plantlets was 85.6%, which increased by 29.1% in comparison with control (56.5%). More vigorous growth was also observed in ABA-pretreated plantlets. From these results, it was found that application of ABA to the last subculture medium could improve acclimatization and promote survival of mulberry plantlets after ex vitro transfer, inducing water stress tolerance and alleviating abiotic stresses.

• Journal of Korean Society of Forest Science
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• v.83 no.3
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• pp.410-423
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• 1994

Seasonal and diurnal changes of stomatal diffusive resistance(S.D.R.) and transpiration rate(T.R.) were investigated for determining the ecophysiological water relations of economic tree species subjected to chronic water stress or exogenous abscisic acid treatment. Four species of oaks including Quercus serrata, Q. mongolica. Q. acutissima, and Q. variabilis were used as the experimental materials and also Fraxinus rhynchophylla was studied together with oaks. Stomatal diffusive resistances were repeatedly measured on the containerized 1-0 year seedlings subjected to two kinds of soil moisture regime (wet and dry) in June, August, and September by LI-1600 Steady State Porometer of LI-Cor, Inc.. Exogenous abscisic acid (ABA) solutions of 0.5 mM and 0.05 mM in July and August, respectively, were absorbed into shoots cut from the containerized seedlings for determining their effects on stomatal behavior and transpiration. Most of measurements in stomatal diffusive resistance maintained about 5 s/cm in the morning after sunrise despite of different treatments. But the values fluctuated frequently to high level above 20 s/cm through the afternoon until sunset in the seedlings subjected to dry soil moisture regime. Despite of various treatments and environmental conditions, stomatal diffusive resistances of Q. variabilis were more stable than those of Q. serrata or Q. acutissima. Their values of F. rhynchophylla changed more irregularly in comparison with those of oak species. Exogenous abscisic acid absorbed into shoots cut from seedlings increased stomatal diffusive resistance obviously in most of the species studied. The stomatal responses to abscisic acid treatment were more sensitive in July especially in Q. serrata than in Q. variabilis and Q. acutissima. But the effects of ABA treatment were presented more remarkably in Q. acutissima in August. The responses to abscisic acid were not certain in F. rhynchophylla because of their various fluctuation patterns.

• The Plant Pathology Journal
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• v.24 no.4
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• pp.400-406
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• 2008

To examine the relationship between plant hormones and the development of pepper anthracnose, we investigated the effects of several plant hormones on the progression of disease symptoms. Of the five plant hormones examined, abscisic acid (ABA) increased the lesion length and disease incidence on detached fruits of Capsicum annuum cv. Nokkwang. The simultaneous application of ABA with inoculation of Colletotrichum acutatum JC24 resulted in increased lesion length, depending the concentration of ABA applied. Additionally, application of ABA caused the development of pepper anthracnose in fruits of Capsicum baccatum cvs. PBC80 and PBC81, which were previously resistant to the disease. Furthermore, ABA administration rendered increased pathogenicity of other isolates of C. acutatum BAC02063, PECH10, and TCBNU3 obtained from the Chinese matrimony vine, peach, and tea tree, respectively. Our data suggest that exogenous ABA may result in the suppression of defense mechanisms of pepper fruits against anthracnose, which leads to a change in the susceptibility of pepper fruits and the development of pepper anthracnose.

• Korean Journal of Environmental Biology
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• v.23 no.1
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• pp.47-51
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• 2005

Three-weeks old Commelina communis was transferred to Hoagland solution (Control, 100 μM Cd/sup 2+/, 100 μM Cd/sup 2+/ + 100 μM ABA, 100 μM Cd/sup 2+/+50 mM KCl) and grown for a week in the solution and then a number of physiological activities were investigated. In cases of Cd/sup 2+/ and Cd/sup 2+/ + ABA treatments, the growth of the plants was inhibited to 71 % and 81 %, respectively, when compared with the control, but there were no significant difference of plant growth between Cd/sup 2+/ and Cd/sup 2+/ + KCl- treated plants. In the treatments of Cd/sup 2+/, Cd/sup 2+/ + ABA and Cd/sup 2+/ + KCl total chlorophyll contents were reduced to 32%, 41% and 29%, respectively. In chlorophyll fluorescence experiments, Fv/Fm ratios were also reduced to 14∼20% and about 23%, respectively, according to the light intensity by Cd/sup 2+/ and Cd/sup 2+/+ABA-treated plants. Water stresses were increased by the treatment of Cd/sup 2+/, Cd/sup 2+/ + ABA and Cd/sup 2+/ + KCI. In Cd/sup 2+/ accumulation experiments Cd/sup 2+/ transport into the plant by ABA was not affected, but the accumulation of Cd/sup 2+/ into the roots was elevated to 13% when compared with the control. Cd/sup 2+/ transport into the root was markedly inhibited to 60% by KCl. Therefore, it could be concluded that ABA did not reduce the toxicities of Cd/sup 2+/, but enhanced Cd/sup 2+/ - induced toxicities and KCl showed no effect on Cd/sup 2+/ - induced toxicities.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.1
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• pp.47-52
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• 1985

A radioimmunoassay technique has been developed for the quantitative analysis of Abscisic acid (ABA). The antibody, obtained by immunizing rabbits against a conjugate of ABA with human serum albumin, had a high affinity (Ka=3.28x10$\^$13/l/mol) for ABA. The use of $^3$H-labelled ABA as tracer and of dextran-coated charcoal for separation of free ABA from antibody-bound ABA permitted detection of as little as 0.5x10$\^$-12/ mol ABA. The measuring range extended to 14x10$\^$-12/ mol. Because of the high specificity of this immunoassay, no extract purification steps were required prior to analysis. And then, only 2 hr in radioimmunoassay was required to ABA analysis. From these results, it is suggested using this assays that more than hundreds samples can be assayed sensitive and simple per day for ABA.

• Journal of Plant Biology
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• v.29 no.1
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• pp.41-51
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• 1986

The plants of Nicotiana tabacum L. cv. NC2326 were germinated in 10 cm D$\times$20 cm H polyethylene pot, and sand-cultured with Hoagland solution near by the window of laboratory room(26$\pm$5$^{\circ}C$). The growing plants were sprayed with various concentrations of ABA around 9 : 00 a.m. once in every two days for 12 weeks in summer. As the results, frequency of stomatal number, stomatal opening, chlorophyll content, respiration rate, and protein content in the leaves were decreased with the increasing of concentrations of ABA, respectively. The plant growth was inhibited by exogenous ABA, but leaf abscission was not found during the experimental period. The ratio of three to one in chlorophyll a to b was not altered by exogenous ABA. All the stomata were closed within three minutes by 100 $\mu\textrm{g}$ ml-1 ABA and within seven minutes by 1-10 $\mu\textrm{g}$ ml-1 ABA after the spraying of ABA, and then reopended after a few hours in 1-10 $\mu\textrm{g}$ ml-1 ABA and after 24 hours in 100 $\mu\textrm{g}$ ml-1 ABA. The polar movement of chloroplast within the guard cells was found in the higher concentrations of 10 and 100 $\mu\textrm{g}$ ml-1 ABA, but not found in the lower concentrations than 1 $\mu\textrm{g}$ ml-1 ABA. During the night and weak light, it was fond that the inhibition of respiration rate by the higher concentration of ABA was owing to firstly the stomatal closure by the spraying of ABA and secondly the decrease of stomatal frequency by the inhibition of stomatal development with exogenous ABA for the long period of 12 weeks. In the band number of leaf protein by the electrophoresis, most of the protein bands were disappeared by the higher concentration of 100 $\mu\textrm{g}$ ml-1 ABA, but were not altered by the lower concentration of ABA in comparison with control.

• Korean Journal of Plant Tissue Culture
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• v.21 no.5
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• pp.287-291
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• 1994

In order to elucidate the effect of abscisic acid (ABA) on the abnormality of somatic embryos, somatic embryos were induced from embryogenic cell clumps derived from cotyledon segment of Aralia cordata. When embryogenic cell clumps were pretreated medium containing 0.2 mg/L ABA for 3 weeks before transferring to MS basal medium, the frequency of embryos with normal cotyledons enhanced 68% as compared with control. However when clumps pretreated in medium containing 0.2 mg/L ABA were transferred to medium containing 0.1 mg/L ABA, the Sequency decreased to about 29%. In the case of globular embryos cultures in medium containing various concentrations of ABA (0.01 to 1.0mg/L), the frequency of dicotyledonary embryo formation decreased propotionally to ABA concentration. Also, when somatic embryos at various stages were cultured in medium containing ABA, those with polycotyledons appeared at higher frequency.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.1
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• pp.113-119
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• 1995

This excperiment was conducted to investigate relation on seed dormancy and vi-viparous germination with sucrose content, fatty acid composition and abscisic acid content of rice seeds. The following results were obtained by this experiment. Sucrose content of brown rice harvested at 20 and 40 days after heading was higher in Japonica and Sare type varieties than in Tongil and Indica type rices. Positive relationship was found be-tween sucrose content of brown rice and viviparous germination rate of rice varieties tested.J aponica and Sare type rice varieties showed low proportion of oleic acid and higher proportion of linoleic acid in brown rice harvested at 20 and 40 days after heading than Tongil and Indica rices tested. Viviparous germination was negatively correlated with the proportion oleic acid and positively with that of linoleic acid. Abscisic acid content in hull of rice seeds stored for 30 days at 25/15$^{\circ}C$ fluctuation temperature condition was decreased more rapidly than 4$^{\circ}C$, and Japonica varieties tested showed lower con-tent of abscisic acid in rice hull than Tongil and Indica varieties used.

• Proceedings of the Botanical Society of Korea Conference
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• 2002.04a
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• pp.87-87
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• 2002

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.3
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• pp.223-231
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• 1994

To investigate effects of water stress on leaf water potential, nitrate reductase activity and abscisic acid content, Paldalkong, Saealkong and Danyeobkong were subjected to water stress by polyethyene glycol(PEG, MW=6,000) in the water culture and withholding irrigation in soil culture. Leaf water potential and nitrate reductase activity decreased with increaseing of PEG concentration in the water culture. These were higher at 3rd and 5th leaf stage than at 1st leaf stage. Leaf water potential showed no significant differance among the varieties, but nitrate redutase activity was higher in Paldalkong than in Saealkong and Danyeobkong. Leaf water potential and nitrate reductase activity decreased approximately 2.2 times (-1.67 MPa/-0.75MPa) and 47%(3.1${\mu}$ mole nitrite/g.DW/hour/15.9${\mu}$ mole nitrite/g.DW/hour) to control, respectively, after 3 days from water stress treatment in the soil culture. According to increasing PEG concentration, abscisic acid content increased in the water culture and was higher at 5th leaf stage than at 1st and 3rd leaf stage. Paldalkong showed the highest abscisic acid content. Abscisic acid content increased approximately 1.7 times (9.9nmole/g.DW/5.7nmole/g.DW) compared to the control after 3 days from water stress treatment in the soil culture.