• Plant Biotechnology Reports
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• 제3권2호
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• pp.147-155
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• 2009

Oryza grandiglumis Chitinase IVa (OgChitIVa) cDNA encoding a class IV chitinase was cloned from wild rice (Oryza grandiglumis). OgChitIVa cDNA contains an open reading frame of 867 nucleotides encoding 288 amino acid residues with a predicted molecular weight of 30.4 kDa and isoelectric point of 8.48. Deduced amino acid sequences of OgChitIVa include the signal peptide and chitin-binding domain in the N-terminal domain and conserved catalytic domain. OgChitIVa showed significant similarity at the amino acid level with related monocotyledonous rice and maize chitinase, but low similarity with dicotyledoneous chitinase. Southern blot analysis showed that OgChitIVa genes are present as two copies in the wild rice genome. It was shown that RNA expression of OgChitIVa was induced by defense/stress signaling chemicals, such as jasmonic acid, salicylic acid, and ethephon or cantharidin and endothall or wounding, and yeast extract. It was demonstrated that overexpression of OgChitIVa in Arabidopsis resulted in mild resistance against the fungal pathogen, Botrytis cinerea, by lowering disease rate and necrosis size. RT-PCR analysis showed that PR-1 and PR-2 RNA expression was induced in the transgenic lines. Here, we suggest that a novel OgChitIVa gene may play a role in signal transduction process in defense response against B. cinerea in plants.

• Journal of Plant Biotechnology
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• 제38권2호
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• pp.105-116
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• 2011

Transgenic zoysiagrass (Zoysia japonica Steud.) expressing the bar gene inserted in the plant genome has been generated previously through Agrobacterium tumefaciens-mediated transformation. The GM zoysiagrass (event: JG21) permits efficient management of weed control of widely cultivated zoysiagrass fields, reducing the frequency and cost of using various herbicides for weed control. Now we have carried out the environmental risk assessment of JG21 prior to applying to the governmental regulatory agency for the commercial release of the GM turf grass outside of test plots. The morphological phenotypes, molecular analysis, weediness and gene flow from each test plot of JG21 and wild-type zoysiagrasses have been evaluated by selectively analyzing environmental effects. There were no marked differences in morphological phenotypes between JG21 and wild-type grasses. The JG21 retained its stable integration in the host plant in T1 generation, exhibiting a 3:1 segregation ratio according to the Mendelian genetics. We confirmed the copy number (1) of JG21 by using Southern blot analysis, as the transgenic plants were tolerant to ammonium glufosinate throughout the culture period. From cross-fertilization and gene flow studies, we found a 9% cross-pollination rate at the center of JG21 field and 0% at distances over 3 m from the field. The JG21 and wild-type zoysiagrass plants are not considered "weed" because zoysiagrasses generally are not dominant and do not spread into weedy areas easily. We assessed the horizontal gene transfer (HGT) of the transgene DNA to soil microorganisms from JG21 and wild-type plants. The bar gene was not detected from the total genomic DNA extracted from each rhizosphere soil of GM and non-GM Zoysia grass fields. Through the monitoring of JG21 transgene's unintentional release into the environment, we found no evidence for either pollen mediated gene flow of zoysiagrass or seed dispersal from the test field within a 3 km radius of the natural habitat.

• Molecules and Cells
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• 제23권2호
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• pp.161-169
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• 2007

We identified two alternatively spliced variants of the peroxisomal targeting signal 1 (PTS1) receptor protein Pex5ps in monocot (rice, wheat, and barley) but not in dicot (Arabidopsis and tobacco) plants. We characterized the molecular and functional differences between the rice (Oryza sativa) Pex5 splicing variants OsPex5pL and OsPex5pS. There is only a single-copy of OsPEX5 in the rice genome and RT-PCR analysis points to alternative splicing of the transcripts. Putative light-responsive cis-elements were identified in the 5' region flanking OsPEX5L and Northern blot analysis demonstrated that this region affected light-dependent expression of OsPEX5 transcription. Using the pex5-deficient yeast mutant Scpex5, we showed that OsPex5pL and OsPex5pS are able to restore translocation of a model PTS1 protein (GFP-SKL) into peroxisomes. OsPex5pL and OsPex5pS formed homo-complexes via specific interaction domains, and interacted with each other and OsPex14p to form hetero-complexes. Although overexpression of OsPex5pL in the Arabidopsis pex5 mutant (Atpex5) rescued the mutant phenotype, overexpression of OsPex5pS only resulted in partial recovery.

• Molecules and Cells
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• 제27권3호
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• pp.329-336
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• 2009

To evaluate the involvement of translation initiation factors eIF4E and eIFiso4E in Chilli veinal mottle virus (ChiVMV) infection in pepper, we conducted a genetic analysis using a segregating population derived from a cross between Capsicum annuum 'Dempsey' containing an elF4E mutation ($pvr1^2$) and C. annuum 'Perennial' containing an elFiso4E mutation (pvr6). C. annuum 'Dempsey' was susceptible and C. annuum 'Perennial' was resistant to ChiVMV. All $F_1$ plants showed resistance, and $F_2$ individuals segregated in a resistant-susceptible ratio of 166:21, indicating that many resistance loci were involved. Seventy-five $F_2$ and 329 $F_3$ plants of 17 families were genotyped with $pvr1^2$ and pvr6 allele-specific markers, and the genotype data were compared with observed resistance to viral infection. All plants containing homozygous genotypes of both $pvr1^2$ and pvr6 were resistant to ChiVMV, demonstrating that simultaneous mutations in elF4E and eIFiso4E confer resistance to ChiVMV in pepper. Genotype analysis of $F_2$ plants revealed that all plants containing homozygous genotypes of both $pvr1^2$ and pvr6 showed resistance to ChiVMV. In protein-protein interaction experiments, ChiVMV viral genome-linked protein (VPg) interacted with both eIF4E and eIFiso4E. Silencing of elF4E and eIFiso4E in the VIGS experiment showed reduction in ChiVMV accumulation. These results demonstrated that ChiVMV can use both eIF4E and eIFiso4E for replication, making simultaneous mutations in eIF4E and eIFiso4E necessary to prevent ChiVMV infection in pepper.

• 한국환경농학회지
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• 제21권2호
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• pp.156-161
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• 2002

냉해나 한발등의 환경스트레스에 대해 저항성을 유발하는 유전자를 환경스트레스에 강한 잡초성벼로부터 선발하고 이들 유전자를 재배벼에 도입하여 도입유전자 산물의 과량 발현을 통해 냉해나 한발 등에 대한 저항성이 향상된 벼를 선발하고자 하였다. 잡초성벼인 Bhutan 14Ad로부터 냉해 및 한발 저항성 유전자로 알려진 superoxide dismutase (SOD) cDNA를 분리하고자 mRNA를 분리하고 이 분리된 mRNA를 이용해 reverse transcriptase PCR방법으로 SOD cDNA를 cloning 하였다. 그 결과 2종의 SOD cDNA가 cloning되어 SOD-A, SOD-B로 명명하였다. 이들 cDNA의 염기서열을 결정한 결과 이들은 아미노산 서열 상동성이 88.4%를 나타내었으며, SOD-A는 Oryza sativa 계열의 Cu/Zn SOD유전자인 GenBank accession No. L36320와 99.3% 동일하였으며, SOD-B는 accession No. D01000과 100% 동일하였다. 이들 SOD-A와 SOD-B cDNA를 재배벼인 낙동벼에 형질전환하여 형질전환체 벼를 선발하였으며, 이들 형질전환체 벼의 냉해저항성및 한발저항성 검정을 통해 저항성이 향상된 형질전환체 벼를 선발하고 있다.

• 생명과학회지
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• 제25권7호
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• pp.839-848
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• 2015

분자 마커는 유기체에서 다른 유기체와 분자적 수준에서 식별하는 마커이다. 유전적 분석을 위한 분자 마커의 발달은 식물 유전학, 다양한 구조와 가능을 이해하는데 기여하였다. DNA 마커는 임의유전자 증폭에서 다형성을 탐지하는 기법이나 방법(예를 들면 서든 블로팅, 핵산 교잡법, PCR을 이용한 중합효소 연쇄 증폭 반응, DNA 서열화)으로 RFLP, AFLP, RAPD, SSR, SNP 등을 이용하였고 현재에도 이용하고 있다. 최근 기능성 유전자를 이용한 기능성 마커가 각광을 받고 있다. 기능성 마커는 다형성 서열에서 유래한 것으로 표현형 변이를 내포하고 있다. 이런 개념에서 출발한 기능성 마커는 모든 유전자를 타깃으로 할 수 있으나 식물에서는 P450, 튜블린 형성 유전자의 다형성(TBPs), 전이요소 마커(TEMs), 병원균 저항성 유전자 마커(RGMs), RNA를 기반으로 한 마커(RBMs) 등이 널리 이용되고 있다. 본 연구는 Poczai 등의 총설을 기반으로 구성하였다. 식물에서 이런 분자 마커의 이용은 식물의 분화, 진화, 생리적 기능성 유전자의 변화 등 생물학 전반에 관한 정보 획득에 도움을 될 것이다.

• 한국자원식물학회지
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• 제27권6호
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• pp.687-700
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• 2014

Rice blast (Magnaporthe oryza B.) is one of the most important diseases in rice that causing great yield losses every year around the world. It is important to screen valuable genetic resources for improving blast resistance. This study was conducted to identify the blast resistance in 279 Korean rice landraces using blast nursery tests and isolate inoculum screening. The results showed that 11 landrace accessions found to be resistant to rice blast in blast nursery and inoculation screening tests and the degree of lesions in most accessions showed that they were susceptible to reactions. In order to find the distribution of blast resistant genes, a molecular survey was conducted to identify the presence of major blast resistance (R) gene in 279 Korean landraces. The results revealed that their frequency distribution was Pik-m (36.2%), Piz (25.4%), Pit (13.6%), and Pik (10%). Besides, the frequency distribution of Piz-t, Pii, Pik-m/Pik-p, Pi-39(t), Pib, Pi-d(t)2, Pita/Pita-2 and Pi-ta genes were identified as less than 10%. The results did not consist with the reactions against blast diseases between genotypes and phenotypic part of the nursery tests and isolate inoculation. For concluding these results, we used genome-wide SSR markers that have closely been located with resistance genes. The PCoA analysis showed that the landrace accessions formed largely two distinct groups according to their degree of blast resistance. By comparing genetic diversities using polymorphic information contents (PIC) value among the resistant, total and susceptible landraces, we found that PIC values decreased in four SSR markers and increased in six markers in the resistant accessions, which showed contrary to total and susceptible groups. These regions might be linked to resistance alleles. In this study, we evaluated the degree of blast resistance and the information about the distribution of rice blast resistant genes in Korean rice landraces. This study might be the basis for association analysis of blast resistance in rice.

• Molecules and Cells
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• 제41권5호
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• pp.390-400
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• 2018

Studies have revealed that miR-103a-3p contributes to tumor growth in several human cancers, and high miR-103a-3p expression is associated with poor prognosis in advanced gastric cancer (GC) patients. Moreover, bioinformatics analysis has shown that miR-103a-3p is upregulated in The Cancer Genome Atlas (TCGA) stomach cancer cohort. These results suggest that miR-103a-3p may function as an oncogene in GC. The present study aimed to investigate the role of miR-103a-3p in human GC. miR-103a-3p expression levels were increased in 33 clinical GC specimens compared with adjacent nontumor stomach tissues. Gain- and loss-of-function studies were performed to identify the correlation between miR-103a-3p and tumorigenesis in human GC. Inhibiting miR-103a-3p suppressed GC cell proliferation and blocked the S-G2/M transition in MKN-45/SGC-7901 cells, whereas miR-103a-3p overexpression improved GC cell proliferation and promoted the S-G2/M transition in vitro. Bioinformatics and dual-luciferase reporter assays confirmed that ATF7 is a direct target of miR-103a-3p. Analysis of the TCGA stomach cancer cohort further revealed that miR-103a-3p expression was inversely correlated with ATF7 expression. Notably, silencing ATF7 showed similar cellular and molecular effects as miR-103a-3p overexpression, namely, increased GC cell proliferation, improved CDK2 expression and decreased P27 expression. ATF7 overexpression eliminated the effects of miR-103a-3p expression. These findings indicate that miR-103a-3p promotes the proliferation of GC cell by targeting and suppressing ATF7 in vitro.

• 한국균학회지
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• 제22권1호
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• pp.107-116
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• 1994

원형질체 융합으로 주름버섯목 느타리버섯과 민주름버섯목 잔나비걸상버섯과의 이목간 체세포잡종을 36균주 얻어 꺽쇠연결체 clamp connections있는 2균주와 꺽쇠연결체 없는 3균주의 자실체를 형성하였다. 꺽쇠연결체 없는 융합주는 한천배지나 액체배지에서는 자실체를 얻을 수 없었다. 그러나 톱밥배지에서 균사가 완전히 성장한 후 일정한 광과 온도를 유지한 결과 꺽쇠연결체가 있는 균사가 새로이 성장하였으며 거의 완전하게 다시 성장한 후 원기가 유도되고 자실체가 성숙하였다. 버섯자실체 특성은 느타리버섯과 유사하였으며, 갓 색택은 느타리와는 다소 다르게 나타났다. 3균주의 담자포자로 유전형질의 분리와 유전자재조합을 조사한 결과 꺽쇠연결체 있는 2균주는 비정상적인 분리 현상을 보였는데, 양친에 없는 ane, rib, ane rib 표지를 가진 것이 나타났다. 3종류의 random primer를 이용하여 핵산 연쇄 중합반응 polymerase chain reaction(PCR)에 의한 4개 체세포잡종의 염색체 DNA의 다형화현상을 조사한 결과 느타리친과 유사한 양상을 가졌으나 비양친의 밴드를 나타내었으며 primer #87, #125의 1.2kbp, 0.6kbp에서 각각 뚜렷하게 구분되었다. 4개 체세포잡종의 미토콘드리아 DNA의 제한효소 EcoR1과 HindIII의 절단결과 2균주는 느타리와 동일하였으며 2균주는 양친과 다른 양상을 나타내었다. 원형질체 융합주, 융합주 자실체로부터의 조직배양주, 융합주의 담자포자 발아주, 양친주를 포함하여 총16균주를 등전점 전기영동으로 동위효소 esterase를 분석한 결과 융합주 6균주중 5균주는 느타리와 유사하였으며 1균주는 양친과 전혀 다른 새로운 밴드양상으로 이들 모두 양친과 뚜렷이 구분되었다. 융합주와 자실체 조직배양주는 밴드양상이 거의 유사하였으나 $F^2$는 다소 차이가 나타났다.

• Tuberculosis and Respiratory Diseases
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• 제67권5호
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• pp.413-421
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• 2009

Background: MicroRNAs (miRNAs) play an important role in the regulation of cell proliferation, apoptosis, development and differentiation. Several studies have shown that aberrant expression of miRNAs is involved in cancer development and progression by regulating the expression of proto-oncogenes or tumor suppressor genes. In this study, we investigated miRNA expression profiles in Korean patients with non-small cell lung cancer (NSCLC). Methods: We performed miRNA microarray analysis containing 60~65 bp oligonucleotide probes representing human 318 miRNAs and validated the results of the microarray with Northern blot analysis or quantitative RT-PCR. Next, we examined the correlation between miRNA expression and the target gene transcriptional profile using a human whole-genome-expression microarray. Results: We showed that 35 miRNAs were expressed differentially in the NSCLCs and corresponding non-malignant lung tissues. We showed that 35 miRNAs were expressed differentially in the NSCLCs and corresponding nonmalignant lung tissues. Thirteen of the 35 differentially expressed miRNAs were newly identified in the present study. Of the 35 miRNAs, 2 (miR-371 and miR-210) were over-expressed in lung cancers, and 33 miRNAs, including miR-145, were under-expressed in lung cancers. miR-99b expression consistently showed a negative correlation with FGFR3 expression. Conclusion: Albeit a small number of patients were examined, these results suggest that miRNA expression profiles in Korean lung cancers may be somewhat different from the expression profiles reported on lung cancers in Western populations. The findings suggest that miR-99b might be a tumor suppressor through its up-regulation of FGFR3.