• KSBB Journal
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• v.10 no.1
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• pp.15-22
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• 1995

The embryos(6-8mm) isolated from seeds of Diospyros kaki were cultured on Murashlge-Skoog(MS), Woody Plant Medium(WPM), Campbell Durzen(CD), Lictvay's Medium(LM), Kao-Michaluk(KM), Nitsch, White, Heller, Wolter-Skoog(WS) media. The results showed that MS and WPM media were most suitable to the development of embryos into plantlets with length of $5.4{\pm}1.2 cm$ and 5-6 leaves. However, when LM and KM media were used, the addition of 1 to $2{\mu} moles/\ell GA_3$ was required for the germination of the embryos. Superoxide dismutase (SOD) activities, one of the changing factors in leaves according to physiological status displayed to be exceptionally significant in the leaves of plantlets germinated from seeds in potting sand soil contrary to those of cultured embryos specially around germination period.

• Journal of Life Science
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• v.14 no.4
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• pp.644-649
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• 2004

During plant development, active gibberellins (GAs) control many aspects of plant growth and development including seed germination, stem elongation, flower induction, anther development and seed growth. To understand the biosynthesis and functional role of active GAs in high plants, this study investigated GA 3$\beta$-hydroxylase gene en-coding $GA_1$ and$GA_4$ catalizing last step in GA biosynthetic pathway. The antisense GA 3$\beta$-hydroxylase gene was inserted into expression vector, pIG121-Hm. Calli derived from mature seeds of rice (Oryza satiiva L. cv. Donjinbyeo) were co-cultivated with Agrohacterium tumefaciens EHA101 earring a pIG121-Hm containing hygromycin resistance ($Hyg^r$) and antisense GA 3$\beta$-hydroxylase gene. Seventeen transgenic plants obtained inhibiting GA 3$\beta$-hydroxylase. Transgenic plants had shorter plant height more than that of the Dongjinbyeo. Stable integration of antisense GA 3$\beta$-hydroxylase gene was confirmed by polymerase chain reaction of genomic DNA isolated from the leaf organs of the $T_o$ generation.

• Journal of Plant Biology
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• v.5 no.4
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• pp.1-5
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• 1962

CHA, Jong Whan (Dept. of Biology, College of Education, Seoul National University). Effect of gibberallin on the growth and internal componsents of Astragalus sinicus L. Kor. Jour. Bot. V(4) : 1-5, 1962. The effect of GA on the growth as well as on the internal components of the leaves of Astragalus sinicus L. under the soil culture was investigated. The result has indicated that small variation in the relative concentration of GA treated on the leaves shows a marked influence on the internal components of the plants. The increase of growth was associated with increasing intensity of GA. Chlorophyll and carotene contents in the leaves were depressed with increasing concentration of GA. It was noticed that the growth was pomoted with the decrease of the contents of chlorophyll and carotene. In contrast the aacorbic acid in the leaves treated with GA decreased in proportion to the degree of the concentration of GA. Carotens content varied with chlorophyll, although the ratio of chlorophyll to carotene was not so high as the results obtained by Beck and Redman. Chlorophyll and ascorbic acid values with respect to growth differed greatly during the two experimental periods. The chlorophyll content was found highly significant in this experimental periods. The chlorophyll content was found highly significant in this experiment. As the concentration of GA was increased, it was noticed that there was a reduction of anthocyanin, sucrose, and reducing sugar contents. The anthocyanin content was not so high in this study as in the results obtained from the corn by Jacob Straus.

• 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.

• Korean Journal of Environmental Agriculture
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• v.34 no.4
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• pp.318-327
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• 2015

BACKGROUND: Trinexapac-ethyl is a plant growth regulator (PGR) that inhibits the biosynthesis of plant growth hormone (gibberellin). It is used for the prevention of lodging, increasing yields of cereals, and reducing mowing of turf. The experiment was conducted to establish a determination method for trinexapac-ethyl and its metabolites trinexapac in agricultural products using LC-MS/MS.METHODS AND RESULTS: Trinexapac-ethyl and trinexapac were extracted from agricultural products with methanol/ distilled water and the extract was partitioned with dichloromethane and then detected by LC-MS/MS. Limit of detection(LOD) was 0.003 mg/kg and limit of quantification(LOQ) was 0.01 mg/kg, respectively. Matrix matched calibration curves were linear over the calibration ranges (0.01-1.0 mg/L) for all the analytes into blank extract withr²> 0.997. For validation purposes, recovery studies were carried out at three different concentration levels (LOQ, 10LOQ, 50LOQ,n=5). Recoveries of trinexapacethyl and trinexapac were within the range of 73.6-106.9%, 72.7-99.2%, respectively. The relative standard deviations (RSDs) were less than 9.0%. All values were consistent with the criteria ranges requested in the CODEX guideline(CAC/GL 40, 2003).CONCLUSION: The proposed analytical method was accurate, effective and sensitive for trinexapac-ethyl and trinexapac determination and it can be used to as an official method in Korea.

• Korean Journal of Food Science and Technology
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• v.13 no.3
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• pp.247-252
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• 1981

As a primary study for the improvement of yield and preference of soybean sprouts, the water absorption rates by soaking and the growing characteristics of sprouts were investigated. When the soybeans were soaked in subterranean water at $18^{\circ}C$ for 4 hours, water absorption rates by weight percent of soybeans were ranged $167.0{\sim}194.5%$, and it means that the absorption rates do not greatly influence its germination rates. The yield of soybean sprout whose common name is Guryetai and of the sprout treated with 1 ppm Gibberellin marked the highest value, 837% and 585%, respectively. In case of industrial cultivation of soybean sprout, it is supposed that sprinkling with subterranean water is good for prevention of deterioration by growth of microorganisms and respiratory heat.

• 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 $100mg{\cdot}L^{-1}$ $GA_3$.

• Horticultural Science & Technology
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• v.34 no.4
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• pp.557-563
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• 2016

To improve the germination of Spiraea fritschiana seeds for mass propagation, we evaluated the effect of a range of temperatures, cold stratification periods, and gibberellic acid ($GA_3$) treatments on three germination characteristics. Final germination percentage (FGP) increased as the temperature for seed germination increased, up to $30^{\circ}C$, while the mean germination time (MGT) and the mean number of days to 30% germination ($T_{30}$) decreased when seeds were germinated at $25-30^{\circ}C$. The optimum germination temperature of S. fritschiana seeds is approximately $30^{\circ}C$ considering FGP, MGT, and $T_{30}$ together. FGP increased with the duration of cold stratification up to a period of 6 weeks, but declined after 8 weeks of cold stratification, as prolonged cold stratification can induce dormancy with a resultant decline in germination. Pretreatment with 6-8 weeks of cold stratification or soaking seeds in distilled water or $500mg{\cdot}L^{-1}$ $GA_3$ for 24 h accelerated and increased the germination of S. fritschiana seeds, regardless of temperature. However, further study might be required to evaluate the effect of $GA_3$ concentrations lower than $500mg{\cdot}L^{-1}$ on the promotion of germination in S. fritschiana seeds.

• Journal of Life Science
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• v.25 no.4
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• pp.390-396
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• 2015

This study was carried out to investigate the action of phytohormones which influence the adventitious root formation of calli originating from the leaves of Persicaria perfoliata. The optimal medium condition for callus formation was ½-strength MS, 1% sucrose, and 4.5 μM 2,4-D. In order to determine which phytohormones had an effect on the adventitious root formation, the calluses were cultured in various media with different kinds of phytohormones. As a result, the medium with GA₃ or IAA was shown to induce root formation. To deeply investigate the effects of GA₃ and IAA, calli were cultured in 0.1, 1, and 10 mg/l levels of phytohormones. Numbers of roots formed per callus were 10.9, 14.2, 22.6 in GA₃, 5.8, 3.9, 1.1 in IAA, respectively. Therefore, the higher GA₃ or the lower IAA concentration, the more roots formed. To confirm this role of GA₃ we tested with inhibitors PBZ and NPA. GA₃ with PBZ resulted in reduction by 52.4~69.4% compared to GA₃ alone. In contrast, GA₃ with NPA resulted in an increase by -8~45.6% compared to GA₃ alone in root formation. Also, results were determined on the effect of GA₃ with other phytohormones on root formation. Kinetin, 2iP and ABA with GA₃ had a negative effect, but IAA with GA₃ showed a similar result to GA₃ alone. From these results we infer GA plays a key role and auxin has subsidiary activity on adventitious root formation. This is the first report that indicates GA₃ promotes adventitious root formation from calli in P. perfoliata.

• Applied Biological Chemistry
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• v.41 no.1
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• pp.47-52
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• 1998

3-Hydroxy-3-methylglutaryl-CoA reductase (HMGR) catalyzes the conversion of HMG-CoA to mevalonic acid, the first intermediate of isoprenoid biosynthetic pathway in plants. The enzyme was solubilized with 0.4% Brij (polyoxyethylene ether) W-1 from a microsomal fraction of etiolated rice seedlings (Oryza sativa L.) in which its maximal activity was observed on the fourth day after germination. HMGR was purified to near homogeneity by employing $(NH_4)_2SO_4$ fractionation plus chromatographic procedures including DEAE-Sephadex A-50 and HMG-CoA-hexane-agarose affinity column. The size of the purified enzyme was estimated to be 55 kDa when judged by SDS-PAGE analysis with silver staining method. The apparent $K_m$ and $V_{max}$ values for HMG-CoA were determined to be $180\;{\mu}M$ and 107 pmol/min/mg, and those for NADPH were $810\;{\mu}M$ and 32.1 pmol/min/mg, respectively.