• Journal of Microbiology and Biotechnology
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• 제15권4호
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• pp.683-688
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• 2005

A transformation system mediated by Agrobacterium tumefaciens is routinely used for the genetic engineering of plants. Here, we report an efficient and stable method for transformation of heterogeneous genes into an industrial Cephalosporium acremonium by using a similar transformation system established in plants. Both the phleomycin-resistant gene and vgb gene were used as screening markers to confirm the success of transformation by either Southern hybridization or PCR amplification. It was found that acetosyringone (AS) was necessary only for protoplast transformation and the heterogeneous genes transferred were integrated into the genome of C. acremonium. The transformation efficiency obtained with this system was much higher than the conventional techniques used for transformation of C. acremonium.

• 미생물학회지
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• 제25권3호
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• pp.173-179
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• 1987

한국산 A, tumefaciens의 3균주에서 분리한 Ti plasmid의 type과 분자량을 조사한 결과로 이들 모두는 octopine type 이었으며 각 plasmid의 분자량은 pTi12가 44Kb이었고, pTi14는 180Kb이었으며, pTi14는 172Kb이었다. 이중 pTi12를 Smal 및 HindIII로 가수분해한 결과 8개의 Smal digest fragment와 10개의 Hind III digest fragment를 얻었으며 Southern hybridization techniques을 이용하여 잠정적인 physical map을 작성하였다.

• 미생물학회지
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• 제21권4호
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• pp.238-244
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• 1983

In order to obtain Ti plasmid which may be used in genetic engineering of higher plants, virulent Agrobacterium tumefaciens were isolated from soil with selective medium. For their identification, morphological and cultural characteristics were investigated in parallel with physiological and turnorigenesis test. 14 strains were isolated from various regions in Korea. 3 of them were identified as biotype 1 and the others were so heterogeneous that they are not yet conformed to any biotypes. However, Ti plasmid was isolated from A. tumefaciens KU 14 strain, one of the above mentioned 14 strains.

• 생명과학회지
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• 제11권4호
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• pp.316-320
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• 2001

Sonication tremendously improves the efficiency of Agrobacterium infection by introducing small and uniform fissures and channels throughout the targeted tissue. Using shoot tips of cotton as explants, the effect of sonication treatment and virulence genes in Agrobacterium tumefaciens on transformation efficiency was investigated. The pat gene which encodes resistance to the herbicide, glufosinate, was used as a selectable marker. Transformation efficiency was evaluated on th basis of survival rates of cocultivated shoot tips on selection medium containing 2.5 mg/l gulfosinate-ammonium(ppt) adn 25. mg/l Clavamax. Sonication from 5 to 15 second has a positive effect on shoop tip survival. However, whil virE as well as virG or vir GN54D showed an enhancement in transformation efficiency, virE,. virG resulted in the most significant enhancement. Overall, the combination of additional virG/virE gene and sonication treatment resulted in the most significant increase in transformation efficiency.

• 생약학회지
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• 제23권3호
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• pp.137-141
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• 1992

The cells of Rubia cordifolia var. pratensis were transformed by Agrobactrium tumefaciens strain 11157. Surface-sterilized young leaves and stems of the plants were cocultivated with bacterial suspensions. Crown galls induced from stems were cultured with variation of culturing conditions and compared with untransformed cells. The growth rates and production of anthraquinone pigments of cells were remarkably improved by transformation. Furthermore, hairy roots were induced by inoculation or cocultivation with Agrobacterium rhizogenes strains.

• Journal of Plant Biotechnology
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• 제31권4호
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• pp.267-271
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• 2004

국내 고구마 율미 품종의 배발생 캘러스를 Agrobacterium 매개 방법을 이용하여 형질전환 식물체를 개발하였다. 배발생 캘러스를 7일 동안 전배양 한 후 Agrobacterium과 2일 간 공동배양할 경우 일시적인 형질전환 효율이 가장 높았다. Agrobacterium과의 공동배양 후 배발생 캘러스를 1mg/L 2,4-D, 100mg/L kanamycin, 400mg/L claforan 이 첨가된 선발배지에서 4주 간격으로 계대배양하였다. 선발된 kanamycin 저항성 캘러스를 2,4-D를 제거한 선발배지로 옮겨 체세포배를 유도하였으며 이후 소식물체로 발달하였다. Southern 분석으로 1-3 copy의 GUS 유전자가 고구마 염색체내로 도입되었음을 확인하였다. 또한 조직학적 분석으로 GUS 유전자가 형질전환 고구마의 배발생 캘러스, 재분화 식물체의 잎, 엽병, 및 뿌리 조직에서 강하게 발현됨을 알 수 있었다.

• 아시안잔디학회지
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• 제18권3호
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• pp.141-148
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• 2004

다양한 Zoysiagrass 4가지 품종들을 식물재료로 사용하여 Agrobacterium만 이용한 방법 그리고 particle bombardment로 배발생캘러스에 상처를 낸 후, Agrobacterium으로 공동배양 시키는 2가지 다른 형질전환 방법을 비교하였다. 예비실험에서 일반적으로 형질전환에 널리 사용되는 kanamycin과 PPT(phospinitricin)의 적적선발농도에 대해서 실험하였는데, kanamycin의 경우 300mg/l 그리고 PPT의 경위 50mg/l의 농도에서 가장 효과적인 선발 효율을 나타내었다. Agrobacterium을 이용한 형질전환은 Agrobacterium을 2일간 배양시킨 다음, 박테리아 농도를 O.D 600nm=1.0-1.2로 맞추고, 배발생캘러스를 30분간 간염 시키는 방법이 효과적이었는데, particle bombardment를 이용하여 캘러스에 상처를 유발시킨 후, Agrobacterium으로 감염시키면 3배 이상 높은 형질전환 수율을 획득할 수 있었다. 이상의 결과는 한국잔디 형질전환에 있어서 particle bombardment과 Agrobacterium을 병행하여 실시한 최초의 보고이고, 이러한 시스템을 기반으로 하여 향후 한국잔디를 포함하여 다른 난지형 및 한지형 잔디의 품종개량에 널리 이용되리라 생각된다.

• Journal of Plant Biotechnology
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• 제6권2호
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• pp.69-75
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• 2004

Optimal protocol for efficient genetic transformation has been defined to aid future strategies of genetic engineering in pigeon pea with agronomically important genes. Transgenic pigeonpea plants were successfully produced through Agrobacterium tumefaciens-mediated genetic transformation method using cotyledonary node explants by employing defined culture media. The explants were co-cultivated with A. tumefaciens strain C-58 harboring the binary plasmid, pCAMBIA-1301 [con-ferring $\beta$-glucuronidase(GUS) activity and resistance to hygromycin] and cultured on selection medium (regeneration medium supplemented with hygromycin) to select putatively transformed shoots. The shoots were then rooted on root induction medium and transferred to pots containing sand and soil mixture in the ratio of 1:1. About 22 putative TO transgenic plants have been produced. Stable expression and integration of the transgenes in the putative transgenics were confirmed by GUS assay, PCR and Southern blot hybridization with a transformation efficiency of over 45%. Stable integration and expression of the marker gene has been confirmed in the TO and T1 transgenics through PCR, and Southern hybridization.

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권3호
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• pp.217-222
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• 2004

As Agrobacterium tumefaciens, which has long been used to transform plants, is known to transfer T-DNA to budding yeast, Saccharomyces cerevisiae, a variety of fungi were subjected to the A. tumefaciens-mediated transformation to improve their transformation frequency and feasibility. The A. tumefaciens-mediated transformation of chestnut blight fungus, Cryphonectria parasitica, is performed in this study as the first example of transformation of a hardwood fungal pathogen. The transfer of the binary vector pBIN9-Hg, containing the bacterial hygromycin B phosphotransferase gene under the control of the Aspergillus nidulans trpC promoter and terminator, as a selectable marker, led to the selection of more than 1,000 stable, hygromycin B-resistant transformants per 1${\times}$10$\^$6/ conidia of C. parasitica. The putative transformants appeared to be mitotically stable. The transformation efficiency appears to depend on the bacterial strain, age of the bacteria cell culture and ratio of fungal spores to bacterial cells. PCR and Southern blot analysis indicated that the marker gene was inserted at different chromosomal sites. Moreover, three transformants out of ten showed more than two hybridizing bands, suggesting more than two copies of the inserted marker gene are not uncommon.

• Journal of Microbiology and Biotechnology
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• 제16권1호
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• pp.118-125
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• 2006

The region responsible for replication of the megaplasmid pAtC58 in the nopaline-type Agrobacterium tumefaciens strain C58 was determined. A derivative ofa Co1E1 vector, pBluscript SK-, incapable of autonomous replication in Agrobacterium spp, was cloned with a 7.6-kb Bg1II-HindIII fragment from a cosmid clone of pAtC58, which contains a region adjacent to the operon for the utilization of deoxyfructosyl glutamine (DFG). The resulting plasmid conferred resistance to carbenicillin on the A. tumefaciens strain UIA5 that is a plasmidfree derivative of C58. The plasmid was stably maintained in the strain even after consecutive cultures for generations. Analysis of nested deletions of the 7.6-kb fragment showed that a 4.3-kb BglII-XhoI region sufficiently confers replication of the derivative of the ColE1 vector on UIA5. The region comprises three ORFs, which have high homologies with repA, repB, and repC of plasm ids in virulent Agrobacterium spp. including pTiC58, pTiB6S3, pTi-SAKURA, and pRiA4b as well as those of symbiotic plasmids from Rhizobium spp. Phylogenie analysis showed that rep genes in pAtC58 are more closely related to those in pRiA4 than to pTi plasmids including pTiC58, suggesting that the two inborn plasmids, pTiC58 and pAtC58, harbored in C58 evolved from distinct origins.