• BMB Reports
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• v.40 no.6
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• pp.952-958
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• 2007

We isolated many genes induced from pepper cDNA microarray data following their infection with the soybean pustule pathogen Xanthomonas axonopodis pv. glycines 8ra. A full-length cDNA clone of the Capsicum annuum ankyrin-repeat domain $C_3H_1$ zinc finger protein (CaKR1) was identified in a chili pepper using the expressed sequence tag (EST) database. The deduced amino acid sequence of CaKR1 showed a significant sequence similarity (46%) to the ankyrin-repeat protein in very diverse family of proteins of Arabidopsis. The gene was induced in response to various biotic and abiotic stresses in the pepper leaves, as well as by an incompatible pathogen, such as salicylic acid (SA) and ethephon. CaKR1 expression was highest in the root and flower, and its expression was induced by treatment with agents such as NaCl and methyl viologen, as well as by cold stresses. These results showed that CaKR1 fusion with soluble, modified green fluorescent protein (smGFP) was localized to the cytosol in Arabidopsis protoplasts, suggesting that CaKR1 might be involved in responses to both biotic and abiotic stresses in pepper plants.

• Journal of Plant Biotechnology
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• v.31 no.2
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• pp.109-113
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• 2004

In order to develop transgenic potato plants with enhanced tolerance to multiple stress, we constructed the transformation vector expressing both superoxide dismutase and ascorbate peroxidase genes in chloroplasts under the control of a stress-inducible SWPA2 promoter. Transgenic potato plants (cv. Superior and Atlantic) were generated using an Agrobacterium-mediated transformation system. Transgenic potato plants were regenerated on MS medium containing 100mg/L kanamycin. Genomic Southern blot analysis confirmed the incorporation of foreign genes into the potato genome. When potato leaf discs were subjected to methyl viologen (MV) at 10 $\mu$M, transgenic plants showed higher tolerance than non-transgenic or vector-transformed plants. To further study we selected the transgenic plant lines with enhanced tolerance against MV. These plants will be used for further analysis of stress-tolerance to multiple environmental stresses.

• Molecules and Cells
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• v.25 no.3
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• pp.368-375
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• 2008

Approximately 120 UDP-glycosyltransferases (UGTs), which are classified into 14 distinct groups (A to N), have been annotated in the Arabidopsis genome. UGTs catalyze the transfer of sugars to various acceptor molecules including flavonoids. Previously, UGT71C1 was shown to glycosylate the 3-OH of hydroxycinnamates and flavonoids in vitro. Such secondary metabolites are known to play important roles in plant growth and development. To help define the role of UGT71C1 in planta, we investigated its expression patterns, and isolated and characterized a loss-of-function mutation in the UGT71C1 gene (named ugt71c1-1). Our analyses by quantitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR), microarray data mining, and histochemical detection of GUS activity driven by the UGT71C1 promoter region, revealed the tissue-specific expression patterns of UGT71C1 with highest expression in roots. Interestingly, upon treatment with methyl viologen (MV, paraquat), ugt71c1-1 plants displayed enhanced resistance to oxidative stress, and ROS scavenging activity was higher than normal. Metabolite profiling revealed that the levels of two major glycosides of quercetin and kaempferol were reduced in ugt71c1-1 plants. In addition, when exposed to MV-induced oxidative stress, eight representative ROS response genes were expressed at lower levels in ugt71c1-1 plants, indicating that ugt71c1-1 probably has higher non-enzymatic antioxidant activity. Taken together, our results indicate that ugt71c1-1 has increased resistance to oxidative stress, suggesting that UGT71C1 plays a role in some glycosylation pathways affecting secondary metabolites such as flavonoids in response to oxidative stress.

• Bulletin of the Korean Chemical Society
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• v.6 no.5
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• pp.287-291
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• 1985

The addition of poly(styrenesulfonate) (PSS) to $Ru(bpy)_3^{2+}$ solutions shifted the emission peak by 3 nm to red, and increased emission intensity by 1.8 times. By contrast, poly(vinylsulfonate) (PVS) had little effect on the fluorescence spectrum. The effects of PSS on the spectral properties of $Ru(bpy)_3^{2+}$, were attributed to the presence of a hydrophobic phenyl group in PSS, which interact with $Ru(bpy)_3^{2+}$ by, at least in part, hydrophobic effect. The binding constant of $Ru(bpy)_3^{2+}$ to PSS in 0.1 M NaCl was $6{\times}10^4\;M^{-1}$, and this value was about $10^3$ times higher than those of methyl viologen ($MV^{2+}$) and $Cu^{2+}$. The Stern-Volmer constants of emission quenching of $Ru(bpy)_3^{2+}$ by $MV^{2+}$ and $Cu^{2+}$ in 0.1 M NaCl solutions were 426 and 40 $M^{-1}$, which correspond to second order rate constants($k_q$) of $1.1{\times}10^9\;and\; 1.0{\times}10^8\;M^{-1}s^{-1}$, respectively. The presence of PSS enhanced $K_{SV's}\;by\;{\sim}50$ times, whereas PVS increased the values only 1-4 times. The large enhancing effect of PSS, despite of lower charge density than PVS, was explained in terms of longer life-time of photoexcited $Ru(bpy)_3^{2+}$ bound to PSS and strong association of $Ru(bpy)_3^{2+}$ to PSS due to a specific interaction involving hydrophobic effect. The variation of $K_{SV's}$ on the concentrations of PVS and PSS were also investigated for $Ru(bpy)_3^{2+}-MV^{2+}\;and \;Ru(bpy)_3^{2+}-Cu^{2+}$ photoredox systems.

• Journal of Plant Biotechnology
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• v.36 no.1
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• pp.75-80
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• 2009

In order to develop transgenic sweetpotato plants [Ipomoea batatas (L.) Lam. cv. Yulmi] with enhanced tolerance to oxidative stress, we constructed transformation vectors expressing 2-Cys peroxiredoxin (Prx) gene under the control of the stress-inducible SWPA2 or enhanced 35S promoter (named as SP or EP). Transgenic sweetpotato plants were attempted to generate from embryogenic calli using an Agrobacterium-mediated transformation system. Embryogenic calli gave rise to somatic embryos and then converted into plantlets on MS medium containing 100 mg/L kanamycin. Transgenic plants were regenerated in the same medium. Southern blot analysis confirmed that the Prx gene was inserted into the genome of the plants. To further study we selected the transgenic plant lines with enhanced tolerance against methyl viologen (MV). When sweetpotato leaf discs were subjected to methyl MV at $20{\mu}M$, transgenic plants showed about 40% higher tolerance than non-transgenic or empty vector-transformed plants.

• FLOWER RESEARCH JOURNAL
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• v.19 no.4
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• pp.269-273
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• 2011

This study was conducted to investigate the resistance to abiotic stress in the progeny obtained by a cross between NDPK2-transgenic line (NDPK2-7-1) and MnSOD (SOD2) transgenic line (SOD2-2-1-1-35) to develop transgenic petunia highly resistant to environmental stress. At the treatment of 100 and $200{\mu}M$ methyl viologene (MV), the progeny was significantly less damaged than its parental plants (SOD2- or NDPK2-transgenic lines) as well as non-transgenic plants, implying its resistance to oxidative stress enhanced than SOD2- or NDPK2-transgenic plants. In an expression of 11 quantitative traits, the progeny remained similar to control plants, although it infrequently displayed slightly longer or wider than non-transgenic control plants. In the color and shape of flowers, there was no significant difference between the progeny and its parents or non-transgenic control.

• Rapid Communication in Photoscience
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• v.3 no.4
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• pp.67-69
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• 2014

Bis(2-thienyl)-diketopyrrolopyrrole having two $Zn^{II}$-cylcens (DPPCy) was synthesized. DPP-aggregates were constructed by self-organization of DPPCy and $dT_n$-DNAs. In the presence of L-ascorbic acid as an electron sacrifice reagent, the DPP aggregates immobilized on a gold electrode exhibit good anodic photocurrent responses as well as cathodic photocurrent responses in the presence of methyl viologen. The anodic photocurrent responses depend on the DNA lengths because of the formation of uniform DPP-aggregates corresponding to the DNA lengths. The present results show that photocurrent responses of the DPP-aggregates can be controlled by DNA lengths and electron sacrifice reagents.

• BMB Reports
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• v.41 no.1
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• pp.86-91
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• 2008

The full-length cDNA of CaAbsi1 encodes a presumptive protein of 134 amino acid residues that has homology to a putative zinc finger protein in its C-terminus. The deduced amino acid sequence has 50% homology to Oryza sativa NP001049-274, the function of which is unknown. Expression of CaAbsi1 was reduced in response to inoculation of non-host pathogens. On the other hand it was induced one hour after exposure to high concentrations of NaCl or mannitol, and six hours after transfer to low temperature. Induction also occurred in response to oxidative stress, methyl viologen, hydrogen peroxide and abscisic acid. Our results suggest that CaAbsi1 plays a role in multiple responses to wounding and abiotic stresses.

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1244-1246
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• 1997

In conducting systems based on Langmuir - Blodgett (LB) films, tetracyanoquinodimethane(TCNQ) derivatives have been extensively studied as electron acceptor molecules. We have fabricated N-docosyl N'-methyl viologen diTCNQ (DMVT) anion radical LB film and investigated the FT-IR, ESR, and AFM images as the optical, magnetic properties and morphology of the LB film. We have measured in-plane electrical conductivity with number of layers. The in-plane conductivities are approximately $10^{-7}{\sim}10^{-6}\;S/cm$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.11a
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• pp.5-8
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• 1997

A study on the electrical conduction characteristics of the ultrathin organic films is one of the important factors for the development of molecular electronic devices. The Langmuir- Blodgett(LB) technique has recently been attracted interest as a method of the deposition ultrathin films. We hate fabricated N-docosyl N\`-methyl viologen-diTCNQ(DMVT) anion radical LB film and investigated the molecular orientation and electrical conduction characteristics. We have measured infrared transmission-reflection spectra. The alkyl chain is found to he well-ordered with the tilt angle of 13$^{\circ}$ with respect to the substrate surface normal and the TCNQ plane is tilted at 76$^{\circ}$ the surface normal. In ESR spectrum, we confirmed that a half-amplitude linewidth is clearly dependent on the incident angle, which indicates conducting species change. The in-plane conductivity of 31 lagers is approximately 1.33$\times$10$^{-6}$ S/cm. The ohmic behaviour was observed below 0.6 V, when current-voltage(I-V) characteristics was measured verically.