• Journal of Plant Biotechnology
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• 제38권3호
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• pp.198-202
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• 2011

Agrobacterium과 자엽절 절편 공동배양으로 오이 형질전환체를 생산하였다. 오이 자엽절 절편 (c.v. Eunsung)은 선발 마커로서 nptII유전자와 유용유전자로서 DQ유전자가 포함된 pPZP211를 EHA101에 형질전환하여 공동 배양하였다. 3회 반복실험으로부터 평균 형질전환 빈도는 4.01%를, 최대 빈도는 5.97%를 보여 주었다. Paromomycin항생제 저항성을 갖는 9개의 식물체를 선발과정을 통해 얻었으며, Southern blot 분석에 의해 6개 식물체의 genome에 nptII유전자자 안정적으로 도입되어 있음을 확인할 수 있었다.

• 농약과학회지
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• 제4권2호
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• pp.37-43
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• 2000

본 시험은 오이 양액재배시 배양액내 규산칼륨($K_{2}SiO_{3}$) 처리에 의한 흰가루병 방제여부를 검토하기 위하여 규산 칼륨($K_{2}SiO_{3}$, $25{\sim}27%$의 $SiO_{2}$ Kanto)을 0.85 mM(50 $mg{\cdot}L-^{-1}$), 1.7 mM(100 $mg{\cdot}L-^{-1}$) 및 3.4 mM(200 $mg{\cdot}L-^{-1}$)의 농도로 배양액에 처리하고 1.7 mM, 8.5 mM, 17 mM 및 34 mM의 농도로 엽면살포하였다. 생육중기(정식 51일)에 규산 3.4 mM 배양액 처리구는 흰가루병 병반면적율이 2.3%로 0.95 mM 처리구의 38.3%에 비해 현저히 억제되었다. 그러나 1.7 mM과 3.4 mM 처리간에는 현저한 차이가 없었다. 배양액내 규산의 농도를 0.05 mM에서 4.10 mM까지 증가시켰을 때 잎당 병반수, 병반면적 및 발아관 길이는 규산의 농도 증가에 따라 감소하였다. 규산을 처리한 잎에서의 분생포자 발아율은 처리농도가 높아질수록 현저하게 감소하였으며, 저농도 처리구(1.40 mM 이하)에서는 $14.7%{\sim}20.3%$, 고농도처리구(1.85 mM 이상)에서는 $9.0%{\sim}12.4%$였다. 2% 물한천 배지에서의 농도시험에서는 발아율이 $1.1%{\sim}2.0%$로 일정한 경향을 나타내지 않았다. 규산칼륨을 17 mM의 농도로 희석하여 엽면살포한 결과 무처리에 비하여 흰가루병 발생이 현저히 억제되었으며, 방제효과 지속기간은 병원균 접종후 4일까지였다.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2005년도 추계학술대회 및 한일 식물생명공학 심포지엄
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• pp.71-80
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• 2005

Effects of low temperature ($8^{\circ}C$) on the hydraulic conductivity of young roots of a chilling-sensitive (cucumber; Cucumis sativus L.) and a chilling-resistant (figleaf gourd; Cucurbita ficifolia Bouche) crop have been measured at the levels of whole root systems (root hydraulic conductivity, $Lp_r$) and of individual cortical cells (cell hydraulic conductivity, Lp). In figleaf gourd, there was a reduction only in hydrostatic $Lp_r$ but not in osmotic $Lp_r$ suggesting that the activity of water channels was not much affected by low root temperature (LRT)treatment in this species. Changes in cell Lp in response to chilling and recovery were similar asroot level, although they were more intense at the root level. Roots of figleaf gourd recovered better from LRT treatment than those of cucumber. In figleaf gourd, recovery (both at the root and cell level) often resulted in Lp and $Lp_r$ values which were even bigger than the original, i.e. there was an overshoot in hydraulic conductivity. These effects were larger forosmotic (representing the cell-to-cell passage of water) than for hydrostatic $Lp_r$. After a short term (1 d) exposure to $8\;^{\circ}C$ followed by 1 d at $20\;^{\circ}C$, hydrostatic $Lp_r$ of cucumber nearly recovered and that of figleaf gourd still remained higher due to the overshoot. On the contrary, osmotic $Lp_r$ and cell Lp in both species remained high by a factor of 3 as compared to the control, possibly due to an increased activity of water channels. After pre-conditioning of roots at LRT, increased hydraulic conductivitywas completely inhibited by $HgCl_2$ at both the root and cell levels. Different from figleaf gourd, recovery from chilling was not complete in cucumber after longer exposure to LRT. It is concluded that at LRT, both changes in the activity of aquaporins and alterations of root anatomy determine the water uptake in both species. To better understand the aquaporin function in plants under various stress conditions, we examined the transgenic Arabidopsisand tobacco plants that constitutively overexpress ArabidopsisPIP1;4 or PIP2;5 under various abiotic stress conditions. No significant differences in growth rates were found between the transgenic and wild-type plants under favorable growth conditions. By contrast, overexpression of PIP1;4 or PIP2;5 had a negative effect on seed germination and seedling growth under drought stress, whereas it had a positive effect under cold stress and no effect under salt stress. Measurement of water transport by cell pressure probe revealed that these observed phenotypes under different stress conditions were closely correlated with the ability of water transport by each aquaporin in the transgenic plants. Together, our results demonstrate that PIP-type aquaporins play roles in seed germination, seedling growth, and stress response of Arabidopsis and tobacco plants under various stress conditions, and emphasize the importance of a single aquaporin-mediated water transport in these cellular processes.

• Journal of Photoscience
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• 제9권2호
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• pp.158-161
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• 2002

UV-B radiation gives harmful effects on plants, such as production of several types of DNA lesions, and growth inhibition. On the other hand, plants have some protective mechanisms, including filtering effect due to accumulation of phenolic compounds in epidermal cells and reactivation of DNA lesions, which are enhanced by UV-B irradiation. We have investigated the mechanism of UV-B effects on plants using cucumber seedlings as plant materials. Cucumber plants were cultivated in an artificially lit growth chamber. Supplemental UV-B irradiation, of which intensity was almost equal to the level of natural sunlight, retarded the growth of first leaves. The growth retardation must result trom the inhibition of cell division and/or cell growth. Microscopical observation of leaf epidermis suggested that the growth retardation might be mainly caused by cell growth inhibition. The retardation was, however, restored within 2 or 3 days after the termination of UV-B irradiation. It is known that UV-B irradiation lowers the activity of photo system II (PS II). In the present experimental conditions, however, UV-B irradiation has little effect on PS II activity as estimated by chlorophyll fluorescence. The stomatal conductance, a major factor determining photosynthetic rate, of first leaves increased during the growth. The increase of stomatal conductance was suppressed by UV-B irradiation and restored by termination of the irradiation. It has not been clear, however, what mechanisms are involved in the suppression of increase of stomatal conductance.

• The Plant Pathology Journal
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• 제25권4호
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• pp.369-375
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• 2009

The potential antiviral effects of the culture filtrates (CF) from Serratia marcescens strain Gsm01 against yellow strain of Cucumber mosaic virus (CMV-Y) were investigated. The culture filtrate of S. marcescens strain Gsm01 applied on Chenopodium amaranticolor showed high inhibitory activity, likewise no necrosis appeared when applied on the tobacco plants 2 days before CMV-Y inoculation. When plants were challenge inoculated with CMV-Y for eighteen days, the disease incidence in plants with culture filtrate of S. marcescens Gsm01 did not exceed 59%, whereas 100% of control plants were severely infected. The results of double antibody sandwich-enzyme linked immunosorbent assay (DAS-ELISA), reverse transcriptase polymerase chain reaction (RT-PCR), dot blotting, and western blotting showed that culture filtrate treatment highly affected the accumulation of CMV-Y or its CP protein gene in the treated plant leaves. It was also observed that the culture filtrate had no RNase activity on genomic RNAs of CMV-Y, suggesting that culture filtrate may not contain ribosome inactivating proteins (RIPs) or proteins with RNase activity. These data shows that culture filtrate of S. marcescens strain Gsm01 seems to be a promising source of antiviral substance for the practical use.

• 한국자원식물학회지
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• 제20권2호
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• pp.216-219
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• 2007

Root colonization by a rhizobacterium, Pseudomonas chlororaphis O6, elicited induced systemic resistance (ISR) in the leaves of cucumber plants against fungal and bacterial pathogens. To understand the role of unique genes during strain O6-mediated ISR, a suppressive subtractive hybridization method was undertaken and led to isolation of twenty-five distinct genes. The transcriptional levels of all the genes showed an increase much earlier under O6 treatment than in water control plants only after challenge with pathogen, while no difference detected on the plants without pathogen challenge. This suggests that O6-mediated ISR is associated with the priming phenomenon, an enhanced capacity for the rapid and effective activation of cellular defense responses after challenge inoculation.

• The Plant Pathology Journal
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• 제28권1호
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• pp.81-86
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• 2012

We developed a reassortant RNA virus vector derived from $Cucumber$ $mosaic$ $virus$ (CMV), which has advantages of very wide host range and can efficiently induce gene silencing in a few model plants. Certain CMV isolates, however, show limited host ranges presumably because they naturally co-evolved with their own hosts. We used a reassortant comprised of two strains of CMV, Y-CMV and Gn-CMV, to broaden the host range and to develop a virus vector for virus-induced gene silencing (VIGS). Gn-CMV could infect chili pepper and tomato more efficiently than Y-CMV. Gn-CMV RNA1, 3 and Y-CMV RNA2-A1 vector were newly reconstructed, and the transcript mixture of RNA1 and 3 genomes of Gn-CMV and RNA2 genome of Y-CMV RNA2 containing portions of the endogenous phytoene desaturase (PDS) gene (CMV2A1::PDSs) was inoculated onto chili pepper (cv. Chung-yang), tomato (cvs. Bloody butcher, Tigerella, Silvery fir tree, and Czech bush) and $Nicotiana$ $benthamiana$. All the tested plants infected by the reassortant CMV vector showed typical photo-bleaching phenotypes and reduced expression levels of $PDS$ mRNA. These results suggest that the reassortant CMV vector would be a useful tool for the rapid induction of the RNA silencing of endogenous genes in chili pepper and tomato plants.

• Mycobiology
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• 제29권1호
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• pp.48-53
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• 2001

Plants have the ability to acquire an enhanced level of resistance to pathogen attack after being exposed to specific biotic stimuli. To obtain plant growth-promoting rhizobacteria inducing resistance against cucumber anthracnose by Colletotrichum orbiculare, more than 800 strains of rhizobacteria were screened in the greenhouse. Among these strains, Bacillus amyloliquefaciens solate EXTN-1 showed significant disease control efficacy on the plants. Induction of pathogenesis-related(PR-la) gene expression by EXTN-1 was assessed using tobacco plants transformed with PR-1a::$\beta$-glucuronidase(GUS) construct. GUS activities of tobacco treated with EXTN-1 and salicylic acid-treated transgenic tobacco were significantly higher than those of tobacco plants with other treatments. Gene expression analyses indicated that EXTN-1 induces the accumulation of defense-related genes of tobacco. The results showed that some defense genes are expressed by the treatment with EXTN-1 suggesting the similar resistance mechanism by salicylic acid.

• Journal of Plant Biotechnology
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• 제4권4호
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• pp.171-178
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• 2002

Chlorophyll (Chl) fluorescence imaging was used to investigate the effectiveness of in vivo incorporation methods for two chemicals, 3-(3',4'-dichlorophenyl)-1,1-dimethylurea (DCMU) and methyl viologen (MV) in rice, a monocot, and cucumber, a dicot, leaves. four different methods (vacuum infiltration, floating, transpiration-aided incorporation through petiole and spraying) were compared, and $F_i$ and $F_v$/$F_m$ were chosen for the imaging of the DCMU- and MV-treated leaves, respectively. The effects of the chemicals in plants were generally heterogeneous over the whole leaf area. Moreover, the effectiveness of the treatment of a chemical in plant leaves was dependent on chemical species, plant species, concentration of the chemical, the treatment method, the duration of the treatment, the existence of light and detergent, etc. In conclusion, we suggest that to achieve the proposed effects of chemicals in plants for an actual experiment, these factors must be considered before the chemical treatment, and the best method for the treatment of the chemicals tested was floating and vacuum infiltration in the dicot and the monocot leaves, respectively, as drawn from Chl fluorescence imaging analysis.

• Journal of Plant Biotechnology
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• 제47권2호
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• pp.150-156
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• 2020

Weeds play an important role in the survival of viruses and are potential inoculum sources of viral diseases for crop plants. In this study, specimens of Pseudostellaria heterophylla exhibiting symptoms of the cucumber mosaic virus (CMV) were collected in Bonghwa, Korea. The characteristics of the disease were described and leaf RNA was extracted and sequenced to identify the virus. Three CMV contigs were obtained and PCR was performed using specific primer pairs. RNA from positive samples exhibiting CMV leaf symptoms was amplified to determine the coat protein. A sequence comparison of the coat protein gene from the CMV BH isolate shared the highest nucleotide identity (99.2%) with the CMV ZM isolate. Phylogenetic analysis showed that CMV-BH belonged to subgroup IA and that the most closely-related isolate was CMV-ZM. All test plants used for the biological assay were successfully infected with CMV and exhibited CMV disease symptoms such as blistering, mosaic, and vein yellowing. To our knowledge, this is the first report of CMV infection in P. heterophylla from Korea.