• 생태와환경
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• 제52권4호
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• pp.394-402
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• 2019

The Agrobacterium tumefaciens mediated gene transfer is widely used to generate genetic transformation of plants and transient assay of temporal exogenous gene expression. Syringe infiltration system into tobacco (Nicotiana benthamiana) leaves is a powerful tool for transient expression of target protein to study protein localization, protein-protein binding and protein production. However, the protocol and technical information of transient gene expression, especially double strand RNA (dsRNA), in tobacco using Agrobacterium is not well known. Recently, dsRNA is crucial for insecticidal effect on destructive agronomic pest such as Corn rootworm. In this study, we investigated the factor influencing the dsRNA expression efficiency of syringe agro-infiltration in tobacco. To search the best combination for dsRNA transient expression in tobacco, applied two Agrobacterium cell lines and three plant vector systems. The efficiency of dsRNA expression has estimated by real-time PCR and digital PCR. As a result, pHellsgate12 vector constructs showed the most effective accumulation of dsRNA in the cell. These results indicated that the efficiency of dsRNA expression was depending on the kind of vector rather than Agrobacterium cells. In summary, the optimized combination of transient dsRNA expression system in tobacco might be useful to in vivo dsRNA expression for functional study and risk assessment of dsRNA.

• Journal of Plant Biotechnology
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• 제30권3호
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• pp.233-239
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• 2003

We have developed a reliable and high-frequency genetic transformation and regeneration system via somatic embryogensis of Eleutherococcus sessiliflorus. Embryogenic callus obtained from seed were co- cultivated with Agrobacterium tumefaciens strain EHA101/pIG121Hm harboring genes for intron-$\beta$-glucoronidase(GUS), kanamycin and hygromycin resistance. Following co-cultivation, two types of samples(fine embrogenic calli and early globular embryo clusters) were cultivated on Murashige and Skoog(MS) medium containing 1 mg/L2.4-D for 3day in dark. Transient expression of GUS gene was found to be higher in the early globular embryo clusters than in the embryogenic calli. Also, co-cultivated period affected expression of GUS gene; the best result was obtained when globular embryo clusters were co-cultivated with Agrobacterium for 3 days. Subsequently, this callus transferred to selective MS medium containing 1mg/L2.4-D, 50mg/L kanamycin or/and 30mg/L hygromycin and 300mg/L cefortaxime. These embryogenic calls were subcultured to the same selection medium at every 2 weeks intervals. Approximately 24.5% of the early globular embryos co-cultivated with Agrobacterium for 3days produced kanamycin or/and hygromycin-resistant calli. Transgenic somatic embryos were converted into plantlets in half strength MS medium supplemented with 3mg/L GA$_3$ kanamycin and were confirmed by GUS histochemical assay and polymerase chain reaction analysis. Genomic Southem blot hybridization confirmed the incorporation of NPT II gene into the host genome.

• 원예과학기술지
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• 제16권2호
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• pp.213-214
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• 1998

본 연구는 Agrobacterium tumefaciens를 이용한 형질전환의 효율성을 높이기 위한 기초자료를 제공하고자 실시되었다. 선발배지에 사용되는 kanamycin에 대한 토마토 자엽전편체의 감응성 검정결과 50mg/L가 적합한 것으로 제시되었다. 토마토 절편체에는 부정적인 영향을 주지 않고 배지내 Agrobacterium의 제거에 적합한 cefotaxime의 농도로는 200mg/L가 선정되었다. Agrobacterium과의 공동배양에 의해 자엽절편체로부터의 callus형성과 신초 재분화가 현저히 억제되었으며 공시된 3품종의 토마토의 경우에는 3일간의 공동배양기간이 callus형성과 신초 재분화에 적합한 것으로 판단되었다. 재분화 신초에 대한 형질전환여부검정은 GUS염색법과 NPTII primer를 이용한 PCR검정을 실시하였으며 공시된 3품종에서 모두 형질전환 신초를 획득하였다.

• Journal of Plant Biotechnology
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• 제48권2호
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• pp.93-99
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• 2021

This study was conducted to develop an Agrobacterium-mediated genetic transformation protocol for the carnation cv. "Jinju" to counteract its ethylene sensitivity. The new protocol involves the use of an improved shoot regeneration medium, optimized minimal concentrations of the selective agent, a pre-culture period, and co-cultivation periods. Silver nanoparticles (NAg) added at a concentration of 2.0 μM to the Murashige and Skoog (MS) basal shoot regeneration medium supplemented with 0.1 mg/L indole-3-butyric-acid (IBA) and 0.2 mg/L thidiazuron (TDZ) improved the shoot regeneration efficiency, number of shoots per explant, and plant growth compared to the control without the addition of NAg. The phosphinothricin (PPT) concentration of 1.0 mg/L was determined to be the minimal and optimal concentration for the selection of putative transgenic plants. When the explants were infected with Agrobacterium cells harboring the acdS gene, the explants that were pre-cultured for three days induced more putative transgenic plants than those that were co-cultivated for four days. Therefore, we expect that the results of this study will benefit researchers who are developing genetic transformations of carnations.

• Journal of Plant Biotechnology
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• 제36권4호
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• pp.336-343
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• 2009

Tall fescue is an open-pollinated, perennial, cool season grass species widely used for forage and turf. Tremendous progress has been made in genetic transformation of tall fescue in the past decade. Methods for generating transgenic tall fescue plants have been developed based on biolistic transformation and Agrobacterium-mediated transformation. Potentially useful agronomic genes have been tested to environmental stress tolerance, herbicide tolerance and improve forage quality in tall fescue plants. We review progress in biotechnological improvement of tall fescue and discuss future molecular breeding of this species.

• Journal of Crop Science and Biotechnology
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• 제11권4호
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• pp.233-236
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• 2008

A positive selectable marker system was adapted for transformation of mature embryo-derived calli of Indica rice (Oryza sativa L.) utilizing the PMI gene encoding for phosphomannose-isomerase that converts mannose-6-phosphate to fructose-6-phosphate. The transformed cells grew on medium supplemented with 3% mannose as carbon source and calli were selected on media containing various concentrations of mannose. Molecular analyses showed that the transformed plants contained the PMI gene. The results indicate that the mannose selection system can be used for Agrobacterium-mediated transformation of mature embryo in rice to substitute the use of conventional selectable markers in genetic transformation.

• 한국연초학회지
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• 제19권2호
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• pp.117-123
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• 1997

Viral coat protein (CP) encoding cDNA with artificial start and stop codons was synthesized by reverse-transcriptase polymerase chain reaction (RT-PCR) from the Korean isolate of potato virus Y-vein nectrosis strain (pVY-VN). To make PVY CP cDNA to untranslatable form, three stop codons were inserted near the start codon by "megaprimer-PCR" method. The untranslatable CP cDNA was subcloned to plant expression vector and transferred to N. tabacum cv. NC82 by Agrobacterium-mediated transformation. Highly resistant plants to PVY infection were screened, based on symptom development after mechanical virus inoculation. By genomic PCR and Southern blot analysis, one or more copies of the untranslatable CP gene were found in all transformants. From northern blot analysis, highly resistant transgenic lines had very low level of CP transcript but susceptible lines had high level, suggesting resistance to PVY infection should be related to RNA-mediated mechanism.mechanism.

• 한국초지조사료학회지
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• 제26권2호
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• pp.77-82
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• 2006

유용유전자 도입을 통한 신품종 톨 페스큐를 개발할 목적으로 Agrobacterium을 이용한 효율적인 식물체 재분화 및 형질전환에 미치는 몇 가지 요인을 조사하였다. 성숙종자로부터 유도된 캘러스를 형태에 따라 3가지 type으로 분류하였고 type II 캘러스는 유백색으로 녹색을 띠며 조직적으로 치밀한 상태이며 식물체로의 재분화효율이 52.6%로 가장 높게 나타났다. 또한 재분화 배지에 $AgNO_3$와 cysteine을 동시에 첨가해 준 경우 무첨가구에 비해 캘러스 유도율은 6.7%, 식물체 재분화율은 12% 씩 각각 증가하였다. 캘러스 type 별 형질전환 효율을 조사한 결과 type II 캘러스는 58.0%로 가장 높은 형질전환효율을 나타내었다. 형질전환체를 PCR 및 PCR-Southern blot 분석을 실시하여 본 결과 발현벡터의 T-DNA 영역이 형질전환 식물체의 genome에 성공적으로 도입되었음을 확인할 수 있었다. 본 연구를 통하여 확립된 효율적인 형질전환 시스템은 분자육종을 통한 신품종 톨페스큐의 개발에 유용하게 이용될 수 있을 것이다.

• Mycobiology
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• 제49권5호
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• pp.491-497
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• 2021

An endolichenic fungus Xylaria grammica EL000614 produces grammicin, a potent nematicidal pyrone derivative that can serve as a new control option for root-knot nematodes. We optimized an Agrobacterium tumefaciens-mediated transformation (ATMT) protocol for X. grammica to support genetic studies. Transformants were successfully generated after co-cultivation of homogenized young mycelia of X. grammica with A. tumefaciens strain AGL-1 carrying a binary vector that contains the bacterial hygromycin B phosphotransferase (hph) gene and the eGFP gene in T-DNA. The resulting transformants were mitotically stable, and PCR analysis showed the integratin of both genes in the genome of transformants. Expression of eGFP was confirmed via fluorescence microscopy. Southern analysis showed that 131 (78.9%) out of 166 transformants contained a single T-DNA insertion. Crucial factors for producing predominantly single T-DNA transformants include 48 h of co-cultivation, pretreatment of A. tumefaciens cells with acetosyringone before co-cultivation, and using freshly prepared mycelia. The established ATMT protocol offers an efficient tool for random insertional mutagenesis and gene transfer in studying the biology and ecology of X. grammica.

• 자연과학논문집
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• 제10권1호
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• pp.33-37
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• 1998

식물의 주요 phytohormone의 하나인 cytokinin은 식물체의 줄기와 뿌리성장 그 외에도 영양의 전달이나 노화방지, 열매숙성 등 식물의 성장과 발달에 미치는 영향은 크고 다양하다. Cytokinin 생합성에 관여하는 효소를 생산하는 것으로 알려져 있으며 토양박테리아 Agrobacterium tumefaciens에 존재하는 유전자인 isopentenyl transferase (jpt)를 이용한 많은 분자생물학적 연구가 진행되어 왔는데 그 중 하나로 이 연구에서 jpt 유전자에 의한 cytokinin의 overproduction이 식물체에 성장과 발달에 어떠한 영향을 주는지 관찰하고 그 결과가 제시할 수 있는 작물의 유전 공학적 이용가능성에 대하여 알아본다.