Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 55
Filtrar
1.
Commun Biol ; 7(1): 850, 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-38992096

RESUMO

Plant pathogens cause billions of dollars of crop loss every year and are a major threat to global food security. Identifying and characterizing pathogens effectors is crucial towards their improved control. Because of their poor sequence conservation, effector identification is challenging, and current methods generate too many candidates without indication for prioritizing experimental studies. In most phyla, effectors contain specific sequence motifs which influence their localization and targets in the plant. Therefore, there is an urgent need to develop bioinformatics tools tailored for pathogen effectors. To circumvent these limitations, we have developed MOnSTER a specific tool that identifies clusters of motifs of protein sequences (CLUMPs). MOnSTER can be fed with motifs identified by de novo tools or from databases such as Pfam and InterProScan. The advantage of MOnSTER is the reduction of motif redundancy by clustering them and associating a score. This score encompasses the physicochemical properties of AAs and the motif occurrences. We built up our method to identify discriminant CLUMPs in oomycetes effectors. Consequently, we applied MOnSTER on plant parasitic nematodes and identified six CLUMPs in about 60% of the known nematode candidate parasitism proteins. Furthermore, we found co-occurrences of CLUMPs with protein domains important for invasion and pathogenicity. The potentiality of this tool goes beyond the effector characterization and can be used to easily cluster motifs and calculate the CLUMP-score on any set of protein sequences.


Assuntos
Motivos de Aminoácidos , Biologia Computacional , Animais , Biologia Computacional/métodos , Doenças das Plantas/parasitologia , Doenças das Plantas/microbiologia , Plantas/parasitologia , Oomicetos/genética , Oomicetos/metabolismo , Nematoides/genética , Proteínas de Helminto/genética , Proteínas de Helminto/metabolismo , Proteínas de Helminto/química , Software
2.
Mol Plant Pathol ; 25(7): e13491, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38961768

RESUMO

Root-knot nematodes (RKNs) are microscopic parasitic worms able to infest the roots of thousands of plant species, causing massive crop yield losses worldwide. They evade the plant's immune system and manipulate plant cell physiology and metabolism to transform a few root cells into giant cells, which serve as feeding sites for the nematode. RKN parasitism is facilitated by the secretion in planta of effector molecules, mostly proteins that hijack host cellular processes. We describe here a conserved RKN-specific effector, effector 12 (EFF12), that is synthesized exclusively in the oesophageal glands of the nematode, and we demonstrate its function in parasitism. In the plant, MiEFF12 localizes to the endoplasmic reticulum (ER). A combination of RNA-sequencing analysis and immunity-suppression bioassays revealed the contribution of MiEFF12 to the modulation of host immunity. Yeast two-hybrid, split luciferase and co-immunoprecipitation approaches identified an essential component of the ER quality control system, the Solanum lycopersicum plant bap-like (PBL), and basic leucine zipper 60 (BZIP60) proteins as host targets of MiEFF12. Finally, silencing the PBL genes in Nicotiana benthamiana decreased susceptibility to Meloidogyne incognita infection. Our results suggest that EFF12 manipulates PBL function to modify plant immune responses to allow parasitism.


Assuntos
Retículo Endoplasmático , Tylenchoidea , Animais , Retículo Endoplasmático/metabolismo , Tylenchoidea/fisiologia , Tylenchoidea/patogenicidade , Proteínas de Helminto/metabolismo , Proteínas de Helminto/genética , Imunidade Vegetal , Nicotiana/parasitologia , Nicotiana/imunologia , Nicotiana/genética , Solanum lycopersicum/parasitologia , Solanum lycopersicum/imunologia , Solanum lycopersicum/genética , Doenças das Plantas/parasitologia , Doenças das Plantas/imunologia , Raízes de Plantas/parasitologia , Raízes de Plantas/imunologia , Interações Hospedeiro-Parasita
3.
Plant Commun ; 5(2): 100723, 2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-37742073

RESUMO

Root-knot nematodes (RKNs) cause huge agricultural losses every year. They secrete a repertoire of effectors to facilitate parasitism through the induction of plant-derived giant feeding cells, which serve as their sole source of nutrients. However, the mode of action of these effectors and their targeted host proteins remain largely unknown. In this study, we investigated the role of the effector Mi2G02 in Meloidogyne incognita parasitism. Host-derived Mi2G02 RNA interference in Arabidopsis thaliana affected giant cell development, whereas ectopic expression of Mi2G02 promoted root growth and increased plant susceptibility to M. incognita. We used various combinations of approaches to study the specific interactions between Mi2G02 and A. thaliana GT-3a, a trihelix transcription factor. GT-3a knockout in A. thaliana affected feeding-site development, resulting in production of fewer egg masses, whereas GT-3a overexpression in A. thaliana increased susceptibility to M. incognita and also root growth. Moreover, we demonstrated that Mi2G02 plays a role in maintaining GT-3a protein stabilization by inhibiting the 26S proteasome-dependent pathway, leading to suppression of TOZ and RAD23C expression and thus promoting nematode parasitism. This work enhances our understanding of how a pathogen effector manipulates the role and regulation of a transcription factor by interfering with a proteolysis pathway to reprogram gene expression for development of nematode feeding cells.


Assuntos
Arabidopsis , Nematoides , Animais , Fatores de Transcrição/genética , Arabidopsis/genética , Plantas Geneticamente Modificadas , Interferência de RNA , Nematoides/genética
4.
New Phytol ; 240(6): 2468-2483, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37823217

RESUMO

Meloidogyne enterolobii is an emerging root-knot nematode species that overcomes most of the nematode resistance genes in crops. Nematode effector proteins secreted in planta are key elements in the molecular dialogue of parasitism. Here, we show the MeMSP1 effector is secreted into giant cells and promotes M. enterolobii parasitism. Using co-immunoprecipitation and bimolecular fluorescent complementation assays, we identified glutathione-S-transferase phi GSTFs as host targets of the MeMSP1 effector. This protein family plays important roles in plant responses to abiotic and biotic stresses. We demonstrate that MeMSP1 interacts with all Arabidopsis GSTF. Moreover, we confirmed that the N-terminal region of AtGSTF9 is critical for its interaction, and atgstf9 mutant lines are more susceptible to root-knot nematode infection. Combined transcriptome and metabolome analyses showed that MeMSP1 affects the metabolic pathways of Arabidopsis thaliana, resulting in the accumulation of amino acids, nucleic acids, and their metabolites, and organic acids and the downregulation of flavonoids. Our study has shed light on a novel effector mechanism that targets plant metabolism, reducing the production of plant defence-related compounds while favouring the accumulation of metabolites beneficial to the nematode, and thereby promoting parasitism.


Assuntos
Arabidopsis , Tylenchoidea , Animais , Arabidopsis/genética , Interações Hospedeiro-Parasita , Tylenchoidea/fisiologia , Glutationa Transferase/metabolismo , Glutationa/metabolismo , Doenças das Plantas/genética
5.
J Exp Bot ; 74(18): 5752-5766, 2023 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-37310189

RESUMO

Root-knot nematodes (RKN) from the genus Meloidogyne induce the dedifferentiation of root vascular cells into giant multinucleate feeding cells. These feeding cells result from an extensive reprogramming of gene expression, and auxin is known to be a key player in their development. However, little is known about how the auxin signal is transmitted during giant cell development. Integrative analyses combining transcriptome and small non-coding RNA datasets with the specific sequencing of cleaved transcripts identified genes targeted by miRNAs in tomato (Solanum lycopersicum) galls. The two auxin-responsive transcription factors ARF8A and ARF8B, and their miRNA167 regulators, were identified as robust gene-miRNA pair candidates to be involved in the tomato response to M. incognita. Spatiotemporal expression analysis using promoter-ß-glucuronidase (GUS) fusions showed the up-regulation of ARF8A and ARF8B in RKN-induced feeding cells and surrounding cells. The generation and phenotyping of CRISPR (clustered regularly interspaced palindromic repeats) mutants demonstrated the role of ARF8A and ARF8B in giant cell development and allowed the characterization of their downstream regulated genes.


Assuntos
MicroRNAs , Solanum lycopersicum , Tylenchoidea , Animais , Ácidos Indolacéticos/metabolismo , Solanum lycopersicum/genética , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Regulação da Expressão Gênica de Plantas , MicroRNAs/metabolismo , Tylenchoidea/fisiologia
6.
New Phytol ; 237(6): 2360-2374, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36457296

RESUMO

To establish persistent infections in host plants, herbivorous invaders, such as root-knot nematodes, must rely on effectors for suppressing damage-induced jasmonate-dependent host defenses. However, at present, the effector mechanisms targeting the biosynthesis of biologically active jasmonates to avoid adverse host responses are unknown. Using yeast two-hybrid, in planta co-immunoprecipitation, and mutant analyses, we identified 12-oxophytodienoate reductase 2 (OPR2) as an important host target of the stylet-secreted effector MiMSP32 of the root-knot nematode Meloidogyne incognita. MiMSP32 has no informative sequence similarities with other functionally annotated genes but was selected for the discovery of novel effector mechanisms based on evidence of positive, diversifying selection. OPR2 catalyzes the conversion of a derivative of 12-oxophytodienoate to jasmonic acid (JA) and operates parallel to 12-oxophytodienoate reductase 3 (OPR3), which controls the main pathway in the biosynthesis of jasmonates. We show that MiMSP32 targets OPR2 to promote parasitism of M. incognita in host plants independent of OPR3-mediated JA biosynthesis. Artificially manipulating the conversion of the 12-oxophytodienoate by OPRs increases susceptibility to multiple unrelated plant invaders. Our study is the first to shed light on a novel effector mechanism targeting this process to regulate the susceptibility of host plants.


Assuntos
Oxirredutases atuantes sobre Doadores de Grupo CH-CH , Tylenchoidea , Animais , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/metabolismo , Oxirredutases/metabolismo , Transporte Biológico , Tylenchoidea/fisiologia , Doenças das Plantas
7.
New Phytol ; 236(1): 283-295, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35801827

RESUMO

Root-knot nematodes (RKNs) are root endoparasites that induce the dedifferentiation of a few root cells and the reprogramming of their gene expression to generate giant hypermetabolic feeding cells. We identified two microRNA families, miR408 and miR398, as upregulated in Arabidopsis thaliana and Solanum lycopersicum roots infected by RKNs. In plants, the expression of these two conserved microRNA families is known to be activated by the SPL7 transcription factor in response to copper starvation. By combining functional approaches, we deciphered the network involving these microRNAs, their regulator and their targets. MIR408 expression was located within nematode-induced feeding cells like its regulator SPL7 and was regulated by copper. Moreover, infection assays with mir408 and spl7 knockout mutants or lines expressing targets rendered resistant to cleavage by miR398 demonstrated the essential role of the SPL7/MIR408/MIR398 module in the formation of giant feeding cells. Our findings reveal how perturbation of plant copper homeostasis, via the SPL7/MIR408/MIR398 module, modulates the development of nematode-induced feeding cells.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , MicroRNAs , Tylenchoidea , Animais , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Cobre/metabolismo , Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica de Plantas , MicroRNAs/genética , MicroRNAs/metabolismo , Raízes de Plantas/metabolismo , Fatores de Transcrição/metabolismo , Tylenchoidea/fisiologia
8.
Diagn Interv Radiol ; 28(2): 108-114, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35548894

RESUMO

PURPOSE This study aims to analyze the ability of quantitative dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to distinguish between prostate cancer (PCa) and benign lesions in transition zone (TZ) and peripheral zone (PZ) using different methods for arterial input function (AIF) determination. Study endpoints are identification of a standard AIF method and optimal quantitative perfusion parameters for PCa detection. METHODS DCE image data of 50 consecutive patients with PCa who underwent multiparametric MRI were analyzed retrospectively with three different methods of AIF acquisition. First, a region of interest was manually defined in an artery (AIFm); second, an automated algorithm was used (AIFa); and third, a population-based AIF (AIFp) was applied. Values of quantitative parameters after Tofts (Ktrans, ve, and kep) in PCa, PZ, and TZ in the three different AIFs were analyzed. RESULTS Ktrans and kep were significantly higher in PCa than in benign tissue independent from the AIF method. Whereas in PZ, Ktrans and kep could differentiate PCa (P < .001), in TZ only kep using AIFpdemonstrated a significant difference (P = .039). The correlations of the perfusion parameters that resulted from AIFm and AIFa were higher than those that resulted from AIFp, and the absolute values of Ktrans, kep, and ve were significantly lower when using AIFp. The values of quantitative perfusion parameters for PCa were similar regardless of whether PCa was located in PZ or TZ. CONCLUSION Ktrans and kep were able to differentiate PCa from benign PZ independent of the AIF method. AIFaseems to be the most feasible method of AIF determination in clinical routine. For TZ, none of the quantitative perfusion parameters provided satisfying results.


Assuntos
Meios de Contraste , Neoplasias da Próstata , Algoritmos , Artérias/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/patologia , Estudos Retrospectivos
9.
Plant Physiol ; 189(3): 1741-1756, 2022 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-35385078

RESUMO

Root-knot nematodes (RKNs) are among the most damaging pests of agricultural crops. Meloidogyne is an extremely polyphagous genus of nematodes that can infect thousands of plant species. A few genes for resistance (R-genes) to RKN suitable for use in crop breeding have been identified, but virulent strains and species of RKN have emerged that render these R-genes ineffective. Secretion of RKN effectors targeting plant functions mediates the reprogramming of root cells into specialized feeding cells, the giant cells, essential for RKN development and reproduction. Conserved targets among plant species define the more relevant strategies for controlling nematode infection. The EFFECTOR18 (EFF18) protein from M. incognita interacts with the spliceosomal small nuclear ribonucleoprotein D1 (SmD1) in Arabidopsis (Arabidopsis thaliana), disrupting its function in alternative splicing regulation and modulating the giant cell transcriptome. We show here that EFF18 is a conserved RKN-specific effector that targets this conserved spliceosomal SmD1 protein in Solanaceae. This interaction modulates alternative splicing events produced by tomato (Solanum lycopersicum) in response to M. incognita infection. The alteration of SmD1 expression by virus-induced gene silencing in Solanaceae affects giant cell formation and nematode development. Thus, our work defines a promising conserved SmD1 target gene to develop broad resistance for the control of Meloidogyne spp. in plants.


Assuntos
Arabidopsis , Solanum lycopersicum , Tylenchoidea , Animais , Arabidopsis/genética , Produtos Agrícolas , Interações Hospedeiro-Parasita/fisiologia , Solanum lycopersicum/genética , Melhoramento Vegetal , Doenças das Plantas/genética , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Ribonucleoproteínas Nucleares Pequenas/metabolismo , Tylenchoidea/fisiologia
10.
New Phytol ; 232(5): 2124-2137, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34449897

RESUMO

Root-knot nematodes, Meloidogyne spp., secrete effectors to modulate plant immune responses and establish a parasitic relationship with host plants. However, the functions and plant targets of C-type lectin (CTL)-like effectors of Meloidogyne incognita remain unknown. Here, we characterized a CTL-like effector of M. incognita, MiCTL1a, and identified its target and role in nematode parasitism. In situ hybridization demonstrated the expression of MiCTL1 in the subventral glands; and in planta, immunolocalization showed its secretion during M. incognita parasitism. Virus-induced gene silencing of the MiCTL1 reduced the infection ability of M. incognita in Nicotiana benthamiana. The ectopic expression in Arabidopsis not only increased susceptibility to M. incognita but also promoted root growth. Yeast two-hybrid and co-immunoprecipitation assays revealed that MiCTL1a interacts with Arabidopsis catalases, which play essential roles in hydrogen peroxide homeostasis. Knockout or overexpression of catalases showed either increased or reduced susceptibility to M. incognita, respectively. Moreover, MiCTL1a not only reduced catalase activity in vitro and in planta but also modulated stress-related gene expressions in Arabidopsis. Our data suggest that MiCTL1a interacts with plant catalases and interferes with catalase activity, allowing M. incognita to establish a parasitic relationship with its host by fine-tuning responses mediated by reactive oxygen species.


Assuntos
Tylenchoidea , Animais , Catalase , Proteínas de Helminto , Lectinas Tipo C , Doenças das Plantas
11.
Front Plant Sci ; 12: 641480, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33897729

RESUMO

Root-knot nematodes are obligate endoparasites that maintain a biotrophic relationship with their hosts over a period of several weeks. They induce the differentiation of root cells into specialized multinucleate hypertrophied feeding cells known as giant cells. Nematode effectors synthesized in the esophageal glands and injected into the plant tissue through the syringe-like stylet play a key role in giant cell ontogenesis. The Meloidogyne incognita MiEFF1 is one of the rare effectors of phytopathogenic nematodes to have been located in vivo in feeding cells. This effector specifically targets the giant cell nuclei. We investigated the Arabidopsis functions modulated by this effector, by using a yeast two-hybrid approach to identify its host targets. We characterized a universal stress protein (USP) and cytosolic glyceraldehyde-3-phosphate dehydrogenases (GAPCs) as the targets of MiEFF1. We validated the interaction of MiEFF1 with these host targets in the plant cell nucleus, by bimolecular fluorescence complementation (BiFC). A functional analysis with Arabidopsis GUS reporter lines and knockout mutant lines showed that GAPCs were induced in giant cells and that their non-metabolic functions were required for root-knot nematode infection. These susceptibility factors are potentially interesting targets for the development of new root-knot nematode control strategies.

12.
PLoS One ; 16(4): e0249532, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33819295

RESUMO

Dynamic contrast enhanced imaging (DCE) as an integral part of multiparametric prostate magnet resonance imaging (mpMRI) can be evaluated using qualitative, semi-quantitative, or quantitative assessment methods. Aim of this study is to analyze the clinical benefits of these evaluations of DCE regarding clinically significant prostate cancer (csPCa) detection and grading. 209 DCE data sets of 103 consecutive patients with mpMRI (T2, DWI, and DCE) and subsequent MRI-(in-bore)-biopsy were retrospectively analyzed. Qualitative DCE evaluation according to PI-RADS v2.1, semi-quantitative (curve type; DCE score according to PI-RADS v1), and quantitative Tofts analyses (Ktrans, kep, and ve) as well as PI-RADS v1 and v2.1 overall classification of 209 lesions (92 PCa, 117 benign lesions) were performed. Of each DCE assessment method, cancer detection, discrimination of csPCa, and localization were assessed and compared to histopathology findings. All DCE analyses (p<0.01-0.05), except ve (p = 0.02), showed significantly different results for PCa and benign lesions in the peripheral zone (PZ) with area under the curve (AUC) values of up to 0.92 for PI-RADS v2.1 overall classification. In the transition zone (TZ) only the qualitative DCE evalulation within PI-RADS (v1 and v2.1) could distinguish between PCa and benign lesions (p<0.01; AUC = 0.95). None of the DCE parameters could differentiate csPCa from non-significant (ns) PCa (p ≥ 0.1). Qualitative analysis of DCE within mpMRI according to PI-RADS version 2.1 showed excellent results regarding (cs)PCa detection. Semi-quantitative and quantitative parameters provided no additional improvements. DCE alone wasn't able to discriminate csPCa from nsPCa.


Assuntos
Meios de Contraste , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Biópsia Guiada por Imagem/métodos , Imageamento por Ressonância Magnética/métodos , Neoplasias da Próstata/patologia , Idoso , Humanos , Masculino , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/cirurgia , Estudos Retrospectivos
13.
Rofo ; 193(7): 763-777, 2021 Jul.
Artigo em Inglês, Alemão | MEDLINE | ID: mdl-33735931

RESUMO

The Working Group Uroradiology and Urogenital Diagnosis of the German Roentgen Society (DRG) revised and updated the recommendations for preparation and scanning protocol of the multiparametric MRI of the Prostate in a consensus process and harmonized it with the managing board of German Roentgen Society and Professional Association of the German Radiologist (BDR e. V.). These detailed recommendation define the referenced "validated quality standards" of the German S3-Guideline Prostate Cancer and describe in detail the topic 1. anamnestic datas, 2. termination of examinations and preparation of examinations, 3. examination protocol and 4. MRI-(in-bore)-biopsy. KEY POINTS:: · The recommendations for preparation and scanning protocol of the multiparametric MRI of the Prostate were revised and updated in a consensus process and harmonized with the managing board of German Roentgen Society (DRG) and Professional Asssociation of the German Radiologist (BDR).. · Detailed recommendations are given for topic 1. anamnestic datas, 2. termination and preparation of examinations, 3. examination protocoll and 4. MRI-(in-bore)-biopsy.. · These recommendations define the referenced "validated quality standards" of the German S3-Guideline Prostate Cancer.. CITATION FORMAT: · Franiel T, Asbach P, Beyersdorff D et al. mpMRI of the Prostate (MR-Prostatography): Updated Recommendations of the DRG and BDR on Patient Preparation and Examination Protocol. Fortschr Röntgenstr 2021; 193: 763 - 776.


Assuntos
Imageamento por Ressonância Magnética Multiparamétrica/métodos , Próstata/diagnóstico por imagem , Neoplasias da Próstata/diagnóstico por imagem , Biópsia por Agulha , Humanos , Masculino , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/terapia , Fatores de Risco , Sociedades Médicas
14.
New Phytol ; 229(6): 3408-3423, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33206370

RESUMO

The root-knot nematode Meloidogyne incognita secretes specific effectors (MiEFF) and induces the redifferentiation of plant root cells into enlarged multinucleate feeding 'giant cells' essential for nematode development. Immunolocalizations revealed the presence of the MiEFF18 protein in the salivary glands of M. incognita juveniles. In planta, MiEFF18 localizes to the nuclei of giant cells demonstrating its secretion during plant-nematode interactions. A yeast two-hybrid approach identified the nuclear ribonucleoprotein SmD1 as a MiEFF18 partner in tomato and Arabidopsis. SmD1 is an essential component of the spliceosome, a complex involved in pre-mRNA splicing and alternative splicing. RNA-seq analyses of Arabidopsis roots ectopically expressing MiEFF18 or partially impaired in SmD1 function (smd1b mutant) revealed the contribution of the effector and its target to alternative splicing and proteome diversity. The comparison with Arabidopsis galls data showed that MiEFF18 modifies the expression of genes important for giant cell ontogenesis, indicating that MiEFF18 modulates SmD1 functions to facilitate giant cell formation. Finally, Arabidopsis smd1b mutants exhibited less susceptibility to M. incognita infection, and the giant cells formed on these mutants displayed developmental defects, suggesting that SmD1 plays an important role in the formation of giant cells and is required for successful nematode infection.


Assuntos
Células Gigantes , Proteínas de Helminto , Doenças das Plantas/parasitologia , Proteínas de Plantas , Spliceossomos , Tylenchoidea , Animais , Arabidopsis , Interações Hospedeiro-Parasita , Solanum lycopersicum , Proteínas de Plantas/genética , Raízes de Plantas
15.
New Phytol ; 228(4): 1417-1430, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32542658

RESUMO

Large amounts of effectors are secreted by the oesophageal glands of plant-parasitic nematodes, but their molecular mode of action remains largely unknown. We characterized a Meloidogyne incognita protein disulphide isomerase (PDI)-like effector protein (MiPDI1) that facilitates nematode parasitism. In situ hybridization showed that MiPDI1 was expressed specifically in the subventral glands of M. incognita. It was significantly upregulated during parasitic stages. Immunolocalization demonstrated MiPDI1 secretion in planta during nematode migration and within the feeding cells. Host-induced silencing of the MiPDI1 gene affected the ability of the nematode to infect the host, whereas MiPDI1 expression in Arabidopsis increased susceptibility to M. incognita, providing evidence for a key role of MiPDI1 in M. incognita parasitism. Yeast two-hybrid, bimolecular fluorescence complementation and coimmunoprecipitation assays showed that MiPDI1 interacted with a tomato stress-associated protein (SlSAP12) orthologous to the redox-regulated AtSAP12, which plays an important role in plant responses to abiotic and biotic stresses. SAP12 silencing or knocking out in Nicotiana benthamiana and Arabidopsis increased susceptibility to M. incognita. Our results suggest that MiPDI1 acts as a pathogenicity factor promoting disease by fine-tuning SAP-mediated responses at the interface of redox signalling, defence and stress acclimation in Solanaceae and Arabidopsis.


Assuntos
Arabidopsis , Tylenchoidea , Animais , Arabidopsis/genética , Proteínas de Choque Térmico , Doenças das Plantas , Nicotiana
16.
Rofo ; 192(5): 441-447, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31622990

RESUMO

OBJECTIVE: To assess the impact of dynamic contrast-enhanced imaging (DCE) in mp-MRI on prostate cancer (PCa) detection in a large patient cohort assigned to PI-RADS category 4. METHOD: This retrospective, single center cohort study includes 193 consecutive patients with PI-RADS assessment category 4 in mp-MRI (T2WI, DWI, DCE) at 3 T with targeted plus systematic biopsy combined as the reference standard. The detection of prostate cancer with and without the use of DCE was compared. RESULTS: Overall, the PCa detection rate in PI-RADS-4 patients was 62 % (119/193) with DCE and 52 % (101/193) without the inclusion of lesions upgraded on the basis of DCE. 48 % (92/193) had clinically significant PCa (csPCa; Gleason score ≥ 3 + 4 = 7) and 40 % (78/193) without use of DCE. 38 of the 193 patients (20 %) had peripheral lesions upgraded from PI-RADS category 3 to an overall PI-RADS category 4 due to focal positive DCE findings. Of these 38 patients, 18 had PCa including 14 with csPCa. Thus, 15 % (18/119) of the patients with PCa and 15 % (14/92) of the patients with csPCa were detected only based on additional DCE information. CONCLUSION: DCE prevents underestimation and misclassification of a significant number of cases of peripheral csPCa and might improve detection rates in PI-RADS-4 patients. The current PI-RADS decision rules regarding upgrading PI-RADS-3 lesions to category 4 due to positive DCE imaging are useful for PCa detection. KEY POINTS: · Positive peripheral DCE upgraded 20 % of patients in PI-RADS category 4 from category 3.. · Clinically significant PCa was found in almost 40 % of upgraded, peripheral PIRADS-3-lesions.. · 15 % of all csPCa in PI-RADS-4-patients was detected in DCE-upgraded lesions.. · In 7 % of all PI-RADS-4-cases csPCa would had been underestimated without DCE upgrade.. CITATION FORMAT: · Ullrich T, Quentin M, Arsov C et al. Value of Dynamic Contrast-Enhanced (DCE) MR Imaging in Peripheral Lesions in PI-RADS-4 Patients. Fortschr Röntgenstr 2020; 192: 441 - 447.


Assuntos
Meios de Contraste , Imageamento por Ressonância Magnética/métodos , Neoplasias da Próstata/diagnóstico por imagem , Idoso , Biópsia , Estudos de Coortes , Humanos , Interpretação de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Próstata/diagnóstico por imagem , Próstata/patologia , Neoplasias da Próstata/patologia , Estudos Retrospectivos , Sensibilidade e Especificidade
17.
Front Plant Sci ; 10: 970, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31417587

RESUMO

Sedentary endoparasitic nematodes, such as root-knot nematodes (RKN; Meloidogyne spp.) and cyst nematodes (CN; Heterodera spp. and Globodera spp.) cause considerable damage to agricultural crops. RKN and CN spend most of their life cycle in plant roots, in which they induce the formation of multinucleate hypertrophied feeding cells, called "giant cells" and "syncytia," respectively. The giant cells result from nuclear divisions of vascular cells without cytokinesis. They are surrounded by small dividing cells and they form a new organ within the root known as a root knot or gall. CN infection leads to the fusion of several root cells into a unique syncytium. These dramatically modified host cells act as metabolic sinks from which the nematode withdraws nutrients throughout its life, and they are thus essential for nematode development. Both RKN and CN secrete effector proteins that are synthesized in the oesophageal glands and delivered to the appropriate cell in the host plant via a syringe-like stylet, triggering the ontogenesis of the feeding structures. Within the plant cell or in the apoplast, effectors associate with specific host proteins, enabling them to hijack important processes for cell morphogenesis and physiology or immunity. Here, we review recent findings on the identification and functional characterization of plant targets of RKN and CN effectors. A better understanding of the molecular determinants of these biotrophic relationships would enable us to improve the yields of crops infected with parasitic nematodes and to expand our comprehension of root development.

18.
Rofo ; 190(5): 419-426, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-28934811

RESUMO

PURPOSE: To assess the current regional acceptance, valuation, and clinical role of multiparametric MRI (mp-MRI) in prostate cancer diagnostics by patients and physicians. MATERIALS AND METHODS: Of 482 distributed standardized questionnaires, 328 patient and 31 physician questionnaires (urological and general practitioners in and around Düsseldorf) were analyzed over a period of 11 months. Questions were asked concerning general knowledge about prostate cancer, current diagnostic procedures, and knowledge about mp-MRI and MRI-guided biopsy. RESULTS: 70 % of the patients regarded accurate and exact diagnostics of prostate carcinomas as very important and 68 % considered MP-MRI a useful technique. 28 % of the patients with elevated PSA levels and negative transrectal ultrasound-guided biopsy (TRUS-GB) received MP-MRI as a secondary diagnostic. More than half of the patients estimated their overall knowledge about prostate cancer mediocre or worse and wished for more information about MR diagnostics. The majority of physicians (55 %) ordered MP-MRI studies of the prostate and 68 % saw their basic role in secondary diagnostics. CONCLUSION: In this regional assessment mp-MRI of the prostate was considered useful by patients and practitioners. Currently, there still is a considerable discrepancy between recommended and the actual number of conducted MP-MRI studies, particularly in patients after previous negative TRUS-GB, although practitioners already see the benefit in this patient collective. Even though the use of prostate MRI is frequently more established than suggested in the current German S3-guideline, its full potential has not yet been exploited. More comprehensive information about the applications and diagnostic benefits of prostate MRI is needed and desired among patients and physicians. KEY POINTS: · The use of prostate MRI is frequently more established than suggested in the current German S3-guideline (12/2016). · The full potential of mp-MRI of the prostate has not been exploited. · More information about the clinical benefit and potential of prostate MRI is necessary and desired by patients and clinicians. CITATION FORMAT: · Ullrich T, Schimmöller L, Oymanns M et al. Current Utilization and Acceptance of Multiparametric MRI in the Diagnosis of Prostate Cancer. A Regional Survey. Fortschr Röntgenstr 2018; 190: 419 - 426.


Assuntos
Atitude do Pessoal de Saúde , Letramento em Saúde , Imageamento por Ressonância Magnética/métodos , Imageamento por Ressonância Magnética/estatística & dados numéricos , Aceitação pelo Paciente de Cuidados de Saúde , Neoplasias da Próstata/diagnóstico por imagem , Idoso , Biópsia , Alemanha , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias da Próstata/patologia , Sensibilidade e Especificidade , Inquéritos e Questionários , Revisão da Utilização de Recursos de Saúde
19.
Bio Protoc ; 8(6): e2766, 2018 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-34179286

RESUMO

The spatio-temporal expression pattern of a gene provides important indications to better understand its biological function. In situ hybridization (ISH) uses a labeled complementary single-stranded RNA or DNA probe to localize gene transcripts in a whole organism, a whole organ or a section of tissue. We adapted the ISH technique to the plant parasite Meloidogyne spp. (root-knot nematode) to visualize RNAs both in free-living preparasitic juveniles and in parasitic stages settled in the plant tissues. We describe each step of the probe synthesis, digoxigenin (DIG) labeling, nematode extraction from plant tissue, and ISH procedure.

20.
Bio Protoc ; 8(10): e2844, 2018 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-34285965

RESUMO

Homeostasis between the cytoplasmic plant hormone salicylic acid (SA) and its' inactive, vacuolar storage forms, SA-2-O-ß-D-glucoside (SAG) and SA-ß-D-Glucose Ester (SGE), regulates the fine-tuning of defense responses to biotrophic pathogens in Arabidopsis thaliana. This protocol describes a simplified, optimized procedure to extract and quantify free SA and total hydrolyzable SA in plant tissues using a classical HPLC-based method.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...