• The Plant Pathology Journal
• /
• v.22 no.4
• /
• pp.386-390
• /
• 2006

Extensive research of the Potato virus X(PVX) has been performed in in vitro transcription system using the bacteriophage T7 promoter. We constructed an efficient T-DNA based binary vector, pSNU1, and modified vectors carrying PVX replicons. The suitability of the construct to transiently express PVX RNA using Agrobacterium tumefaciens was tested by analysis of infectivity in plants. The expressed PVX RNA was infectous and systemically spread in three plant species including Nicotiana benthamiana, N. tabacum cv. Xanthi-nc, and Capsicum annuum cv. Chilsungcho. The PVX full length construct, pSPVXp31, was caused severe mosaic symptoms on N. benthamiana, severe necrotic lesions on C. annuum while milder symptoms and delayed mosaic symptoms were appeared on the systemic leaves on N. tabaccum. RT-PCR analysis confirmed the presence of PVX RNAs on both inoculated and systemic leaves in all three plant species tested. Our results indicated that PVX replicons were efficiently expressed PVX RNA in at least three tested species. Further investigation win be needed to elucidate the mechanism of PVX replication, translation, movement and assembly/disassembly processes.

• ETRI Journal
• /
• v.40 no.3
• /
• pp.396-409
• /
• 2018

Elliptic curve cryptography (ECC) can achieve relatively good security with a smaller key length, making it suitable for Internet of Things (IoT) devices. DNA-based encryption has also been proven to have good security. To develop a more secure and stable cryptography technique, we propose a new hybrid DNA-encoded ECC scheme that provides multilevel security. The DNA sequence is selected, and using a sorting algorithm, a unique set of nucleotide groups is assigned. These are directly converted to binary sequence and then encrypted using the ECC; thus giving double-fold security. Using several examples, this paper shows how this complete method can be realized on IoT devices. To verify the performance, we implement the complete system on the embedded platform of a Raspberry Pi 3 board, and utilize an active sensor data input to calculate the time and energy required for different data vector sizes. Connectivity and resilience analysis prove that DNA-mapped ECC can provide better security compared to ECC alone. The proposed method shows good potential for upcoming IoT technologies that require a smaller but effective security system.

• Journal of Plant Biotechnology
• /
• v.41 no.2
• /
• pp.81-88
• /
• 2014

Salt cress (Thellungiella halophila or Thellungiella parvula), species closely related to Arabidopsis thaliana, represents an extremophile adapted to harsh saline environments. To isolate salt-tolerance genes from this species, we constructed a cDNA library from roots and leaves of salt cress plants treated with 200 mM NaCl. This cDNA library was subsequently shuttled into the destination binary vector [driven by the cauliflower mosaic virus (CaMV) 35S promoter] designed for plant transformation and expression via recombination- assisted cloning. In total, 305,400 pools of transgenic BASTA-resistant lines were generated in Arabidopsis using either T. halophila or T. parvula cDNA libraries. These were used for functional screening of genes involved in salt tolerance. Among these pools, 168,500 pools were used for primary screening to date from which 7,157 lines showed apparent salt tolerant-phenotypes in the initial screen. A secondary screen has now identified 165 salt tolerant transgenic lines using 1,551 (10.6%) lines that emerged in the first screen. The prevalent phenotype in these lines includes accelerated seed germination often accompanied by faster root growth compared to WT Arabidopsis under salt stress condition. In addition, other lines showed non-typical development of stems and flowers compared to WT Arabidopsis. Based on the close relationship of the tolerant species to the target species we suggest this approach as an appropriate method for the large-scale identification of salt tolerance genes from salt cress.

• Plant Biotechnology Reports
• /
• v.3 no.4
• /
• pp.277-283
• /
• 2009

One of the limitations to conducting maize Agrobacterium-mediated transformation using explants of immature zygotic embryos routinely is the availability of the explants. To produce immature embryos routinely and continuously requires a well-equipped greenhouse and laborious artificial pollination. To overcome this limitation, an Agrobacterium-mediated transformation system using explants of type II embryogenic calli was developed. Once the type II embryogenic calli are produced, they can be subcultured and/or proliferated conveniently. The objectives of this study were to demonstrate a stable Agrobacterium-mediated transformation of maize using explants of type II embryonic calli and to evaluate the efficiency of the protocol in order to develop herbicide-resistant maize. The type II embryogenic calli were inoculated with Agrobacterium tumefaciens strain C58C1 carrying binary vector pTF102, and then were subsequently cultured on the following media: co-cultivation medium for 1 day, delay medium for 7 days, selection medium for $4{\times}14$ days, regeneration medium, and finally on germination medium. The T-DNA of the vector carried two cassettes (Ubi promoter-EPSPs ORF-nos and 35S promoter-bar ORF-nos). The EPSPs conferred resistance to glyphosate and bar conferred resistance to phosphinothricin. The confirmation of stable transformation and the efficiency of transformation was based on the resistance to phosphinothricin indicated by the growth of putative transgenic calli on selection medium amended with $4mg\;1^{-1}$ phosphinothricin, northern blot analysis of bar gene, and leaf painting assay for detection of bar gene-based herbicide resistance. Northern blot analysis and leaf painting assay confirmed the expression of bar transgenes in the $R_1$ generation. The average transformation efficiency was 0.60%. Based on northern blot analysis and leaf painting assay, line 31 was selected as an elite line of maize resistant to herbicide.

• Journal of Plant Biotechnology
• /
• v.35 no.4
• /
• pp.275-280
• /
• 2008

One of the limitation for Agrobacterium-mediated transformation via organogenesis from cotyledon explants routinely in cucumber is the production of chimeric plants. To overcome the limitation, Agrobacterium-mediated transformation system via somatic embryogenesis from hypocotyl explants of cucumber (c.v., Eunsung) on the selection medium with paromomycin as antibiotics was developed. The hypocotyl explants were inoculated with Agrobacterium tumefaciens strain EHA101 carrying binary vector pPTN290; then were subsequently cultured on the following media: co-cultivation medium for 2 days, selection medium for $5{\times}14$ days, and regeneration medium. The T-DNA of the vector (pPTN290) carried two cassettes, Ubi promoter-gus gene as reporter and 35S promoter-nptll gene conferring resistance to paromomycin as selectable agent. The confirmation of stable transformation and the efficiency of transformation was based on the resistance to paromomycin indicated by the growth of putative transgenic calli on selection medium amended with 100mg/L paromomycin, and GUS gene expression. Forty eight clones (5.2%) with GUS gene expressed of 56 callus clones with resistance to paromomycin were independently obtained from 928 explants inoculated. Of 48 clones, transgenic plants were only regenerated from 5 clones (0.5%) at low frequency. The histochemical GUS assay in the transgenic seeds ($T_1$) also revealed that the gus gene was successfully integrated and segregated into each genome of transgenic cucumber.

• Horticultural Science & Technology
• /
• v.29 no.6
• /
• pp.623-632
• /
• 2011

To increase the anti-carcinogens phenylethylisothiocyanate (PEITC), myrosinase (MYR), and glutathione S-transferase (GST), genes related to PEITC pathway were isolated and the gene expressions were regulated by Agrobacterium transformation. Isolated cDNAs, MYR, and GST genes were 1,647 bp and 624 bp, respectively, and the protein expression was confirmed through pET system. Thereafter, we constructed a sense-oriented over-expressing myrosinase (pBMY) and RNAi down-regulated GST (pJJGST) binary vectors for the Chinese cabbage transformation. After the transformation, thirteen over-expressing transgenic Chinese cabbage plants (IMS) with pBMY and five down-regulated ones (IGA) with pJJGST were selected by PCR analysis. Selected $T_0$ transgenic plants were generated to $T_1$ plants by self-pollination. Based on the Southern blot analysis on these $T_1$ transgenic plants, 1-4 copies of T-DNA were transferred to Chinese cabbage genome. Thereafter, RNA expression level of myrosinase gene or GST gene was analyzed through real-time RT PCR of IMS, IGA, and non-transgenic inbred lines. In case of IMS lines, myrosinase gene was increased 1.03-4.25 fold and, in IGA lines, GST gene was decreased by 26.42-42.22 fold compared to non-transgenic ones, respectively. Analysis of PEITC concentrations using GC-MS it showed that some IMS lines and some IGA lines increased concentrations of PEITC up to 4.86 fold and up to 3.89 fold respectively compared to wild type. Finally in this study IMS 1, 3, 5, 12, and 15 and IGA 1, 2, and 4 were selected as developed transgenic lines with increasing quantities of anti-carcinogen PEITC.