scholarly journals Expression analysis of host defense responses against the 8K (KDa) cysteine-rich viral silencing suppressor protein in Nicotiana benthamiana

Plant Omics ◽  
2018 ◽  
Vol 11 (02) ◽  
pp. 113-119
Author(s):  
Aminallah Tahmasebi ◽  
◽  
Alireza Afsharifar ◽  
Ahmad Heydari ◽  
Mohammad Mehrabadi ◽  
...  
Keyword(s):  
Expression Analysis ◽  
Host Defense ◽  
Nicotiana Benthamiana ◽  
Defense Responses ◽  
Silencing Suppressor ◽  
Viral Silencing Suppressor

scholarly journals Potyviral Gene-Silencing Suppressor HCPro Interacts with Salicylic Acid (SA)-Binding Protein 3 to Weaken SA-Mediated Defense Responses

2018 ◽  
Vol 31 (1) ◽  
pp. 86-100 ◽  
Author(s):  
Sylvain Poque ◽  
Hui-Wen Wu ◽  
Chung-Hao Huang ◽  
Hao-Wen Cheng ◽  
Wen-Chi Hu ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Viral Infection ◽  
Host Defense ◽  
Binding Protein ◽  
Constitutive Expression ◽  
Defense Responses ◽  
Negative Regulator ◽  
Bimolecular Fluorescence Complementation ◽  
Silencing Suppressor ◽  
Ability To Act

The viral infection process is a battle between host defense response and pathogen antagonizing action. Several studies have established a tight link between the viral RNA silencing suppressor (RSS) and the repression of salicylic acid (SA)-mediated defense responses, nonetheless host factors directly linking an RSS and the SA pathway remains unidentified. From yeast two-hybrid analysis, we identified an interaction between the potyviral RSS helper-component proteinase (HCPro) and SA–binding protein SABP3. Co-localization and bimolecular fluorescence complementation analyses validated the direct in vivo interaction between Turnip mosaic virus (TuMV) HCPro and the Arabidopsis homologue of SABP3, AtCA1. Additionally, transient expression of TuMV HCPro demonstrated its ability to act as a negative regulator of AtCA1. When the plants of the AtCA1 knockout mutant line were inoculated with TuMV, our results indicated that AtCA1 is essential to restrict viral spreading and accumulation, induce SA accumulation, and trigger the SA pathway. Unexpectedly, the AtCA1 overexpression line also displayed a similar phenotype, suggesting that the constitutive expression of AtCA1 antagonizes the SA pathway. Taken together, our results depict AtCA1 as an essential regulator of SA defense responses. Moreover, the interaction of potyviral HCPro with this regulator compromises the SA pathway to weaken host defense responses and facilitate viral infection.

scholarly journals A Conserved Carboxylesterase Inhibits Tobacco mosaic virus (TMV) Accumulation in Nicotiana benthamiana Plants

Viruses ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 195
Author(s):  
Song Guo ◽  
Sek-Man Wong
Keyword(s):  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Host Defense ◽  
Nicotiana Benthamiana ◽  
Tobacco Rattle Virus ◽  
Defense Responses ◽  
Transcriptional Level ◽  
Carboxylic Ester ◽  
Rna Accumulation

A carboxylesterase (CXE) or carboxylic-ester hydrolase is an enzyme that catalyzes carboxylic ester and water into alcohol and carboxylate. In plants, CXEs have been implicated in defense, development, and secondary metabolism. We discovered a new CXE gene in Nicotiana benthamiana that is related to virus resistance. The transcriptional level of NbCXE expression was significantly increased after Tobacco mosaic virus (TMV) infection. Transient over-expression of NbCXE inhibited TMV accumulation in N. benthamiana plants. Conversely, when the NbCXE gene was silenced with a Tobacco rattle virus (TRV)-based gene silencing system, TMV RNA accumulation was increased in NbCXE-silenced plants after infection. NbCXE protein was shown to interact with TMV coat protein (CP) in vitro. Additionally, the expressions of host defense-related genes were increased in transient NbCXE-overexpressed plants but decreased in NbCXE silenced N. benthamiana plants. In summary, our study showed that NbCXE is a novel resistance-related gene involved in host defense responses against TMV infection.

scholarly journals Advanced Engineering of Lipid Metabolism in Nicotiana benthamiana Using a Draft Genome and the V2 Viral Silencing-Suppressor Protein

PLoS ONE ◽  
2012 ◽  
Vol 7 (12) ◽  
pp. e52717 ◽  
Author(s):  
Fatima Naim ◽  
Kenlee Nakasugi ◽  
Ross N. Crowhurst ◽  
Elena Hilario ◽  
Alexander B. Zwart ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
Nicotiana Benthamiana ◽  
Draft Genome ◽  
Silencing Suppressor ◽  
Viral Silencing Suppressor

scholarly journals Recovery of Nicotiana benthamiana Plants from a Necrotic Response Induced by a Nepovirus Is Associated with RNA Silencing but Not with Reduced Virus Titer

2007 ◽  
Vol 81 (22) ◽  
pp. 12285-12297 ◽  
Author(s):  
Juan Jovel ◽  
Melanie Walker ◽  
Hélène Sanfaçon
Keyword(s):  
Host Defense ◽  
Nicotiana Benthamiana ◽  
Rna Silencing ◽  
Defense Mechanism ◽  
Fluorescent Protein ◽  
Virus Titer ◽  
Defense Responses ◽  
Viral Rna ◽  
Small Interfering Rnas ◽  
Green Fluorescent

ABSTRACT Recovery of plants from virus-induced symptoms is often described as a consequence of RNA silencing, an antiviral defense mechanism. For example, recovery of Nicotiana clevelandii from a nepovirus (tomato black ring virus) is associated with a decreased viral RNA concentration and sequence-specific resistance to further virus infection. In this study, we have characterized the interaction of another nepovirus, tomato ringspot virus (ToRSV), with host defense responses during symptom induction and subsequent recovery. Early in infection, ToRSV induced a necrotic phenotype in Nicotiana benthamiana that showed characteristics typical of a hypersensitive response. RNA silencing was also activated during ToRSV infection, as evidenced by the presence of ToRSV-derived small interfering RNAs (siRNAs) that could direct degradation of ToRSV sequences introduced into sensor constructs. Surprisingly, disappearance of symptoms was not accompanied by a commensurate reduction in viral RNA levels. The stability of ToRSV RNA after recovery was also observed in N. clevelandii and Cucumis sativus and in N. benthamiana plants carrying a functional RNA-dependent RNA polymerase 1 ortholog from Medicago truncatula. In experiments with a reporter transgene (green fluorescent protein), ToRSV did not suppress the initiation or maintenance of transgene silencing, although the movement of the silencing signal was partially hindered. Our results demonstrate that although RNA silencing is active during recovery, reduction of virus titer is not required for the initiation of this phenotype. This scenario adds an unforeseen layer of complexity to the interaction of nepoviruses with the host RNA silencing machinery. The possibility that viral proteins, viral RNAs, and/or virus-derived siRNAs inactivate host defense responses is discussed.

scholarly journals Core RNA Interference Genes Involved in miRNA and Ta-siRNA Biogenesis in Hops and Their Expression Analysis after Challenging with Verticillium nonalfalfae

2021 ◽  
Vol 22 (8) ◽  
pp. 4224
Author(s):  
Urban Kunej ◽  
Jernej Jakše ◽  
Sebastjan Radišek ◽  
Nataša Štajner
Keyword(s):  
Rna Interference ◽  
Expression Analysis ◽  
Cannabis Sativa ◽  
Defense Responses ◽  
Resistant Cultivar ◽  
Post Inoculation ◽  
Biotic Stresses ◽  
Argonaute 2 ◽  
Expression Of Genes ◽  
Verticillium Nonalfalfae

RNA interference is an evolutionary conserved mechanism by which organisms regulate the expression of genes in a sequence-specific manner to modulate defense responses against various abiotic or biotic stresses. Hops are grown for their use in brewing and, in recent years, for the pharmaceutical industry. Hop production is threatened by many phytopathogens, of which Verticillium, the causal agent of Verticillium wilt, is a major contributor to yield losses. In the present study, we performed identification, characterization, phylogenetic, and expression analyses of three Argonaute, two Dicer-like, and two RNA-dependent RNA polymerase genes in the susceptible hop cultivar Celeia and the resistant cultivar Wye Target after infection with Verticillium nonalfalfae. Phylogeny results showed clustering of hop RNAi proteins with their orthologues from the closely related species Cannabis sativa, Morus notabilis and Ziziphus jujuba which form a common cluster with species of the Rosaceae family. Expression analysis revealed downregulation of argonaute 2 in both cultivars on the third day post-inoculation, which may result in reduced AGO2-siRNA-mediated posttranscriptional gene silencing. Both cultivars may also repress ta-siRNA biogenesis at different dpi, as we observed downregulation of argonaute 7 in the susceptible cultivar on day 1 and downregulation of RDR6 in the resistant cultivar on day 3 after inoculation.

scholarly journals Paracoccidioides spp. catalases and their role in antioxidant defense against host defense responses

2017 ◽  
Vol 100 ◽  
pp. 22-32 ◽  
Author(s):  
Diana Tamayo ◽  
José F. Muñoz ◽  
Agostinho J. Almeida ◽  
Juan D. Puerta ◽  
Ángela Restrepo ◽  
...  
Keyword(s):  
Host Defense ◽  
Antioxidant Defense ◽  
Defense Responses ◽  
Paracoccidioides Spp

scholarly journals High-level HIV-1 Nef transient expression in Nicotiana benthamiana using the P19 gene silencing suppressor protein of Artichoke Mottled Crinckle Virus

2009 ◽  
Vol 9 (1) ◽  
pp. 96 ◽  
Author(s):  
Raffaele Lombardi ◽  
Patrizia Circelli ◽  
Maria Villani ◽  
Giampaolo Buriani ◽  
Luca Nardi ◽  
...  
Keyword(s):  
Gene Silencing ◽  
Transient Expression ◽  
Nicotiana Benthamiana ◽  
Silencing Suppressor ◽  
High Level ◽  
Hiv 1

Staphylococcal enterotoxin B induces fever, brain c-Fos expression, and serum corticosterone in rats

2001 ◽  
Vol 280 (5) ◽  
pp. R1434-R1439 ◽  
Author(s):  
Lisa E. Goehler ◽  
Ron P. A. Gaykema ◽  
Michael K. Hansen ◽  
Jayme L. Kleiner ◽  
Steven F. Maier ◽  
...  
Keyword(s):  
T Cell ◽  
Host Defense ◽  
Intraperitoneal Injection ◽  
Defense Responses ◽  
Plasma Corticosterone ◽  
Significant Rise ◽  
Staphylococcal Enterotoxin ◽  
Staphylococcal Enterotoxin B ◽  
Enterotoxin B ◽  
Fos Expression

The paraventricular nucleus of the hypothalamus (PVH) occupies a pivotal point within the network of brain nuclei coordinating critical host-defense responses. In mice, T cell-dependent immune stimuli, including the bacterial superantigen staphylococcal enterotoxin B (SEB), can activate the PVH. To determine whether T cell-dependent immune stimuli activate the PVH in rats, we assessed plasma corticosterone (Cort) levels, fever responses, and c-Fos expression in the PVH in animals treated with intraperitoneal injections of SEB. In animals with previously implanted abdominal thermisters, intraperitoneal injection of 1 mg/kg SEB resulted in a significant rise in body temperature, with a latency of 3.5–4 h. In separate animals, intraperitoneal injection of 1 mg/kg SEB resulted in a significant elevation of plasma Cort and induced c-Fos expression in parvocellular neurons within the PVH. These results support the idea that T cell-dependent immune stimuli activate brain pathways mediating host-defense responses such as fever and neuroendocrine changes.

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