Structural Investigation of a Flexible MOF [Cu(BF₄)₂(1,3-bis(4-pyridyl)propane)₂] Showing Selective Gate Adsorption with Dynamic Pore-Opening/Pore-Closing Processes

Structural analyses of a flexible 1D MOF [Cu­(BF₄)₂(bpp)₂] (bpp =1,3-bis­(4-pyridyl)­propane) with/without guest molecules were performed by synchrotron powder X-ray diffraction analysis and single crystal structural analysis. The guest-free MOF is composed of 1D chains composed of Cu­(II) ions and bpp ligands which are accumulated to form quasi-2D layers, resulting in a quasi-layered compound. The guest-free MOF has no open pore windows; it, however, has latent quasi-hexagonal cavities surrounded by six BF₄ anions. This MOF shows molecular selective sorption, which stems from guest-dependent dynamic structural transformation including pore-opening/closing processes. It shows selective alcohol sorption based on the molecular recognition properties; it sorbs C1–C3 alcohols, but not a C4 alcohol (1-butanol). Sorption properties can be enhanced by accumulation of several functionalities. In the case of the flexible MOF, the sorption properties should be synergetically enhanced by several key properties; it has molecular recognition properties and accommodate selected species with pore-opening, and furthermore prevent other species from entering cavities by pore-closing

Disease resistance in transgenic 35S::Thi2.4 plants to <i>F.</i><i>graminearum</i> and F. sporotrichioides.

<p>Photographs of representative leaves (A–D, I–L) and flower buds (F, G, N, O) in wild type (WT) (A, C, F, I, K, N) and transgenic plants (35S::Thi2.4) (B, D, G, J, L, O) at 3 dpi. <i>F. graminearum</i> (A–H) and <i>F. sporotrichioides</i> (I–P). (A, B, F, G, I, J, N, O) Scale bars: 1 cm. (C, D, K, L) Trypan blue staining of <i>F. graminearum</i>-inoculated leaves. (C, D, K, L) Scale bars: 100 µm. (E, H, M, P) Relative values of disease symptoms in <i>F. graminearum</i> (n = 12) and <i>F. sporotrichioides</i> inoculated leaves (n = 12). These data shown are representative. The bars show disease severity. (E, M) Blue (class 1): normal. Purple (class 2): leaf has turned black. Green (class 3): partial hyphae. Red (class 4): expanded aerial hyphae. (H, P) Orange (class A): normal. Pink (class B): aerial mycelium visible on flower. Yellow (class C): drying of flowers. Brown (class D): stem constriction within flower head. The asterisks indicate significant differences from the wild type (*P<0.05, based on Mann-Whitney <i>U</i> test).</p

Expression patterns of <i>PR1</i> and <i>PDF1.2</i> genes in FFBL-infiltrated Arabidopsis leaves using RT-PCR.

<p>(A) The amounts of <i>PR1</i> mRNA induced by FFBL. (B) The amounts of <i>PDF1.2</i> mRNA induced by FFBL. FFBL-infiltrated Arabidopsis leaves were incubated in the growth chamber for 5 days. The amounts of <i>PR1</i> and <i>PDF1.2</i> mRNAs were normalized against <i>ACTIN2/8</i>. Data are the mean of triplicate experiments ± s.d.</p

Microporous Brookite-Phase Titania Made by Replication of a Metal–Organic Framework

Metal–organic frameworks (MOFs) provide access to structures with nanoscale pores, the size and connectivity of which can be controlled by combining the appropriate metals and linkers. To date, there have been no reports of using MOFs as templates to make porous, crystalline metal oxides. Microporous titania replicas were made from the MOF template HKUST-1 by dehydration, infiltration with titanium isopropoxide, and subsequent hydrothermal treatment at 200 °C. Etching of the MOF with 1 M aqueous HCl followed by 5% H₂O₂ yielded a titania replica that retained the morphology of the parent HKUST-1 crystals and contained partially ordered micropores as well as disordered mesopores. Interestingly, the synthesis of porous titania from the HKUST-1 template stabilized the formation of brookite, a rare titania polymorph

The viability of <i>F.</i><i>graminearum</i> and <i>F. sporotrichioides</i> to Thi2.4 was measured by MTT analysis.

<p>Conidia of <i>F. graminearum</i> and <i>F. sporotrichioides</i> were cultured on SN liquid medium for 2 days. Thi2.4 protein was added with the conidial suspension. The growth of <i>F. graminearum</i> and <i>F. sporotrichioides</i> was measured by the 3-(4,5-di-methylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, yellow tetrazole (MTT) analysis. MTT analysis is the quantitative colorimetric method to determine cell proliferation. The asterisks indicate significant differences from the wild type (*P<0.05, **P<0.01, based on Student's <i>t</i>-test). Data are the mean of triplicate experiments ± s.d.</p

Yeast two-hybrid analysis of Thi2.4 and FFBL.

<p>(A) P53-BD/T-antigen-AD indicates positive control. LamC-BD/T-antigen-AD indicates negative control. (B and C) SD medium without 3-aminotriazol (3-AT). (D and E) The SD medium containing 10 mM 3-AT. (B and D) SD medium without histidine (−His). (C and E) SD medium with histidine (+His). This experiment was analyzed in 3 independent lines and performed 3 times.</p

The subcellular localization of Thi2.4 protein in <i>F.</i><i>graminearum</i>-inoculated flower buds of Arabidopsis.

<p>(A–F) The subcellular localization of Thi2.4 protein in flower buds of Arabidopsis. (A–C) The subcellular localization of Thi2.4 in cell interior. (D–F) The subcellular localization of Thi2.4 in cell surface. (G–I) The subcellular localization of Thi2.4 protein in <i>F. graminearum</i>. (A, D, G) Thi2.4 was detected by an FITC-conjugated anti-Th2.4 antibody. (B, E, H) Autofluorescence in Arabidopsis. (C, F, I) Merged images of (A) and (B), (D) and (E), (G) and (H), respectively. (J) Magnification of (F). (K) Magnification of (I). Sp; sepal of plant. P; parenchyma of plant. Epi; epidermal cell of plant. CW; cell wall of plant. H; hyphae of fungi. (A–K) Scale bars: 10 µm. This experiment was repeated twice (n = 10). (L) The subcellular localization of Thi2.4 protein using the western blot analysis. The flower buds were homogenized and fractionated to soluble (Sol.), insoluble 1 (Insol. 1) and insoluble 2 (Insol. 2) fractions. Insoluble 1 and insoluble 2 fraction mainly includes the cell walls and thylakoid membrane, respectively. Each lane was loaded with 1 µg proteins.</p

The Secreted Antifungal Protein Thionin 2.4 in <i>Arabidopsis thaliana</i> Suppresses the Toxicity of a Fungal Fruit Body Lectin from <i>Fusarium graminearum</i>

<div><p>Plants possess active defense systems and can protect themselves from pathogenic invasion by secretion of a variety of small antimicrobial or antifungal proteins such as thionins. The antibacterial and antifungal properties of thionins are derived from their ability to induce open pore formation on cell membranes of phytopathogens, resulting in release of potassium and calcium ions from the cell. Wheat thionin also accumulates in the cell walls of <i>Fusarium</i>-inoculated plants, suggesting that it may have a role in blocking pathogen infection at the plant cell walls. Here we developed an anti-thionin 2.4 (Thi2.4) antibody and used it to show that Thi2.4 is localized in the cell walls of Arabidopsis and cell membranes of <i>F. graminearum</i>, when flowers are inoculated with <i>F. graminearum</i>. The Thi2.4 protein had an antifungal effect on <i>F. graminearum</i>. Next, we purified the Thi2.4 protein, conjugated it with glutathione-S-transferase (GST) and coupled the proteins to an NHS-activated column. Total protein from <i>F. graminearum</i> was applied to GST-Thi2.4 or Thi2.4-binding columns, and the fungal fruit body lectin (FFBL) of <i>F. graminearum</i> was identified as a Thi2.4-interacting protein. This interaction was confirmed by a yeast two-hybrid analysis. To investigate the biological function of FFBL, we infiltrated the lectin into Arabidopsis leaves and observed that it induced cell death in the leaves. Application of FFBL at the same time as inoculation with <i>F. graminearum</i> significantly enhanced the virulence of the pathogen. By contrast, FFBL-induced host cell death was effectively suppressed in transgenic plants that overexpressed Thi2.4. We found that a 15 kD Thi2.4 protein was specifically expressed in flowers and flower buds and suggest that it acts not only as an antifungal peptide, but also as a suppressor of the FFBL toxicity. Secreted thionin proteins are involved in this dual defense mechanism against pathogen invasion at the plant-pathogen interface.</p></div

The incidence of aerial hyphae induced by FFBL in rosette leaves of Arabidopsis.

<p>(A) Leaves were inoculated with <i>F. graminearum</i> conidia without FFBL. (B, C) Leaves were inoculated with <i>F. graminearum</i> conidia plus 0.1 or 1.0 µM FFBL. (D) The incidence of <i>F. graminearum</i> aerial hyphae. The incidence of hyphae indicates the ratio of aerial hyphae-observed leaves to all <i>F. graminearum</i>-inoculated leaves. Data are the mean of triplicate experiments ± s.d (n = 45). The asterisks indicate significant differences from 0 µM FFBL (P<0.01, based on Student's <i>t</i>-test). (E) The amount of <i>FFBL</i> mRNA in <i>F. graminearum</i> H3 (H3) and <i>FFBL</i> gene-disrupted <i>F. graminearum</i> H3 (Δ<i>FgFFBL</i>). <i>FFBL</i> gene expression was investigated using four independent Δ<i>FgFFBL</i> lines by RT-PCR. <i>α-Tubulin</i> was used as reference gene. (F) The incidence of Δ<i>FgFFBL</i> aerial hyphae of Δ<i>FgFFBL</i>. The incidence of hyphae indicates the ratio of aerial hyphae-observed leaves to all Δ<i>FgFFBL</i>-inoculated leaves. Data are the mean of triplicate experiments ± s.d (n = 24). The asterisks indicate significant differences from H3 (wild type) (*P<0.05, **P<0.01, based on Student's <i>t</i>-test).</p

Data_Sheet_1_Regulatory mechanism of trichothecene biosynthesis in Fusarium graminearum.pdf

Among the genes involved in the biosynthesis of trichothecene (Tri genes), Tri6 and Tri10 encode a transcription factor with unique Cys2His2 zinc finger domains and a regulatory protein with no consensus DNA-binding sequences, respectively. Although various chemical factors, such as nitrogen nutrients, medium pH, and certain oligosaccharides, are known to influence trichothecene biosynthesis in Fusarium graminearum, the transcriptional regulatory mechanism of Tri6 and Tri10 genes is poorly understood. Particularly, culture medium pH is a major regulator in trichothecene biosynthesis in F. graminearum, but it is susceptible to metabolic changes posed by nutritional and genetic factors. Hence, appropriate precautions should be considered to minimize the indirect influence of pH on the secondary metabolism while studying the roles of nutritional and genetic factors on trichothecene biosynthesis regulation. Additionally, it is noteworthy that the structural changes of the trichothecene gene cluster core region exert considerable influence over the normal regulation of Tri gene expression. In this perspective paper, we consider a revision of our current understanding of the regulatory mechanism of trichothecene biosynthesis in F. graminearum and share our idea toward establishing a regulatory model of Tri6 and Tri10 transcription.</p