• Korean Journal of Plant Resources
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• v.10 no.2
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• pp.107-113
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• 1997

Transformants of White Clover(Trifolium repens L.) were efficiently produced from immature seed derived callus cocultivated with Agrobacterium twnefaciens LBA4404 harboring plant binary vector. pBI121, using acetosyringone. The mean frequencies of transformants on the two kanamycin-containing media were 16 to 19% when the immature seed-derived calli were infected with bacteria cultured in the presence of 100$\mu$M acetosyringone compared with 7% in media without acetosyringone. Transgenic white clover was subject to molecular analysis for integration into plant nuclear genome and expression of $\beta$-glucuronidase(GUS) gene. PCR and Northern blot analyses demonstrated that GUS gene was integrated into white clover nuclear genome and expressed into its mRNA. The expression of GUS gene into its protein was confirmed by spectrophotometric assay of GUS activity.

• Journal of Plant Biotechnology
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• v.37 no.4
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• pp.511-516
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• 2010

The process to acquire intron-GUS gene-expressed transformants from somatic embryos (including embryogenic calli) of Rosa hybrida cv. 'Sweet Yellow' using Agrobacterium-meditated transformation method was reported in this study. Somatic embryos including embryogenic calluses were infected with Agrobacterium tumefaciens AGL1 strain (O.D = 0.7~1.6) including intron-GUS gene for 30 min, and were co-cultured for 3 days. After co-cultivation, they were cultured on embryo germination medium (EGM) supplemented with $250\;mg{\cdot}L^{-1}$ cefotaxim at $4^{\circ}C$ for 7 days. Then, transient GUS gene expression was observed. Shoots were regenerated from the shoot primodia induced from the intron-GUS gene-transferred either somatic embryos or embryogenic calli cultured on EGM supplemented with both cefotaxim $250\;mg{\cdot}L^{-1}$ and ppt $2\;mg{\cdot}L^{-1}$. Before induction of rooting from shoots cultured on shoot growing medium supplemented with both cefotaxim $250\;mg{\cdot}L^{-1}$ and ppt $2\;mg{\cdot}L^{-1}$, the shoots were cultured on multi-shoot induction medium supplemented with both cefotaxim $250\;mg{\cdot}L^{-1}$ and ppt $2\;mg{\cdot}L^{-1}$ to induce multi-shoots. When expression of the gene from a part of the multi-shoots was identified by GUS transient assay, the putative transgenic multishoots were transferred to rooting medium supplemented with cefotaxim $250\;mg{\cdot}L^{-1}$. After the formation of healthy roots, transgenic plantlets were transferred to the greenhouse after acclimatization. The expression rate of the intron-GUS gene in the multi-shoots was 100%.

• Korean Journal of Plant Tissue Culture
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• v.21 no.5
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• pp.315-318
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• 1994

To obtain transformed plants, we cocultured cotyledonary explants of Codonopsis lanceolata with Agrobacterium tumefaciens LBA4404, a disamed strain harboring a binary vector pBI121 carrying the CaMV35S promoter-$\beta$-glucuronidase (GUS) gene fusion used as a reporter gene and NOS promoter-neomycin phosphotransferase gene as a positive selection marker in MS liquid medium with 1mg/L BA. After 48 h of culture, explants were transferred onto MS solid medium with Img/L BA, 250mg/L carbenicillin, and 100mg/L kanamycin sulfate and cultured in the dark. Numerous adventitious buds formed on the cut edges of the explants after 2 weeks of culture. When subjected to GUS histochemical assay buds showed a positive response at a frequency of 15%. Explants formed adventitious shoot at a frequency of 56.7%, after 6 weeks of culture. Upon transfer onto the basal medium, most of the shoots were rooted and subsequently the regenerants were transplanted to potting soil. Southern blot analysis confirmed that the GUS gene was incorporated into the genomic DNA of the GUS-positive regenerants.

• Fisheries and Aquatic Sciences
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• v.9 no.4
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• pp.135-139
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• 2006

We optimized the biological and physical parameters for DNA delivery into thalli of the red alga Porphyra yezoensis using a particle bombardment device. The efficiency of transformation was determined using the ${\beta}-glucuronidase$ (GUS) assay. The optimal helium pressure, distance of tungsten particle flight, and ratio of DNA to tungsten particles were $23kgf/cm^2$, 8 cm, and $5{\mu}g/mg$ tungsten, respectively. During bombardment, osmotic treatment with a mixture of 0.6 M mannitol and sorbitol increased the efficiency of GUS transformation. After 2 days, the blue color indicating GUS activity was observed using a histochemical assay.

• Korean Journal of Plant Tissue Culture
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• v.25 no.5
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• pp.329-333
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• 1998

$\beta$-Glucuronidase (GUS) gene of Escherichia coli was introduced into sweet potato (Ipomoea batatas (L.) Lam.) cells by particle bombardment and expressed in the regenerated plants. Microprojectiles coated with DNA of a binary vector pBI121 carrying CaMV35S promoter-GUS gene fusion and a neomycin phosphotransferase gene as selection marker were bombarded on embryogenic calli which originated from shoot apical meristem-derived callus and transferred to Murashige and Skoog (MS) medium supplemented with 1 mg/L 2,4-dichlorophenoxyacetic acid and 100 mg/L kanamycin. Bombarded calli were subcultured at 4 week intervals for six months. Kanamycin-resistant calli transferred to MS medium supplemented with 0.03 mg/L 2iP, 0.03 mg/L ABA, and 50 mg/L kanamycin gave rise to somatic embryos. Upon transfer to MS basal medium without kanamycin, they developed into plantlets. PCR and northern analyses of six regenerants transplanted to potting soil confirmed that the GUS gene was inserted into the genome of the six regenerated plants. A histochemical assay revealed that the GUS gene was preferentially expressed in the vascular bundle and the epidermal layer of leaf, petiole, and tuberous root.

• Korean Journal of Plant Tissue Culture
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• v.25 no.1
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• pp.37-43
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• 1998

The highest transformation frequency was observed when cotyledonary and hypocotyl explants of flowering cabbage (Brassica oleracea var. acephala DC) 'Eunbae' were cultured on shoot induction medium without kanamycin for 1 day, then cocultured with Agrobacterium tumefaciens LBA4404;;pGA1036 harboring tomato inhibitor II promoter and $\beta$-glucuronidae (GUS) fusion gene for 3 days. These explants were transferred to MS medium containing 20 mg/L kanamycin, 500 mg/L carbenicillin, and 1 mg/L BA. The explants were subsequently subcultured every 2 weeks. Incorporation of the GUS gene into flowering cabbage was confirmed by PCR analysis of DNA. Southern blot analysis showed that ECL-labeled GUS gene was hybridized to the expected amplified genomic DNA fragment of about 366 bp from transgenic flowering cabbage. Histochemical analysis based on the enzymatic activity of the GUS protein indicated that PI-II promoter activity was sysmatically associated with vascular tissue in wonded as well as in non-wounded leaves, petioles and stems, but not in roots. Partial wounding with razor blade showed not systemic induction but partial induction.

• Journal of Plant Biology
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• v.37 no.3
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• pp.371-380
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• 1994

To determine the patterns and the levels of expression of the cauliflower mosaic virus (CaMV 35S) promoter and the rice actin 1 (Act1) promoter in rice, transgenic rice plants containing CaMV 35S-$\beta$-glucuronidase (GUS) and Act1-GUS constructs were generated and examined by fluorometric and histochemical analyses. The fluorometric analysis of stably transformed calluses showed that the activity of the rice Act1 promoter was stronger than that of the CaMV 35S promoter in rice cells. In a histochemcial study of the transgenic rices, it was shown that the GUS activity directed by the CaMV 35S promoter was localized mainly in parenchymal cells of vascular tissues of leaves and roots and mesophyll cells of leaves. These results are similar to those of potato, a dicot plant. In contrast, rice plant transformed with Act1-GUS fusion construct revealed strong GUS activity in parenchymal cells of vascular tissue, mesophyll cells, epidermal cells, bulliform cells, guard subsidiary cells of leaves and most cells of the root, suggesting that the rice Act1 promoter is more constitutive than the CaMV 35S promoter. It was also confirmed that in both types of transgenic rice little or no staining was localized in metaxylen tracheary elements of vascular tissue from leaves or roots. These results indicate that the rice Act1 promoter can be utilized more successfully for expression of a variety of foreign gene in rice than the CaMV 35S promoter.

• Plant Breeding and Biotechnology
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• v.2 no.3
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• pp.289-300
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• 2014

A tissue-specific and developmentally expressed gene was isolated from Chinese cabbage (Brassica rapa L. ssp. pekinensis), designated BrREF (B. rapa Rubber elongation factor). BrREF transcripts were expressed at high levels in seedlings and at low levels in flower buds and roots. To study the activity of this promoter, the 2.2 kb upstream sequence of BrREF gene was fused to a β-glucuronidase (GUS) reporter gene and was introduced into Arabidopsis thaliana and B. napus by Agrobacterium-mediated transformation. Strong expression of GUS driven by the BrREF promoter was detected in the cotyledons and hypocotyls of transgenic plant seedlings, but GUS expression was weak in roots, excluding the root tips. GUS expression in the cotyledons and hypocotyls decreased dramatically as the seedlings matured and was not detected in the tissues of mature plants. During floral development, GUS expression was observed in immature anthers. These findings suggest that the BrREF promoter can modulate the tissue-specific and developmental expression of gene at the early stages of growth and development.

• BMB Reports
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• v.32 no.1
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• pp.51-59
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• 1999

The Korean radish cationic peroxidase (KRCP) promoter, comprising nucleotides -471 to +704 relative to the transcriptional initiation site, was fused to the GUS gene and transformed to tobacco BY-2 cells. We examined how auxin (2,4-dichlorophenoxyacetic acid, 2,4-D), cytokinin (6-benzylaminopurine, BAP), gibberellic acid ($GA_3$), abscisic acid (ABA), methyl jasmonate (MeJA), and phosphatidic acid (PA) affect the GUS expression in the presence or absence of 2,4-D in a modified LS medium. Exogenous 2,4-D or BAP greatly decreased the GUS expression regulated by the KRCP promoter in a modified LS medium containing 0.2 mg/l 2,4-D. $GA_3$ increased the GUS expression and ABA completely reduced the inductive effect of $GA_3$. The GUS expression was also increased dose-dependently by plant defense regulators, MeJA and PA. In contrast to the above results, auxin deprivation from the modified LS medium increased the GUS expression after treatment with exogenous 2,4-D whereas BAP still greatly decreased the GUS expression dose-dependently. $GA_3$ or MeJA slightly decreased the GUS expression. The data suggest that auxin deprivation changes the sensitivity of the suspension cells to exogenous chemicals and that the regulation of the KRCP promoter by 2,4-D, $GA_3$, and MeJA is dependent on auxin, whereas the regulation by BAP is not. This study will be valuable for understanding the function and expression mode of the Korean radish cationic peroxidase in Korean radish.

• Journal of Plant Biotechnology
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• v.32 no.3
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• pp.161-165
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• 2005

Agrobacterium tumefaciens-mediated cotyledonary explants transformation was used to produce transgenic cucumber. Cotyledonary explants of cucumber (c.v., Eunchim) were co-cultivated with strains Agrobaderium (LBA4404, GV3101, EHA101) containing the binary vector (pPTN289) carrying with CaMV 355 promoter-gus gene as reporter and NOS promoter-bar gene conferring resistance to glufosinate (herbicide Basta) as selectable marker. There was a significant difference in the transformation frequency depending Agrobacterium strains. The EHA101 of bacterial strains employed gave the maximum frequency (0.35%) for cucumber transformation. Histochemical gus and leaf painting assay showed that 15 individual lines were transgenic with the gus and bar gene. Southern blot analysis also revealed that the gus gene was successfully integrated into each genome of transgenic cucumber.