• 대한의생명과학회지
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• 제18권3호
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• pp.201-209
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• 2012

Apoptosis is a physiological programmed cell death process. Tubercle bacilli inhibit apoptosis of alveolar macrophages and phagolysosome fusion. We investigated whether the Bcl-2 family anti-apoptotic member, Bfl-1/A1, plays an important role in the anti-apoptotic process during mycobacterial infection. PMA-treated human monocytoid THP-1 cells were infected with mycobacteria (H37Rv, BCG, and K-strain) at a multiplicity of infection (MOI) of 10 for 0, 1.5, 3, 6, 9, 12, 18, 24, 48, or 72 h. In addition, PMA-treated THP-1 cells were pretreated with specific inhibitors for 45 min before stimulation with mycobacteria at an MOI of 10 for 4 h. After the indicated time, the cells were subject to reverse transcription-polymerase chain reaction (RT-PCR) analysis, and a Bfl-1/A1-specific Western blot was performed. In PMA-differentiated THP-1 cells, the expression level of Bfl-1/A1 mRNA was increased by Mycobacterium tuberculosis (MTB) H37Rv infection. The mRNA level of Bfl-1/A1 peaked 3 h after MTB infection, then declined gradually until 9 h. However, Bfl-1/A1 mRNA induction gradually re-increased from 24 h to 72 h after MTB infection. No difference in Bfl-1/A1 expression was detected following infection with MTB H37Rv, K-strain, or M. bovis BCG. These results were not dependent on mycobacterial virulence. Moreover, mRNA levels of other anti-apoptotic molecules (Mcl-1, Bcl-2, and Bcl-xL) were not increased after MTB H37Rv or K-strain infection. These results suggest that mycobacteria induce the innate immune host defense mechanisms that utilize Bfl-1/A1 molecules at early time points, regardless of virulence.

• 한국환경농학회지
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• 제30권4호
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• pp.402-408
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• 2011

BACKGROUND: Effect of various light wavelength and plant defense molecules were evaluated on the hardness and the contents of free amino acid including ${\gamma}$-aminobutyric acid (GABA) in soybean sprouts. METHODS AND RESULTS: Germinating soybean seeds were treated with various single wavelength of light (380, 440, 470, and 660 nm) or without light at $25^{\circ}C$ for six days. Soybean seeds were also treated with stress-signaling molecule ethephon or $H_2O_2$ at the same time. Soybean sprouts treated with 470 nm substantially raised the hardness almost two times than the control. The free amino acid contents were higher in 470 nm and $H_2O_2$ treated soybean seeds than the control. Nutritionally beneficial GABA contents were increased by the treatments of 470 nm, 440 nm, ethephon, and $H_2O_2$. CONCLUSION: These results suggest that the hardness and the contents of amino acids can be regulated by stimuli, which stimuli could be composed of various wavelength and plant defense molecules. Especially, single wavelength 470 nm illumination has the effect of increasing GABA contents with increased hardness.

• Molecules and Cells
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• 제28권4호
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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.

• 한국식물학회:학술대회논문집
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• 한국식물학회 1998년도 The 12th Symposium on Plant Biotechnology Vol.12
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• pp.10-18
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• 1998

For improvement of plants in disease resistance, it is most important to elucidate the mechanism to perceive and respond to the signal molecules of invaders. A model system with pea and its pathogen, Mycosphaerella pinodes, showed that the fungal elicitor induced defense responses in all plant species tested but that the suppressor of the fungus blocked or delayed the expression of defense responses and induced accessibility only in the host plant. In the world, many researchers believe that the pathogens` signals are recognized only on the receptors in the plasma membranes. Though we found that the ATPase and polyphosphoinositide metabolism in isolated plasma membranes responded to these fungal signals, we failed to detect specific actions of the suppressor in vitro on these plasma membrane functions. Recently, we found that ATPase (NTPases) and superoxide generating system in isolated cell wall were regulated by these fungal signals even in vitro, especially, by the suppressor in a strictly species-specific manner and also that the cell wall alone prepared an original defense system. The effects of both fungal signals on the isolated cell wall functions in vitro coincide perfectly with those on defense responses in vivo. In this treatise, we discuss the key role of the cell wall, which is plant-specific and the most exterior organelle, in determining host-parasite specificity and molecular target for improvement of plants.

• Molecular & Cellular Toxicology
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• 제4권3호
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• pp.199-204
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• 2008

The bio-molecules involved in defense mechanisms can be used as efficient biomarkers for physiological changes in organisms caused by both of internal and external stress. Thus, the expression level of genes which encoding such molecules serve as critical 'early warning system' for environmental assessment as well as health diagnosis of biological organisms. In this study, Cytochrome P450, Heat shock protein 90, Ubiquitin and ${\beta}$-actin gene were isolated for the first time from a red alga Gracilaria textorii. The quantitative differential gene expression analyses of three genes, GteCYP1A, GteHsp90 and Gte-UB, were carried out in G. textorii sporophytes collected from two different localities, polluted Sujeong (Masan, Korea) and potentially unpolluted Danggeum (Daemaemuldo Is., Korea). The transcripts of all three tested genes were highly expressed in the Sujeong population. The results suggest: 1) the Sujeong site was more polluted than the Danggeum site; 2) G. textorii could be applicable to marine environment monitoring in coastal regions.

• Molecules and Cells
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• 제23권2호
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• pp.207-214
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• 2007

lant ${\beta}$-1, 3-glucanases are involved in plant defense and in development. Very little data are available on the expression of rice glucanases both in developmental tissues and under various stresses. In this study, we cloned and characterized twenty-seven rice ${\beta}$-1, 3-glucanases (OsGlu) from at total of 71 putative glucanases. The OsGlu genes were obtained by PCR from a cDNA library and were classified into seven groups (Group I to VII) according to their DNA or amino acid sequence homology. Analysis of the expression of the twenty-seven OsGlu genes by Northern blotting revealed that they were differentially expressed in different developmental tissues as well as in response to plant hormones, biotic stress, high salt etc. OsGlu11 and 27 in Group IV were clearly expressed only in stem and leaf and were also induced strongly by SA (5 mM), ABA ($200{\mu}M$), and M. grisea. OsGlu1, 10, 11, and 14 were induced earlier and to higher levels in incompatible M. grisea interaction than in compatible one. Taken together, our findings suggest that the twenty-seven rice OsGlu gene products play diverse roles not only in plant defense but also in hormonal responses and in development.

• Molecules and Cells
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• 제22권1호
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• pp.58-64
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• 2006

WRKY family proteins are a class of plant-specific transcription factors involved in stress response signaling pathways. In this study a gene encoding a putative WRKY protein was isolated from a pepper EST database (http://genepool.kribb.re.kr). The cDNA, named Capsicum annuum WRKY2 (CaWRKY2), encodes a putative polypeptide of 548 amino acids, containing two WRKY domains with zinc finger motifs and two potential nuclear localization signals. Northern blot analyses showed that CaWRKY2 mRNA was preferentially induced during incompatible interactions of pepper plants with PMMoV, Pseudomonas syringae pv. syringae 61, and Xanthomonas axonopodis pv. vesicatoria race 3. Furthermore, CaWRKY2 transcripts were strongly induced by wounding and ethephon treatment, whereas only moderate expression was detected following treatment with salicylic acid and jasmonic acid. CaWRKY2 was translocated to the nucleus when a CaWRKY2-smGFP fusion construct was expressed in onion epidermal cells. CaWRKY2 also had transcriptional activation activity in yeast. Taken together our data suggest that CaWRKY2 is a pathogen-inducible transcription factor that may have a role in early defense responses to biotic and abiotic stresses.

• 한국염색가공학회지
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• 제31권1호
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• pp.33-41
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• 2019

In this report, nano-sized catalysts were introduced onto fabric surface to eliminate toxic chemicals assisted by physical adsorption. For chemical removal of toxic compounds, a series of zirconium-containing catalysts were synthesized and treated on fabric to catalyze the hydrolysis and oxidation of target molecules. Antimicrobial was also introduced for the research purpose to prove the compatibility of as-synthesized catalysts with other solutions. Zirconium ligated with hydroxyl group and MOF(Metal-Organic Frameworks) were exploited as catalyst for removal of toxic compounds, while zinc complex was used for an antimicrobial to culminate in a chemical shield. Once fabrics were functionalized, fabrics were washed 2 or 5 times for a washing durability test. The amount of catalyst in textile were measured by ICP-MS and weight increasing ratio of fabrics.

• 동의생리병리학회지
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• 제30권4호
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• pp.250-256
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• 2016

The prevalence of renal disease is increased with the overweight and obesity. High fat diet-associated oxidative stress increases production of reactive oxygen species (ROS) and induces apoptosis. There are two types of antioxidant defense mechanisms for oxidative stress. One is the enzyme defense mechanism by antioxidant enzymes such as superoxide dismutase (SOD), and catalase (CAT). The other is non-enzyme defense mechanism by signaling molecules such as nuclear factor-like 2 (Nrf-2), HO-1. In this study, we induced obesity in mice with high fat diet for six weeks and thereafter administered orally Viola mandshurica for 4 weeks. V. mandshurica is known to clear heat, detoxify and cool blood, and subside a swelling effect. In the V. mandshurica administered group, the immunoreactive signal of the Tunel staining was weaker than that of obesity group. Proapoptotic Bax, caspase 3 immunoreactives of the V. mandshurica administered group was lower than those of obesity group, whereas anti-apoptotic Bcl-2 immunoreactity was higher in the V. mandshurica administered group. Antioxidant enzyme mechanism such as superoxide dismutase 2 (SOD2), catalase (CAT) immunoreactives of the V. mandshurica administered group and Antioxidant non-enzyme mechanism such as Nuclear factor-like 2 (Nrf2), Heme Oxygenase 1 (HO-1) immunoreactives of the V. mandshurica administered group was higher than those of obesity group. These results demonstrate that V. mandshurica had the antioxidant and anti-apoptosis effects on obese mice.

• Molecules and Cells
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• 제28권2호
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• pp.105-109
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• 2009

We reported previously that overexpression of a salicylic acid (SA) methyltransferase1 gene from rice (OsBSMT1) or a SA glucosyltransferase1 gene from Arabidopsis thaliana (AtSAGT1) leads to increased susceptibility to Pseudomonas syringae due to reduced SA levels. To further examine their roles in the defense responses, we assayed the transcript levels of AtBSMT1 or AtSAGT1 in plants with altered levels of SA and/or other defense components. These data showed that AtSAGT1 expression is regulated partially by SA, or nonexpressor of pathogenesis related protein1, whereas AtBSMT1 expression was induced in SA-deficient mutant plants. In addition, we produced the transgenic Arabidopsis plants with RNAi-mediated inhibition of AtSAGT1 and isolated a null mutant of AtBSMT1, and then analyzed their phenotypes. A T-DNA insertion mutation in the AtBSMT1 resulted in reduced methyl salicylate (MeSA) levels upon P. syringae infection. However, accumulation of SA and glucosyl SA was similar in both the atbsmt1 and wild-type plants, indicating the presence of another SA methyltransferase or an alternative pathway for MeSA production. The AtSAGT1-RNAi line exhibited no altered phenotypes upon pathogen infection, compared to wild-type plants, suggesting that (an)other SA glucosyltransferase(s) in Arabidopsis plants may be important for the pathogenesis of P. syringae.