• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.5
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• pp.548-555
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• 1997

Sorghum seedlings lacking one of the phytochromes, phyB, have elongated internode, suggesting that they may have an alteration in gibberellin physiology. To test the possibility that phyB mutations affect seedling gibberellin perception and metabolism, the responsiveness of wild-type and phyB-1 seedlings to exogenous $GA_3$ was investigated. The phyB-1 showed higher internode elongation rate than the wild type in response to lower concentrations of exogenous $GA_3$ application, showing that the mutation causes an increase in responsiveness to GA. However, at the higher concentrations of $GA_3$ application, phyB-l and wild-type showed similar elongation rate, impling that responsiveness to higher concentrations of GA is not controlled by phytochrome. These results suggest that, although GAs are required for internode elongation, phyB does not act primarily by changing absolute levels of GAs but rather by decreasing seedling responsiveness to GAs at lower concentrations.

• Journal of Life Science
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• v.7 no.4
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• pp.342-346
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• 1997

This experiment was carried out to clarify the effects of gibberellin(GA) aplication and bagging on repeening and quality in 'Delaware' grape berries. Treatments are 4 plots(2X2 factorial experiment); GA, GA+bagging, bagging and control. The clusters were dipped twice in 100 ppm GA with GA treatment : 10 days before and after the full bloom. The results obtained as follows: 1. GA treatment made the seedless grape berry reduced in the fresh weight but it hastened the ripening period about 2 weeks. 2. Total soluble solid(TSS), viscosity and pH value of berry juice increased with maturation. The concentration of TSS and viscosity were higher in GA treatment plot than GA non-treatment. 3. Berry-hardness, titratable acidity and alcohol inslouble solid(AIS) decreased with maturation. Expically berry-hardness and AIS decreased more greatly in GA non-treatment than GA treatment. 4. The concentration of anthocyanin increased with ripening but pectic substance didn't fluctuate nearly. These of anthocyanin and pectin were higher in GA non-treatment plot than GA treatment. 5. By analysis of factorial experiment GA treatment was highly significant with the $^{o}$Brix/Acidity ratio, juice viscosity and AIS, but high negatively, significant with berry-hardness and berry fresh weight. And it was significant with T S S and negatively, titratable acidity. Bagging was significant with $^{o}$Brix/Acidity ratio and AIS content, but negatively, titratable acidity. 6. Qualitative characters were high correlated with the $^{o}$Brix/Acidity ratio in simple correlation but direct effect by the path-coefficient analysis didn't coincide with simple correlation. The direct effect of pH was large and juice viscosity, the next. And that of berry-hardness was negligible but, AIS, small negatively.

• Journal of Life Science
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• v.17 no.5 s.85
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• pp.641-645
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• 2007

We conducted a seed germination screening under saline conditions to identify salt tolerance(sto) mutants with ethyl methane sulfonate(EMS) mutagenesis seed pool. During the screening, we identified three mutant lines that seemed to confer elevated salt tolerance in high concentrations of NaCl. At 175 mM NaCl, germination rate of sto42-14 mutant(one of the EMS salt tolerance mutants) was 7-fold higher than that of wild-type plants. Interestingly, sto42-14 mutant exhibited insensitivity to high glucose concentration and growth inhibition to gibberellin. Our results suggest that sto42-14 is involved in salt stress tolerance as well as in glucose and gibberellin response in Arabidopsis.

• Journal of Radiation Industry
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• v.6 no.3
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• pp.281-287
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• 2012

The model plant, Arabidopsis thaliana is the subject of an international genome research project. Massive doses of ionizing radiation have been shown to induce physiological changes in plants. The wild-type (Ler) Arabidopsis plants were irradiated with 100 Gy and 800 Gy of gamma-ray. Gibberellin (GA) affects developmental processes and responses according to the various environment conditions in diverse plant. The 13 GA isomers were analyzed at vegetative (VE) and reproductive (RE) stages by HPLC. Total GA contents were reduced with the increase in radiation doses at VE and RE stages. Specifically, levels of GA3, GA4, GA12, and GA34 were significantly reduced with the increase of radiation doses. Oligonucleotide microarrays analysis was performed with Arabidopsis plants at different developmental stages and doses of gamma-ray. Through the microarray data, we isolated 41 genes related to GA biosynthesis and signaling transduction. Expression of these genes was also decreased as the reduction of GA contents. Interestingly, in GA signaling related gene expression, gibberellin-responsive protein, putative (At2g18420) was down-regulated at VE and RE stages. Myb21 (At3g27810), Myb24 (At5g40350), and Myb57 (At3g01530) was down-regulated at RE stage. In GA biosynthesis related gene expression, YAP169 (At5g07200) and GA20ox2 (At5g51810) were down-regulated at 100 Gy treatment of VE stage and 800 Gy treatment of RE stage in cytoplasm, respectively. However, exceptively, GA3ox2 (At1g80340) was up-regulated at 100 Gy treatment of RE stage in cytoplasm. In this study, the wild type (Ler) Arabidopsis plants showed differences in response with development stage at the various doses of gamma-rays. GA contents change was reported in gamma irradiated plant.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.s01
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• pp.4-15
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• 1989

The objective of this paper is to compare and summarize the procedure and effectiveness of some bioassay systems and to point out ways to obtain reliable results from each bioassay. Detailed C:escriptions were given for those widely-adapted bioassay methods, such as mungbean rooting (auxin), Avena first internode straight growth (auxin), dwarf rice growth (gibberellin), dwarf pea epicotyl elongation (gibberellin), radish cotyledon expansion test (cytokinin), and tobacco stem pith callus growth (cytokinin), and the effects of various plant growth regulators including some recently introduced growth retardants (Paclobutrazol, Uniconazol, etc.) were also summarized.

• Journal of Microbiology and Biotechnology
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• v.23 no.5
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• pp.623-629
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• 2013

Gibberellins (GAs) are a group of phytohormones that control many developmental processes in higher plants. We report the cloning and expression pattern of gibberellin biosynthesis genes from a new GA-producing fungus, Fusarium proliferatum (strain KGL0401). These genes sequences are deposited in the National Center for Biotechnology Information (NCBI) under accession numbers EF119831, EF119832, DQ313173, DQ313174, DQ313175, DQ313176, and DQ313177. The expression level of these genes was maximal at a 0.5 M : 0.17 M carbon : nitrogen ratio, and minimal at a 0.25 M : 0.47 M carbon : nitrogen ratio.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.6
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• pp.523-526
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• 2006

When $GA_{4}$ was applied to heading stage, it was examined to understand the change of plant hormones and starch during grain filling and ripening. Exogenous gibberellin caused a dramatic decrease in endogenous ABA content. Endogenous $GA_{4}$ content in both superior and inferior part was more promoted in $GA_{4}-treated$ rice grain than in the control. $GA_{1}$ content of an inferior part was not detected in the control and $GA_{4}-treated$ rice otherwise $GA_{4}$ was detected in all grain parts. Ripened grain rate in $GA_{4}-treated$ rice grain was lower than that of the control plant. Amylopectin from $GA_{4}-treated$ grain contained more very short chains with degree of polymerization (DP) between 4 and 8 than amylopectin from the control plant. It suggests strongly that fine structure of rice endosperm may be changed by exogenously applied $GA_{4}$ in rice plants.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.1
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• pp.94-98
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• 2011

Proximate chemical components (protein, oil, carbohydrate, ash, fiber, and starch) were determined from tubers grown in upland and wetland conditions. The contents of crude protein, oil, carbohydrate, and starch were higher in upland condition than in wetland condition. Eight gibberellins were commonly identified and quantified in leaves and tuber of chufa grown in wetland and upland field during growing season. Gibberellin content was always higher specifically in the leaves and tubers grown in wetland condition than in those grown in upland condition. The current knowledge of gibberellin biosynthesis suggests that the two endogenous bio-active gibberellins both $GA_1$ and $GA_4$ are differently metabolized according to cultural conditions. Major gibberellin biosynthesis route is ascertained dominantly the non C-13 hydroxylation pathway leading $GA_4$ in chufa plants.

• Journal of Forest and Environmental Science
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• v.38 no.4
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• pp.284-289
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• 2022

This study was conducted to determine the seed dormancy types of Sambucus racemosa subsp. pendula Nakai and S. williamsii Hance. Low temperature stratification (1, 2, 3, 4 months) and GA3 treatment (1,000 mg/L) were performed on seeds to determine the type of seed dormancy. After the treatment, seeds were placed on a petri dish at 25℃ under light conditions. The germination rate and mean germination time were investigated. Results showed that cold stratification was effective in breaking the dormant state of the seed in both species. In the low temperature stratification treatment, the seed germination performance was improved as the treatment period was prolonged. Gibberellin treatment was effective in breaking the dormant state of S. racemosa subsp. pendula without low temperature stratification. However, S. williamsii did not break the dormant state of the seed by gibberellin treatment without low temperature stratification treatment. In the gibberellin treatment, germination performance was improved according to the low temperature stratification treatment period. As a result of this study, the seeds of S. williamsii have both an intermediate complex and a deep complex morphophysiological dormancy (MPD). In comparison, it was found that the S. racemosa subsp. pendula had intermediate composite MPD.

• Journal of Bio-Environment Control
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• v.33 no.1
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• pp.12-21
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• 2024

The aim of this research was to investigate the effect of gibberellin on improving seedling growth characteristics and enhancing strawberry quality in cutting propagation. Cuttings of the cultivar 'Seolhyang' were treated with GA₃ for 30 and 60 minutes at concentrations of 50, 100, and 150 mg·L^-1, with distilled water used for dipping as the control. Evaluation of seedling growth showed a positive correlation between the duration of gibberellin dipping and growth characteristics such as leaf number and SPAD value. Plant height, petiole length, leaf length and width, and leaf area varied significantly based on the interaction between dipping time and concentration. Crown diameter exhibited differences depending on the dipping time, with cuttings producing superior seedlings having a diameter of 8.0 mm or more for all treatments except the 30-minute, 100 mg·L^-1 treatment. The T/R ratio was significantly lower in the 30-minute, 50 mg·L^-1 treatment, indicating the highest plant vigor. Quantum yield was lower at a concentration of 150 mg·L^-1, showing a decreasing trend with increasing gibberellin concentration. Nonphotochemical quenching was significantly smaller in the 30-minute, 150 mg·L^-1 treatment, indicating an effective reduction of stress in the cuttings. Antioxidant content was highest in the 30-minute, 50 mg·L^-1 treatment and the 60-minute, 150 mg·L^-1 treatment. Moreover, the results of post-transplanting growth assessment showed no negative effect of gibberellin on flowering induction. Therefore, it was confirmed that gibberellin treatment during the cutting propagation of 'Seolhyang' strawberries had a positive effect on the production of high-quality seedlings. Dipping the cuttings in 50 mg·L^-1 gibberellin for 30 minutes is considered to be the most suitable method for improving growth and quality compared to the control.