• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.s01
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• pp.16-25
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• 1989

A bioassay is a test system using a living organism (in whole or in part) to determine the presence or relative potency of chemical substances. The development and uses of bioassay are intimately linked to the discovery and characterization of the major classes of plant hormones. An application of this relationship is helpful for understanding the concept of plant hormones as well as the use of bioassay. And plant bioassay have been development and employed not only for the discovery and characterization of the biological activity of plant growth regulators but also have served several important secondary roles. The ideal bioassay should possess the characteristic of high specificity. great sensitivity. short response time, low cost and ease of obtaining plant material. acceptable ease of manipulation, and minimal space and equipment requirements.

• Proceedings of the Botanical Society of Korea Conference
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• 1987.07a
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• pp.117-132
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• 1987

Plants are inherited spatial and temporal coordination systems in their growth and differentiation processes which are precisely governed by the two interlocked control systems; autogenous and environmental. Looking into the overall course of plant development from molecular to organismal level, it can be comparable to a concerto for plant hormones, environmental stimuli and plant genomic orchestra conducted by an unidentified virtuoso. Some of the recent significant attempts to puzzle out the mystery of the life processes of plant development are briefly reviewed. The revolutionary advances in understanding the mystic processes are contemporarily achieved by the application of various molecular techniques. The characterization of plant genomes is now attained through recombinant DNA approaches, and the sensitive detection of specific gene products during the plant development is perimitted by the immunochemical procedures. However, along with the recognition of underlying molecular events such as developmental changes in gene expression and hormone-receptor interrelation associated with tissue sensitivity to hormones, more emphasis should be placed upon the physiological approaches of organismal level for the understanding the correlative systems of the developmental processes of plants as intact eukaryotic organisms.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.s01
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• pp.40-47
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• 1989

In spite of the development of highly sophisticated instrument, the precise quantitation of plant hormones still has many difficulties. Due to their high specificity, sensitivity and minimal sample purification steps, immunological assays have been widely applied for plant hormone assay. Enzme-linked immunosorbent assay technique for the determination of plant hormones was developed by Voller in 1978. Immunological assays are accomplished by competition of labeled tracer antigen and unlabeled antigen for a limited number of specific antibodies. The use of enzyme as replacement labels for radioisotopes enabled much of the sensitivity and specificity of radioimmunoassay (RIA) to be retained but without the inherent disadvantage of high capital cost, potential health hazard, and short shelf life of the labeled reactants.

• The Plant Pathology Journal
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• v.24 no.4
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• pp.400-406
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• 2008

To examine the relationship between plant hormones and the development of pepper anthracnose, we investigated the effects of several plant hormones on the progression of disease symptoms. Of the five plant hormones examined, abscisic acid (ABA) increased the lesion length and disease incidence on detached fruits of Capsicum annuum cv. Nokkwang. The simultaneous application of ABA with inoculation of Colletotrichum acutatum JC24 resulted in increased lesion length, depending the concentration of ABA applied. Additionally, application of ABA caused the development of pepper anthracnose in fruits of Capsicum baccatum cvs. PBC80 and PBC81, which were previously resistant to the disease. Furthermore, ABA administration rendered increased pathogenicity of other isolates of C. acutatum BAC02063, PECH10, and TCBNU3 obtained from the Chinese matrimony vine, peach, and tea tree, respectively. Our data suggest that exogenous ABA may result in the suppression of defense mechanisms of pepper fruits against anthracnose, which leads to a change in the susceptibility of pepper fruits and the development of pepper anthracnose.

• Journal of Environmental Science International
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• v.2 no.4
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• pp.279-289
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• 1993

Light qualities and three kinds of plant hormones, NAA, GA3 and BA were treated on maize seedlings to investigate the effect on formation of the chlorophyll-protein complexes. Each three kinds of plant hormones accelerated the chlorophyll proteins formation, particularly LHCP-1 and LHCP-3, but two kinds of hormonal combinations didn't promote these proteins accumulation under sun light condition. The formation of chlorophyll proteins of LHCP-1, CPA and LHCP-3 associated with PSII was promoted under red light compared to sun light, on the contrary the formation of chlorophyll proteins was not affected by white light. Plant hormones under red light induced chlorophyll proteins formation associated with PSII at early state of chloroplast development and two kinds of hormonal combinations under red light were very effective in accumulation of chlorophyll proteins of PSII in contrast to sun light. The results obtained suggest that light may play an important role compared to plant hormones in the formation of chlorophyll proteins.

• Molecules and Cells
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• v.19 no.2
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• pp.228-231
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• 2005

Recent characterization of several genes involved in plant defense responses suggested that ubiquitin-mediated protein degradation has a role in these responses. We isolated two cDNAs (NtUBA1 and NtUBA2) encoding ubiquitin-activating enzyme (E1) from Nicotiana tabacum cv. BY-2. The open reading frames of both encoded 1080 amino acids, corresponding to molecular masses of 120 kDa. The E1s and corresponding transcripts were upregulated by infection with tobacco mosaic virus (TMV) and tomato mosaic virus (ToMV), and to a lesser extent by cucumber mosaic virus (CMV). Furthermore, they were also upregulated by wounding stress, and the plant hormones salicylic acid, jasmonic acid and the ethylene precursor, aminocyclopropane-1-carboxylic acid (ACC). Our findings support the idea that the ubiquitin-proteasome system plays a role in plant disease defenses.

• Mycobiology
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• v.38 no.3
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• pp.176-179
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• 2010

The effect of plant hormones on the growth of lichen-forming fungi (LFF) was evaluated. The use of 2,3,5-triiodobenzoic acid and indole-3-butyric acid resulted in a 99% and 57% increase in dry weight of the lichen-forming fungus Nephromopsis ornata. The results suggest that some plant hormones can be used as inducers or stimulators of LFF growth for large-scale culture.

• The Plant Pathology Journal
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• v.40 no.2
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• pp.99-105
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• 2024

Land plants produce glucose (C₆H₁₂O₂) through photosynthesis by utilizing carbon dioxide (CO₂), water (H₂O), and light energy. Glucose can be stored in various polysaccharide forms for later use (e.g., sucrose in fruit, amylose in plastids), used to create cellulose, the primary structural component of cell walls, and immediately metabolized to generate cellular energy, adenosine triphosphate, through a series of respiratory pathways including glycolysis, the tricarboxylic acid cycle, and oxidative phosphorylation. Additionally, plants must metabolize glucose into amino acids, nucleotides, and various plant hormones, which are crucial for regulating many aspects of plant physiology. This review will summarize the biosynthesis of different plant hormones, such as auxin, salicylic acid, gibberellins, cytokinins, ethylene, and abscisic acid, in relation to glucose metabolism.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.3
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• pp.288-298
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• 1992

Since the major important factors limiting plant growth and crop productivity are environmental stresses, of which low temperature is the most serious. It has been well known that many physiological processes are alterant in response to the environmental stress. With regard to the relationship between plant hormones and the regulation of chilling tolerance in rice seedlings, the major physiological roles of plant hormones: abscisic acid, ethylene and polyamines are evaluated and discussed in this paper. Rice seedlings were grown in culture solution to examine the effect of such plant hormones on physiological characters related to chilling tolerance and also to compare the different responses among tested cultivars. Intact seedlings about 14 day-old were chilled at conditions of 5$^{\circ}C$ and 80% relative humidity for various period. Cis-(＋)-ABA content was measured by the indirect ELISA technique. Polyamine content and ethylene production in leaves were determined by means of HPLC and GC respectively. Chilling damage of seedlings was evaluated by electrolyte leakage, TTC viability assay or servival test. Our experiment results described here demonstrated the physiological functions of ABA, ethylene, and polyamines related to the regulation of chilling tolerance in rice seedlings. Levels of cis-(＋)-ABA in leaves or xylem sap of rice seedlings increased rapidly in response to 5$^{\circ}C$ treatment. The tolerant cultivars had significant higher level of endogenous ABA than the sensitive ones. The ($\pm$)-ABA pretreatment for 48 h increased the chilling tolerance of the sensitive indica cultivar. One possible function of abscisic acid is the adjustment of plants to avoid chilling-induced water stress. Accumulation of proline and other compatible solutes is assumed to be another factor in the prevention of chilling injuies by abscisic acid. In addition, the expression of ABA-responsive gene is reported in some plants and may be involving in the acclimation to low temperature. Ethylene and its immediate precusor, 1-amincyclopropane-1-carboxylic acid(ACC) increased significantly after 5$^{\circ}C$ treatment. The activity of ACC synthase which converts S-adenosylmethionine (SAM) to ACC enhanced earlier than the increase of ethylene and ACC. Low temperature increased ACC synthase activity, whereas prolonged chilling treatment damaged the conversion of ACC to ethylene. It was shown that application of Ethphon was beneficial to recovering from chilling injury in rice seedlings. However, the physiological functions of chilling-induced ethylene are still unclear. Polyamines are thought to be a potential plant hormone and may be involving in the regulation of chilling response. Results indicated that chilling treatment induced a remarkable increase of polyamines, especially putrescine content in rice seedlings. The relative higher putrescine content was found in chilling-tolerant cultivar and the maximal level of enhanced putrescine in shoot of chilling cultivar(TNG. 67) was about 8 folds of controls at two days after chilling. The accumulation of polyamines may protect membrane structure or buffer ionic imbalance from chilling damage. Stress physiology is a rapidly expanding field. Plant growth regulators that improve tolerance to low temperature may affect stress protein production. The molecular or gene approaches will help us to elucidate the functions of plant hormones related to the regulation of chilling tolerance in plants in the near future.

• Korean Journal of Plant Resources
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• v.7 no.2
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• pp.171-175
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• 1994

The effects of medium, hormones, and PFP on the proliferation of red callus in leaf tissue cultures of Garden orach(Atriplex hortensis L.) was investigated. As a result,88% of leaf tissues formed eallus on MS nledium containing 2mg/$\ell$ 2,4-D. Fresh weight of callus was higher on MS medium than on Bsand NN media. It was also found that 2, 4-D was more effective than Dicamba and Picloram. The op-timum concentrations of hormones for callus proliferation depended on culture media. Isolated red cal-lus grew markedly both on MS medium supplemented with 1-2mg/$\ell$ 2, 4-D and Bs medium contain-ing 2-4111g/$\ell$ 2,4D. Callus proliferated on B5 and NN media containing Dicabma Img/$\ell$ as well as onthe same media containing 2mg/$\ell$ Picioram. The addition of PFP concentrations of 2, 5, and 40mg/ $\ell$rcspectiely to culture medium caused increase of callus fresh weight, especially under light condition.