• Journal of Plant Biotechnology
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• v.31 no.1
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• pp.83-88
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• 2004

Expression of an anionic peroxidase swpa2 gene isolated from cultured cells of sweetpotato (Ipomoea batatas) was investigated under various stress conditions by RT-PCR. The swpa2 gene was not expressed in any tissues of intact sweetpotato plant grown at the normal condition. The expression of this gene was strongly induced in leaf tissue by treatment of $H_2O$$_2$ (440mM). Treatment of NaCl (100mM), ABA (0.1mM) and methyl jasmonate(MeJA, 0.1mM) also induced the expression of swpa2 gene. Interestingly, salicylic acid (SA, 0.1 mM) did not induce the expression of swpa2 gene, indicating that anionic swpa2 POD is differently involved in SA and MeJA signaling pathways. In addition, swpa2 gene was strongly induced in sweetpoato leaf tissues infected with Pectobacterium chrysanthemi, indicating that swpa2 is involved in defense related to the pathogenesis of P. chrysanthemi in sweetpotato plants. These results strongly suggest that swpa2 gene is involved in overcoming oxidative stresses caused by both abiotic and biotic stress.

• BMB Reports
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• v.37 no.3
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• pp.343-350
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• 2004

A cDNA clone for a salicylic acid-induced gene in Chinese cabbage (Brassica rapa subsp. pekinensis) was isolated and characterized. The cabbage gene encoding a protein of 392 amino acids contained a tandem array of two thiJ-like sequences. ThiJ is a thiamin biosynthesis enzyme that catalyzes the phosphorylation of hydroxymethylpyrimidine (HMP) to HMP monophosphate. Although the cabbage gene shows a similarity to bacterial thiJ genes, it also shares a similarity with the human DJ-1, a multifunctional protein that is involved in transcription regulation, male fertility, and parkinsonism. The cabbage thiJ-like gene is strongly induced by salicylic acid and a nonhost pathogen, Pseudomonas syringae pv. tomato, which elicits a hypersensitive response in Chinese cabbage. Treatment of the cabbage leaves with BTH, methyl jasmonate, or ethephon showed that the cabbage thiJ-like gene expression is also strongly induced by BTH, but not by methyl jasmonate or ethylene. This indicates that the cabbage gene is activated via a salicylic acid-dependent signaling pathway. Examination of the tissue-specific expression revealed that the induction of the cabbage gene expression by BTH occurs in the leaf, stem, and floral tissues but not in the root.

• The Plant Pathology Journal
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• v.30 no.2
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• pp.208-214
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• 2014

Wild rice, Oryza grandiglumis shows hyper-resistance response to pathogen infection. In order to identify genes necessary for defense response in plants, we have carried out a subtractive hybridization coupled with a cDNA macroarray. An acidic PATHOGENESIS-RELATED1 (PR1) gene of the wild rice is highly identical to the acidic PR1 genes of different plant species. The OgPR1a cDNA has an apparent single open reading frame with a predicted molecular mass 40,621 Da and an isoelectic point of 5.14. Both in silico analysis and a transient expression assay in onion epidermal cells revealed that the OgPR1a protein could be localized in intercellular space in plants. The OgPR1a mRNA was strongly transcribed by the exogenous treatment with ethylene and jasmonic acid as well as protein phosphatase inhibitors. Additionally, ectopic expression of the OgPR1a conferred disease resistance on Arabidopsis to the bacterial and fungal infections.

• Molecules and Cells
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• v.26 no.3
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• pp.270-277
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• 2008

This study addresses the physiological functions of the Ran-binding protein homolog NbRanBP1 in Nicotiana benthamiana. Virus-induced gene silencing (VIGS) of NbRanBP1 caused stunted growth, leaf yellowing, and abnormal leaf morphology. The NbRanBP1 gene was constitutively expressed in diverse tissues and an NbRanBP1:GFP fusion protein was primarily localized to the nuclear rim and the cytosol. BiFC analysis revealed in vivo interaction between NbRanBP1 and NbRan1 in the nuclear envelope and the cytosol. Depletion of NbRanBP1 or NbRan1 reduced nuclear accumulation of a NbBTF3:GFP marker protein. In the later stages of development, NbRanBP1 VIGS plants showed stress responses such as reduced mitochondrial membrane potential, excessive production of reactive oxygen species, and induction of defense-related genes. The molecular role of RanBP1 in plants is discussed in comparison with RanBP1 function in yeast and mammals.

• Journal of Microbiology
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• v.41 no.4
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• pp.295-299
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• 2003

Adenovirus (Ad) precursor to the terminal protein (pTP) plays an essential roles in the viral DNA replication. Ad pTP serves as a primer for the synthesis of a new DNA strand during the initiation step of replication. In addition, Ad pTP forms organized spherical replication foci on the nuclear matrix (NM) and anchors the viral genome to the NM. Here we identified the interferon inducible gene product 1-8D (Inid) as a pTP binding protein by using a two-hybrid screen of a HeLa cDNA library. Of the clones obtained in this assay, nine were identical to the Inid, a 13-kDa polypeptide that shares homology with genes 1-8U and Leu-13/9-27, most of which have little known functions. The entire open reading frame (ORF) of Inid was cloned into the tetracycline inducible expression vector in order to determine the biological functions related with adenoviral infection. When Inid was introduced to the cells along with adenoviruses, fifty to sixty percent of Ad-infected cells expressing Inid had rounded morphology, which was suggestive of apoptosis. Results from the terminal deoxynucleotidyl transferase (TdT) and DNA fragmentation assays confirmed that Inid induces apoptosis in Ad-infected or in uninfected cells. The Inid binding to pTP may target the cell for apoptotic destruction as a host defense mechanism against the viral infection.

• The Plant Pathology Journal
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• v.35 no.3
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• pp.257-273
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• 2019

Tomato (Solanum lycopersicum) is one of the most widely grown and economically important vegetable crops in the world. Tomato chlorosis virus (ToCV) is one of the recently emerged viruses of tomato distributed worldwide. ToCV-tomato interaction was investigated at the molecular level for determining changes in the expression of tomato genes in response to ToCV infection in this study. A cDNA library enriched with genes induced in response to ToCV infection were constructed and 240 cDNAs were sequenced from this library. The macroarray analysis of 108 cDNAs revealed that the expression of 92 non-redundant tomato genes was induced by 1.5-fold or greater in response to ToCV infection. The majority of ToCV-induced genes identified in this study were associated with a variety of cellular functions including transcription, defense and defense signaling, metabolism, energy, transport facilitation, protein synthesis and fate and cellular biogenesis. Twenty ToCV-induced genes from different functional groups were selected and induction of 19 of these genes in response to ToCV infection was validated by RT-qPCR assay. Finally, the expression of 6 selected genes was analyzed in different stages of ToCV infection from 0 to 45 dpi. While the expression of three of these genes was only induced by ToCV infection, others were induced both by ToCV infection and wounding. The result showed that ToCV induced the basic defense response and activated the defense signaling in tomato plants at different stages of the infection. Functions of these defense related genes and their potential roles in disease development and resistance to ToCV are also discussed.

• Journal of Plant Biotechnology
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• v.33 no.2
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• pp.93-97
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• 2006

The calmodulin as a Ca$^{2+}$-binding protein mediates cellular Ca$^{2+}$ signals in response to a wide array of stimuli in higher eukaryotes. Plants produce numerous calmodulin isoforms that exhibit differential gene expression patterns and sense different Ca$^{2+}$ signals. SCaM-5 is a soybean calmodulin that is involved in plant defense signaling. Here, we constructed a SCaM-5 CDNA under control of CaMV 35S promoter and transformed it into tomato (Lycopersicon esculentum). The constitutive over-expression of SCaM-5 in tomato plants exhibited a high levels of pathogenesis-related (PR) gene expression, and conferred an enhanced resistance to two fungal pathogen (Phytophthora capsici, Fusarium oxysporum), and a bacterial pathogen, Pseudomonas syringae pv. tomato DC3000. Thus, this results collectively suggest that SCaM-5 plays an important role in plant defense of tomato.

• Applied Biological Chemistry
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• v.42 no.1
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• pp.34-38
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• 1999

We observed the structure of phenylalanine ammonia-lyase gene (PAL) which is one of the best studied plant defense-related genes responding to pathogen infection by producing suberin, lignin, and phytoalexins. In tomato, at least 5 different genetic loci have been identified by genomic southern blot hybridization and nucleotide sequence analyses of partially cloned gene fragments (Lee et al. 1992). However, our results suggest that two other isoforms designated as PAL X1 and PAL X2 are located on the chromosome in tomato plant. Furthermore, the preliminary results obtained from southern blot hybridization analyses of subcloned fragment digested with several restriction endonuclease indicated that PAL X1 and PAL X2 clones contain at least two copies of PAL gene and partial nucleotide sequence analyses of each subcloned fragment with the same primer taken from known nucleotide sequence of PAL5 gene indicated that they are located side by side on the same chromosome.

• Molecular & Cellular Toxicology
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• v.4 no.2
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• pp.113-123
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• 2008

Microglia, which is the primary immune effector cells in the central nervous system, constitutes the first line of defense against infection and injury in the brain. The goal of this study was to determine the protective (anti-inflammation) mechanisms of forsythia suspense (FS) on LPS-induced activation of BV-2 microglial cells. The effects of FS on gene expression profiles in activated BV-2 microglial cells were evaluated using microarray analysis. BV-2 microglial cells were cultured in a 100mm dish $(1{\times}10^7/dish)$ for 24hr and then pretreated with $1{\mu}g/mL$ FS or left untreated for 30 min. Next, $1{\mu}g/mL$ LPS was added to the samples and the cells were reincubated at $37^{\circ}C$ for 30 min, 1hr, and 3hr. The gene expression profiles of the BV-2 microglial cells varied depending on the FS. The oligonucleotide microarray analysis revealed that MAPK pathway-related genes such as Mitogen activated protein kinase 1 (Mapk1), RAS protein activator like 2 (Rasal2), and G-protein coupled receptor 12 (Gpr12) and nitric oxide biosynthesis-related genes such as nitric oxide synthase 1 (neuronal) adaptor protein (Nos1ap), and dimethylarginine dimethylaminohydrolase 1 (Ddah1) were down regulated in FS-treated BV-2 microglial cells. FS can affect the MAPK pathway and nitric oxide biosynthesis in BV-2 microglial cells.

• Molecules and Cells
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• v.28 no.4
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• pp.321-329
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• 2009

Rapid production of nitric oxide (NO) and reactive oxygen species (ROS) has been implicated in the regulation of innate immunity in plants. A potato calcium-dependent protein kinase (StCDPK5) activates an NADPH oxidase StRBOHA to D by direct phosphorylation of N-terminal regions, and heterologous expression of StCDPK5 and StRBOHs in Nicotiana benthamiana results in oxidative burst. The transgenic potato plants that carry a constitutively active StCDPK5 driven by a pathogen-inducible promoter of the potato showed high resistance to late blight pathogen Phytophthora infestans accompanied by HR-like cell death and $H_2O_2$ accumulation in the attacked cells. In contrast, these plants showed high susceptibility to early blight necrotrophic pathogen Alternaria solani, suggesting that oxidative burst confers high resistance to biotrophic pathogen, but high susceptibility to necrotrophic pathogen. NO and ROS synergistically function in defense responses. Two MAPK cascades, MEK2-SIPK and cytokinesis-related MEK1-NTF6, are involved in the induction of NbRBOHB gene in N. benthamiana. On the other hand, NO burst is regulated by the MEK2-SIPK cascade. Conditional activation of SIPK in potato plants induces oxidative and NO bursts, and confers resistance to both biotrophic and necrotrophic pathogens, indicating the plants may have obtained during evolution the signaling pathway which regulates both NO and ROS production to adapt to wide-spectrum pathogens.