• Plant Biotechnology Reports
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• 제4권4호
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• pp.293-301
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• 2010

The feasibility of two strategies for transgene pyramiding using Agrobacterium-mediated transformation was investigated to develop a transgenic potato (Solanum tuberosum L. cv. Iwa) with resistance to potato tuber moth (PTM) (Phthorimaea operculella (Zeller)). In the first approach, cry1Ac9 and cry9Aa2 genes were introduced simultaneously using a kanamycin (nptII) selectable marker gene. The second approach involved the sequential introduction (re-transformation) of a cry1Ac9 gene, using a hygromycin resistance (hpt) selectable marker gene, into an existing line transgenic for a cry9Aa2 gene and a kanamycin resistance (nptII) selectable marker gene. Multiplex polymerase chain reaction (PCR) confirmed the presence of the specific selectable marker gene and both cry genes in all regenerated lines. The relative steady-state level of the cry gene transcripts in leaves was quantified in all regenerated lines by real-time PCR analysis. Re-transformation proved to be a flexible approach to effectively pyramid genes for PTM resistance in potato, since it allowed the second gene to be added to a line that was previously identified as having a high level of resistance. Larval growth of PTM was significantly inhibited on excised greenhouse-grown leaves in all transgenic lines, although no lines expressing both cry genes exhibited any greater resistance to PTM larvae over that previously observed for the individual genes. It is anticipated that these lines will permit more durable resistance by delaying the opportunities for PTM adaptation to the individual cry genes.

• The Plant Pathology Journal
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• 제18권3호
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• pp.130-137
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• 2002

Potato virus Y (PVY) is one of the most important viruses in many field crops in Korea. In this study, 31 PVY isolates were isolated from infected potato (Solanum tuberosum), tobacco (Nicotiana tabacum), pea (Pisum sativum), and weeds (Veronica persica, Lamium amplexicause and Capsella bursa-pastoris) showing different mosaic symptoms in Jeonbuk, Chungnam, Gangwon, and Gyeongbuk areas in Korea. The 640 nucleotide region containing the C-terminal portion of coat protein (CP) gene and 3'non-translated region (NTR) was amplified by reverse transcription-polymerase chain reaction (RT-PCR) using PVY-specific oligonucleotide primers. Sequence analyses of the amplified DNA fragments showed that the C-terminal portion of CP gene was not significantly different from that of previously reported PVY strains from potato (PVY-OK and -T) and tobacco (PVY-VN) in Korea. Homologies of the deduced CP amino acid sequences were 93.3-99.0% to corresponding regions of the other PVY strains including PV $Y^{N}$, PV $Y^{o}$ , PV $Y^{OK}$ , PV $Y^{T}$ , and PV $Y^{VN}$ . In contrast the sequences located at the 3'-NTR showed more diverse sequence homologies (76.4-99.7%). These results indicate that the C-terminal portion of the CP gene was relatively conserved while sequences at the 3'NTR were more diverse and variable over the host species and the regions where they were isolated.e isolated.

• The Plant Pathology Journal
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• 제30권2호
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• pp.200-207
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• 2014

A viral disease causing severe mosaic, necrotic, and yellow symptoms on Vigna angularis var. nipponensis was prevalent around Suwon area in Korea. The causal virus was characterized as Cucumber mosaic virus (CMV) on the basis of biological and nucleotide sequence properties of RNAs 1, 2 and 3 and named as CMV-wVa. CMV-wVa isolate caused mosaic symptoms on indicator plants, Nicotiana tabacum cv. Xanthi-nc, Petunia hybrida, and Cucumis sativus. Strikingly, CMV-wVa induced severe mosaic and malformation on Cucurbita pepo, and Solanum lycopersicum. Moreover, it caused necrotic or mosaic symptoms on V. angularis and V. radiate of Fabaceae. Symptoms of necrotic local or pin point were observed on inoculated leaves of V. unguiculata, Vicia fava, Pisum sativum and Phaseolus vulgaris. However, CMV-wVa isolate failed to infect in Glycine max cvs. 'Sorok', 'Sodam' and 'Somyeong'. To assess genetic variation between CMV-wVa and the other known CMV isolates, phylogenetic analysis using 16 complete nucleotide sequences of CMV RNA1, RNA2, and RNA3 including CMV-wVa was performed. CMV-wVa was more closely related to CMV isolates belonging to CMV subgroup I showing about 85.1-100% nucleotide sequences identity to those of subgroup I isolates. This is the first report of CMV as the causal virus infecting wild Vigna angularis var. nipponensis in Korea.

• 원예과학기술지
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• 제35권3호
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• pp.300-313
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• 2017

'Unicon' cherry tomato (Solanum lycopersicum) is one of the most highly perishable horticultural crops due to its high water content and respiration rate. This study was carried out to assess the effect of continuous application of $CO_2$ (control [air], 3%, and 5%) on the quality and shelf life of cherry tomato fruits stored at $10^{\circ}C$ and $85{\pm}5%$ relative humidity (RH) at two maturity stages (pink and red). Continuous application of $CO_2$ did not affect the soluble solids content (SSC) or titratable acidity (TA) of the fruit at either maturity stage during storage. However, there was a significant difference among treatments in terms of flesh firmness, cell wall thickness, pectin content, vitamin C content, skin color, lycopene content, weight loss, ethylene production rate, respiration rate, and acetaldehyde and ethanol production. Fruits treated with 5% $CO_2$ maintained their high quality with regards to vitamin C, skin color ($a^*$), lycopene content, weight loss, physiological parameters (ethylene production rate, respiration rate, and volatile compounds), flesh firmness, cell wall thickness, and pectin content at both maturity stages compared with 3% $CO_2$ treatment and the control. Continuous application of $CO_2$ (5%) reduced the ethylene production rate and the production of volatile compounds during storage. Therefore, cherry tomato 'Unicon' fruit can be stored for two weeks without losing fruit quality at both maturity stages under continuous application of 5% $CO_2$ as a postharvest treatment.

• The Plant Pathology Journal
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• 제30권3호
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• pp.288-298
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• 2014

We examined the efficacy of a bacterium for biocontrol of the root-knot nematode (RKN) Meloidogyne hapla in carrot (Daucus carota subsp. sativus) and tomato (Solanum lycopersicum). Among 542 bacterial isolates from various soils and plants, the highest nematode mortality was observed for treatments with isolate C1-7, which was identified as Bacillus cereus based on cultural and morphological characteristics, the Biolog program, and 16S rRNA sequencing analyses. The population density and the nematicidal activity of B. cereus C1-7 remained high until the end of culture in brain heart infusion broth, suggesting that it may have sustainable biocontrol potential. In pot experiments, the biocontrol efficacy of B. cereus C1-7 was high, showing complete inhibition of root gall or egg mass formation by RKN in carrot and tomato plants, and subsequently reducing RKN damage and suppressing nematode population growth, respectively. Light microscopy of RKN-infected carrot root tissues treated with C1-7 showed reduced formation of gall cells and fully developed giant cells, while extensive gall cells and fully mature giant cells with prominent cell wall ingrowths formed in the untreated control plants infected with RKNs. These histopathological characteristics may be the result of residual or systemic biocontrol activity of the bacterium, which may coincide with the biocontrol efficacies of nematodes in pots. These results suggest that B. cereus C1-7 can be used as a biocontrol agent for M. hapla.

• Journal of Plant Biotechnology
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• 제31권2호
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• pp.109-113
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• 2004

산화스트레스에 내성을 지닌 형질전환 감자 식물체를 개발하기 위하여 산화스트레스에 의해 발현이 강하게 유도되는 SWPA2 프로모터에 CuZnSOD와 APX 유전자가 엽록체에서 동시에 발현되도록 연결한 형질전환 벡터 (pSSA-K)를 제작한 후 Agrobacterium 매개로 형질전환 하였다. 기관 발생 경로에 의해 kanamycin 저항성 식물체를 재분화 시킨후 Southern 분석으로 외래 유전자가 안정적으로 감자 게놈내로 삽입되었음을 확인하였다. 형질전환 감자 식물체의 잎 조직에 10$\mu$M methyl viologen을 처리하여 산화스트레스 내성 검정을 조사한 결과 형질전환체는 MV에 대해 강한 내성을 지님을 확인하였다. 내성을 보인 개체 중에서 환경스트레스에 대한 내성 조사를 위하여 품종별로 2 개체씩 선발하였다. 선발된 식물체는 건조, 고온 등의 여러 가지 환경스트레스 내성검정에 이용될 것이며 향후 복합재해 내성 감자 품종이 개발될 수 있을 것으로 기대한다.

• Plant Biotechnology Reports
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• 제4권1호
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• pp.15-21
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• 2010

The over-expression of Arabidopsis CAX1 and CAX2 causes transgenic tomato plants to reveal severe $Ca^{2+}$ deficiency-like symptoms such as tip-burn and/or blossom end rot, despite there being sufficient $Ca^{2+}$ in each plant part. To correct the symptoms and to moderately enhance the calcium level, a worldwide vegetable tomato was genetically engineered using a modified Arabidopsis cation/$H^+$ antiporter sCAX2A, a mutant form of Arabidopsis CAX2. Compared with the wild-type, the sCAX2A-expressing tomato plants demonstrated elevated $Ca^{2+}$ levels in the fruits with almost no changes in the levels of $Mn^{2+}$, $Cu^{2+}$, and $Fe^{2+}$. Moreover, expression of sCAX2A in tomato plants did not show any significant alterations in their morphological phenotypes. Unlike 35S::sCAX1 construct, sCAX2A antiporter gene driven by 35S promoter can be a valuable tool for enriching $Ca^{2+}$ contents in the tomato fruit without additional accumulation of the undesirable cations.

• Journal of Plant Biotechnology
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• 제37권1호
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• pp.110-114
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• 2010

조직배양 감자줄기를 1/3 MS 액체배지가 첨가된 18 L 바이오리액터 배양기에서 배양하였을 때 생중량 증식이 가장 양호하였고, 1/4 MS 액체배지, 1/2 MS 액체배지 순으로 감자줄기의 생중량이 증가하였다. 감자 소괴경 형성은 감자줄기를 배양한 바이오리액터에서 배지를 따라 내고, 소괴경 형성용 배지로 교환하여 어두운 곳에서 암배양하면 소괴경이 형성되었다. 소괴경은 암배양 1주후부터 줄기 마디의 측아에서 생성되기 시작하여 3주 정도에 대부분이 형성되고 1.5 MS 액체배지와 $20^{\circ}C$ 온도 조건이 최적이었다. 이 조건에서는 6주 정도 배양하면 18L 바이오리액터 배양기에서 1,000개 이상의 소괴경을 생산할 수 있었다. 어두운 배양조건에서 소괴경이 거의 성장하면 바이오리액터를 빛이 있는 조건으로 옮겨 1주정도 배양한 후 녹화된 소괴경를 수확하였다.

• Journal of Plant Biotechnology
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• 제37권1호
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• pp.89-95
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• 2010

Dihydroflavonol 4-reductase(DFR)는 flavonoid 생합성 경로의 가장 중심부에 작용하는 효소로 2R,3R-trans-dihydroflavonols로부터 leucoanthocyanidins 으로의 변환을 촉매한다. 본 연구에서는 색소유전자의 전이를 통하여 새로운 색소발현체계를 가진 품종을 육종하기 위한 기초연구로 안개초 (Gypsophila paniculata L.)의 꽃봉오리로부터 cDNAlibrary를 합성하였고 카네이션의 DFR 유전자를 probe로 사용하여 anthocyanin 합성경로의 중요 효소의 하나인 DFR 유전자를 분리하였다. 염기서열분석을 수행하여 분리유전자의 크기가 1279 bp이며 이 중 coding region은 1063 bp임을 확인하였다. 이미 밝혀진 다른 식물체의 DFR 유전자와 서로 염기서열의 일치성을 비교해 본 결과 Cheddar pink, 카네이션, 양배추, 개나리, 페튜니아, cup flower, 장미, 과꽃 및 거베라에서 각각 62% 이상을 나타내었다. 분리유전자의 발현을 확인하기 위하여 Northern blot 분석 및 인위적으로 기내에서의 transcription과 translation을 수행하였고, 분리한 유전자의 효소활성을 측정해 본 결과 leucopelargonidin의 작은 peak를 확인하였다. Southern blot 분석 결과 안개초의 DFR 유전자는 다른 대부분의 식물체와 유사하게 한 개가 존재함을 확인하였다.

• 한국약용작물학회지
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• 제6권4호
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• pp.311-322
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• 1998

60종(種)의 자생 약용식물과 식용작물을 대상으로 항산화활성의 생리활성을 조사함으로써 약용식물과 식용작물의 유용성 측면의 확인뿐만 아니라 새로운 생리활성물질 탐색의 가능성을 검토하기 위해서 실시한 실험 결과는 다음과 같다. 자생 약용식물 및 식용작물에 대한 50% EtOH 추출물을 이용하여 TBA법. DPPH법에 의하여 1차 활성검정 결과 처리방법에 따라 활성값에 차이가 있으나 TBA법에서는 검정콩의 추출액이 87.3%, DPPH법에서는 까마중 추출액이 80.6%로서 가장 높은 활성을 보였고 두가지 방법에서 동시에 활성이 높은 것은 검정콩을 비롯하여 10종 이었다. SOD활성정도도 검정식물에 따라 큰 차이가 있으나 검정콩이 53.5%로서 가장 높은 SOD활성을 나타내었으며 SOD종류는 Cu/ZnSOD, FeSOD을 포함하는 것으로 나타났다. Cu/ZnSOD만을 함유하고 있는 잔대는 SOD활성 정도가 10.37%로서 실험 대상식물 중 가장 낮은 활성을 보였다.