• 한국초지조사료학회지
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• 제20권2호
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• pp.97-102
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• 2000

To increase thennotolerance of forage crops, transgenic rice plants as a model for transformation of monocots were generated. A cDNA encoding the chloroplast-localized small heat shock protein (small HSP) of rice, Oshsp21, was introduced into rice plants via Agrobacterium-mediated gene transfer system. Calli induced from scutella were co-cultivated with a A. tumefaciens strain EHAlOl canying a plasmid, pIGhsp21. A large number of transgenic plants were regenerated on a medium containing hygromycin. Integration of Oshsp2l gene was confirmed by PCR and Southern blot analyses with genomic DNA. Northern blot and immunoblot analyses revealed that the Oshsp21 gene was constitutively expressed and accumulated as mature protein in transgenic plants. Effects of constitutive expression of the OshspZl on thermotolerance were first probed with the chlorophyll fluorescence. Results indicate that inactivation of electron transport reactions in photosystem I1 (PSII), were mitigated by constitutive expression of the Oshsp21. These results suggest that the chloroplast small HSP plays an important role in protecting photosynthetic machinery during heat stress. (Key words : Thermotolerance, Rice, Transgenic, cDNA)

• Journal of Microbiology and Biotechnology
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• 제24권10호
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• pp.1421-1426
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• 2014

Although a large number of AroA enzymes (EPSPS: 5-enopyruvylshikimate-3-phosphate synthase) have been identified, cloned, and tested for glyphosate resistance, only two AroA variants, derived from Agrobacterium tumefaciens strain CP4 and Zea mays, have been utilized to produce the commercial glyphosate-resistant crops. Here, we have used a PCR-based twostep DNA synthesis method to synthesize an aroA gene ($aroA_{A.\;metalliredigens}$) from Alkaliphilus metalliredigens, encoding a new EPSPS. Furthermore, transgenic Arabidopsis with the new $aroA_{A.\;metalliredigens}$ gene was obtained to confirm the potential of the novel aroA gene in developing glyphosate-resistant crops.

• 한국자원식물학회지
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• 제10권2호
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• pp.107-113
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• 1997

화이트 클로버의 배축, 잎, 미숙배 유래의 embryogenic callus에 식물 binary vector인 pBI121을 포함하는 A. tumefaciens LBA4404를 접종하여 효과적으로 화이트 클로버를 형질전환시켰다. A. tumefaciens를 이용한 화이트 클로버의 형질전환은 acetosyringone을 사용함으로써 품종간의 차이가 없이 배발생 캘러스에서 16-19%를 보였다. 재분화 식물체의 PCR 및 Northern 분서글 통하여 형질 전환된 화이트 클로버의 염색체내에 GUS 유전자가 안정되게 도입되었고 식물체내에서 mRAN로 발현됨을 확인하였다. 또한, GUS 유전자가 식물체내에서 단백질로 발현됨을 확인하기 위하여 형질 전환되어진 화이트 클로버부터 단백질을 추출하고 분광분석법에 의하여 GUS의 활성을 측정하였으며, 시료간에 약간의 차이는 있으나 유의적인 GUS 활성을 확인하였다.

• Plant Biotechnology Reports
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• 제5권1호
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• pp.61-69
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• 2011

The dehydration-responsive element binding proteins (DREB1)/C-repeat (CRT) binding factors (CBF) function as transcription factors and play an important role in agricultural biotechnology and molecular biology studies of drought and freezing stress tolerance. We generated transgenic Lolium perenne plants containing the PCR-cloned Arabidopsis DREB1A/CBF3 gene (AtDREB1A/CBF3) to study the function of this gene construct in drought and freezing tolerance in a species of turfgrass. Compared to the control, AtDREB1A/CBF3 transgenic L. perenne plants showed enhanced drought and freezing stress tolerance. The activities of the enzymes superoxide dismutase (SOD) and peroxidase (POD) were higher in transgenic plants than in the non-transgenic plant control. These results demonstrate that the expression of the AtDREB1A/CBF3 gene in transgenic L. perenne plants enhanced drought and freezing tolerance and that the increased stress tolerance was associated with the increased activities of antioxidant enzymes. These results are relevant to stress biology and biotechnology studies of turfgrass.

• Journal of Microbiology and Biotechnology
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• 제11권5호
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• pp.804-811
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• 2001

In many Gram-negative bacteria, autoinducers, such as N-acyl-L-homoserine lactone(acyl-HSL) and its derivative molecules, mediate the cell-density-dependnet expression of certain operons. The current study identified the autoinducers produced by Burkholderia cepacia G4, a trichloroethylene-degrading lagoon isolate, using TLC bioassays with Agrobacterium tumefaciens NT1(pDCI141E33) and Chromobacterium violaceum CVO26, and a GC-MS analysis. The ${R_f}\;and\;{R_t}$ values and mass spectra were compared with those of synthetic compounds. Based on the analyses, it was confirmed that G4 produces N-hexanoyl (C6)-, N-octanoyl (C8)-, N-decanoyl (C10)-, N-dodecanoyl (C12)-HSL, and an unknown active species. The integration of the GC peak areas exhibited a ratio of C8-HSL:C10-HSL:C12-HSL at 3:17:1 with C6-HSL and C10-HSL production at trace and micromolar levels, respectively, in the culture supernatants. Nutants partially defective in producing acyl-HSLs were also partially defective in the biosynthesis of an antibiotic substance. These results indicate that the autoinducer-dependent gene regulation in G4 is dissimilar to the clinical B. cepacia strains isolated from patients with cystic fibrosis.

• Plant Biotechnology Reports
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• 제4권1호
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• pp.75-83
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• 2010

Glycine betaine has been reported as an osmoprotectant compound conferring tolerance to salinity and osmotic stresses in plants. We previously found that the expression of betaine aldehyde dehydrogenase 1 gene (OsBADH1), encoding a key enzyme for glycine betaine biosynthesis pathway, showed close correlation with salt tolerance of rice. In this study, the expression of the OsBADH1 gene in transgenic tobacco was investigated in response to salt stress using a transgenic approach. Transgenic tobacco plants expressing the OsBADH1 gene were generated under the control of a promoter from the maize ubiquitin gene. Three homozygous lines of $T_2$ progenies with single transgene insert were chosen for gene expression analysis. RT-PCR and western blot analysis results indicated that the OsBADH1 gene was effectively expressed in transgenic tobacco leading to the accumulation of glycine betaine. Transgenic lines demonstrated normal seed germination and morphology, and normal growth rates of seedlings under salt stress conditions. These results suggest that the OsBADH1 gene could be an excellent candidate for producing plants with osmotic stress tolerance.

• 한국자원식물학회지
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• 제11권2호
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• pp.188-194
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• 1998

This experiment was conducted to introduce phosphinothricin acetyl -transferase(PAT) gene, resistant to basta and non-selective herbidide, into tobacco(Nicotiana tabacum cv.BY4). For shoot formation,tobacco leaf disks were placed on the MS medium supplemented with 2.0mg/L BA and 0.1mg/L NAA. In this medium condition, tobacco leaf disces were cocultivated with A. tumefaciens MP90 containing NPT IIand PAT resistant to kanamycin and Basta, respectively. Shoots were obtained in the medium containing antibiotics, and those were transferred to rooting medium supplemented with 0.1mg/L NAA and antibiotics. The plants obtaining roots were transplanted into soil. Phenotype of transgenic tobacco plant was mostly as normal plant. However, about 5% was abnormal plant, which did not set seeds. PCR analysis and southern blot were performed to determine transformation. As the results, it was confirmed that PAT gene was stably integrated into tobacco genome.When herbicide, basta, was sprayed to the plants confirmed by PCR, the transgenic plants showed normal growth, whereas normal plants died. Therefore, the result of this experiment show that tobacco transformation for the resistance to basta, non-selective herbicide, was successful because PAT gene was stably integrated into tobacco.

• Plant Resources
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• 제6권2호
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• pp.108-113
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• 2003

This study was carried out to obtain basic information for possibility of oral vaccine in carrot using Agrobacteruim -mediated transformation system. The epitope region of porcine epidemic diarrhea virus (PEDV) spike gene which is classified as a member of the Coronaviridae and causes an acute enteritis in pigs was successfully expressed in carrot (Daucus carota) using the Agrobacterium-mediated transformation system. Hypocotyl segments of in vitro germinated plantlets were infected with Agrobacteriun tumefaciens LBA 4404 harboring PEDV spike gene. Embryogenic callus (EC) was induced on MS selection medium with 1 mg/L 2,4-D, 50 mg/L kanamycin and 300 mg/L cefotaxime after 45 days of culture. Subcultured ECs on MS selection medium without 2,4-D were converted to somatic embryos (SE) of various stage; globular, heart and torpedo stage. Putative transgenic embryos were selected on MS medium with 50 mg/L kanamycin and 300 mg/L cefotaxime. Regenerated plantlets from transformed SE were induced on MS medium containing 50 mg/L kanamycin after 30 days of culture. Genomic PCR confirmed the integration of PEDV spike gene into nuclear genome of carrot and northern blot analysis demonstrated the expression of PEDV spike gene in transgenic carrot.

• 한국식물학회:학술대회논문집
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• 한국식물학회 1999년도 제13회 식물생명공학심포지움 New Approaches to Understand Gene Function in Plants and Application to Plant Biotechnology
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• pp.45-49
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• 1999

Plant cell culture is emerging to express bioactive foreign proteins because it has several advantages in that it is safe, economical, genetically stable and eukaryotic expression system comparing with other expression systems. However several limitations such as slow growth rate, low expression level and lack of well established down stream process need to be answered. As a preliminary approach to produce the immunologically interested molecules through the plant cell culture, we tested if granulocyte-macrophage colony stimulating factors (GM-CSFs) from both murine (mGM-CSF) and human (hGM-CSF) are produced as a biologically active form through plant cell culture. The murine and human GM-CSF genes were cloned into the plant expression vector, pBI121, and Ti-plasmid mediated transformation of tobacco leaves was conducted using Agrobacterium tumefaciens harboring both recombinant GM-CSF (rGM-CSF) genes. Cell suspension culture was established from the leaf-derived calli of transgenic tobacco plant. Northern blot analysis indicated the expression of the introduced mGM-CSF gene in both transgenic plant and cell suspension cultures. In addition, the biological activities of both murine and human GM-CSF from plant cell culture were confirmed by measuring the proliferation of the GM-CSF dependent FDC-PI and TF-1 cells, respectively.

• 한국연초학회지
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• 제19권1호
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• pp.11-17
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• 1997

A flue-cured tobacco variety (Nicotiana tabacum cv. Wisconsin) was used for Plant transformation with the complementary DNA (cDNA) of potato virus Y-necrosis strain (PVY-VN) replicase gone (Nb) which was synthesized through reverse-transcription Primed with oligo(dT) and Polymerization using RNase H-digested template. The cDNA was cloned into Plant expression vector Plasmid (PMBP2), and introduced into tobacco plants by co-culturing tobacco leaf disks with Agrobacterium tumefaciens LBA4404 containing the plasmid before Plant regeneration. Eight Plants, in which the inserted cDNA fragment was detected by Polymerase chain reaction (PCR), out of 70 putative transformants inserted with sense-oriented Mb cDNA showed no symptom at 3 weeks after inoculation, while the other 62 plants, and all plants with vector gone only and antisense-oriented NIb cDNA had susceptible vein-necrosis symptoms. However, only 2 of the 8 resistant plants were highly resistant, which remained symptomless up to 10 weeks after inoculation. Among the first progenies (T1) from self-fertilized seeds of the two resistant transgenic plants, less than 10 % of 71 plants appeared highly resistant (with no symptom), 70% moderately resistant (with mild symptoms on 1 - 2 leaves), and about 20% susceptible (with susceptible symptoms on 3 or more leaves) at 3 weeks after inoculation. These results suggest that the PVY resistance was inherited in the 71 generation. Key words : potato virus Y. viral replicase gene, transgenic tobacco Plants, resistance.