• Title/Summary/Keyword: Biology and Life Science

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A Role for Arabidopsis miR399f in Salt, Drought, and ABA Signaling

  • Baek, Dongwon;Chun, Hyun Jin;Kang, Songhwa;Shin, Gilok;Park, Su Jung;Hong, Hyewon;Kim, Chanmin;Kim, Doh Hoon;Lee, Sang Yeol;Kim, Min Chul;Yun, Dae-Jin
    • Molecules and Cells
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    • v.39 no.2
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    • pp.111-118
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    • 2016
  • MiR399f plays a crucial role in maintaining phosphate homeostasis in Arabidopsis thaliana. Under phosphate starvation conditions, AtMYB2, which plays a role in plant salt and drought stress responses, directly regulates the expression of miR399f. In this study, we found that miR399f also participates in plant responses to abscisic acid (ABA), and to abiotic stresses including salt and drought. Salt and ABA treatment induced the expression of miR399f, as confirmed by histochemical analysis of promoter-GUS fusions. Transgenic Arabidopsis plants overexpressing miR399f (miR399f-OE) exhibited enhanced tolerance to salt stress and exogenous ABA, but hypersensitivity to drought. Our in silico analysis identified ABF3 and CSP41b as putative target genes of miR399f, and expression analysis revealed that mRNA levels of ABF3 and CSP41b decreased remarkably in miR399f-OE plants under salt stress and in response to treatment with ABA. Moreover, we showed that activation of stress-responsive gene expression in response to salt stress and ABA treatment was impaired in miR399f-OE plants. Thus, these results suggested that in addition to phosphate starvation signaling, miR399f might also modulates plant responses to salt, ABA, and drought, by regulating the expression of newly discovered target genes such as ABF3 and CSP41b.

Functional Analysis of the Stress-Inducible Soybean Calmodulin Isoform-4 (GmCaM-4) Promoter in Transgenic Tobacco Plants

  • Park, Hyeong Cheol;Kim, Man Lyang;Kang, Yun Hwan;Jeong, Jae Cheol;Cheong, Mi Sun;Choi, Wonkyun;Lee, Sang Yeol;Cho, Moo Je;Kim, Min Chul;Chung, Woo Sik;Yun, Dae-Jin
    • Molecules and Cells
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    • v.27 no.4
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    • pp.475-480
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    • 2009
  • The transcription of soybean (Glycine max) calmodulin isoform-4 (GmCaM-4) is dramatically induced within 0.5 h of exposure to pathogen or NaCl. Core cis-acting elements that regulate the expression of the GmCaM-4 gene in response to pathogen and salt stress were previously identified, between -1,207 and -1,128 bp, and between -858 and -728 bp, in the GmCaM-4 promoter. Here, we characterized the properties of the DNA-binding complexes that form at the two core cis-acting elements of the GmCaM-4 promoter in pathogen-treated nuclear extracts. We generated GUS reporter constructs harboring various deletions of approximately 1.3-kb GmCaM-4 promoter, and analyzed GUS expression in tobacco plants transformed with these constructs. The GUS expression analysis suggested that the two previously identified core regions are involved in inducing GmCaM-4 expression in the heterologous system. Finally, a transient expression assay of Arabidopsis protoplasts showed that the GmCaM-4 promoter produced greater levels of GUS activity than did the CaMV35S promoter after pathogen or NaCl treatments, suggesting that the GmCaM-4 promoter may be useful in the production of conditional gene expression systems.

Efficient Production of Porcine Circovirus Type 2 Capsid Protein using Baculovirus

  • Lee, Jun-Beom;Bae, Sung-Min;Kim, Hee-Jung;Lee, Won-Woo;Heo, Won-Il;Shin, Tae-Young;Choi, Jae-Bang;Woo, Soo-Dong
    • International Journal of Industrial Entomology and Biomaterials
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    • v.24 no.1
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    • pp.23-27
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    • 2012
  • Porcine circovirus type 2 (PCV2) is a single-stranded circular DNA virus associated with Postweaning multisystemic wasting syndrome (PMWS), which is considered to be an important infectious swine viral disease. PCV2 capsid protein encoded by ORF2 is a structural protein and expected as the high immunogenicity protein. In this study, we generated recombinant baculovirus containing ORF2 of PCV2 and analyzed the optimal conditions for the production of capsid protein in insect cell. Production and status of recombinant capsid protein in insect cell were confirmed by SDS-PAGE and Western blot analysis using His tag antibody and anti-PCV2 serum. The yield of recombinant capsid protein was high like as shown visible on SDS-PAGE. Optimal multiplicity of infection (MOI) and infection time of recombinant virus were determined as 5 MOI and 4 days, respectively. ORF2 is known to have N-linked glycosylation site, but we couldn't detect the glycosylation of recombinant protein in insect cells.

Pathogen Associated Molecular Pattern (PAMP)-Triggered Immunity Is Compromised under C-Limited Growth

  • Park, Hyeong Cheol;Lee, Shinyoung;Park, Bokyung;Choi, Wonkyun;Kim, Chanmin;Lee, Sanghun;Chung, Woo Sik;Lee, Sang Yeol;Sabir, Jamal;Bressan, Ray A.;Bohnert, Hans J.;Mengiste, Tesfaye;Yun, Dae-Jin
    • Molecules and Cells
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    • v.38 no.1
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    • pp.40-50
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    • 2015
  • In the interaction between plants and pathogens, carbon (C) resources provide energy and C skeletons to maintain, among many functions, the plant immune system. However, variations in C availability on pathogen associated molecular pattern (PAMP) triggered immunity (PTI) have not been systematically examined. Here, three types of starch mutants with enhanced susceptibility to Pseudomonas syringae pv. tomato DC3000 hrcC were examined for PTI. In a dark period-dependent manner, the mutants showed compromised induction of a PTI marker, and callose accumulation in response to the bacterial PAMP flagellin, flg22. In combination with weakened PTI responses in wild type by inhibition of the TCA cycle, the experiments determined the necessity of C-derived energy in establishing PTI. Global gene expression analyses identified flg22 responsive genes displaying C supply-dependent patterns. Nutrient recycling-related genes were regulated similarly by C-limitation and flg22, indicating re-arrangements of expression programs to redirect resources that establish or strengthen PTI. Ethylene and NAC transcription factors appear to play roles in these processes. Under C-limitation, PTI appears compromised based on suppression of genes required for continued biosynthetic capacity and defenses through flg22. Our results provide a foundation for the intuitive perception of the interplay between plant nutrition status and pathogen defense.

Study on Selective Media for Isolation of Entomopathogenic Fungi

  • Shin, Tae-Young;Choi, Jae-Bang;Bae, Sung-Min;Koo, Hyun-Na;Woo, Soo-Dong
    • International Journal of Industrial Entomology and Biomaterials
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    • v.20 no.1
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    • pp.7-12
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    • 2010
  • To determine the optimal isolation conditions of the entomopathogenic fungi from soil, we compared their growth characteristics with non-entomopathogenic fungi on agar media containing various concentrations of cooper (II) chloride ($CuCl_2$) or dodine. The result showed that dodine medium is more selective, and the optimal concentration of dodine is determined with $50{\mu}g$/ml. We could isolate several putative entomopathogenic fungi from soil using this, and identify them using ITS analysis. As a result, 64% fungi were identified as typical entomopathogenic fungi. This selective medium may be useful to the rapid and simple isolation of entomopathogenic fungi from soil.

Triptolide Inhibits Histone Methyltransferase EZH2 and Modulates the Expression of Its Target Genes in Prostate Cancer Cells

  • Tamgue, Ousman;Chai, Cheng-Sen;Hao, Lin;Zambe, John-Clotaire Daguia;Huang, Wei-Wei;Zhang, Bin;Lei, Ming;Wei, Yan-Ming
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.10
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    • pp.5663-5669
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    • 2013
  • The histone methyltransferase EZH2 (enhancer of zeste homolog 2) plays critical roles in prostate cancer (PCa) development and is a potential target for PCa treatment. Triptolide possesses anti-tumor activity, but it is unknown whether its therapeutic effect relates with EZH2 in PCa. Here we described EZH2 as a target for Triptolide in PCa cells. Our data showed that Triptolide suppressed PCa cell growth and reduced the expression of EZH2. Overexpression of EZH2 attenuated the Triptolide induced cell growth inhibition. Moreover, Triptolide treatment of PC-3 cells resulted in elevated mRNA levels of target genes (ADRB2, CDH1, CDKN2A and DAB2IP) negatively regulated by EZH2 as well as reduced mRNA levelsan of EZH2 positively regulated gene (cyclin D1). Our findings suggest the PCa cell growth inhibition mediated by Triptolide might be associated with downregulation of EZH2 expression and the subsequent modulation of target genes.