• Journal of Plant Biotechnology
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• v.35 no.4
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• pp.275-280
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• 2008

One of the limitation for Agrobacterium-mediated transformation via organogenesis from cotyledon explants routinely in cucumber is the production of chimeric plants. To overcome the limitation, Agrobacterium-mediated transformation system via somatic embryogenesis from hypocotyl explants of cucumber (c.v., Eunsung) on the selection medium with paromomycin as antibiotics was developed. The hypocotyl explants were inoculated with Agrobacterium tumefaciens strain EHA101 carrying binary vector pPTN290; then were subsequently cultured on the following media: co-cultivation medium for 2 days, selection medium for $5{\times}14$ days, and regeneration medium. The T-DNA of the vector (pPTN290) carried two cassettes, Ubi promoter-gus gene as reporter and 35S promoter-nptll gene conferring resistance to paromomycin as selectable agent. The confirmation of stable transformation and the efficiency of transformation was based on the resistance to paromomycin indicated by the growth of putative transgenic calli on selection medium amended with 100mg/L paromomycin, and GUS gene expression. Forty eight clones (5.2%) with GUS gene expressed of 56 callus clones with resistance to paromomycin were independently obtained from 928 explants inoculated. Of 48 clones, transgenic plants were only regenerated from 5 clones (0.5%) at low frequency. The histochemical GUS assay in the transgenic seeds ($T_1$) also revealed that the gus gene was successfully integrated and segregated into each genome of transgenic cucumber.

• Korean Journal of Plant Tissue Culture
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• v.24 no.3
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• pp.153-160
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• 1997

Cucumber mosaic virus (CMV) leads to a cause of poor crop productivity and quality. To solve this problem, we attempted to develop a virus-resistance tobacco plants by using viral coat protein (CP) gene. Transgenic tobacco plants expressing CMV CP gene were analysed by the resistance upon CMV infection. The virus-resistance was measured in $\textrm{T}_{1}$, generation by the inhibition of plant growth and the expression of the mosaic symptoms infected with CMV. The transgenic lines were divided into four groups: highly resistant, resistant, moderate and susceptible based on their growth and symptom severity. Out of 39 transgenic lines, 16 lines showed significant virus-resistance. And of resistant lines, 2 lines were designated highly resistant based on the facts that they achieved similar plant height to that of non-infected tobacco plants and showed lower disease symptom than that of other lines. The steady state level of CP RNA and coat protein level were measured by northern blot and immunoblot analysis. The CP RNA was highly accumulated in most resistant and moderate lines but barely detected in susceptible lines. The coat protein was detected in most lines regardless of their resistance to CMV. from this result, virus-resistance appeared to correlate more with CP RNA level than the level of coat protein. However, in two highly resistant lines, CP RNA level was unexpectedly low. This unexpected phenomenon need to be further investigated.

• Korean Journal of Medicinal Crop Science
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• v.21 no.1
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• pp.32-38
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• 2013

FPS (farnesyl diphosphate synthase) plays an essential role in organ development in plants. However, FPS has not previously been identified as a key regulatory enzyme in triterpene biosynthesis. In order to investigate the effect of FPS on ginsenosides biosynthesis, we over-expressed FPS of Centella asiatica (CaFPS) in Panax giseng adventitious roots. PCR analysis showed the integrations of the CaFPS and hygromycin phosphotransferase genes and we ultimately selected three lines. The result of Southern blot analysis demonstrated the introduction of the CaFPS gene into genome of ginseng. In addition, the results of RT-PCR analysis revealed that CaFPS gene overexpression induced an accumulation of its transcription in the ginseng adventitious roots. To determine whether or not the overexpression of the CaFPS gene contributes to the downstream gene expression associated with triterpene biosynthesis, the level of mRNAs was analyzed by real-time PCR. The result showed that no differences were detected in any expression of all genes. To determine quantitatively the content of ginsenosides in transgenic ginseng adventitious roots, HPLC analysis was conducted. The content of total 7 ginsenosides was increased to 1.8, 1.4, and 1.7 times than that of the controls, respectively. This indicated that the overexpression of CaFPS in ginseng adventitious roots causes an increase in ginsenoside content, although down stream genes of FPS gene were suppressed by CaFPS overexpression.

• Molecules and Cells
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• v.41 no.4
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• pp.342-350
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• 2018

Flowering time is determined by florigens. These genes include, Heading date 3a (Hd3a) and Rice FT 1 (RFT1) in rice, which are specifically expressed in the vascular tissues of leaves at the floral transition stage. To study the cis-regulatory elements present in the promoter region of Hd3a, we generated transgenic plants carrying the 1.75-kb promoter fragment of Hd3a that was fused to the ${\beta}$-glucuronidase (GUS) reporter gene. Plants expressing this construct conferred a vascular cell-specific expression pattern for the reporter gene. However, GUS was expressed in leaves at all developmental stages, including the early seedling stage when Hd3a was not detected. Furthermore, the reporter was expressed in roots at all stages. This suggests that the 1.75-kb region lackings cis-elements that regulate leaf-specific expression at the appropriate developmental stages. Deletion analyses of the promoter region indicated that regulatory elements determining vascular cell-specific expression are present in the 200-bp region between -245 bp and -45 bp from the transcription initiation site. By transforming the Hd3a-GUS construct to rice cultivar 'Taichung 65' which is defective in Ehd1, we observed that Ehd1 is the major regulatory element that controls Hd3a promoter activity.

• Molecules and Cells
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• v.42 no.5
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• pp.406-417
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• 2019

RICE FLOWERING LOCUS T 1 (RFT1) is a major florigen that functions to induce reproductive development in the shoot apical meristem (SAM). To further our study of RFT1, we overexpressed the gene and examined the expression patterns of major regulatory genes during floral transition and inflorescence development. Overexpression induced extremely early flowering in the transgenics, and a majority of those calli directly formed spikelets with a few spikelets, thus bypassing normal vegetative development. FRUITFULL (FUL)-clade genes OsMADS14, OsMADS15, and OsMADS18 were highly induced in the RFT1-expressing meristems. OsMADS34 was also induced in the meristems. This indicated that RFT1 promotes the expression of major regulatory genes that are important for inflorescence development. RFT1 overexpression also induced SEPALLATA (SEP)-clade genes OsMADS1, OsMADS5, and OsMADS7 in the greening calli before floral transition occurred. This suggested their possible roles at the early reproductive stages. We found it interesting that expression of OsFD1 as well as OsFD2 and OsFD3 was strongly increased in the RFT1-expressing calli and spikelets. At a low frequency, those calli produced plants with a few leaves that generated a panicle with a small number of spikelets. In the transgenic leaves, the FUL-clade genes and OsMADS34 were induced, but SEP-clade gene expression was not increased. This indicated that OsMADS14, OsMADS15, OsMADS18, and OsMADS34 act immediately downstream of RFT1.

• Korean journal of applied entomology
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• v.53 no.2
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• pp.193-197
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• 2014

Transgenic crops that produce insecticidal toxins have a great potential for controlling target pest insects, but there is a growing concern about unintended influences on non-target species. In the present study, the preferences and performance of non-target green peach aphid, Myzus persicae (Sulzer), on transgenic cabbages (Brassica oleracea) that produce Bt toxin (Cry1Ac1) and untransformed control plants were investigated as a part of risk assessment. In a free-choice situation, the number of nymphs larviposited by 10 winged adults over 3 days was $21.9{\pm}1.8$ and $22.5{\pm}2.2$ on transgenic and the control plants, respectively, indicating that the aphids did not discriminate between the two types of plants. In a performance assay, the development time (D) and intrinsic rate of increase (rm) of wingless aphids reared on transgenic and control plants were also similar (D, $5.8{\pm}0.2$ and $5.9{\pm}0.1$ (days) and rm, $0.7{\pm}0.1$ and $0.8{\pm}0.1$, for transgenic and control plants, respectively). These results suggest that M. persicae is not significantly affected by transgenic Bt cabbage.

• Korean Journal of Medicinal Crop Science
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• v.12 no.2
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• pp.171-178
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• 2004

The objectives of this study were to establish the genetic transformation system of stilbene synthase in Rehmannia glutinosa. Resveratrol, which is both a phytoalexin with antifungal activity and a phytochemical associated with reduced cancer risk and reduced cardiovascular disease, is synthesized in a limited number of plant species including peanut. Resveratrol synthesis is catalyzed by the enzyme stilbene synthase including resveratrol synthase (RS). Stilbene synthase gene (RS3) obtained from peanut, Arachis hypogaea, Fabaceae has been transferred into chinese foxglove, Rehmannia glutinosa by using Agrobacterium mediated transformation. PCR analysis with RS3 primer confirmed that the targeted gene was introduced into the plant genome, 904 bp in size. Further analyses of identification of transformation using developed other molecular techniques and transgenic plants that RS t-DNA introduced to chinese foxglove (R. glutinosa L) and its reaction product, stilbene such as resveratrol will be isolate and characterize using NMR, MS, and HPLC.

• Korean Journal of Medicinal Crop Science
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• v.12 no.2
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• pp.135-140
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• 2004

Total RNAs were isolated from cultured roots of Scopolia parviflora, $poly(A)^+$ RNA was obtained through the mRNA purification, cDNA library of Hnh6h was constructed. Recombinant baculoviruses in Spodoptera frugiperda (Sf) cells were constructed by use of the transfer vector pBacPAK, which has the AcNPV sequence under the polyhedrin promoter. The expression vector carrying Hnh6h gene was transferred to S. parviflora and obtained transgenic hairy root lines. Our results confirmed the over expression of the H6H protein was used by anti-pBacPAK about cDNAs of S. parviflora. This study will served for production of tropane alkaloids by metabolic engineering.

• Korean Journal of Medicinal Crop Science
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• v.12 no.5
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• pp.424-427
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• 2004

Microsomal ${\omega}-3$ fatty acid desaturase (FAD3) is an essential enzyme in the production of the n-3 polyunsaturated fatty acid ${\alpha}-linolenic$ acid during the seed developing stage. To understand the regulatory mechanism of the gene encoding the ${\omega}-3$ fatty acid desaturase, a genomic fragment corresponding to the previously isolated perilla seed PfFAD3 cDNA was amplified from perilla (Perilla frutescens Britt) by GenomeWalker PCR. Sequence analysis of the fragment provided with identification of a 1485-bp 5'-upstream region and a 241-bp intron in the open reading frame. To determine the tissue-specificity of the PfFAD3 gene expression, the 5'-upstream region was fused to the ${\beta}-glucuronidase$ (GUS) gene and incorporated into Arabidopsis thaliana. Histochemical assay of the transgenic plants showed that GUS expression was restricted to seed and pollen, showing that PfFAD3 gene was exclusively expressed in those tissues.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.118-118
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• 2017

A high-resolution physical map targeting a cluster of yield-related QTLs on the long arm of rice chromosome 9 was constructed across a 35.5kb region containing the six predicted genes including the probable ascorbate peroxidase (OsApx). The $BC_3F_6$ near isogenic lines (NILs) were derived from a cross between the Oryza sativa Hwaseong and O. rufipogon. The plant height and length of internodes were compared between Hwaseong and NILs. There were significant differences in plant height between Hwaseong and NILs. The NILs internodes were longer than Hwaseong, showing dramatic elongation in the first and fourth internodes; thereby, leading to increased plant height. The antioxidant activity of Hwaseong and NILs was also analyzed by 3,3-diaminobenzidine (DAB) staining and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. In order to understand whether or not OsApx gene is important in scavenging $H_2O_2$ in rice, DAB staining was used. Intense dark-brown coloration was observed in Hwaseong than NILs. In addition, DPPH scavenging ability of Hwaseong showed lower value than NILs. These results indicated that the internode elongation and antioxidant activity might possibly be controlled by OsApx. To know the causative relationship of the gene and phenotype, we will further analyze the gene expression and use it for functional studies by complementation transgenic approach.