• Proceedings of the Plant Resources Society of Korea Conference
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• 2001.11a
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• pp.49-58
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• 2001

We tried to introduce two forsythia genes related in lignan biosynthesis, dirigent protein and pinoresinol/lariciresinol (P/L) reductase, into potatoes for accumulation of lignans in transgenic potatoes. We made binary vectors overexpressing dirigent protein gene and P/L reductase gene driven by a CaMV35S promoter and transformed into potatoes via Agrobacterium mediated transformation. And in order to control the metabolic flux of lignan biosynthesis pathway, we tried to inhibit chalcone synthase genes of potatoes by antisense inhibition technique also. We tried to use PCR screening method for selection of transgenic plants of different vectors. We tried to determine and compare lignan contents from different transgenic potato lines.

• Journal of Microbiology
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• v.43 no.4
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• pp.361-365
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• 2005

In this study, we chronicle the establishment of a novel transformation system for the unicellular marine green alga, Dunaliella salina. We introduced the CaMV35S promoter-GUS construct into D. salina with a PDS1000/He micro-particle bombardment system. Forty eight h after transformation, via histochemical staining, we observed the transient expression of GUS in D. salina cells which had been bombarded under rupture-disc pressures of 450 psi and 900 psi. We observed no GUS activity in either the negative or the blank controls. Our findings indicated that the micro-particle bombardment method constituted a feasible approach to the genetic transformation of D. salina. We also conducted tests of the cells' sensitivity to seven antibiotics and one herbicide, and our results suggested that 20 ${\mu}g$/ ml of Basta could inhibit cell growth completely. The bar gene, which encodes for phosphinothricin acetyltransferase and confers herbicide tolerance, was introduced into the cells via the above established method. The results of PCR and PCR-Southern blot analyses indicated that the gene was successfully integrated into the genome of the transformants.

• Journal of Plant Biotechnology
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• v.34 no.4
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• pp.323-329
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• 2007

Transgene expression was analyzed in tomato plants. Four lines of neomycin phosphotransferase II gene (NPTII) and the trehalose biosynthetic fusion gene (TPSP) transformed $T_0$ plants showed kanamycin resistance on selection medium. However, the analysis of phenotype (kanamycin resistance) and mRNA expression in $T_1$ plants indicated that the expression of the NPTII and TPSP transgenes was down-regulated to an undetectable level in two independent lines 1 and 11. Southern analysis demonstrated that the lines 1 and 11 had multicopies of the transgenes, whereas the typical transgenic lines 2 and 10 had 1 or 2 copies. DNA methylation analysis using methylation sensitive enzyme detected accumulated CpG DNA methylation on TPSP coding region and CaMV35S promoter region in the line 11, but not the typical transgenic line 2. These results suggest that multicopy transgene in plants is attributed to down-regulation of the transgene expression via transcriptional gene silencing.

• Journal of Plant Biotechnology
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• v.34 no.2
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• pp.145-152
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• 2007

Lactoferrin is an 80-kDa iron-binding glycoprotein known to exert many biological activities, such as facilitating iron absorption and having antimicrobial and anti-inflammatory effects. Rice can be a useful target for edible food plants to introduce human lactoferrin, because it has lower allergenicity and is likely to be safer than microorganisms or transgenic animals. A cDNA fragment encoding human lactoferrin (HLF) driven by the maize polyubiquitin promoter, along with herbicide resistance gene (bar) driven by CaMV 35S promoter, was introduced into rice (Oryza sativa L. cv. Dong Jin) using the Agrobacterium -mediated transformation system. Putative transformants were initially selected on the medium containing bialaphos. The stable integration of the bar and HLF genes into transgenic rice plants was further confirmed through polymerase chain reaction (PCR) and Southern blot analyses. The expression of the full length HLF protein from various tissues such as grains and young leaves of transgenic rice was verified by Western blot analysis. Analysis of progeny also demonstrated that introduced genes were stably inherited to the next generation at the Mendelian fashion.

• Journal of Plant Biotechnology
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• v.45 no.1
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• pp.63-70
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• 2018

Brazzein is the smallest sweet protein and was isolated from the fruit pulp of Pentadiplandra brazzeana Baillon, native to tropical Africa. From ancient times, the indigenous people used this fruit in their diet to add sweetness to their daily food. Brazzein is 500 to 2000 times sweeter than sucrose on a weight basis and 9500 times sweeter on a molar basis. This unique property has led to increasing interest in this protein. However, it is expensive and difficult to produce brazzein other than in its native growing conditions which limits its availability for use as a food additive. In this study, we report high production yields of, brazzein protein in transgenic rice plants. An ORF region encoding brazzein and driven by the $2{\times}CaMV\;35S$ promoter was introduced into rice genome (Oryza sativa Japonica) via Agrobacterium-mediated transformation. After transformation, 17 regenerated plant lines were obtained and these transgene-containing plants were confirmed by PCR analysis. In addition, the selected plant lines were analyzed by Taqman PCR and results showed that 9 T0 lines were found to have a single copy out of 17 transgenic plants. Moreover, high and genetically stable expression of brazzein was confirmed by western blot analysis. These results demonstrate that recombinant brazzein was efficiently expressed in transgenic rice plants, and that we have developed a new rice variety with a natural sweetener.

• Journal of Korean Society of Forest Science
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• v.86 no.3
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• pp.261-269
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• 1997

Excised immature ovules and calli derived from the stems of cottonwood were bombarded with microprojectiles carrying plasmid DNA containing CaMV-35S promoter and ${\beta}$-glucuronidase(GUS) gene. After bombarded, the expression of GUS gene was detected by the assay of 5-bromo-4-chloro-3-indolyl-${\beta}$-gluconide(X-gluc). Transient gene expression was measured by counting the number of distinct regions of GUS activity per explant. As major parameters, the number of shots and the period of exposure to X-gluc after the bombardment were investigated for detecting GUS gene expression. In this experiment, the percents of GUS gene expression showing spots were 56.8 from immature ovules and 75.9 from micro-calli of cottonwood species. Among the treatments, two consecutive shots and 48 hour exposure produced about $25.75{\pm}2.77$(per ovule), $11.43{\pm}1.22$(per mini petridish) spots, respectively, Microprojectile particle bombardment provides a useful method to assay transient expression in both types of explants. Furthermore, our results represent that the excised ovule and/or the calli might be stably transformed by the biolistics.

• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.4
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• pp.299-306
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• 2009

Oxidative stress is the main limiting factor in crop productivity. To solve global environmental problems using the plant biotechnology, we have developed on the oxidative stress-tolerant transgenic tall fescue plants via Agrobacterium-mediated genetic transformation method. In order to develop transgenic tall fescue (Festuca arundinacea Schreb.) plants with enhanced tolerance to multiple environmental stresses, nucleotide diphosphate kinase gene under the control of CaMV35S promoter were introduced into genome of tall fescue plants. Proteomic analysis revealed that transgenic tall fescue not only accumulated NDP kinase 2 protein in their cells, but also induced several other antioxindative enzyme-related proteins. When leaf discs of transgenic plants were subjected to cold stress, they showed approximately 30% less damage than wild-type plants. In addition, transgenic tall fescue plants showed normal growth when transgenic plants were subjected to $4^{\circ}C$ for 3 days treatments. These results suggest that transgene is important in ROS scavenging by induction of antioxidative proteins, and could improve abiotic stress tolerance in transgenic tall fescue plants.

• Journal of Plant Biotechnology
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• v.36 no.1
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• pp.75-80
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• 2009

In order to develop transgenic sweetpotato plants [Ipomoea batatas (L.) Lam. cv. Yulmi] with enhanced tolerance to oxidative stress, we constructed transformation vectors expressing 2-Cys peroxiredoxin (Prx) gene under the control of the stress-inducible SWPA2 or enhanced 35S promoter (named as SP or EP). Transgenic sweetpotato plants were attempted to generate from embryogenic calli using an Agrobacterium-mediated transformation system. Embryogenic calli gave rise to somatic embryos and then converted into plantlets on MS medium containing 100 mg/L kanamycin. Transgenic plants were regenerated in the same medium. Southern blot analysis confirmed that the Prx gene was inserted into the genome of the plants. To further study we selected the transgenic plant lines with enhanced tolerance against methyl viologen (MV). When sweetpotato leaf discs were subjected to methyl MV at $20{\mu}M$, transgenic plants showed about 40% higher tolerance than non-transgenic or empty vector-transformed plants.

• Journal of Life Science
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• v.20 no.10
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• pp.1563-1568
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• 2010

In the course of a research concerning the molecular mechanism of hypocotyl elongation that occurs during soybean seedling growth in darkness, we have generated a number of ESTs from a cDNA library prepared from the hypocotyls of dark-grown soybean seedlings. Comparison of the ESTs assigned a cDNA clone as a putative plastidic ATP-binding-cassette (ABC) protein homologue. The soybean GmNAP1 protein contains an N-terminal transit peptide which targets it into the chloroplast. The transcription level of the GmNAP1 gene was investigated under continuous red light, continuous far-red light, and complete darkness. The main function of this NAP1 protein is the transport of protoporphyrin IX which is the precursor of chlorophyll from the cytoplasm to the chloroplast. The GmNAP1 gene was transferred into the Arabidopsis under the CaMV 35S promoter. The chlorophyll level of this transgenic Arabidopsis plant was much higher than the chlorophyll level of the wild type Arabidopsis plant.

• Journal of Plant Biotechnology
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• v.47 no.2
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• pp.157-163
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• 2020

Calmodulin (CaM) mediates cellular Ca²⁺ signals in the defense responses of plants. We previously reported that GmCaM-4 and 5 are involved in salicylic acid-independent activation of disease resistance responses in soybean (Glycine max). Here, we generated a GmCaM-4 cDNA construct under the control of the cauliflower mosaic virus (CaMV) 35S promoter and transformed this construct into potato (Solanum tuberosum L.). The constitutive over-expression of GmCaM-4 in potato induced high-level expression of pathogenesis-related (PR) genes, such as PR-2, PR-3, PR-5, phenylalanine ammonia-lyase (PAL), and proteinase inhibitorII (pinII). In addition, the transgenic potato plants exhibited enhanced resistance against a bacterial pathogen, Erwinia carotovora ssp. Carotovora (ECC), that causes soft rot disease and showed spontaneous lesion phenotypes on their leaves. These results strongly suggest that a CaM protein in soybean, GmCaM-4, plays an important role in the response of potato plants to pathogen defense signaling.