• Journal of Ginseng Research
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• v.23 no.3 s.55
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• pp.130-134
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• 1999

Somatic embryos were induced directly from cotyledon explants of Korean ginseng (Panax ginseng C.A. Meyer) on Murashige and Skoog (MS) medium with 2,4-D, BAP, kinetin or lacking growth regulators. When somatic embryos formed on all media grew to cotyledonary stage, the further development of embryos was ceased and remained in white color. By gibberellic acid (over 1.0 mg/1 $GA_3$) treatment, all the somatic embryos turned rapidly to green and germinated within 3 weeks. Chilling treatment also induced the germination of somatic embryos. The effective temperature regime was $-2^{\circ}C$ for over 8 weeks but more higher temperature than $0^{\circ}C$ did not effective for germination of somatic embryos. Ultrastructural observation revealed that the cotyledon cells of somatic embryos without chilling or $GA_3$ treatment contained numerous lipid reserves, dense cytoplasm, proplastids and non-activated mitochondria with poorly differentiated internal structure, but the cotyledon cells of germinating somatic embryos after chilling or $GA_3$ treatment highly vacuolated and contained well-developed chloroplasts and active state of mitochondria enclosing numerous cristae. The above results indicate that in vitro developed somatic embryos of Panax ginseng may be dormant after mature similar to zygotic embryos.

• Korean Journal of Medicinal Crop Science
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• v.22 no.6
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• pp.423-428
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• 2014

This study was performed to identify optimal harvesting time of ginseng seeds and to examine the effect of $GA_3$ treatment for improvement of seed stratification rate. Ginseng seeds harvested from Land race, Chunpoong and Yunpoong cultivar in July 20 were tested for stratification rate. It was shown that stratification rates of land race, Yunpoong and Chunpoong cultivar were 94.1%, 93.1%, and 82.6%, respectively. Seeds of Chunpoong cultivar harvested 10-15 days later showed a comparable stratification rate to that of Land race, indicating that late harvest of Chunpoong seeds is beneficial for the increase of stratification rate. The higher stratification rate was found in mature seeds (92.3%) than immature seeds (37.8%), both of which were harvested in July 20. Stratification rate of mature seeds harvested in July 15 was 87.5%, demonstrating optimal harvesting time of ginseng seeds with higher stratification rate is after mid-July. An exponential growth of endosperms of ginseng seeds was observed from early June to mid-June and then slow growth was observed. There was no obvious growth of embryos from fertilization to mid-August. After the this time, embryos quickly grew until late October. Thus, appropriate stratification control is essential during the period (from early September to late October) in order to optimize embryo growth and development. While no increase of stratification rate was observed in seeds treated with 50 ppm of $GA_3$, significant increases were observed in seeds treated with 100 ppm of $GA_3$. At this concentration of $GA_3$, the stratification rate of Land race, Chunpoong and Yunpoong cultivar was 95.0%, 95.3%, and 96.5%, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.4
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• pp.350-359
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• 1993

The effect of gibberellic acid ($GA_3) and abscisic acid (ABA) on KCl-enhanced proteolysis of senescing leaves of rice(Oryza sativa L. cv. Chilsung) was studied. Emphasis was given to their effects on KCI-enhanced efflux of amino acids and proteinase activity. When treated singly, $GA_3 affected leaf proteolysis little, while ABA increased proteolysis, the rate of amino acid efflux, and ribulose -1,5 -bisphosphate carboxylase / oxygenase (Rubisco)-degrading endoproteinase activity. An additive increase in all three parameters mentioned above was observed when leaves were treated with ABA and KCl. No such an additive effect was found when $GA_3 was treated with KCl. Both $GA_3 and ABA helped to alleviate the KCI-suppressed activity of Rubisco-degrading exoproteinases. The additive increase in proteolysis of rice leaves in the presence of both ABA and KCl could thus be ascribed to a further increase in the efflux of protein hydrolyzates and Rubisco-degrading endoproteinase activity. An increase in proteolysis was accompanied by a decrease in water absorption, and the combined treatment of ABA with KCl resulted in a further reduction of water absorption.

• Journal of Life Science
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• v.25 no.9
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• pp.1021-1026
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• 2015

Invertase (β-D-fructosfuranosidase, EC 3.2.1.26) catalyzes the hydrolysis of sucrose into D-glucose and D-fructose. Three biochemical subgroups of invertases have been investigated in plants: vacuolar (soluble acid), cytoplasmic (soluble alkaline), and cell wall-bound (insoluble acid) invertases. An isoform of neutral invertase was purified from pea seedlings (Pisum sativum L.) and treated with gibberellic acid (GA) by sequential procedures consisting of ammonium sulfate precipitation, ion-exchange chromatography, absorption chromatography, and reactive green-19 affinity chromatography. The results of the overall insoluble invertase purification were a 430-fold increase. The purified neutral invertase was not glycosylated and had an optimum pH between neutral and alkaline (pH 6.8-7.5). It was inhibited by Tris, as well as by heavy metals, such as Hg²⁺ and Cu²⁺. Typical Michaelis–Menten kinetics were observed when the activity of the purified invertase was measured, with sucrose concentrations up to 100 mM. The K_m and V_max values were 12.95 mM and 2.98 U/min, respectively. The molecular mass was around 20 kDa. The sucrose-cleaving enzyme activity of this enzyme is similar to that of sucrose synthase and fructosyltransferase, but its biochemical characteristics are different from those of sucrose synthase and fructosyltransferase. Based on this biochemical characterization and existing knowledge, neutral INV is an invertase isoform in plants.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.284-284
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• 2022

The overall effects of gibberellic acid (GA3) with NaCl on different rice genotypes are inadequately understood. The present study determines the effect of different GA3 concentrations on the morphophysiological, molecular and biochemical effects of 120 mM NaCl salt stress in rice seedlings. Salt stress reduced germination percentages and seedling growth and decreased bioactive GA content. It also downregulated the relative expression of a-amylase-related genes - OsAmy1A, OsAmy1C, and OsAmy3C in the salt-sensitive IR28 cultivar. Salt stress differentially regulated the expression of GA biosynthetic genes. Salt stress increased antioxidant activity in all rice genotypes tested, except in IR28. GA3 (50 and 100 µM) mitigates the effect of salt stress, rescuing seed germination and growth attributes. GA3 significantly increased bioactive GA content in Nagdong and pokkali (50 µM) and Cheongcheong and IR28 (100 µM) cultivars. The a-amylase genes were also significantly upregulated by GA3. Similarly, GA3 upregulated OsGA2oxl and OsGA2ox9 expression in the Cheongcheong and salt-sensitive IR28 cultivars. The present study demonstrated that salt stress inactivates bioactive GA - inhibiting germination and seedlings growth - and decreases bioactive GA content and GSH activity in IR28 and Pokkali cultivars. Further, GA3 significantly reversed the effects of 120 mM NaCl salt stress in different rice genotypes. The current study also suggests if we know the coastal area water NaCl concentration we can apply the exogenous GA3 accordingly. Thus, we would be able to grow rice cultivars near the coastal area and reduce the rice damage by salinity.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.2
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• pp.250-254
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• 1995

Isolated barley aleurone layers were used to examine response of (1-3)- and $(1-3,1-4)-{\beta}-glucanases{\;}to{\;}GA_3$. Protein content and levels of (1-3)- and $(1-3,1-4)-{\beta}-glucanases$ increased in the presense of added $GA_3$. However, (1-3)- and $(1-3,1-4)-{\beta}-glucanases$ showed different response to $GA_3$ in their production and secretion patterns. $(1-3,1-4)-{\beta}-glucanases$ showed higher increase in enzyme activity than $(1-3)-{\beta}-glucanase$ in the early stage of$GA_3$treatment. Secretion of enzyme by $GA_3$ into the surrounding medium was more enhanced in $(1-3,1-4)-{\beta}-glucanases$ than in $(1-3)-{\beta}-glucanase$, The differential response of the enzymes might be related to the physiological role of the enzymes in germination of barley grain.

• Journal of Bio-Environment Control
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• v.28 no.2
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• pp.178-184
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• 2019

Strawberry ($Fragaria{\times}ananassa$) is one of the most important and popular fruit crops in the world, and 'Sulhyang' is one of the principal cultivars cultivated in the Republic of Korea for the domestic market. The growth and flower induction in strawberry is the process which influences directly on fruit bearing and yield of this crop. In this study, effect of benzyladenine (BA), gibberellic acid ($GA_3$), and salicylic acid (SA) on growth and flower bud induction in strawberry 'Sulhyang' was investigated. The 3-week-old runner plants, grown in 21-cell propagation trays, were potted and cultivated in growth chambers with $25^{\circ}C/15^{\circ}C$ (day/night) temperatures, 70% relative humidity (RH), and light intensity of $300{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ photosynthetic photon flux density (PPFD) provided by white light emitting diodes (LEDs). The runner plants were treated with one of three concentrations, 0 (control), 100, and $200mg{\cdot}L^{-1}$ of BA, $GA_3$, or SA solution. The chemicals were sprayed two times on leaves of runner plants at an interval of two weeks. After 9 weeks the results showed that the application of all chemicals caused reduction of root length and chlorophyll (SPAD) content as compared to the control. The lowest chlorophyll (SPAD) content was recorded in plants treated with $GA_3$. However, the treatment of $200mg{\cdot}L^{-1}$ $GA_3$ promoted leaf area, leaf fresh weight, and plant fresh weight. The greatest flower induction (85%) and number of inflorescences (4.3 inflorescences per plant) were observed in the treatment of $200mg{\cdot}L^{-1}\;SA$, followed by $100mg{\cdot}L^{-1}\;SA$. Overall, results suggest that foliar application of $GA_3$ solution could accelerate plant growth, while foliar application of SA solution could induce hastened flowering. Further studies may be needed to find out the relationship between $GA_3$ and SA solutions treated in a combination, and the molecular mechanism involved in those responses observed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.2
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• pp.128-138
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• 1994

To improve seed vigour in rice, barley and soybean, several methods of presowing treatment, using chemicals and priming in polyethylene glycol solution, were investigated. Gibberellic acid($GA_3$) slightly improved germination of rice, but other chemical treatments showed no beneficial effect on seed vigour. Aged seeds were primed in polyethylene glycol solution then rinsed and germinated with drying back. In general mean germination time increased and percentage germination decreased with in- creasing water potential of the priming solution, but there were no significant effects on spread of germination times. Priming also showed no marked improvement in germination under cold, wet, or osmotic conditions. None of the treatments used was successful in practically improving the seed germination and vigour of the tested crops. However, seed treated with GA$_3$ gave the best overall germination response.

• 한국약용작물학회:학술대회논문집
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• 2012.05a
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• pp.155-156
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• 2012

• Journal of Plant Biotechnology
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• v.45 no.4
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• pp.347-356
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• 2018

Chionanthus retusus is a small deciduous tree that is widely used in landscaping due to its beautiful white spring flowers and ornamental value. Conventional propagation through seeds requires one to two years of breaking dormancy. The objective of this study was to determine the conditions of in vitro germination in C. retusus. In vitro embryo culture was carried out to investigate the effects of six factors: basal media (McCown Woody Plant Medium (WPM) and Murashige and Skoog (MS)); plant growth regulators (different combinations and concentrations of naphthaleneacetic acid (NAA), 6-Benzylaminopurine (BA), and gibberellic acid ($GA_3$)); embryo age (collected weekly beginning 36 days after fruit setting); low temperature pretreatment (storing $4^{\circ}C$ for 1, 2, 3, and 4 weeks); coconut additives (100, 200, and $300ml{\cdot}L^{-1}$); and genotype (grouping plants depending on their flowering nature). The basal medium used in this study was WPM with $2mg{\cdot}L^{-1-1}\;GA_3$, $20g{\cdot}L^{-1}$ sucrose, and $6g{\cdot}L^{-1}$ Agar. WPM medium mixed with $GA_3$, resulted in higher germination rate as compared to when using a combination of auxin and cytokinin. $GA_3$ at $2mg{\cdot}L^{-1}$ was the most effective of all combinations and concentrations of PGRs. WPM medium with $2mg{\cdot}L^{-1}GA_3$ resulted in better and faster germination (75.93%). Embryos collected at 57 days after fruit setting had the highest percent of germinated seeds (87.04%) while low-temperature pretreatment of fruits at $4^{\circ}C$ for two weeks produced the highest germination (95.37%). These results of this study could be an open ground for development of an efficient protocol for commercial production of the ornamental tree.