• The Korean Journal of Ecology
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• 제2권1호
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• pp.15-20
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• 1978

Pathological and anatomical studies on the cause of the crown gall like symptoms associated with the chestnut nurse grafts were undertaken. The crown gall bacterium, Agrobacterium tumefaciens, was isolated from the gall tissues of chestnut nurese grafts by using selective media developed by S초개소 et al. and kado and Heskett. Typical crown gall symptoms appeared on tomato, castor bean and geranium plants 10~21 days following inoculation with the bacterium isolated from the gall tissues of chestnut nurse grafts. Agrobacterium tumefaciens was reisolated from crown gall tissues of tomato, castor bean and geranium. Anatomical studies on the origin, growth and differentiation of the gall tissues of the chestnut nurse grafts confirmed that the gall tissues are of crown gall origin. Masses of Agrobacterium tumefaciens were observed from gall tissues of chestnut nurse grafts, so it could be confirmed that the crown gall symptoms prevalent on chestnut nurse grafts are caused by the crown gall bacterium, Agrobacterium tumefaciens.

• 미생물학회지
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• 제25권1호
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• pp.17-22
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• 1987

For the purpose of securing of strains which can be usefully utilized to study symbiosis between Rhizobium and legume plant, A. tumefaciens T7 was isolated and characterized and then subgroup biovar was determined. A. tumefaciens T7 induced smooth tumor like nopaline type one and did not grow at $37^{\circ}C$ and in the presence of 2% NaCl on yeast extract mannitol medium. The strain was able to grow on the New and Kerr selective media and utilize erythritol but not phenylalanine, tryptophan, and tartarate as a sole carbon source. Negative results were obtained from 3-keto-lactose production and oxidase test. The strain produced alkalifrom malonate and citrate and showed acid litmus milk reaction At least two large plasmids were detected in the cell lysate. According to all of these results, it could be concluded that subdivision of isolated strain was biovar 2.

• Journal of Microbiology and Biotechnology
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• 제18권7호
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• pp.1245-1251
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• 2008

Oxalate decarboxylases (OXDCs) (E.C. 4.1.1.2) are enzymes catalyzing the conversion of oxalate to formate and $CO_2$. The OXDCs found in fungi and bacteria belong to a functionally diverse protein superfamily known as the cupins. Fungi-originated OXDCs are secretory enzymes. However, most bacterial OXDCs are localized in the cytosol, and may be involved in energy metabolism. In Agrobacterium tumefaciens C58, a locus for a putative oxalate decarboxylase is present. In the study reported here, an enzyme was overexpressed in Escherichia coli and showed oxalate decarboxylase activity. Computational analysis revealed the A. tumefaciens C58 OXDC contains a signal peptide mediating translocation of the enzyme into the periplasm that was supported by expression of signal-peptideless and full-length versions of the enzyme in A. tumefaciens C58. Further site-directed mutagenesis experiment demonstrated that the A. tumefaciens C58 OXDC is most likely translocated by a twin-arginine translocation (TAT) system.

• Journal of Forest and Environmental Science
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• 제25권3호
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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.

• Asian-Australasian Journal of Animal Sciences
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• 제17권10호
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• pp.1390-1394
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• 2004

We have achieved efficient transformation system for forage-type tall fescue plants by Agrobacterium tumefaciens. Mature seed-derived embryogenic calli were infected and co-cultivated with each of three A. tumefaciens strains, all of which harbored a standard binary vector pIG121Hm encoding the neomycin phosphotransferase II (NPTII), hygromycin phosphotransferase (HPT) and intron-containing $\beta$-glucuronidase (intron-GUS) genes in the T-DNA region. Transformation efficiency was influenced by the A. tumefaciens strain, addition of the phenolic compound acetosyringone and duration of vacuum treatment. Of the three A. tumefaciens strains tested, EHA101/pIG121Hm was found to be most effective followed by GV3101/pIG121Hm and LBA4404/pIG121Hm for transient GUS expression after 3 days co-cultivation. Inclusion of 100 $\mu$M acetosyringone in both the inoculation and co-cultivation media lead to an improvement in transient GUS expression observed in targeted calli. Vacuum treatment during infection of calli with A. tumefaciens strains increased transformation efficiency. The highest stable transformation efficiency of transgenic plants was obtained when mature seed-derived calli infected with A. tumefaciens EHA101/pIG121Hm in the presence of 100 $\mu$M acetosyringone and vacuum treatment for 30 min. Southern blot analysis indicated integration of the transgene into the genome of tall fescue. The transformation system developed in this study would be useful for Agrobacterium-mediated genetic transformation of tall fescue plants with genes of agronomic importance.

• 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.

• 식물조직배양학회지
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• 제21권1호
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• pp.55-58
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• 1994

Agrobacterium-based vector를 이용하여 상추를 형질전환 및 재분화 하였다. 즉 $C_{a}$ MV 35S promoter와 GUS 유전자를 reporter로 가지고 있는 pBl121을 Agrobacterium tmfaciens LBA4404에 도입시킨 후 상추의 자엽 절편과 cocultivation을 통하여 형질전환 시키고 재분화 시켰다. Southern 및 Northern 분석을 통하여 형질 전환 및 재분화된 상추에 GUS 유전자가 안정하게 도입되고 식물체내에서 mRNA로 발현됨을 확인하였다. 또한 GUS 유전자가 식물 체내에서 단백질로 발현됨을 확인하기 위하여 상추 잎의 단백질 추출액을 이용하여 분광분석법에 의하여 GUS의 활성을 측정하였다. 시료간의 약간의 차이는 있으나 시료로부터 유의적인 GUS 활성을 확인하였다.

• 한국초지조사료학회지
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• 제22권2호
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• pp.101-106
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• 2002

환경 스트레스에 의해 야기되는 활성 산소종에 의한 피해에 내성을 가지는 식물의 개발을 위하여 딸기 유래의 cytosolic ascorbate peroxidase 유전자(ApxSC7)를 Agrobacterium tume-faciens LBA4404를 매개로 형질전환 시켰다. Hygromycin으로 선발된 캘러스로부터 재분화 된 식물체는 야생형과 비교하여 형태적으로 차이를 나타내지 않았다. PCR 및 Southern blot 분석을 통하여 형질전환 식물체의 염색체 내에 ApxSC7 유전자가 integration 되었음을 확인하였다. 담배 잎으로부터 total RNA를 분리하여 Northern blot 분석을 실시한 결과, 도입된 유전자가 형질전환 식물체 내에서 지속적으로 발현된다는 것을 확인하였다.

• Mycobiology
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• 제45권2호
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• pp.84-89
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• 2017

Fungi of the Metarhizium genus are a very versatile model for understanding pathogenicity in insects and their symbiotic relationship with plants. To establish a co-transformation system for the transformation of multiple M. robertsii genes using Agrobacterium tumefaciens, we evaluated whether the antibiotic nourseothricin has the same marker selection efficiency as phosphinothricin using separate vectors. Subsequently, in the two vectors containing the nourseothricin and phosphinothricin resistance cassettes were inserted eGFP and mCherry expression cassettes, respectively. These new vectors were then introduced independently into A. tumefaciens and used to transform M. robertsii either in independent events or in one single co-transformation event using an equimolar mixture of A. tumefaciens cultures. The number of transformants obtained by co-transformation was similar to that obtained by the individual transformation events. This method provides an additional strategy for the simultaneous insertion of multiple genes into M. robertsii.

• 미생물학회지
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• 제4권2호
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• pp.1-4
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• 1966

As a part of studies of plant tumor induction, this experiment was prepared for the purpose of studying the ability of tumor induction and the tendency of tumor initiation in some Korean plants using the various Agrobacterium tumefaciens strains. Results obtained from this experiment are as follows. The virulences of five strains used in this experiment were gradually decreased in order of strain A6Kl, B6, 11BV7, T37 and 11 BNV6. Especially strain T37 which is known to the host limited strain showed virulent effect to the most of plants given for the materials as well as strain A6Kl, B 6 and 11BV7. Concerning the grade of tumor development, in plants which has tough stem, for example, Glycine max Meer, tumor induction was not well developed after the inoculation of all strains. Particullary in Ricinus communes Linne all strains showed virulent effect but tumor tissues were declined in relation to the development of lignification. It was also confirmed that the induction of tumor tissues on plants is to delay according to the increase of the age of host plants.