• Journal of Plant Biology
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• v.22 no.4
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• pp.95-100
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• 1979

As a part of the studies on the regulatory mechanism of gene expression by $GA_{3}$ , the effects of $GA_{3}$ on the protein biosynthesis and phosphorylation in maize seedlings were investigated. 1. The optimum concentration of $GA_{3}$ for the stimulation of the protein biosynthesis was 0.3mM. 2. The protein biosynthesis was remarkably increase by $GA_{3}$ during the germination. The reason for the decrease in the protein biosynthesis by 48hrs. after germination seems to be a staggered gene expression, and/or increases in protease and RNase activities. 3. The ratio of the amount of the newly synthesized protein in germinating seeds treated with $GA_{3}$ to the amount of proteins secreted into the endosperm was similar to that ratio in control. According to this result, it seems that $GA_{3}$ stimulates only the expression of certain definite genes. 4. By the treatment with $GA_{3}$, the rates of biosynthesis and phosphorylation of proteins were increased up to about 1.5 times during germination and 6 times by 72hrs. after germination, respectively. The ratio of the total soluble proteins to the phosphorpoteins considerably increased in the early germination stage (24hrs.) but decreased after 24hrs. According to the above mentioned results, the stimulation of the phosphorylation of proteins of $GA_{3}$ seems to be attributed to the increases in the activities of protein kinases.

• Journal of Ginseng Research
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• v.5 no.1
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• pp.35-40
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• 1981

Explants of mature root tissues and calli derived from root and cotyledon of Panax ginseng were cultured in vitro on Murashige and Skoog medium supplemented with 2, 4-dichlorophen-oxyacetic acid(3,4-D), naphthaleneacetic acid(NAA), benzyladenine, and gibberellic acid to assess their capacity to regenerate organs. Root formation at high percentage (46.2-61.1%) was obtained 20-30 days after culturing on media supplemented with combinations of NAA(5 mg/l) and kinetin (1 mg/l), And calli derived from cotyledon produced numerous embryoids in media($\frac{1}{2}$MS) containing 2,4-D(0.5 mg/l) and kinetin (0.5 mg/l). Reculture of these embryoids in media($\frac{1}{2}$MS) enriched with 1 mg/l of benzyladenine and 1 mg/l of gibberellic acid resulted in more plantlet regeneration.

• Journal of Plant Biology
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• v.20 no.2
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• pp.91-101
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• 1977

Using barley seeds (Hordeum sativum Jess, var.), the influences of gibberellic acid (GA) and indole-3-acetic acid(IAA) on the amylase synthesis and that of the nucleic acid metabolism were investigated. 1. With the deembrynized barley seeds, the increase of amylase treated with a $10^{-5}M$ of GA and the decrease of amylase treated with $10^{-5}M$IAA were matched by a proportionate increase and decrease in the amount of RNA. The influence of the hormones on the RNA synthesis has appeared immediately after the treatment but on the amylase synthesis it has appeared 8 hours later. But no influence on the DNA synthesis was observed on both hormones. 2. The amylase from deembryonized barley seeds treated with GA and IAA have been fractionated by gel filteration on Sephadex G-100. The amylase components showed four fractions on both enzymes treated with GA and IAA. Fraction I(FI) was differed from fraction Ⅵ(FIV) in Km value and the effects of temperature, pH and metal ions. On the basis of their emzymatic properties, it was considered that the FI was $\beta$-amylase and FIV was $\alpha$-amylase. The influences of GA and IAA on each fractions appeared to be similar but on the amylase units per souble protein, IAA inhibited the production of amylase FIV while it promoted that of amylase FI. 3. An experiment was conducted to determine whether IAA inhibits GA-promoted amylase synthesis competitively or non-competitively. Using a Lineweaver-Burk plot, it was clear that IAA was acting in a non-competitive fashion. From this, IAA was probably not competing with GA at the same site, but it was acting at some other site which resutled in partial blocking of the action of GA on the amylase synthesis.

• The Plant Pathology Journal
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• v.37 no.3
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• pp.268-279
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• 2021

Citrus scab, caused by the fungal pathogen Elsinoë fawcettii, is one of the most important fungal diseases affecting Citrus spp. Citrus scab affects young tissues, including the leaves, twigs, and fruits, and produces severe fruit blemishes that reduce the market value of fresh fruits. To study the molecular responses of satsuma mandarin (C. unshiu) to E. fawcettii, plant hormone-related gene expression was analyzed in response to host-compatible (SM16-1) and host-incompatible (DAR70024) isolates. In the early phase of infection by E. fawcettii, jasmonic acid- and salicylic acid-related gene expression was induced in response to infection with the compatible isolate. However, as symptoms advanced during the late phase of the infection, the jasmonic acid- and salicylic acid-related gene expression was downregulated. The gene expression patterns were compared between compatible and incompatible interactions. As scabs were accompanied by altered tissue growth surrounding the infection site, we conducted gibberellic acid- and abscisic acid-related gene expression analysis and assessed the content of these acids during scab symptom development. Our results showed that gibberellic and abscisic acid-related gene expression and hormonal changes were reduced and induced in response to the infection, respectively. Accordingly, we propose that jasmonic and salicylic acids play a role in the early response to citrus scab, whereas gibberellic and abscisic acids participate in symptom development.

• The Korean Journal of Mycology
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• v.21 no.1
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• pp.9-15
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• 1993

ABSTRACT: The cell fusants were constructed from complementary auxotrophic mutants of Phffia rhodozyma. The nuclear fusion of the fusants was demonstrated by several techniques including comparision of cell volume, estimation of DNA content and nuclear staining. The cell fusants were very stable for succeeding transfer culture on complex medium for more than one year. Malt extract (1%, w/v) and abscisic acid(1 mM) increased the carotenoid formation whereas gibberellic acid(5mM) and riboflavin(0.1 mM) decreased the corresponding content.

• Journal of Plant Biology
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• v.25 no.1
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• pp.3-8
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• 1982

As a part of the studies on the regulatory mechanism of gene expression by gibbrellic acid, the effects of $GA_3$ on the protein biosynthesis and phosphorylation in maize seedlings were investigated in the presence of actinomycin D. The activities of protein biosynthesis and phosphorylation in germinating seeds treated with $GA_3$ were greater than those of the control at the 3-day point after germination. It is assumed that the enhancement of protein biosynthesis by $GA_3$ in the presence of actinomycin D is due to the effects of $GA_3$ on the translational processes in which protein is produced from the mRNA synthesized previously.

• Journal of Ginseng Research
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• v.40 no.4
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• pp.409-414
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• 2016

Background: The low survival rate of in vitro regenerated Panax ginseng plantlets after transfer to soil is the main obstacle for their successful micropropagation and molecular breeding. In most cases, young plantlets converted from somatic embryos are transferred to soil. Methods: In vitro thickened taproots, which were produced after prolonged culture of ginseng plantlets, were transferred to soil. Results: Taproot thickening of plantlets occurred near hypocotyl and primary roots. Elevated concentration of sucrose in the medium stimulated the root thickening of plantlets. Senescence of shoots occurred following the prolonged culture of plantlets. Once the leaves of plantlets senesced, the buds on taproots developed a dormant tendency. Gibberellic acid treatment was required for dormancy breaking of the buds. Analysis of endogenous abscisic acid revealed that the content of abscisic acid in taproots with senescent shoots was comparatively higher than that of taproots with green shoots. Thickened taproots were transferred to soil, followed by exposure to gibberellic acid or a cold temperature of $2^{\circ}C$ for 4 mo. Cold treatment of roots at $2^{\circ}C$ for 4 mo resulted in bud sprouting in 84% of roots. Spraying of 100 mg/L gibberellic acid also induced the bud sprouting in 81% roots. Conclusion: Soil transfer of dormant taproots of P. ginseng has advantages since they do not require an acclimatization procedure, humidity control of plants, and photoautotrophic growth, and a high soil survival rate was attained.

• Journal of Plant Biotechnology
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• v.44 no.1
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• pp.61-68
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• 2017

Gibberellic Acid-Stimulated Arabidopsis (GASA) genes are involved in plant hormone signaling, cell division and elongation, as well as in responses to stress conditions in plants. In this study, we isolated a GASA gene from hybrid poplar (Populus alba ${\times}$ P. glandulosa) and analyzed its physiological phenotype and molecular functions in poplar. PagGASA cDNA encodes a putative protein composed of 95 amino acids containing an N-terminal signal peptide and a conservative cysteine-rich C-terminal domain. Southern blot analysis revealed that one or two copies of the PagGASA are present in the poplar genome. The PagGASA transcripts were highly detected in flowers and roots. Moreover, the expression of PagGASA was induced by growth hormone (gibberellic acid) and stress hormones (abscisic acid, jasmonic acid, and salicylic acid). By using transgenic analysis, we showed that the upregulation of PagGASA in poplar provides high tolerance to drought stress. Therefore, our results suggest that PagGASA plays an important role in drought stress tolerance via stress-related plant hormone signaling in poplar.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.24 no.1
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• pp.99-106
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• 1979

The undehiscent ginseng seed did not germinate, even if the seeds were treated with GA_3, kinetin or IAA. Only GA_3 stimulated germination of dehiscent ginseng seed. The physiological roles of gibberellic acid on stimulation of the seed germination were enhancing production of soluble carbohydrate and sucrose. Then gibberellic acid stimulated biosynthesis of insoluble cellural materials and amino acids from sugars and incorporation of amino acids into protein. The fruit coat of ginseng seed did not impede water imbibition, but did function as water absorbor and reservoir.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.04a
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• pp.128-128
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• 2022