• Molecules and Cells
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• v.39 no.9
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• pp.705-713
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• 2016

The efficiency of Agrobacterium-mediated transformation in plants depends on the virulence of Agrobacterium strains, the plant tissue culture conditions, and the susceptibility of host plants. Understanding the molecular interactions between Agrobacterium and host plant cells is crucial when manipulating the susceptibility of recalcitrant crop plants and protecting orchard trees from crown gall disease. It was discovered that Arabidopsis voltage-dependent anion channel 1 (atvdac1) mutant has drastic effects on Agrobacterium-mediated tumorigenesis and growth developmental phenotypes, and that these effects are dependent on a Ws-0 genetic background. Genetic complementation of Arabidopsis vdac1 mutants and yeast porin1-deficient strain with members of the AtVDAC gene family revealed that AtVDAC1 is required for Agrobacterium-mediated transformation, and there is weak functional redundancy between AtVDAC1 and AtVDAC3, which is independent of porin activity. Furthermore, atvdac1 mutants were deficient in transient and stable transformation by Agrobacterium, suggesting that AtVDAC1 is involved in the early stages of Agrobacterium infection prior to transferred-DNA (T-DNA) integration. Transgenic plants overexpressing AtVDAC1 not only complemented the phenotypes of the atvdac1 mutant, but also showed high efficiency of transient T-DNA gene expression; however, the efficiency of stable transformation was not affected. Moreover, the effect of phytohormone treatment on competence to Agrobacterium was compromised in atvdac1 mutants. These data indicate that AtVDAC1 regulates the competence of Arabidopsis to Agrobacterium infection.

• Journal of The Korean Society of Grassland and Forage Science
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• v.20 no.1
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• pp.13-18
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• 2000

An efficient method for Agrobacterium-mediated transformation of forage crop alfalfa (Medicago sativa L.) was established using secondary somatic embryogenic calli. Agrobacterium tumefaciens strain EHAlOl and a binary vector pIG121-Hm which has selection markers for kanamycin and hygromycin have been shown to be an efticient materials for alfalfa transformation. The secondary somatic embryogenic calli originated from hypocotyl explants of alfalfa were efficient infection materials for Agrobacterium EHAlOl and normally germinated into plantlets. The introduced gene (GUS) was constitutively expressed in all tissues of transgenic alfalfa with different expression levels. These results indicate that the use of pIG121-Hm vector, Agrobacterium EHAlOl and improved culture system of callus facilitate the transformation of alfalfa. (Key words : Agrobacterium, Alfalfa, Gene transfer, Transformation)

• Journal of Ginseng Research
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• v.10 no.1
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• pp.45-54
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• 1986

These studies were carried out to obtain the basic information about transformation of ginseng plant by potential vector system, utilization of opine compound by Agrobacterium sap. , and initiation of crown gall tumor callus. Crown gall tumors were induced from stem of Panax ginseng C.A. Meyer by infection of Agrobacterium tumefaciens. Therefore, it was clarified that transformation of ginseng by Ti plasmid was possible. The crown gall tumors induced by Agrobacterium tumefaciens isolated. from the soil were different in a shape, size, and growth rate. Especially, infection of ginseng by Agrobacterium tumefaciens Y104 led to the amorphic tumor, Tumor tissue derived from stem crown gall could not be continuously cultured on the medium which did not contain phytohormone, and did not form the callus even on the medium supplemented with 2,4-D. On the other hand, the root crown gall tumors formed the calli but the formation rate of callus was quite low. As for the utilization of octopine and nopaline, it was found that 3 strains of Agrobacterium app., Y104, Y110 and C58, utilized nopaline only, Y109 utilized octopine, and Y101 failed to utilize either compound.

• The Korean Journal of Mycology
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• v.39 no.3
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• pp.235-238
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• 2011

Agrobacterium harboring vector pCHBs with hygromycin phosphotransferase(hph) and hepatitis B virus surface antigen(HBsAg)gene was transformed into the mycelial culture of Flammulina velutipes. In particular, mild NaOH solution was treated to the mycelia before Agrobacterium infection step. This was purposed to generate putative surface wounds in the mycelial cell walls. The results showed that hygromycin-resistant($hyg^r$) mycelia could be obtained only from NaOH-treated mycelia but not from intact mycelia. The integration of $hyg^r$ gene in fungal genome was confirmed by PCR. In addition, a single transgene integration and heterologous protein expression in F. velutipes could be verified by Southern blot hybridization and western blot analysis, respectively. This study demonstrated an efficient tool for the Agrobacterium-mediated transformation of F. velutipes mycelia.

• Korean Journal of Plant Tissue Culture
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• v.27 no.5
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• pp.387-393
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• 2000

The process by which Agrobacterium tumefaciens genetically transforms plants involves a complex series of reactions communicated between the pathogen and the plants. To identify plant factors involved in agrobacterium-mediated plant transformation, a large number of T-DNA inserted Arabidopsis thaliana mutant lines were investigated for susceptibility to Agrobacterium infection by using an in vitro root inoculation assay. Based on the phenotype of tumorigenesis, twelve T-DNA inserted Arabidopsis mutants(rat) that were resistant to Agrobacterium transformation were found. Three mutants, rat1, rat3, and rat4 were characterized in detail. They showed low transient GUS activity and very low stable transformation efficiency compared to the wild-type plant. The resistance phenotype of rat1 and rats resulted from decreased attachment of Agrobacterium tumefaciens to inoculated root explants. They may be deficient in plant actors that are necessary for bacterial attachment to plant cells. The disrupted genes in rat1, rat3, and rat4 mutants were coding a arabinogalactan protein, a likely cell wall protein and a cellulose synthase-like protein, respectively.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.1087-1090
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• 2009

This study was carried out to research antimicrobial agents from medicinal plants, Glycyrrhiza uralensis, Dryopteris crassirhizoma, Dictamnus albus, Paeonia lactiflora, Angelica dahurica, Spirodela polyrhiza, Cimicifuga heracleifolia, Bupleurum falcatum, Magnolia kobus, Artemisia princeps, Arctium lappa, Aster tataricus, Hovenia dulcis, Citrus unshiu, Asparagus cochinchinensis, Gardenia jasminoides, Smilax china, Hovenia dulcis, Prunus sargentii, Scutellaria baicalensis. The ethanol extracts of 20 medicinal plants were tested for the antimicrobial activity against Agrobacterium tumefaciens. The extracts of Glycyrrhiza uralensis, Dryopteris crassirhizoma, Cimicifuga heracleifolia, Bupleurum falcatum showed antimicrobial activities against Agrobacterium tumefaciens.

• Korean Journal Plant Pathology
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• v.12 no.2
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• pp.197-201
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• 1996

우리나라 포도재배 지역인 포천, 남양주 및 수원의 포도나무 줄기혹병에 이병된 포장으로부터 채집한 줄기혹(gall), 수액(sap) 및 근권토양으로부터 56균주의 유사 Agrobacterium를 분리하였으며, 이들 중 7균주가 포도나무 유묘의 줄기에 혹ㅇ르 형성시키는 병원성 Agrobacterium biovar의 선택배지에서의 생장, oxidase의 생성, Na L-tartrate로부터 알칼리의 성장, 2% NaCl 첨가 배지에서 생장, 3-ketolactose의 비생산, mesoerythritol과 ethanol로부터 산을 생성하지 못하는 등 Agrobacterium biovar 3인 A. vitis로 동정되었다.

• Journal of Plant Biotechnology
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• v.31 no.3
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• pp.185-190
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• 2004

We established a transient gene expression system in chili pepper leaves based on Agrobacterium-mediated transformation of GUS gene. For the best GUS transient expression, two step culture system was adopted. When the Agrobacterium tumefaciens cell density of pre-culture was $A_{600nm}$ 0.3, the cells were harvested and diluted to $A_{600nm}$ 0.8 with virulence induction medium after cell harvested. The addition of acetosyringone (200 $\mu$M) in virulence induction step was a key factor for successful transient expression. Additionally, Younger leaves showed more effective transient expression than older leaves. Temporally, the strongest intensity of GUS expression was detected at 2 days after infiltration. These results demonstrate that Agrobacterium-mediated transient expression can be used for a simple in vivo assays of plant promoters, transcription factors and furthermore provide efficient protocol for chili pepper transformation.

• Journal of Crop Science and Biotechnology
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• v.10 no.2
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• pp.92-97
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• 2007

Antibiotics used for suppressing Agrobacterium in plant transformation procedure might have negligible effects on plant tissues and regeneration. The effects of antibiotics on growth suppression of Agrobacterium and plant regeneration were investigated for enhancing Agrobacterium-mediated transformation using wheat mature embryos. Antibiotics tested, except carbenicillin, were able to suppress that embryos were coated with a layer of Agrobacterium cells in callus induction medium. Agrobacterium growth was suppressed minimally at 50 mg/l of timentin, while cefotaxime and clavamox were completely suppressed at relative high concentration of 250 mg/l. In the treatment of carbenicillin, initiation of growth suppression of Agrobacterium occurred at 750 mg/l of concentration because Agrobacterium KYRT1 contains the carbenicillin resistant gene. In Agrobacterium inoculation, effects of antibiotics were significantly different on the rate of callus induction and shoot formation. Almost embryos were induced calli at 50 mg/l of timentin whereas callus induction rate was achieved above 90% at 100 mg/l and 250 mg/l of cefotaxime and clavamox, respectively. Shoot formation rate was higher in the treatment of timentin than that of cefotaxime and clavamox at 500 mg/l of concentration, respectively. Timentin can be used as a good antibiotics in Agrobacterium-mediated wheat transformation.

• Journal of Forest and Environmental Science
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• v.25 no.3
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• pp.195-204
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• 2009

Agrobacterium-mediated genetic transformation has been widely used for the production of genetically modified transgenic plants to obtain specific desired traits. Most of the molecular mechanisms that underlie the transformation steps have been well elucidated over the years. However, a few steps, such as nuclear targeting, T-DNA integration, and Agrobacterium-plant proteins involved remain largely obscure and are still under extensive studies. This review describes the major steps involved in the molecular mechanism of Agrobacterium-mediated transformation and provides insight in the recent developments in studies on the Agrobacterium-mediated genetic transformation system. Some factors affecting the transformation efficiency are also briefly discussed.