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Klaus Apel - One of the best experts on this subject based on the ideXlab platform.
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systemic and local induction of an arabidopsis Thionin gene by wounding and pathogens
Plant Journal, 1998Co-Authors: Alberto Vignutelli, Klaus Apel, Claus Wasternack, Holger BohlmannAbstract:Summary The Arabidopsis Thi2.1 Thionin gene was cloned and sequenced. The promoter was fused to the uidA gene and stably transformed into Arabidopsis to study its regulation. GUS expression levels correlated with the steady-state levels of Thi2.1 mRNA, thus demonstrating that the promoter is sufficient for the regulation of the Thi2.1 gene. The sensitivity of the Thi2.1 gene to methyl jasmonate was found to be developmentally determined. Systemic and local expression could be induced by wounding and inoculation with Fusarium oxysporum f sp. matthiolae. A deletion analysis of the promoter identified a fragment of 325 bp upstream of the start codon, which appears to contain all the elements necessary for the regulation of the Thi2.1 gene. These results support the view that Thionins are defence proteins, and indicate the possibility that resistance of Arabidopsis plants to necrotrophic fungal pathogens is mediated through the octadecanoid pathway.
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overexpression of an endogenous Thionin enhances resistance of arabidopsis against fusarium oxysporum
The Plant Cell, 1997Co-Authors: Petra Epple, Klaus Apel, Holger BohlmannAbstract:Thionins are antimicrobial proteins that are thought to be involved in plant defense. Concordant with this view, we have recently shown that the Arabidopsis Thionin Thi2.1 gene is inducible by phytopathogenic fungi. Here, we demonstrate that constitutive overexpression of this Thionin enhances the resistance of the susceptible ecotype Columbia (Col-2) against attack by Fusarium oxysporum f sp matthiolae. Transgenic lines had a reduced loss of chlorophyll after inoculation and supported significantly less fungal growth on the cotyledons, as evaluated by trypan blue staining. Moreover, fungi on cotyledons of transgenic lines had more hyphae with growth anomalies, including hyperbranching, than on cotyledons of the parental line. No transcripts for pathogenesis-related PR-1, PR-5, or the pathogen-inducible plant defensin Pdf1.2 could be detected in uninoculated transgenic seedlings, indicating that all of the observed effects of the overexpressing lines are most likely the result of the toxicity of the THI2.1 Thionin. Our findings strongly support the view that Thionins are defense proteins.
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an arabidopsis thaliana Thionin gene is inducible via a signal transduction pathway different from that for pathogenesis related proteins
Plant Physiology, 1995Co-Authors: Petra Epple, Klaus Apel, Holger BohlmannAbstract:Two cDNAs encoding Thionin preproproteins have been isolated from Arabidopsis thaliana. The corresponding genes have been designated Thi2.1 and Thi2.2. Southern blot analysis suggests that A. thaliana most probably contains single genes for both Thionins. Thi2.2 transcripts have a low basal level in seedlings and show circadian variation. Thi2.2 transcripts were also detected in rosette leaves. No potent elicitors have been found for the Thi2.2 gene. Transcripts of the Thi2.1 gene are not detectable in seedlings but are present in rosette leaves and at a very high level in flowers and in siliques. The expression of the Thi2.1 gene is highly inducible in seedlings by pathogens, silver nitrate, and methyl jasmonate, but not by salicylate, indicating that the gene is induced by a signal transduction pathway that is at least partly different from that for the pathogenesis-related proteins.
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specific and different expression patterns of two members of the leaf Thionin multigene family of barley in transgenic tobacco
Plant Science, 1995Co-Authors: Sonke Holtorf, Klaus Apel, Holger BohlmannAbstract:Thionins are cysteine-rich, basic, and toxic proteins that are assumed to be involved in the defense against pathogens. Barley (Hordeum vulgare L. cv. Carina) contains a large gene family coding for leaf-specific Thionins that comprises more than 50 genes per haploid genome. How the expression of these variants is regulated was not known. To address this question, we have cloned 2 of these Thionin genes, BTH6 and BTH7, each belonging to one of 2 subgroups, and analysed their sequences. Both code for typical leaf Thionin proteins. Their promoter regions have an identity of about 40% except for a region of 90 bp in the downstream region which has an identity of 80%. As reflected by these sequence differences, both promoters behave differently when placed in front of the uidA gene and analysed in transgenic tobacco plants. Whereas the BTH6 promoter is constitutively expressed in most tissues of transgenic tobacco plants except the roots, the BTH7 promoter is only active in the vascular strands of the stem and older leaves. The BTH6 promoter is highly active in the epidermis and in xylem elements whereas the BTH7 promoter shows very high activity in phloem elements. In addition, both promoters are differently regulated by light. The BTH7 promoter is only active in the light. The BTH6 promoter shows a differential regulation in seedlings, being active in the hypocotyl in darkness but not in the cotyledons and vice versa in the light. Our results indicate that the expression of the barley leaf Thionin multigene family is regulated differentially at the transcriptional level.
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The Formation of Leaf Thionins and their Effecton the Viability of Isolated Protoplasts of Barley (Hordeum vulgare L.)
Journal of Plant Physiology, 1995Co-Authors: Klaus Apel, Horst BindingAbstract:Summary Thus far, reliable regeneration of plants from isolated protoplasts of cereals is restricted to embryogenicin vitro cultures as the starting material. In the present work we provide evidence that Thionins released from the leaf material may contribute to the regeneration incompetence of barley leaf protoplasts. This conclusion is based on the following observations: Leaf Thionins and their corresponding RNA are not found in young sexual embryos used for initiating embryogenic cultures or in embryogenic cells yielding regenerable protoplasts, but occur in significant amounts in non-regenerable callus and leaves; furthermore, wounding of leaves during the preparation of protoplasts induced a strong increase in leaf Thionin mRNA. Improved stability and microcallus formation of leaf protoplasts were obtained when an antiserum against leaf Thionins was added to the sample.
Leo P Vernon - One of the best experts on this subject based on the ideXlab platform.
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stimulation of prothrombinase activity by the nonapeptide thr trp ala arg asn ser tyr asn val a segment of a plant Thionin
Peptides, 2003Co-Authors: Valdemar Osorio R E Castro, Leo P VernonAbstract:Abstract Pyrularia Thionin (PT) is a basic 47 amino acid peptide isolated from the nuts of Pyrularia pubera. Its structure and properties have been studied in some detail. Its receptor site is a domain of membrane phosphatidyl serine (PS), where it binds with a relatively high specificity. A segment of its covalent structure, the nonapeptide Thr-Trp-Ala-Arg-Asn-Ser-Tyr-Asn-Val, designated serine nonapeptide (SNP), corresponds to amino acids 7–15 of the Thionin, except for the position 12 (Ser), which substitutes for Cys, to give stability. This peptide represents what we consider to be the active site of the Thionin, and it also binds to PS domains, but less tightly than Thionin does. The peptide has an effect on the prothrombinase assay using the chromophore S2238 to measure the thrombin produced by the prothrombinase complex. It is shown that SNP stimulates the prothrombinase complex activity, instead of inhibiting it, as would be expected if it simply covered the PS sites on the membrane of erythrocyte ghosts, used in the prothrombinase assay. SNP appears to substitute for Va in the prothrombinase complex reaction, in a Ca2+ independent manner, being even more effective in the absence than in the presence of ghosts. In the clotting system, SNP can also substitute for Factor Va.
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mechanisms by which Thionin induces susceptibility of s49 cell membranes to extracellular phospholipase a2
Biochimica et Biophysica Acta, 1997Co-Authors: Heather A Wilson, Leo P Vernon, Wenhao Huang, Jacqueline B Waldrip, Allan M Judd, John D BellAbstract:Whereas cells normally resist attack by PLA2, they become susceptible under certain pathological conditions. To ascertain the regulatory mechanisms that induce cellular susceptibility to PLA2, the effect of Thionin on S49 cells was examined in the presence of PLA2. Thionin alone was unable to evoke hydrolysis of the lipid bilayer. Likewise, the addition of PLA2 alone caused production of only a minimal amount of free fatty acid. However, Thionin and PLA2 together resulted in significant hydrolysis of the cell membrane. Thionin caused perturbation of the bilayer structure as suggested by the changes in the emission spectra of laurdan and the permeability of the membrane to propidium iodide. These changes correlated quantitatively with the susceptibility of the lipid bilayer to PLA2. Furthermore, Thionin induced a modest increase in intracellular Ca2+. The source of this Ca2+ was the extracellular fluid since EDTA in the extracellular medium inhibited the Ca2+ influx. Moreover, cobalt chloride, a universal Ca2+ channel blocker, prevented the rise in intracellular Ca2+, the uptake of propidium iodide, and the susceptibility to PLA2 induced by Thionin. In contrast, the changes in the laurdan emission caused by the Thionin were not affected by the cobalt. Furthermore, incubation of the cells with the calcium ionophore A23187 also caused the cells to become susceptible to PLA2. We hypothesize that Thionin causes S49 cell membranes to become susceptible to PLA2 by a Ca2+-dependent perturbation of the bilayer structure.
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interactions of Thionin from pyrularia pubera with dipalmitoylphosphatidylglycerol large unilamellar vesicles
Biochemistry, 1997Co-Authors: Wenhao Huang, Leo P Vernon, Lee D Hansen, John D BellAbstract:The peptide toxin Thionin from Pyrularia pubera binds to dipalmitoylphosphatidylglycerol (DPPG) large unilamellar vesicles as shown by an increase in the intensity and blue-shift of the fluorescence emission spectrum of the single tryptophan residue of the protein. The magnitude of these fluorescence changes increased with temperature near the thermotropic phase transition of DPPG (about 40 °C). Fluorescent probes sensitive to the structure and dynamics of the membrane were used to assess the effect of Thionin binding on bilayer properties. The fluorescence emission spectra of Prodan, Patman, and Laurdan all showed spectral changes consistent with an increase in bilayer polarity at temperatures below the DPPG phase transition but a decrease in polarity at higher temperatures. Fluorescence polarization experiments and the ratio of monomer-to-excimer fluorescence of the probe 1,3-bis(1-pyrene)propane suggested that Thionin increases the bilayer order above the transition temperature. Differential scanning c...
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enhancement of adenylate cyclase activity in s49 lymphoma cell membranes by the toxin Thionin from pyrularia pubera
Toxicon, 1994Co-Authors: Wenhao Huang, Leo P Vernon, John D BellAbstract:Abstract W. Huang , L. P. Vernon and J. D. Bell . Enhancement of adenylate cyclase activity in S49 lymphoma cell membranes by the toxin Thionin from Pyrularia pubera. Toxicon 32, 789–797, 1994.—We investigated the mode of action of Pyrularia Thionin on adenylate cyclase in S49 lymphoma cell membranes. Thionin increased the forskolin-induced cAMP production in both wild-type and cyc - variant cell membranes. Thionin increased the apparent efficacy, but not potency, of the stimulation of adenylate cyclase by forskolin. Our results also indicated that the stimulatory G protein (G s ) was not involved in the action of Thionin on adenylate cyclase; however, Thionin appeared to reduce the effect of G i on adenylate cyclase. We examined the effect of Thionin on the temperature dependence of adenylate cyclase activity. The effect of Thionin was not quantitatively the same at all temperatures. The effect was greatest in the range of about 30°C to 50°C. In addition, cardiotoxin, a structurally distinct peptide that alters the properties of biological membranes similarly to Thionin, also enhanced the activity of adenylate cyclase. It seems reasonable to suspect that Thionin influences the activity of adenylate cyclase indirectly by acting on the membrane.
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pyrularia Thionin increases arachidonate liberation and prolactin and growth hormone release from anterior pituitary cells
Toxicon, 1992Co-Authors: Allan M Judd, Leo P Vernon, Robert M MacleodAbstract:Pyrularia Thionin is a 47 amino acid peptide isolated from the nuts of Pyrularia pubera. This peptide does not have intrinsic phospholipase A2 activity, but it increases the liberation of arachidonate from several tissues. Exposure of anterior pituitary cells to this toxin increases the liberation of arachidonate, increases the cellular levels of lysophospholipids, and decreases cellular phospholipids. Thus, phospholipase A2 is involved in the liberation of arachidonate stimulated by this peptide. Because this toxin also increases stearate liberation from the pituitary cells, either diacylglycerol lipase, phospholipase A1 or lysophospholipase may be directly or indirectly activated by this toxin. In addition to increasing fatty acid liberation, Pyrularia Thionin increases the release of prolactin and growth hormone from anterior pituitary cells over the identical concentration ranges that this toxin liberates the fatty acids. Pyrularia Thionin increased arachidonate liberation and prolactin release from perifused pituitary cells within 2 min, and following withdrawal of the toxin, arachidonate liberation and prolactin release returned to near basal levels within 6 min. Dopamine, a physiological inhibitor of prolactin release that closes calcium channels, decreased prolactin release stimulated by Pyrularia Thionin. However, dopamine had no effect on the arachidonate liberation stimulated by this peptide. Similarly, D-600, an organic calcium channel blocker, decreased the prolactin and growth hormone release stimulated by the toxin without affecting the toxin-stimulated arachidonate liberation. Therefore, Pyrularia Thionin increases arachidonate liberation through the rapid activation of phospholipase A2 by a mechanism that is not dependent on calcium uptake via D-600-inhibitable calcium channels. In contrast, the prolactin and growth hormone release stimulated by this toxin requires calcium uptake via D-600 inhibitable calcium channels.
Holger Bohlmann - One of the best experts on this subject based on the ideXlab platform.
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arabidopsis Thionin like genes are involved in resistance against the beet cyst nematode heterodera schachtii
Plant Physiology and Biochemistry, 2019Co-Authors: Bachar Almaghrabi, Adil Zahoor, Kausar Hussain Shah, Holger BohlmannAbstract:Abstract Plants express various antimicrobial peptides including Thionins to protect themselves against pathogens. It was recently found that, in addition to four Thionin genes, Arabidopsis contains 67 Thionin-like (ThiL) genes including six pseudogenes. It is known that Thionins have antimicrobial activity and are part of the plant defense system, however, nothing is known about ThiL genes. In this study, we present a bioinformatic analysis of the (ThiL) gene family in Arabidopsis. We identified 15 different motifs which positioned the ThiL peptides in four groups. A comparison of amino acid sequences showed that the ThiL peptides are actually more similar to the acidic domain of Thionin proproteins than to the Thionin domain. We selected 10 ThiL genes to study the expression and possible function in the Arabidopsis plant. RT-PCR and promoter:GUS fusions showed that most genes were expressed at a very low level but in several organs and at different developmental stages. Some genes were also expressed in syncytia induced by the beet cyst nematode Heterodera schachti in roots while others were downregulated in syncytia. Some overexpression lines supported lower number of nematodes that developed on the roots after inoculation. Two of the genes resulted in a strong hypersensitive response when infiltrated into leaves of Nicotiana benthamiana. These results indicate that ThiL genes might be involved in the response to biotic stress. ThiL genes have been expanded in the Brassicales and specifically the Brassicaceae. The most extreme example is the CRP2460 subfamily that contains 28 very closely related genes from Arabidopsis which are mostly the result of tandem duplications.
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isolation and characterization of a Thionin proprotein processing enzyme from barley
Journal of Biological Chemistry, 2015Co-Authors: Stephan Plattner, Clemens Gruber, Johannes Stadlmann, Stefan Widmann, Christian W Gruber, Friedrich Altmann, Holger BohlmannAbstract:Thionins are plant-specific antimicrobial peptides that have been isolated from the endosperm and leaves of cereals, from the leaves of mistletoes, and from several other plant species. They are generally basic peptides with three or four disulfide bridges and a molecular mass of similar to 5 kDa. Thionins are produced as preproproteins consisting of a signal peptide, the Thionin domain, and an acidic domain. Previously, only mature Thionin peptides have been isolated from plants, and in addition to removal of the signal peptide, at least one cleavage processing step between the Thionin and the acidic domain is necessary to release the mature Thionin. In this work, we identified a Thionin proprotein-processing enzyme (TPPE) from barley. Purification of the enzyme was guided by an assay that used a quenched fluorogenic peptide comprising the amino acid sequence between the Thionin and the acidic domain of barley leaf-specific Thionin. The barley TPPE was identified as a serine protease (BAJ93208) and expressed in Escherichia coli as a strep tag-labeled protein. The barley BTH6 Thionin proprotein was produced in E. coli using the vector pETtrx1a and used as a substrate. We isolated and sequenced the BTH6 Thionin from barley to confirm the N and C terminus of the peptide in planta. Using an in vitro enzymatic assay, the recombinant TPPE was able to process the quenched fluorogenic peptide and to cleave the acidic domain at least at six sites releasing the mature Thionin from the proprotein. Moreover, it was found that the intrinsic three-dimensional structure of the BTH6 Thionin domain prevents cleavage of the mature BTH6 Thionin by the TPPE.
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comparison of periplasmic and intracellular expression of arabidopsis Thionin proproteins in e coli
Biotechnology Letters, 2013Co-Authors: Amjad Abbas, Stephan Plattner, Kausar Hussain Shah, Holger BohlmannAbstract:Thionins are antimicrobial plant peptides produced as preproproteins consisting of a signal peptide, the Thionin domain, and a so-called acidic domain. Only Thionin itself has been isolated from plants. To study the processing of the precursor, it has to be produced in a heterologous system. Since both domains contain several cysteines and, due to the known antimicrobial activity of the Thionin, we tested the expression of all four Arabidopsis proproteins as fusion proteins. Periplasmic expression as fusion with maltose binding protein was not successful but cytoplasmic expression as His-tagged TRX fusion proteins with a TEV recognition sequence resulted in proteins of correct size. Use of the SHuffle strain C3030 further improved the expression. Fusion proteins inhibited growth of Escherichia coli. They could be cleaved by TEV protease, releasing authentic proproteins without any additional amino acid at the N-terminus.
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systemic and local induction of an arabidopsis Thionin gene by wounding and pathogens
Plant Journal, 1998Co-Authors: Alberto Vignutelli, Klaus Apel, Claus Wasternack, Holger BohlmannAbstract:Summary The Arabidopsis Thi2.1 Thionin gene was cloned and sequenced. The promoter was fused to the uidA gene and stably transformed into Arabidopsis to study its regulation. GUS expression levels correlated with the steady-state levels of Thi2.1 mRNA, thus demonstrating that the promoter is sufficient for the regulation of the Thi2.1 gene. The sensitivity of the Thi2.1 gene to methyl jasmonate was found to be developmentally determined. Systemic and local expression could be induced by wounding and inoculation with Fusarium oxysporum f sp. matthiolae. A deletion analysis of the promoter identified a fragment of 325 bp upstream of the start codon, which appears to contain all the elements necessary for the regulation of the Thi2.1 gene. These results support the view that Thionins are defence proteins, and indicate the possibility that resistance of Arabidopsis plants to necrotrophic fungal pathogens is mediated through the octadecanoid pathway.
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overexpression of an endogenous Thionin enhances resistance of arabidopsis against fusarium oxysporum
The Plant Cell, 1997Co-Authors: Petra Epple, Klaus Apel, Holger BohlmannAbstract:Thionins are antimicrobial proteins that are thought to be involved in plant defense. Concordant with this view, we have recently shown that the Arabidopsis Thionin Thi2.1 gene is inducible by phytopathogenic fungi. Here, we demonstrate that constitutive overexpression of this Thionin enhances the resistance of the susceptible ecotype Columbia (Col-2) against attack by Fusarium oxysporum f sp matthiolae. Transgenic lines had a reduced loss of chlorophyll after inoculation and supported significantly less fungal growth on the cotyledons, as evaluated by trypan blue staining. Moreover, fungi on cotyledons of transgenic lines had more hyphae with growth anomalies, including hyperbranching, than on cotyledons of the parental line. No transcripts for pathogenesis-related PR-1, PR-5, or the pathogen-inducible plant defensin Pdf1.2 could be detected in uninoculated transgenic seedlings, indicating that all of the observed effects of the overexpressing lines are most likely the result of the toxicity of the THI2.1 Thionin. Our findings strongly support the view that Thionins are defense proteins.
Francisco Garciaolmedo - One of the best experts on this subject based on the ideXlab platform.
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synthetic and structural studies on pyrularia pubera Thionin a single residue mutation enhances activity against gram negative bacteria
FEBS Letters, 2003Co-Authors: Miquel Vilaperello, Antonio Molina, Francisco Garciaolmedo, Andrea Sanchezvallet, David AndreuAbstract:The Thionin from Pyrularia pubera (Pp-TH), a 47-residue peptide with four internal disulfide bonds, was efficiently produced by chemical synthesis. Its antimicrobial activity in vitro against several representative pathogens (EC50=0.3–3.0 μM) was identical to that of natural Pp-TH. This peptide has a unique Asp32 instead of the consensus Arg found in other Thionins of the same family. In order to evaluate the effect of this mutation, the Arg32 analogue (Pp-TH(D32R)) was also synthesized and showed a significant increase in antibiotic activity against several Gram-negative bacteria, whereas it retained the same activity against other pathogens. The overall structure of Pp-TH(D32R) was maintained, though a slight decrease in the helical content of the peptide was observed.
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processing of Thionin precursors in barley leaves by a vacuolar proteinase
FEBS Journal, 1997Co-Authors: Alicia Romero, Jocefa M Alamillo, Francisco GarciaolmedoAbstract:Thionins are synthesized as precursors with a signal peptide and a long C-terminal acidic peptide that is post-translationally processed. A fusion protein including the maltose-binding protein from Eschrrichia coli (MalE), Thionin DG3 froin barley leaves, and its acidic C-terminal peptide has been used to obtain antibodies that recognize both domains of the precursor. In barley leaf sections. mature Thionins accuinulated in the vacuolar content, while the acidic peptide was not detected in any cell fraction. Brefeldin A and inonensin inhibited processing of the precursor but its export from the microsomal fraction was not inhibited. Both purified vacuoles aiid an acid (pH 5.5) extract from leaves processed the fusion protein into a MalE-Thionin and an acidic peptide fragment. A 70-kDa proteinase that effected this cleavage was purified froin the acid extract. Processing of the fusion protein by both lysed vacuoles and the purified proteinase was inhibited by Zn2+ and by Cu2+, but not by inhibitors of the previously described vacuolar processing thiol or aspartic proteinases. In vivo processing of the Thionin precursor in leaf sections was also inhibited by Zn+, and Cu2+, Variants of the fusion protein with altered processing sites that represented thme of Thionin precursors from different taxa were readily processed by the proteinase, whereas changing the polarity of either the C-terminal or N-terminal residues of the processing site prevented cleavage by the proteinase.
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expression of the α Thionin gene from barley in tobacco confers enhanced resistance to bacterial pathogens
Plant Journal, 1993Co-Authors: M J Carmona, Antonio Molina, Jose A Fernandez, Juan Jose Lopezfando, Francisco GarciaolmedoAbstract:Thionins are cysteine-rich, 5 kDa polypeptides which are toxic to plant pathogens in vitro. Expression of the gene encoding alpha-Thionin from barley endosperm, under the 35S promoter from cauliflower mosaic virus, conferred to transgenic tobacco enhanced resistance to the bacterial plant pathogens Pseudomonas syringae pv. tabaci 153 and P. syringae pv. syringae. The barley alpha-Thionin gene, which has two introns, was correctly spliced in tobacco. The alpha-Thionin in transgenic plants had the expected mobility in the gradient, when separated by high- performance liquid chromatography, reacted with monospecific antibodies and showed the expected antibiotic properties in vitro
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extreme divergence of a novel wheat Thionin generated by a mutational burst specifically affecting the mature protein domain of the precursor
Journal of Molecular Biology, 1992Co-Authors: A Castagnaro, Pilar Carbonero, Carmen Marana, Francisco GarciaolmedoAbstract:A new type of neutral Thionin (type V), specifically expressed in developing wheat endosperm, has been found to be encoded by a set of single-copy genes located in the long arms of chromosomes 1A, 1B and 1D, within less than 10,000 base-pairs of those corresponding to the highly basic type-I Thionins. Divergence between types I and V has occurred through a process of accelerated evolution that has affected the amino acid sequence of the mature Thionin but not the precursor domains corresponding to the N-terminal signal peptide and the long C-terminal acidic peptide. This process involved a deletion and a non-synonymous nucleotide substitution rate equal to the synonymous rate in the Thionin sequence.
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characterization and analysis of Thionin genes
Characterization and analysis of thionin genes | En: Genes Involved in Plant Defense | pag. 283-302 | Springer Verlag | 1992, 1992Co-Authors: Francisco Garciaolmedo, M J Carmona, Antonio Molina, A Castagnaro, J J Lopezfando, J A Fernandez, C Hernandezlucas, Pilar CarboneroAbstract:The general designation of Thionins has been proposed for a family of homologous proteins that have been isolated from different tissues in a wide range of plant taxa and have been variously named puroThionins, viscotoxins, crambins, etc. (see Garcia-Olmedo et al., 1989). The possible involvement of Thionins in plant defense was first suggested, on the basis of their in vitro toxicity to plant pathogens, by Fernandez de Caleya et al., (1972). Those observations had been prompted by earlier reports concerning the antimicrobial properties of these polypeptides (Stuart and Harris, 1942; Balls and Harris, 1944). Work on the Thionins, which has been actively pursued over the past half-century, has been recently reviewed in detail (Garcia-Olmedo et al., 1989). For this reason. earlier work will only be partially summarized in the present chapter, which will focus on recent developments concerning Thionin genes and their potential role in plant defense mechanisms.
Valdirene Moreira Gomes - One of the best experts on this subject based on the ideXlab platform.
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Thionin like peptide from capsicum annuum fruits mechanism of action and synergism with fluconazole against candida species
BMC Microbiology, 2016Co-Authors: Gabriel Bonan Taveira, Andre De Oliveira Carvalho, Rosana Rodrigues, Fernanda Gomes Trindade, Maura Da Cunha, Valdirene Moreira GomesAbstract:Background Thionins are a family of plant antimicrobial peptides (AMPs), which participate in plant defense system against pathogens. Here we describe some aspects of the CaThi Thionin-like action mechanism, previously isolated from Capsicum annuum fruits. Thionin-like peptide was submitted to antimicrobial activity assays against Candida species for IC50 determination and synergism with fluconazole evaluation. Viability and plasma membrane permeabilization assays, induction of intracellular ROS production analysis and CaThi localization in yeast cells were also investigated.
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Thionin like peptides from capsicum annuum fruits with high activity against human pathogenic bacteria and yeasts
Biopolymers, 2014Co-Authors: Gabriel Bonan Taveira, Andre De Oliveira Carvalho, Rosana Rodrigues, Luciana S Mathias, Olney Vieira Da Motta, Olga Lima Tavares Machado, Andre Teixeiraferreira, Jonas Perales, Ilka M Vasconcelos, Valdirene Moreira GomesAbstract:Plants defend themselves against pathogens with production of antimicrobial peptides (AMPs). Herein we describe the discovery of a new antifungal and antibacterial peptide from fruits of Capsicum annuum that showed similarity to an already well characterized family of plant AMPs, Thionins. Other fraction composed of two peptides, in which the major peptide also showed similarity to Thionins. Among the obtained fractions, fraction 1, which is composed of a single peptide of 7 kDa, was sequenced by Edman method and its comparative sequence analysis in database (nr) showed similarity to Thionin-like peptides. Tests against microorganisms, fraction 1 presented inhibitory activity to the cells of yeast Saccharomyces cerevisiae, Candida albicans, and Candida tropicalis and caused growth reduction to the bacteria species Escherichia coli and Pseudomonas aeruginosa. Fraction 3 caused inhibitory activity only for C. albicans and C. tropicalis. This fraction was composed of two peptides of ∼7 and 10 kDa, and the main protein band correspondent to the 7 kDa peptide, also showed similarity to Thionins. This plasma membrane permeabilization assay demonstrates that the peptides present in the fractions 1 and 3 induced changes in the membranes of all yeast strains, leading to their permeabilization. Fraction 1 was capable of inhibiting acidification of the medium of glucose-induced S. cerevisiae cells 78% after an incubation time of 30 min, and opposite result was obtained for C. albicans. Experiments demonstrate that the fraction 1 and 3 were toxic and induced changes in the membranes of all yeast strains, leading to their permeabilization. © 2013 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 102: 30–39, 2014.
