• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.2
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• pp.131-136
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• 2008

With the development of diverse agricultures worldwide, biofortified rice noted for its preferable marketability and palatability plays an important role in the world's agricultural economics and rice breeding programs. In this report, several $M_5$ of T-DNA inserted lines derived from the donor cultivars, 'Hwayong' and 'Dongjin', were selected for high or low protein, high lipid and low amylose content, respectively. The coefficients and ranges of variation for the chemical constituents between $M_4$ and $M_5$ T-DNA inserted lines were evaluated in comparison with those of the donor varieties. Results indicated that T-DNA insertion might be an effective way to generate useful variations for chemical composition of rice grains which could be used for the development of biofortified rice cultivars.

• Journal of Plant Biotechnology
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• v.7 no.1
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• pp.51-55
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• 2005

Many cloning vectors in which cDNAs can be inserted to the sense orientation have been developed. Uni-ZAP XR vector (Stratagene) should contain clones that are oriented to sense direction with respect to T3 RNA polymerase primer. Unexpectedly, large portions of cDNAs in Chinese cabbage cDNA library showed unusual insertions, antisense orientation and a hybrid of two different clones. Using two clones, 4H03 and 53-B10, derived from different cDNA libraries, we proposed and demonstrated the possibility of unusual-construct formation by in vitro translation and northern blot analysis. The 4H03 clone was inserted with inverse direction, and its transcript and translation product could be produced by T7 RNA polymerase, indicating that this clone is definitely inserted into inverse orientation. The 53-B10 that contains two independent genes was turned out to be a hybrid in which two genes are inserted to opposite direction each other. All unusual constructs might be due to the presence of small fragments of DNA, like adapter. However, the mechanism underlined the formation of unusual constructs is still remain to be solved.

• Plant Biotechnology Reports
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• v.4 no.3
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• pp.201-211
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• 2010

We present a highly effective T-DNA inserted gene screening method as part of a reverse genetics model system using the Chinese cabbage (Brassica rapa L. spp. pekinensis). Three-step two-dimensional (2D) matrix strategies are potentially accurate and useful for the identification of specific T-DNA inserted mutants from a large population. To construct our Chinese cabbage model, we utilized a forward genetics screening approach for the abnormal phenotypes that were obtained from transgenic plants of Brassica rapa generated with Agrobacteria tumefaciens containing the pRCV2 vector. From one transgenic plant with an abnormal phenotype, we observed that the st1 gene (which is related to senescence-associated process proteins) contained a T-DNA fragment, and that its expression level was decreased. This T-DNA insert was then used as a control to construct an effective screening pool. As a result, the optimum template concentration was found to be 0.1-1 ng in our PCR strategy. For other conditions, positive changes to the Gibbs free energy prevented the formation of oligo dimers and hairpin loop structures, and autosegment extension gave better results for long fragment amplification. Using this effective reverse genetics screening method, only 23 PCR reactions were necessary to select a target gene from a pool of 100 individual DNAs. Finally, we also confirmed that the sequence we obtained from the above method was identical to the flanking sequence isolated by rescue cloning.

• Korean Journal of Plant Tissue Culture
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• v.27 no.5
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• pp.387-393
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• 2000

The process by which Agrobacterium tumefaciens genetically transforms plants involves a complex series of reactions communicated between the pathogen and the plants. To identify plant factors involved in agrobacterium-mediated plant transformation, a large number of T-DNA inserted Arabidopsis thaliana mutant lines were investigated for susceptibility to Agrobacterium infection by using an in vitro root inoculation assay. Based on the phenotype of tumorigenesis, twelve T-DNA inserted Arabidopsis mutants(rat) that were resistant to Agrobacterium transformation were found. Three mutants, rat1, rat3, and rat4 were characterized in detail. They showed low transient GUS activity and very low stable transformation efficiency compared to the wild-type plant. The resistance phenotype of rat1 and rats resulted from decreased attachment of Agrobacterium tumefaciens to inoculated root explants. They may be deficient in plant actors that are necessary for bacterial attachment to plant cells. The disrupted genes in rat1, rat3, and rat4 mutants were coding a arabinogalactan protein, a likely cell wall protein and a cellulose synthase-like protein, respectively.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.11a
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• pp.361-366
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• 2005

Opium poppy (Papaver somniferum L.) is one of the most important medicinal plants, which is used as a sole commercial source of narcotic analgesic, morphine. The transformant of opium poppy we have established by infection of Rhizobium rhizogenes (formerly Agrobacterium rhizogenes) strain MAFF03-01724 showed aberrant morphology and altered opium alkaloid composition. The major alkaloid produced by this transformant was thebaine (16.3%, opium dry weight) instead of morphine. It is likely that this 'thebaine poppy' phenotype was caused by the integration of T-DNA(s) into the poppy genome DNA, and their inserted loci are of great interest. To gain an insight into the mechanism of nonnarcotic thebaine accumulation for the further approach toward the creation of 'codeine poppy' which produces codeine as a major alkaloid, the genetical and morphological analyses on the transformant was carried out. Here we report the results of the detailed analysis on the T-DNA inserted loci of T0 transfromant and the correlation between opium alkaloid composition and segregated T-DNA integration pattern in the self-pollinated T1 transformants.

• Journal of the Korean Society of Tobacco Science
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• v.19 no.1
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• pp.11-17
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• 1997

A flue-cured tobacco variety (Nicotiana tabacum cv. Wisconsin) was used for Plant transformation with the complementary DNA (cDNA) of potato virus Y-necrosis strain (PVY-VN) replicase gone (Nb) which was synthesized through reverse-transcription Primed with oligo(dT) and Polymerization using RNase H-digested template. The cDNA was cloned into Plant expression vector Plasmid (PMBP2), and introduced into tobacco plants by co-culturing tobacco leaf disks with Agrobacterium tumefaciens LBA4404 containing the plasmid before Plant regeneration. Eight Plants, in which the inserted cDNA fragment was detected by Polymerase chain reaction (PCR), out of 70 putative transformants inserted with sense-oriented Mb cDNA showed no symptom at 3 weeks after inoculation, while the other 62 plants, and all plants with vector gone only and antisense-oriented NIb cDNA had susceptible vein-necrosis symptoms. However, only 2 of the 8 resistant plants were highly resistant, which remained symptomless up to 10 weeks after inoculation. Among the first progenies (T1) from self-fertilized seeds of the two resistant transgenic plants, less than 10 % of 71 plants appeared highly resistant (with no symptom), 70% moderately resistant (with mild symptoms on 1 - 2 leaves), and about 20% susceptible (with susceptible symptoms on 3 or more leaves) at 3 weeks after inoculation. These results suggest that the PVY resistance was inherited in the 71 generation. Key words : potato virus Y. viral replicase gene, transgenic tobacco Plants, resistance.

• Plant Biotechnology Reports
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• v.3 no.4
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• pp.317-324
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• 2009

The insecticidal toxin gene of Bacillus thuringiensis (Bt) is one of the most commonly used in the development of genetically modified (GM) crops. In this research, we analyzed Bt rice showing lepidopteran pest-resistance. The Bt gene is a synthetic Cry1Ac composed of optimal codons for plants, and the Bt protein is targeted to the chloroplast by a transit peptide. Three Cry1Ac rice events (C103-3, C127-1, and C7-1) were analyzed for molecular characterization. C103-3 contains two copies of T-DNA where the left border (LB) region is truncated. Both C7-1 and C127-1 have a single copy of T-DNA, but a part of the vector backbone DNA is inserted into the genome of C127-1; thus, only C7-1 had intact T-DNA. Progenies of C7-1 crossed with the original cultivar, Nakdong, and double-haploid lines from anther culture of lines crossed with the elite cultivar, Dongjin, were analyzed for T-DNA flanking genomic DNA and genotyping. Results showed that an intact T-DNA region without the vector backbone was inserted into the genome and was stably inherited through generations. The C7-1 homozygous event could be used as breeding material to develop GM rice with pest resistance.

• Horticultural Science & Technology
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• v.33 no.2
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• pp.242-250
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• 2015

Insertional mutagenesis induced by T-DNA or transposon tagging offers possibilities for analysis of gene function. However, its potential remains limited unless good methods for detecting the target locus are developed. We describe a PCR technique for efficient identification of DNA sequences adjacent to the inserted T-DNA in a higher plant, Chinese cabbage (Brassica rapa ssp. pekinensis). This strategy, which we named variable argument thermal asymmetric interlaced PCR (VA-TAIL PCR), was designed by modifying a single-step annealing-extension PCR by including a touch-up PCR protocol and using long gene-specific primers. Amplification efficiency of this PCR program was significantly increased by employing an autosegment extension method and linked sequence strategy in nested long gene-specific primers. For this technique, arbitrary degenerate (AD) primers specific to B. rapa were designed by analyzing the Integr8 proteome database. These primers showed higher accuracy and utility in the identification of flanking DNA sequences from individual transgenic Chinese cabbages in a large T-DNA inserted population. The VA-TAIL PCR method described in this study allows the identification of DNA regions flanking known DNA fragments. This method has potential biotechnological applications, being highly suitable for identification of target genomic loci in insertional mutagenesis screens.

• Korean Journal of Microbiology
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• v.21 no.4
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• pp.229-237
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• 1983

Total tRNA genes from Aspergillus nidulans were cloned for the further investigation of the structure and expression of Aspergillus tRNA genes. Aspergillus DNA was isolated from spores and cloned into pBR322 plasmid DNA using BamHI and $T_4$ ligase. The recombinant hybrid DNA was transformed into E. coli HB101 and some 30,000 transformants were initially selected. Of these, about 5,300 E. coli clones containing Aspergillus DNA inserted into plasmid pBR322 at BamHl site have been isolated. The hybridization data obtained from the labeled Aspergillus $^{32}P-tRNA$ indicated that 105 colonies carried the total tRNA genes. From the data above and cohybridization experiment, tRNA genes of Aspergillus nidulans seem to be twice more clustered than those of yeast.

• Korean Journal of Plant Tissue Culture
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• v.27 no.5
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• pp.379-385
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• 2000

tRNA and 7SL RNA based antisense vehicles were prepared by inserting conserved anti-viral and anti-viroid domains. Anti-PVS coat protein leader sequence (ACPL) and antistructural antihairpin domain of PSTVd (AHII) were inserted in tRNA cassette; anti- zing finger domain of PVS, AHII and anti hop latent viroid ribozyme were inserted in 7SL RNA gene isolated from A. thaliana. These constructs were shown to be transcribed both, in in vitro and in in vivo conditions. However, it followed from our work that closely linked position of PoIII reference genes and PoIIII antisense genes within T-DNA lead to the impairment of RNA expression in transgenic plants. To assay in vivo transcription of antisense genes, hairy root potato cultures were established using h. tumefaciens A4-24 bearing both, Ri plasmid and PoIII-promoterless plant expression vectors with antisense RNA genes. Expression of antisense RNA in transgenic potato tissues was proven by specific RT-PCR reactions.