• 미생물학회지
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• 제31권4호
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• pp.292-299
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• 1993

국내에서 분리된 Agrobacterium tumefaciens KU12 는 많은 식물체에서 종양을 유발하여 octopine 을 유일한 탄소원과 질소원으로 이용할 수 있다. A. tumefaciens KU12 내에는 크기가 각각 45.5 kb, 240 kb 및 240 kb 이상인 3종류의 플라스미드가 존재하는 것으로 확인되었다. KU12내에 존재하는 octopine type Ti plasmid 를 확인하기 위하여 플라스미드를 가지고 있지 않은 A. tumefaciens A136 을 direct transformation 방법에 따라 KU12 에서 분리한 플라스미드 시료로 형질전환시킨후 질소원으로 octopine 만을 가지로 있는 AB 최소배지를 이용하여 Ti plasmid 에 의해 형질전환된 형질정환체를 선별하였다. 선별된 형질전환체를 A. tumefaciens KU911 이라고 명명하였으며 KU911 내에는 240 kb 크기의 플라스미드만이 존재하였다. 종양형성능 및 Southern hybridization 을 이용하여 octopine type Ti plasmid 인 pTiKU12 로 명명된 240 kb 크기의 플라스미드가 Ti plasmid 임을 확인되었다.

• Journal of Plant Biology
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• 제33권2호
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• pp.97-104
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• 1990

In order to investigate the host range of Agrobacterium tumefaciens KU12 containing pTi-12, 28 species of dicotyledonous plants were infected with KU12, A136 without Ti plasmid and A348 containing pTi A6, respectively. KU12 and A348 induced tumor in 20 species and 14 species, respectively. This results showed that KU12 has a wide host range. Therefore, it was confirmed that KU12 and pTi-12 are very useful for developing plant vector system having a broad host range.

• Journal of Plant Biology
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• 제34권3호
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• pp.245-251
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• 1991

In order to investigate the phenolic compounds inducing the expression of Ti-plasmid vir genes of Agrobacterium tumefaciens KU12, we tested whether the eighteen phenolic compounds known as vir gene inducer have the activity to induce vir operon of the Ti-plasmid in A. tumefaciens KU12 transformed with pSM358cd. Also, the phenolic compounds in some tumor-uninduced dicotyledons and the attachment ability of a. tumefaciens KU12 on such dicotyledonous plants were investigated in an effort to analyze the reason why no tumor is formed on the plants. As results, fifteen among eighteen phenolic compounds known as vir gene inducer induced the expression of the Ti-plasmid vir genes. Some dicotyledonous plants which do not form the tumor have the phenolic compounds inducing the vir genes, but have less ability of the attachment than the dicotyledonous plants forming tumor.

• 미생물학회지
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• 제32권1호
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• pp.53-59
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• 1994

Agrobacterium tumefaciens KU12내에 존재하는 240kb 크기으 octopine형 Ti 플라스미드인 pTiKU12와 45kb 크기의 잠재 플라스미드인 pTi12를 제거하여 무독성의 A. tumefaciens 균주를 제조하였다. Octopine형 Ti 플라스미드인 pTiKU12는 고온(37${\circ}C$)에서의 배양과 ethidium bromide가 첨가되어 있는 배지에서의 배양을 각각 실시하여 제거하였으며, 잠재 플라스미드인 pTi12는 pTi12의 복제기원이 클로닝되어 잇는 재조합 플라스믿인 pYWXP와의 비화합성을 이용하여 제거하였다. pYWXP는 ethidium bromide가 첨가되어 있는 배지에서 고온(37${\circ}C$)으로 배양하여 제거하였다.

• Journal of Plant Biology
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• 제39권3호
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• pp.179-184
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• 1996

The purpose of this study is to obtain the most efficient combination of Agrobacterium tumefaciens strains and Ti plasmids for the construction of dicotyledonous plant vector system. Ti plasmid-curing A. tumefaciens A136 and KU12C3 were transformed with four kinds of Ti plasmids, pTiBo542, pTiA6, pTiKU12 and pTiAch5, respectively. The stems of 28 species of dicotyledonous plants were then inoculated with these transformants and examined for crown gall formation. The different combination of A. tumefaciens strains and Ti plasmids showed quite a difference in terms of the crown gall formation. Agrobacterium strins A136 and KU12C3 have a same plant host range in case that both strains harour the same kind of Ti plasmid, pTiBo542 or pTiAch5. However, the above-mentioned both strains have quite different host range in the event of containing the same Ti plasmid, pTiKU12 or pTiA6. In case that KU12C3 contains pTiA6 or pTiKU12, this strain has a wider plant host range than A136. The plant host range of pTiBo542 is the widest, followed by pTiA6, pTiKU12 and pTiAch5. Twelve plants among 28 tested plants are not transformed by any virulent Agrobacterium strains used in this study. In conclusion, A. tumefaciens KU12C3 and A136 harboring pTiBo542 showed the widest host range for transforming dicotyledonous plants. Also, it was acertained that the host range of Ti plasmids is affected by chromosomal level.

• 미생물학회지
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• 제24권1호
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• pp.1-6
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• 1986

Tumor-inducing (Ti) plasmid which may be used in genetic engineering of higher plants, was isolated from Agrobacterium tumefaciens in Korea. Among the 7 strains of A. tumefaciens isolated from various regions in Korea, KU12, KU13, KU14, and KU49 strains were confirmed to contain plasmid. The isolated Ti plasmids were digested with 4 kinds of restriction enzymes, respectively. According to the result of the cleavage patterns, we confirmed that these plasmids in the KU12, KU13, KU14 and KU49 strains are different.

• Journal of Plant Biology
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• 제38권1호
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• pp.19-24
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• 1995

The vir genes expression of Ti plasmid is induced by a family of related phenolic compounds. We investigated the effects of various phenolic compounds, Ti plasmids and hosts on the expression of the vir genes in the same type of octopine Ti plasmids, pTiKU12, pTiAch5 and pTiA6. The vir gene induction of pTiKU12 was remarkably stimulated by p-coumaric acid in relation to acetosyringone, but those of pTiAch5 and pTiA6 were more stimulated by acetosyringone than by p-coumaric acid. The effect of phenolic compound on the vir gene induction was different according to the kind of Ti plasmids. Also, the vir gene expression of A. tumefaciens KU913, which has pTiKU12 was about 6.2 times as much as that of A. tumefaciens KU915, which has pTiKU12 in KU12 host, in the presence of ferulic acid. But no difference was shown in the presence of p-coumaric acid. The vir gene induction abilities of phenolic compounds are different according to the kinds of phenolic compounds, Ti plasmids and hosts.

• Journal of Plant Biology
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• 제38권4호
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• pp.365-371
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• 1995

Binary vectors, pBI-ActR1, pBI-ActF1 and pBSH-ActR1, were constructed using pGA642, the replication origin of pTi12 and the rice actin promoter. The sizes of pBI-ActR1, pBI-ActF1 and pBSH-ActR1 were 12.9 kb, 13.2 kb and 11.95 kb, respectively. These vectors containing a rice actin promoter followed by a GUS structural gene could induce stronly the expression of GUS gene in transformed rice cells. Rice explants from 3-4 day old seedlings after germinatin were cocultured with A. tumefaceins harboring pBI-ActR1, pBI-ActF1 or pBSH-ActR1, and then GUS expression in the explants was assayed. Transformation of rice explants by these binary vectors was tissue-specific, such that the meristematic regions of shoot apex, root and hypocotyl were transformed by these binary vectors.

• 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.

• 한국자원식물학회지
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• 제18권1호
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• pp.15-21
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• 2005

염류내성 식물은 염류농도의 변화에 따라 세포내의 삼투압을 유지하기 위한 화합물을 합성하는 기작을 가지고 있는데 이런 화합물은 주로 proline, glycine, betaine, polyols, sugar등으로 체내에 축적함으로서 고농도의 염류에 견디는 것으로 알려져 있다. Betaine은 미생물에서 2단계 반응을 통해 choline에서 합성되는데, 첫단계는 choline dehydrogenase (CDH)에 의해서 촉매되고(Bet A gene), bet B 유전자의 산물인 betaine aldehyde dehydrogenase(BADH)에 의해 수행된다. 본 실험에서는 Bet A, Bet B 유전자를 아그로박테리움에 도입하여 새로운 conjugants 2 종을 획득하였으며 (Agrobacterium tumefaciens MP90/pBet A, Agrobacterium tumefaciens MP90/pBet B), 먼저 재조합된 binary vector가 식물에서 발현 및 형질 전환되는지 여부를 조사하기 위해서 이미 담배에 형질전환을 시켰으며, 형질전환된 담배에서는 ,고농도의 kanamycin배지에서 생장이 가능하였고, PCR에 의하여 NPT II, Bet A, Bet B gene를 조사한 결과 담배 유식물체 모두 band가 형성되어 형질전환체임을 확인할 수 있었다. 인삼에 Beth, BetB gene의 도입은 1M의 mannitol이 함유된 식물호르몬 무첨가 MS 배지에서 단일배 발생방법에 형질전환체를 획득하였으나, 형질전환체의 발생빈도$(12\%)$가 매우 낮았다.