• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.s01
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• pp.33-39
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• 1989

Ethylene gas classified as one of five major plant hormones plays an important role in various plant metabolism. The precise analysis of ethylene production of plants or plant parts is a valuable research procedure because knowledge of ethylene production facilitates measures of the physiological activity within the tissue. This paper describes procedures for analyzing ethylene from plant tissues by gas chromatography and discusses problems associated with extracting gas samples either by introducing a vacuum to plant samples or by using a hypodermic syringe. Introduced are a continuous flow system for efficient analysis and an automated system for sampling, analyzing, calculating and recording ethylene production data.

• Journal of Plant Biotechnology
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• v.5 no.1
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• pp.25-31
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• 2003

As a consequence of tissue culture of rice, RAPD analysis was peformed to determine whether extended culture periods as undifferentiated calli affected the subsequent genetic constancy, and whether any resulting DNA rearrangements could be detected between sibling plants produced from the same callus. Somaclonal variation was induced at the initial stage of tissue culture and it increased with the length of culture maintenance. Of the 192 total bands, the number of polymorphic bands was 22 (11.5%), 33 (17.2%), and 49 (25.5%) in the callus of 1,3, and 6 months culture, respectively. A significantly higher level of genotypic polymorphisms between regenerants from two different somaclones was also detected, although all the regenerants were derived from a single genotype. In comparison of DNA polymorphisms between regenerants from non-irradiated and from irradiated calli, a scope of variation spectrum by gamma ray irradiation was larger than that by tissue culture. Consideration must be given to this genomic variation where attempts are to be made to use desirable somaclonal variants for plant breeding purpose and in genetic engineering program.

• Korean Journal of Plant Tissue Culture
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• v.25 no.4
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• pp.237-243
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• 1998

To understand the tissue specific expression pattern of S RNase genes associated with self-incompatibility in L. peruvianum, two promoter regions of $S_{11}$ and $S_{12}$ RNase genes were compared. Homologous sequences between two S RNase gene promoters were found within 300 bp upstream of transcription start site. Moreover short direct repeat sequences within $S_{11}$ RNase gene promoter existed in the vicinity of 350-500 bp upstream of transcription start site. To identify whether the unique promoter sequences of $S_{11}$ RNase gene confer the tissue specific expression, six deletion fragments for $S_{11}$ genomic gene promoter constructed by PCR were fused to $\beta$-glucuronidase gene, and introduced into various tissues of L. peruvianum by microprojectile bombardment. Transient expression assays indicated that $S_{11}$ RNase gene promoter contained the positive and negative regulatory sequences, which can control the floral tissue-specific expression in L. peruvianum.

• Journal of Plant Biotechnology
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• v.30 no.4
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• pp.341-346
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• 2003

In an effort to optimize tissue culture conditions for genetic transformation of orchardgrass (Dactylis glomerata L.), an efficient and high-frequency plant regeneration system from seed-derived calli was established. Embryogenic calli induced on MS medium containing 3mg/L 2,4-D and 0.1mg/L BA had significantly improved regeneration ability. Plant regeneration rate was 92％ when embryogenic calli were cultured on N6 medium supplemented with 1mg/L 2,4-D and 3mg/L BA. Among three kinds of medium, MS and N6 medium were optimal for embryogenic callus induction and plant regeneration, respectively. Ho difference in callus induction frequency was observed among four cultivars of orchardgrass, however, "Roughrider" cultivar showed higher regenerability with the frequency of 61％. Addition of maltose to the regeneration medium as a carbon source dramatically increased regeneration frequency up to 69％. A short tissue culture period and high-frequency regeneration system would be beneficial for molecular breeding of orchardgrass through genetic transformation.

• The Plant Pathology Journal
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• v.17 no.5
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• pp.271-275
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• 2001

Phytoalexin scoparone (6,7-dimethoxycoumarin) was induced in flavedo tissue of lemon fruit inoculated with Penicillium digitatum during heat treatment for 3 days at $36^{\circ}$. The compound was also induced in the flavedo tissue after UV illuminatiion. Induction of scoparone was deteected in the flavedo tissue by histological analysis. This fluorescent scoparone accumulated only on the 4-5 layers of cells adjacent to the inoculation site. Preinoculation with P. digitatum and subsequent heat-treatment induced resistance in the lemon fruit tissues after challenge-inoculation at the site of the first infection. the data obtained in the study suggest that lemon fruit acquired resistance against P. digitatum parallel with the scoparone production at the infection site.

• 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.

• Journal of Plant Biology
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• v.37 no.1
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• pp.17-25
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• 1994

Two potato (Solanum tuberosum L.) cultivars were transformed by Agrobacterium tumefaciens harboring cauliflower mosaic virus (CaMV) 35S promoter and $\beta$-glucuronidase (GUS) gene. Expression patterns of the CaMV 35S promoter according to tissue types and developmental stages, and genetic stability of GUS gene were investigated in the clonal progenies of transgenic potatoes. Kanamycin-resistant shoot emerged from tuber disc after 4 weeks of culture, and root was induced 6 weeks after culture on the selection medium. Shooting frequency of cvs. Superior and Dejima were 43% and 27%, respectively. Mature transformants and their clonal progenies showed no phenotypical abnormality. GUS activity was expressed primarily at parenchymatous cells of phloem tissue around the vascular cambium in the stem and root, and higher activity was found at the apical meristem of shoot, root and adventious shoot bud. GUS activity was higher at tubers of young explants than at stored tubers. These facts indicate that expression level of the CaMV 35S promoter differed according to tissue types and developmental stages of the organs. The GUS gene was stably inherited to each clonal progeny and normally expressed.

• Journal of Plant Biology
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• v.38 no.4
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• pp.343-348
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• 1995

Treatment of Pisum sativum tissue with the protein kinase inhibitor staurosphorine resulted in impairment of 3H-indoleacetic acid transport in etiolated stem segments. The transport inhibitiion was accompanied by an increase in net uptake of labeled auxin in the tissue. The magnitude of auxin accumulation in tissue treated with the phytotropin N-1-naphthylphthalaic acid (NPA) which specifically blocks the efflux of auxin in the plasma membrane was reduced by the protein kinase inhibitor, suggesting that inhibition of protein phosphorylation could lead to hindrance of the auxin-exporting function of NPA receptors. The flavonoid genistein which is also known to inhibit protein kinase likewise reduced NPA-induced auxin accumulation. However, the flavonoid did not bring about auxin accumulation by itself, nor did it inhibit auxin transport. In view of the finding that the flavonoid also competes with NPA for a common binding site, a mechanism for the flavonoid effect on the NPA action will be proposed.

• Korean Journal of Plant Tissue Culture
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• v.24 no.6
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• pp.323-327
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• 1997

Addition of growth inhibitors such as ancymidol, ABA, chloromequat, and pachlobutrazol into MS medium had no effect to preventing vitrification in cultures of Rehmania glutinosa. Anatomical investigation revealed that vitrified thick leaf tissue in vitro had larger intercellular space with poor development of sponge and pallisade tissue compared to those of in vitro grown glaucous and field grown plants. In vitro grown glaucous leaf had smaller and round type stomata showing distinguishable guard and subsidiary cell than those of reestablished plantlets into soil whereas abnormal stomata and poor development of epicuticular wax on the surface of leaf was observed in verified plantlet.

• Journal of Plant Biotechnology
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• v.37 no.4
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• pp.456-464
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• 2010

Potato is one of the most important crops in the world. Due to vegetative propagation of this crop, techniques of plant tissue culture and genetic transformation are often applied for potato researches and a lot of progress has been made in the breeding programs using these techniques during the last decades. In potato, there have been several trials to introduce GM potato varieties to the world market, but they so far failed due to the changed legislation and unwillingness of large processors to process GM potatoes. These issues are highly associated with the general acceptances of the public and other political decisions. In addition to these, there are still obstacles to overcome to achieve the development of commercial potato variety and several factors to improve horticulturally important traits. In this study, therefore, we reviewed recent advances and research status on tissue culture and genetic transformation in potato and discussed future perspective.