• Plant Biotechnology Reports
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• 제3권4호
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• pp.277-283
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• 2009

One of the limitations to conducting maize Agrobacterium-mediated transformation using explants of immature zygotic embryos routinely is the availability of the explants. To produce immature embryos routinely and continuously requires a well-equipped greenhouse and laborious artificial pollination. To overcome this limitation, an Agrobacterium-mediated transformation system using explants of type II embryogenic calli was developed. Once the type II embryogenic calli are produced, they can be subcultured and/or proliferated conveniently. The objectives of this study were to demonstrate a stable Agrobacterium-mediated transformation of maize using explants of type II embryonic calli and to evaluate the efficiency of the protocol in order to develop herbicide-resistant maize. The type II embryogenic calli were inoculated with Agrobacterium tumefaciens strain C58C1 carrying binary vector pTF102, and then were subsequently cultured on the following media: co-cultivation medium for 1 day, delay medium for 7 days, selection medium for $4{\times}14$ days, regeneration medium, and finally on germination medium. The T-DNA of the vector carried two cassettes (Ubi promoter-EPSPs ORF-nos and 35S promoter-bar ORF-nos). The EPSPs conferred resistance to glyphosate and bar conferred resistance to phosphinothricin. The confirmation of stable transformation and the efficiency of transformation was based on the resistance to phosphinothricin indicated by the growth of putative transgenic calli on selection medium amended with $4mg\;1^{-1}$ phosphinothricin, northern blot analysis of bar gene, and leaf painting assay for detection of bar gene-based herbicide resistance. Northern blot analysis and leaf painting assay confirmed the expression of bar transgenes in the $R_1$ generation. The average transformation efficiency was 0.60%. Based on northern blot analysis and leaf painting assay, line 31 was selected as an elite line of maize resistant to herbicide.

• Journal of Plant Biotechnology
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• 제32권2호
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• pp.91-95
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• 2005

옥수수 미숙배배양과 Agrobacterium tumefaciens공동배양법에 의해 형질전환체를 생산하였다. Hi II계통의 미숙배를 Ubiquitin 1 promoter-GUS유전자와 선발마커로서 nptII 유전자로 제작된 pPTN290벡터를 C58C1에 도입한 후 형질전환 균주로 사용하였다. 7개의 paromomycin저항성 배 발생캘러스를 얻었으며, GUS양성반응을 나타내는 7개의 독립적인 식물체를 얻었다. Southern분석법에 의하여 $T_1$세대 식물체로부터 nptII유전자가 안정적으로 도입되어 있음을 확인하였다.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2005년도 추계학술대회 및 한일 식물생명공학 심포지엄
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• pp.260-260
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• 2005

• 식물조직배양학회지
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• 제21권6호
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• pp.319-326
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• 1994

십자화과 식물의 유용유전자를 cloning하기 위한 기초연구로서 십자화과 식물인 Armoracia rusicna의 재분화계와 형질전환계를 확립하고, gene tagging을 하기 위하여 binary vector에 삽입된 옥수수의 transposon 유전자 Ac/Ds를 도입한 결과, NAA 0.1 mg/L와 BA 1.0 mg/L를 함유한 MS 배지에서 최적의 shoot를 유기할 수 있었으며, MS 기본배지에 옮기면 쉽게 발근을 유도할 수 있었다. 옥수수의 Ac/Ds의 유전자를 잎에 형질전환시킨 결과 8-10%의 형질전환율을 보였으며, 엽병의 경우에도 4%의 형질전환 식물체가 얻어졌다. Kanamycin 100 mg/L 농도에서 선발한 개체를 PCR 분석 및 Southern blot분석을 행하였던 결과 PCR분석으로부터 Ds유전자가 식물에 도입된 것이 확인되었고, Southern blot 분석으로부터 Ac/Ds 모두가 도입된 것이 확인되었다.

• 한국작물학회지
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• 제47권2호
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• pp.116-122
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• 2002

Dehydrins (LEA Dll proteins) are one of the typical families of plant proteins that accumulate in response to dehydration, cold stress, abscisic acid, or during seed maturation. A 1.3-kb cDNA was cloned from a cDNA expression library of 5-day-old germinating maize scutellums under drought stress. The deduced protein sequence indicated a dehydrin gene encoding SK$_3$ LEA protein typically expressed during cold acclimation, but not by drought stress in barley and wheat. Thus, it was named maize DEHYDRIN2 (ZmDhn2). It accumulates rapidly and highly in drought-stressed scutellum and leaf tissues at any stage, but not under cold stress. ZmDhn2 gene was transformed into Arabidopsis thaliana for functional analysis under drought condition. From electrolyte leakage test, no significant difference showed between wild type and transformants under normal growth condition, but the leakage level of electrolyte in wild type plants was about 3 times as high as that in the transformed plants under drought stress. It suggests that ZmDHN2 playa role in increasing drought tolerance.

• Journal of Plant Biotechnology
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• 제5권1호
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• pp.19-23
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• 2003

The Ac (activator) which is one of the well-characterized transposable elements from maize was examined for its transposition possibility to the heterologous plant (P.nigra x maximowiczii) genome via Agrobacterium tumefacience (LBA4404) mediated transformation system. A number of transgenic plants were successfully recovered after 30 weeks by amount reduction from 50 to 15 g/$m\ell$ kanamycin for in vitro selection to minimize phytotoxic effects and to increase callus growth and regeneration efficiency. Among transgenic plants, 62 out of 106 transgenic poplars (58.5%) showed abnormal phenotypes such as severe serrated leaves and light leaf coloration. Indigo staining with X-gluc proved indirectly the restoration of Gus enzyme function and the presence of Ac in poplar genome by PCR. Southern analysis indicated the transposition and existence of Ac element in poplar genomes. In this research, an Agrobacterium-mediated transformation system in poplar species was developed and identified that Ac derived from maize can be excised and trans posed into other poplar genomes.

• Journal of Plant Biotechnology
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• 제4권4호
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• pp.135-141
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• 2002

Agrobacterium-mediated transformation has been unsuccessful for monocot plants except for a few important crops such as barley, rice, maize and wheat. We discussed here that a successful transformation of monocots demands certain critical conditions. The requirements for an efficient transformation are a selection of target tissues competent for plant regeneration and Agrobacterium-infection, and various factors promoting Agrobacterium-infection. The factors were divided into two to activate Agrobacterium and to increase plant cell's susceptibility against Agrobacterium. Optimization of these factors significantly increased transformation efficiency of zoysia grass and rice plants. A technical improvement in transformation system for monocots will promote improvement of the breed as well as a study of gene functions in monocots.

• Plant Biotechnology Reports
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• 제2권4호
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• pp.267-270
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• 2008

We have successfully used the low-pressure BioWare gene gun, developed for gene transfer in animal cells, for plant tissues. The BioWare device is easy to manipulate. Just 50 psi helium pressure was sufficient to transfer foreign genes into the aleurone layer and embryo of maize without causing tissue damage in the impact area. As shown by expression signals from invasive histochemical ${\beta}-glucuronidase$ (GUS) activity, the foreign reporter gene expressed well in bombarded tissues. This successful GUS-transient expression extends the application of this low-pressure gene gun from animal cells to plant tissues.

• Journal of Plant Biotechnology
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• 제41권1호
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• pp.50-55
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• 2014

Plant-based vaccines possess some advantages over other types of vaccine biotechnology such as safety, low cost of mass vaccination programs, and wider use of vaccines for medicine. This study was undertaken to develop the transgenic maize as edible vaccine candidates for humans. The immature embryos of HiII genotype were inoculated with A. tumefaciens strain C58C1 containing the binary vectors (V662 or V663). The vectors carrying nptII gene as selection marker and scEDIII (V662) or wCTB-scEDIII (V663) target gene, which code EIII proteins inhibite viral adsorption by cells. In total, 721 maize immature embryos were transformed and twenty-two putative transgenic plants were regenerated after 12 weeks selection regime. Of them, two- and six-plants were proved to be integrated with scEDIII and wCTB-scEDIII genes, respectively, by Southern blot analysis. However, only one plant (V662-29-3864) can express the gene of interest confirmed by Northern blot analysis. These results demonstrated that this plant could be used as a candidated source of the vaccine production.

• Journal of Plant Biotechnology
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• 제44권1호
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• pp.49-55
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• 2017

옥수수의 최적 조직 배양 조건을 확립하기 위하여 옥수수 국내 5 계통과 국외 11 계통 총 16 계통을 포트와 포장 재배하여 미성숙 배를 분리하여 배발생 캘러스 유도 및 식물체 재분화율을 조사하였다. MS 배지에 auxin으로 1.5 mg/L Dicamba와 0.5 mg/L 2,4-D 가 첨가된 배지에서 캘러스 형성은 본 실험에 사용된 옥수수 계통 모두에서 높은 빈도로 유도되었으며, 캘러스로부터 식물체 재분화는 5mg/L zeatin이 첨가된 재분화 배지에서 높은 재분화율을 보였다. 또한 포장에서 재배된 옥수수로부터 미성숙 배를 분리하여 사용하였을 때 캘러스 유기 및 식물체 재분화 효율이 높았던 것으로 보아 미성숙 배를 분리하기 위한 옥수수 상태 및 genotype이 중요한 영향을 준다는 것을 알 수 있었다. 본 실험을 통하여 배 발생 캘러스 형성 및 식물체 재분화 효율이 조사된 옥수수 계통들은 생명공학 기술을 활용한 신품종 개발을 위한 형질전환 시스템 개발에 유전자원으로 활용될 수 있는 정보를 제공할 것으로 사료된다.