• 한국균학회소식:학술대회논문집
• /
• 2014.10a
• /
• pp.9-9
• /
• 2014

Null mutants generated by targeted gene replacement are frequently used to reveal function of the genes in fungi. However, targeted gene deletions may be difficult to obtain or it may not be applicable, such as in the case of redundant or lethal genes. Constitutive expression system could be an alternative to avoid these difficulties and to provide new platform in fungal functional genomics research. Here we developed a novel platform for functional analysis genes in Magnaporthe oryzae by constitutive expression under a strong promoter. Employing a binary vector (pGOF1), carrying $EF1{\beta}$ promoter, we generated a total of 4,432 transformants by Agrobacterium tumefaciens-mediated transformation. We have analyzed a subset of 54 transformants that have the vector inserted in the promoter region of individual genes, at distances ranging from 44 to 1,479 bp. These transformants showed increased transcript levels of the genes that are found immediately adjacent to the vector, compared to those of wild type. Ten transformants showed higher levels of expression relative to the wild type not only in mycelial stage but also during infection-related development. Two transformants that T-DNA was inserted in the promotor regions of putative lethal genes, MoRPT4 and MoDBP5, showed decreased conidiation and pathogenicity, respectively. We also characterized two transformants that T-DNA was inserted in functionally redundant genes encoding alpha-glucosidase and alpha-mannosidase. These transformants also showed decreased mycelial growth and pathogenicity, implying successful application of this platform in functional analysis of the genes. Our data also demonstrated that comparative phenotypic analysis under over-expression and suppression of gene expression could prove a highly efficient system for functional analysis of the genes. Our over-expressed transformants library would be a valuable resource for functional characterization of the redundant or lethal genes in M. oryzae and this system may be applicable in other fungi.

• Journal of Intelligence and Information Systems
• /
• v.18 no.1
• /
• pp.125-141
• /
• 2012

These days, the malicious attacks and hacks on the networked systems are dramatically increasing, and the patterns of them are changing rapidly. Consequently, it becomes more important to appropriately handle these malicious attacks and hacks, and there exist sufficient interests and demand in effective network security systems just like intrusion detection systems. Intrusion detection systems are the network security systems for detecting, identifying and responding to unauthorized or abnormal activities appropriately. Conventional intrusion detection systems have generally been designed using the experts' implicit knowledge on the network intrusions or the hackers' abnormal behaviors. However, they cannot handle new or unknown patterns of the network attacks, although they perform very well under the normal situation. As a result, recent studies on intrusion detection systems use artificial intelligence techniques, which can proactively respond to the unknown threats. For a long time, researchers have adopted and tested various kinds of artificial intelligence techniques such as artificial neural networks, decision trees, and support vector machines to detect intrusions on the network. However, most of them have just applied these techniques singularly, even though combining the techniques may lead to better detection. With this reason, we propose a new integrated model for intrusion detection. Our model is designed to combine prediction results of four different binary classification models-logistic regression (LOGIT), decision trees (DT), artificial neural networks (ANN), and support vector machines (SVM), which may be complementary to each other. As a tool for finding optimal combining weights, genetic algorithms (GA) are used. Our proposed model is designed to be built in two steps. At the first step, the optimal integration model whose prediction error (i.e. erroneous classification rate) is the least is generated. After that, in the second step, it explores the optimal classification threshold for determining intrusions, which minimizes the total misclassification cost. To calculate the total misclassification cost of intrusion detection system, we need to understand its asymmetric error cost scheme. Generally, there are two common forms of errors in intrusion detection. The first error type is the False-Positive Error (FPE). In the case of FPE, the wrong judgment on it may result in the unnecessary fixation. The second error type is the False-Negative Error (FNE) that mainly misjudges the malware of the program as normal. Compared to FPE, FNE is more fatal. Thus, total misclassification cost is more affected by FNE rather than FPE. To validate the practical applicability of our model, we applied it to the real-world dataset for network intrusion detection. The experimental dataset was collected from the IDS sensor of an official institution in Korea from January to June 2010. We collected 15,000 log data in total, and selected 10,000 samples from them by using random sampling method. Also, we compared the results from our model with the results from single techniques to confirm the superiority of the proposed model. LOGIT and DT was experimented using PASW Statistics v18.0, and ANN was experimented using Neuroshell R4.0. For SVM, LIBSVM v2.90-a freeware for training SVM classifier-was used. Empirical results showed that our proposed model based on GA outperformed all the other comparative models in detecting network intrusions from the accuracy perspective. They also showed that the proposed model outperformed all the other comparative models in the total misclassification cost perspective. Consequently, it is expected that our study may contribute to build cost-effective intelligent intrusion detection systems.

• The Journal of Natural Sciences
• /
• v.4
• /
• pp.103-142
• /
• 1991

These studies were carried out to select somatic hybrid using selectable marker genes of Nicotiana glauca transformed by NPTII gene and Solanum tuberosum transformed by T- DNA, and to study characteristics of transformant. The results are summarized as follows. 1. Crown gall tumors and hairy roots were formed on potato tuber disc infected by A. tumefaciens Ach5 and A. rhizogenes ATCC15834. These tumors and roots could be grown on the phytohormone free media. 2. Callus formation from hairy root was prompted on the medium containing 2, 4 D 2mg/I with casein hydrolysate lg/l. 3. The survival ratio of crown gall tumor callus derived from potato increased on the medium containing the activated charcoal 0. 5-2. 0mg/I because of the preventions on the other hand, hairy roots were necrosis on the same medium. 4. Callus derived from hairy root were excellently grown for a short time by suspension culture on liquid medium containing 2, 4-D 2mg/I and casein hydrolysate lg/l. 5. The binary vector pGA643 was mobilized from E. coli MC1000 into wild type Agrobacteriurn tumefaciens Ach5, A. tumefaciens $A_4T$ and disarmed A. tuniefaciens LBA4404 using a triparental mating method with E. ccli HB1O1/pRK2013. Transconjugants were obtained on the minimal media containing tetracycline and kanamycin. pGA643 vectors were confirmed by electrophoresis on 0.7% agarose gel. 6. Kanamycin resistant calli were selected on the media supplemented with 2, 4-D 0.5mg/1 and kanamycin $100\mug$/ml after co- cultivating with tobacco stem explants and A. tumefaciens LBA4404/pGA643, and selected calli propagated on the same medium. 7. The multiple shoots were regenerated from kanamycin resistant calli on the MS medium containing BA 2mg/l. 8. Leaf segments of transformed shoot were able to grow vigorusly on the medium supplemented with high concentration of kanamycin $1000\mug$/ml. 9. Kanamycin resistant shoots were rooting and elongated on medium containing kanamycin $100\mug$/ml, but normal shoot were not. 10. For the production of protoplast from potato calli transformed by T-DNA and mesophyll tissue transformed by NPTII gene, the former was isolated in the enzyme mixture of 2.0% celluase Onozuka R-10, 1.0% dricelase, 1.0% macerozyme. and 0.5M mannitol, the latter was isolated in the enzyme mixture 1.0% Celluase Onozuka R-10, 0.3% macerozyme, and 0.7M mannitol. 11. The optimal concentrationn of mannitol in the enzyme mixture for high protoplast yield was 0.8M at both transformed tobacco mesophyll and potato callus. The viabilities of protoplast were shown above 90%, respectively. 12. Both tobacco mesophyll and potato callus protoplasts were fused by using PEG solution. Cell walls were regenerated on hormone free media supplemented with kanamycin after 5 days, and colonies were observed after 4 weeks culture.

• Horticultural Science & Technology
• /
• v.17 no.4
• /
• pp.473-475
• /
• 1999

This study was carried out to restore the fertility by suppression of male sterility-induced gene using an antisense construct. Tobacco (cv. Petit Havana SR1) was transformed with the binary vector containing a GBAN215-6 promoter, an antisense diphtheria toxin (DTx-A) gene (pKDA215b) and a hygromycin resistant gene. Seventy-six confirmed transgenic plants regenerated from leaf disks were designated as the $R_0$ generation and selfed to produce the $R_1$ generation. From the inheritance study, five $R_1$ lines with multiple copies of the antisense construct were selected and selfed to identify homozygosity for the antisense construct. In order to restore fertility and finally to select restore lines, five $R_2$ lines with multiple copies of the antisense construct were crossed with male sterile plants. From these crosses, three different phenotypes have been observed: completely restored, partially restored, and not restored pollens, and otherwise tobacco plants were phenotypically same as normal plants. These plants were scored for the degree of restoration and selected for further study.

• Journal of Plant Biotechnology
• /
• v.33 no.1
• /
• pp.19-25
• /
• 2006

With the use of Agrobacterium and gene-gun, cold regulated gene (BN115) has been injected in Chrysanthemum leaf disc and transgenic plants have been produced successfully on the selection media containing phytohormone. To determine the presence of the transferred cold regulated gene (BN115) in the transgenic Chrysanthemum, PCR-amplification indicated the presence of that gene. Real-Time PCR for confirmation of the putative transgenic plants was established. The copy number of cold regulated gene (BN115) is extrapolated on the basis of a standard curve. Serial dilutions of known number of gene copies were in triplicates. In this diagram, PCR cycles are plotted against the fluorescence intensity. The cycle at which the fluorescence reaches a threshold cycle is inversely proportional to the starting amount of target DNA.

• Journal of Plant Biotechnology
• /
• v.34 no.3
• /
• pp.253-261
• /
• 2007

This study was conducted to develop an antibiotics marker-free potato (Solanum tuberosum L., cv. Taedong valley) plant having resistance against two herbicides. Agrobacterium tumefaciens strain EHA105, harboring a binary vector plasmid pCAMBIA3300 containing bar gene under the control of a promoter CaMV35S and linked CP4-EPSPS genes driven by CaMV35S promoter, was used in the current study. The leaf segments of newly bred potato variety (cv. Taedong Valley) was co-cultured with Agrobacterium. Then, the regenerated individual shoots were excised and transferred to potato multiplication medium supplemented with 0.5 mg/L phosphinothricin. The shoots were rooted in MS medium without hormone and obtained putative transgenic plant E3-6. Integration of target genes into the E3-6 plant and their expression was confirmed by PCR, Southern analysis, and ELISA test. The tissue necrosis test on young leaf blade and shikimic acid accumulation test using the tissue of E3-6 plant were conducted to investigate the resistance to glufosinate-ammonium and glyphosate, respectively. The transgenic plants (E3-6) simultaneously showed a high resistance to both herbicides. The same results were surely obtained also in the whole plants foliar-treated with alone or mixture of two herbicides, glufosinate-ammonium and glyphosate.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.30 no.1
• /
• pp.46-54
• /
• 1997

Sporulation in the fission yeast Schizosaccharomyces pombe has been regarded as an important model of cellular development and differentiation. S. pombe cells proliferate by mitosis and binary fission on growth medium. Deprivation of nutrients especially nitrogen sources, causes the cessation of mitosis and initiates sexual reproduction by malting between two sexually compatible cell types. Meiosis is then followed in a diploid cell in the absence of nitrogen source. DNA fragment complemented with the mutations of sporulation gene was isolated from the S. pombe gene library constructed in the vector, pDB 248' and designated as pDB (spo 5)1. We futher analyzed six recombinant plasmids, pDB (spo 5)2, pDB(spo 5)3, pDB(spo 5)4, pDB(spo 5)5, pDB(spo 5)6, pDB(spo 5)7, and found each plasmids is able to rescue the spo 5-2, spo 5-3, spo 5-4, spo 5-5, spo 5-6, spo 5-7, mutations, respectively. Mapping of the integrated plasmid into the homologous site of the S. pombe chromosomes demonstrated that pDB (spo 5)1, and pDB (spo 5)R1 contained the spo 5 gene. Transcipts of spo 5 gene were analyzed by Northern hybridization. Two transcripts of 3.2 kb and 25 kb were detected with 5 kb Hind III fragment containing a part of the spo 5 gene as a probe. The small mRNA (2.5 kb) appeared only when a wild-type strain was cultured in the absence of nitrogen source in which condition the large mRNA (3.2 kb) was produced constitutively. Appearance of a 2.5 kb spo 5-mRNA depends upon the function of the mei1, mei2 and mei3 genes.

• Journal of Korea Multimedia Society
• /
• v.8 no.11
• /
• pp.1496-1509
• /
• 2005

In this paper, an adaptive license plate recognition system which detects and recognizes license plate at real-time by using projected plane convolution and Decision Tree Classifier is proposed. And it was tested in circumstances which presence of complex background. Generally, in expressway tollgate or gateway of parking lots, it is very difficult to detect and segment license plate because of size, entry angle and noisy problem of vehicles due to CCD camera and road environment. In the proposed algorithm, we suggested to extract license plate candidate region after going through image acquisition process with inputted real-time image, and then to compensate license size as well as gradient of vehicle with change of vehicle entry position. The proposed algorithm can exactly detect license plate using accumulated edge, projected convolution and chain code labeling method. And it also segments letter of license plate using adaptive binary method. And then, it recognizes license plate letter by applying hybrid pattern vector method. Experimental results show that the proposed algorithm can recognize the front and rear direction license plate at real-time in the presence of complex background environments. Accordingly license plate detection rate displayed $98.8\%$ and $96.5\%$ successive rate respectively. And also, from the segmented letters, it shows $97.3\%$ and $96\%$ successive recognition rate respectively.

• Korean Journal of Medicinal Crop Science
• /
• v.15 no.5
• /
• pp.339-345
• /
• 2007

Field performance and morphological characterization was conducted on seven transgenic lines of Codonopsis lanceolata expressing ${\gamma}-TMT$ gene. The shoots were obtained from leaf explants after co-cultivation with Agrobacterium tume-faciens strain LBA 4404 harboring a binary vector pYBI 121 that carried genes encoding ${\gamma}-Tocopherol$ methyltransferase gene (${\gamma}-TMT$) and a neomycin phosphotransferase II gene (npt II) for kanamycin resistance. The transgenic plants were transferred to a green house for acclimation. Integration of T-DNA into the $T_0\;and\;T_1$ generation of transgenic Codonopsis lanceolata genome was confirmed by the polymerase chain reaction and southern blot analysis. The progenies of transgenic plants showed phenotypic differences within the different lines and with relative to control plants. When grown in field, the transgenic plants in general exhibited increased fertility, significant improvement in the shoot weight, root weight, shoot height and rachis length with relation to the control plants. However, all seven independently derived transgenic lines produced normal flower with respect to its shape, size, color and seeds number at its maturity. Indicating that the addition of a selectable marker gene in the plant genome does not effect on seed germination and agronomic performance of transgenic Codonopsis lanceolata. $T_1$ progenies of these plants were obtained and evaluated together with control plant in a field experiment. Overall, the agronomic performance of $T_1$ progenies of transgenic Codonopsis lanceolata showed superior to that of the seed derived non-transgenic plant. In this study, we report on the morphological variation and agronomic performance of transgenic Codonopsis lanceolata developed by Agrobacterium transformation.

• Journal of Plant Biotechnology
• /
• v.35 no.1
• /
• pp.69-74
• /
• 2008

This study aims to establish the efficient soybean transformation system and develop soybean [Glycine max (L.) Merill] transformants using cotyledonary node explants. The cotyledonary node of soybean were co-cultivated with Agrobacterium tumefaciens strains (KYRT1, EHA105). These strains contain the binary vector pCAMBIA3301 which carries a herbicide-resistant far gene. Korean cultivars (Danbaekkong, Eunhakong) and foreign cultivars (Jack, Peking) were the most efficient in regenerating cotyledonary node. Therefore, they were chosen for the transformation. Results showed that the T-DNA transfer reached up to 60% and transformation efficiency reached up to 3% in the cotyledonary node explants from Jack cultivar, co-cultivated with EHA105 strain. Histochemical GUS evaluation showed that 12 individual lines, transformed with the 현 gene, have positive response. The transformed soybeans have been confirmed in the $T_0$ generation through phenotypic assay using herbicide $Basta^{(R)}$ and Southern blot analysis.