• Korean Journal of Medicinal Crop Science
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• v.13 no.1
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• pp.57-62
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• 2005

Salt-tolerant transgenic Panax ginseng plants were produced by introducing the SAL1 geue (3'(2'), 5'-bis-phosphate nucleotidase) that confers tolerance to the salts through Agrobacterium tumefaciens co-cultivation. Cotyledon explants of immature ginseng zygotic embryos cultured on Murashige and Skoog medium lacking growth regulators formed somatic embryos directly with below 10%, but the 74% tranformation rate were observed at the treatment of phytohormone with 1.0 mg/l 2,4-D and 0.5 mg/l kinetin. Somatic embryos were initially cultured on MS medium supplemented with 250 mg/l cefotaxime for 3 weeks and subsequently subcultured five times to a medium containing 100 mg/l kanamycin and 250 mg/l cefotaxime. Upon development into the cotyledonary stage, these somatic embryos were transferred to on the medium containing 50 mg/l kanamycin and 10 mg/l gibberellic acid to induce germination and strong selection. Integration of the transgene into the plants was confirmed by polymerase chain reaction with specific primers. The ginseng transformants with well-developed shoots and roots were successfully acclimatized in a greenhouse when they were planted in soil.

• Journal of Plant Biology
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• v.35 no.3
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• pp.191-195
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• 1992

Changes in activity of gibberellin C20-hydroxylase which converts $[^{14}C]GA_{12}\;to\;GA_{l5}$ were studied during seed maturation using the partially purified enzyme preparations of two cultivars, Kentucky Wonder (normal) and Masterpiece (dwarf) of Phaseolus vulgaris. The preparations obtained by methanol precipitation and hydrophobic interaction chromatography efficiently converted; $GA_{l2}\;to\;GA_{4},\;via\;GA_{15},\;GA_{24}\;and\;GA_{9};\;GA_{20}\;to\;GA_{1},\;GA_{5}\;and\;GA_{6}$. The activities of C20-hydroxylase which converts $GA_{l2}\;to\;GA_{l5}$ were almost the same in both cultivars. The C20-hydroxylase activity per protein reached a maximum at the very early immature seed stage, followed by a subsequent rapid decrease during seed maturation, whereas the enzyme specific activity per seed reached a maximum at 21 days after flowering, and showed a similar fiuctuation to that of the 313-hydroxylase which converts $GA_{20}\;to\;GA_{l}$ during seed maturation.ration.

• Journal of Life Science
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• v.16 no.4
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• pp.699-703
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• 2006

Maize (Zea mays L.) is a monoecious plant, which separates male (tassel) and female (ear) floret that evolved into increasing heterogeneity. In each floret, male or female, bears both one pistil and three stamens primodia before diverged to unisexual state. When diverged to tassel, pistil cell death occurs in the pistil primodium, which is mediated by TASSELSEED genes. In contrast, cell protection occurs in the ear pistil from TASSELSEED-mediated cell death, which is mediated by SILKLESS1 gene. On the other hand, cell cycle arrest occurred for a long time in the ear stamens and then the stamens eventually dye. The cell cycle regulating genes such as CYCLIN B and WEE1 are involved in this process. Furthermore, the temporal and spatial regulation of gibberellin biosynthesis may cause cell cycle block in arresting stamen cells. This review describes the cell death, cell protection, and cell cycle arrest mechanism during maize sex determination process at the molecular, cellular and developmental biology, and genetic levels.

• Weed & Turfgrass Science
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• v.2 no.2
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• pp.152-158
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• 2013

Dandelion (Taraxacum officinale) is a member of family Asteraceae that grows all over the Korea. Recently, dandelion was cultivated for medicinal crops because of its positive medicinal effects. However, dandelion is considered as a troublesome weed in grass lawns of golf course and orchards. This study was conducted to investigate the effect of plant growth regulators [gibberellins ($GA_3$); kinetin; salicylic acid (SA); ethephon)] with different concentration on seed germination control of dandelion. Seed germination rates were increased in all concentration of $GA_3$ and kinetin treatment compared to control. In the 0.5 mM of ethephon application, seed germination rate was more increased than that of control while seed germination rate was reduced in 1.0 and 1.5 mM of ethephon treatments. Seed germination rate was significantly decreased with different SA dilutions compared to control. The germination rate was more reduced when SA was applied in combination with $GA_3$ than only SA treatments.

• Horticultural Science & Technology
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• v.16 no.2
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• pp.244-246
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• 1998

This study was carried out to investigate the effects of plant growth regulators on the growth and development of pot 'Pinto Rose' and 'Pinto Scarlet' geraniums. Plant height was increased by $GA_3$ treatments in both 'Pinto Rose' and 'Pinto Scarlet' geranium. However, the number of branches was not affected by $GA_3$ and daminozide treatments. The combined treatments of $GA_3$ and daminozide delayed the days to first flowering in 'Pinto Scarlet' geranium. Also, in 'Pinto Rose', $GA_3$ or the combination of $GA_3$ and daminozide treatments delayed the first flowering time. 'Pinto Scarlet' geranium was more sensitive to growth regulator treatments than 'Pinto Rose'. The number of flower stalks and branches were increased by uniconazole in 'Pinto Scarlet', while the flower stalk length and canopy diameter were severely decreased by uniconazole treatments in both cultivars. The days to first flowering tended to be delayed by all growth retardant treatments in geranium.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.04a
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• pp.82-82
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• 2019

종자은행은 종자를 보존하는 가장 경제적이고 효율적인 보전방법이지만, 수종에 따라 저장특성의 차이가 커서 수종별 저장방법의 확립이 필요하다. 초저온저장 방법은 세포 분열, 대사 작용을 정지 상태로 유지하므로 현재까지 장기간 보존을 위한 비용이 효율적이며 안정적인 방법이다. 공시재료는 멸종위기 야생식물 등 22종을 대상으로 하였다. 액체질소에 7일간 종자를 침지한 후 $37^{\circ}C$ 항온수조에서 10분간 해동하였다. 휴면이 있는 수종은 파종 전 종자를 저온습윤 하였고, 저온습윤 처리 후에도 휴면타파 되지 않는 수종은 농황산, 지베렐린을 개별 또는 혼용으로 처리하였다. 발아 및 유묘 평가는 $25^{\circ}C/20^{\circ}C$(광12h/암12h)조건에서 진행하였으며, 매일 28일차까지 발아조사를 수행한 후 평가하였다. 진달래속의 꼬리진달래와 철쭉이 초저온 민감성을 보였으며, 오리나무속의 물오리나무, 사방오리는 부분 민감성을 보였다. 민산초나무는 지하부건물중이 유의하게 감소한 결과를 보였으며, 이외의 수종은 초저온 민감성을 보이지 않았으므로 장기보존을 위한 초저온 동결보존이 가능한 것으로 보였다.

• Horticultural Science & Technology
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• v.32 no.5
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• pp.645-654
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• 2014

This study was conducted to investigate the effect of 1-methylcyclopropene (1-MCP, $1.0{\mu}L{\cdot}L^{-1}$), a known ethylene action inhibitor, on fruit quality and incidence of physiological disorders during a simulated marketing period at $25^{\circ}C$ for 20 days in early-season Asian pear (Pyrus pyrifolia Nakai) 'Hanareum' that had been treated with 0, 0.5, 1.2 or 2.4% $GA_{4+7}$. Weight loss of stored fruits increased with $GA_{4+7}$ concentration, and the 1-MCP treatment slightly reduced the weight loss rates during the marketing period. Flesh firmness decreased abruptly in all 1-MCP-untreated fruits as the storage period extended to 10 d, whereas the firmness of 1-MCP-treated fruits remained high (> 30 N) during 15 days shelf-life. The effect of 1-MCP was significantly reduced when fruits were subjected to increased GA concentration. Higher soluble solids content and acidity during extended shelf-life were also apparent in 1-MCP-treated 'Hanareum' pears. The L-values (lightness) and hue angles of 1-MCP treated samples were higher than those of controls during 20 days shelf-life, but the a-value (redness) was lower in 1-MCP treated fruits. 1-MCP treatment did not decrease the level of ethylene evolution regardless of $GA_{4+7}$ concentration during shelf-life in early-season Asian pear 'Hanareum'. By contrast, 1-MCP treatment decreased the respiration rate significantly during shelf-life. The efficacy of 1-MCP was greatest in the GA-untreated fruit and was reduced as the $GA_{4+7}$ concentration increased. 1-MCP treatment influenced the severity of physiological disorders including core browning and mealiness: 1-MCP treatment completely blocked the incidence of core browning of during 15 days shelf-life, and reduced the severity of mealiness during 20 days shelf-life regardless of $GA_{4+7}$ concentration. Based on our results, we conclude that the use of $1{\mu}L{\cdot}L^{-1}$ 1-MCP can be of great benefit for maintaining quality and preventing physiological disorders in early-season pear cultivar 'Hanareum' pear, whereas its efficacy decreases with the concentration of $GA_{4+7}$ whereas its efficacy gradually decreases when the concentration of $GA_{4+7}$ paste increased.

• Journal of Bio-Environment Control
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• v.27 no.4
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• pp.407-414
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• 2018

This study was aimed to evaluate the effect of application method and concentration of gibberellin $A_3$ ($GA_3$) on the growth, runner production, and seedling quality of strawberry plants (Fragaria ${\times}$ ananassa Duch. cv. Maehyang) during nursery period. The mother plants of strawberry were transplanted in pot ($64{\times}27{\times}18cm$) filled with commercial growing medium on March 20, 2018. $GA_3$ concentration was applied as 0, 50, 100 or $200mg{\cdot}L^{-1}$ with spray or drench to 45 mL per plant at 4 weeks after transplanting, respectively. Nutrient solution was supplied with the EC $1.5dS{\cdot}m^{-1}$ after the transplanting and supplied 350 mL per pot twice a day (15 min per one time) after rooting. The growth characteristics of mother plants of strawberry were measured at 7 weeks after treatment, and growth characteristics of daughter plants of strawberry were measured at 10 weeks after treatment. Runner length and diameter of mother plant was the longest or thickest in the spray with $200mg{\cdot}L^{-1}$ than the other treatments, respectively. Soil-plant analysis development (SPAD) value of mother plant was the lowest in spray with $200mg{\cdot}L^{-1}$. However, leaf length, leaf width, and crown diameter showed no significant differences in all treatment among application method and concentration of $GA_3$. As the concentration of $GA_3$ increased, physiological disorder like stretchiness of crown occurred more. The physiological disorder was the most occurred in spray treatment with $200mg{\cdot}L^{-1}$, but drench treatment occurred less than spray treatment. The number of runners and daughter plants increased with increasing concentration of $GA_3$ regardless of application methods. In the growth characteristics of the daughter plants, leaf length and leaf width of first daughter plant, plant height, crown diameter, leaf area and SPAD value of second daughter plant, and plant height of third daughter plant were the significantly greatest in drench with $100mg{\cdot}L^{-1}$ treatment. This results indicate that growth and runner production of mother plants and growth of daughter plants of strawberry were the best achieved by drench application in the $100mg{\cdot}L^{-1}$ $GA_3$.

• Korean Journal of Environmental Agriculture
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• v.32 no.4
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• pp.343-347
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• 2013

BACKGROUND: Control of alternate bearing satsuma mandarin in Jeju is very important to maintain the optimum price of fruit and get the sustainable income of farmers. Unlike orange, Satsuma mandarin is well known to sensitive on alternate bearing. We carried out the experiment to know the effect of foliar application of $GA_3$ on the flowering and fruit quality of satsuma mandarin (C. unshiu Marc. cv. Miyagawa). METHODS AND RESULTS: To experiment, the treatments consist of control, different concentration of $GA_3$ (25, 50 and 100 mg/L), machine oil emulsion 100 times and mixture of various concentration of $GA_3$ (25 and 50 mg/L) with machine oil emulsion 100 times which it was applied on 15 year-old Miyagawa satsuma mandarin at December 29, 2011. Foliar application of $GA_3$ in winter reduced the flowering of satsuma mandarin. Flower-leaf ratio was significantly reduced at 100 mg/L $GA_3$, while no differences observed in low concentration of $GA_3$ (25 and 50 mg/L). However, it was significantly decreased to 0.19 in application of $GA_3$ 25 and 50 mg/L with machine oil emulsion 100 times mixture. Number of leaves per fruit was significantly increased as foliar application of $GA_3$ also it reduced the fruits remarkably. Soluble solid contents and Hunter's a of peel color ratio showed no difference among $GA_3$ single treatments, but it was reduced in $GA_3$ 25 and 50 mg/L with machine oil emulsion 100 times mixtures significantly. From the results, it has been found that higher $GA_3$ concentration can reduce the number of flowers on the alternate bearing of satsuma mandarin. However, it was found that lower concentration of $GA_3$ with machine oil emulsion mixture 100 times can reduce flowering. CONCLUSION(S): The foliar application of $GA_3$ (100 mg/L) can alleviate alternate beraring. Also, mixture of lower concentration of $GA_3$ with machine oil emulsion 100 times can retard flowering more significantly while it needs further confirmation.

• Korean Journal of Environmental Agriculture
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• v.20 no.4
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• pp.232-237
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• 2001

This study was conducted to clarify the effects of physical stimulation to the rice plant by free-ranging ducks (Chinese native ducks) on growth, lodging resistance and yield of the rice plants in a rice-duck farming system. Two paddy fields were used for this experiment, one exposed to physical stimulation (PS) and the other with no physical stimulation (NPS). Fifteen days after ducks were introduced into the paddy plot, rice plants in the PS field were significantly (P<0.05) shorter than those in the NPS field. Measurements of lodging characteristics showed that, the 3rd internode was significantly (P<0.05) shorter in the PS treatment than in the NPS treatment, but neither the 4th internode length nor the center of gravity of the rice plants differed between treatments. The breaking strength of $N_4$ in PS rice was significantly (P<0.05) higher than in NPS rice, however the bending moment and the lodging index of $N_3$ (distance between fulcra - 5 cm) was significantly (P<0.05) lower in PS than in NPS. The number of panicles per $m^2$ was significantly (P<0.05) greater in PS rice than in NPS, but there was no such difference in spikelet number per panicle, percentage of ripened grain or weight per 1000 kernels. Paddy rice yield per $m^2$ in the PS treatment was significantly (P<0.05) higher than that in the NPS treatment.