scholarly journals Role of the Variable Domain in Modulating Potato Spindle Tuber Viroid Replication

Virology ◽  
1996 ◽  
Vol 219 (1) ◽  
pp. 45-56 ◽  
Author(s):  
YI HU ◽  
PAUL A. FELDSTEIN ◽  
PAUL J. BOTTINO ◽  
ROBERT A. OWENS
Keyword(s):  
Potato Spindle Tuber Viroid ◽  
Variable Domain ◽  
Viroid Replication

scholarly journals Suppression of RNA-Dependent RNA Polymerase 6 Favors the Accumulation of Potato Spindle Tuber Viroid in Nicotiana Benthamiana

Viruses ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 345 ◽  
Author(s):  
Charith Raj Adkar-Purushothama ◽  
Jean-Pierre Perreault
Keyword(s):  
Nicotiana Benthamiana ◽  
Small Rnas ◽  
Rna Viruses ◽  
Fold Increase ◽  
Potato Spindle Tuber Viroid ◽  
Rna Dependent Rna Polymerase ◽  
Viroid Infection ◽  
Genes Encoding ◽  
Plant Genes

To date, two plant genes encoding RNA-dependent RNA polymerases (RdRs) that play major roles in the defense against RNA viruses have been identified: (i) RdR1, which is responsible for the viral small RNAs (vsRNAs) found in virus-infected plants, and, (ii) RdR6, which acts as a surrogate in the absence of RdR1. In this study, the role of RdR6 in the defense against viroid infection was examined by knock-down of RdR6 followed by potato spindle tuber viroid (PSTVd) infection. The suppression of RdR6 expression increased the plant’s growth, as was illustrated by the plant’s increased height. PSTVd infection of RdR6 compromised plants resulted in an approximately three-fold increase in the accumulation of viroid RNA as compared to that seen in control plants. Additionally, RNA gel blot assay revealed an increase in the number of viroids derived small RNAs in RdR6 suppressed plants as compared to control plants. These data provide a direct correlation between RdR6 and viroid accumulation and indicate the role of RDR6 in the plant’s susceptibility to viroid infection.

scholarly journals RNAi-Mediated Down-Regulation of Dicer-Like 2 and 4 Changes the Response of ‘Moneymaker’ Tomato to Potato Spindle Tuber Viroid Infection from Tolerance to Lethal Systemic Necrosis, Accompanied by Up-Regulation of miR398, 398a-3p and Production of Excessive Amount of Reactive Oxygen Species

Viruses ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 344 ◽  
Author(s):  
Takahiro Suzuki ◽  
Sho Ikeda ◽  
Atsushi Kasai ◽  
Akito Taneda ◽  
Misato Fujibayashi ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Reactive Oxygen ◽  
Potato Spindle Tuber Viroid ◽  
Ros Production ◽  
Oxygen Species ◽  
Superoxide Dismutase 1 ◽  
Systemic Necrosis ◽  
Viroid Infection ◽  
Infected Line

To examine the role of RNA silencing in plant defenses against viroids, a Dicer-like 2 and 4 (DCL2&4)–double knockdown transgenic tomato plant line, 72E, was created. The expression of endogenous SlDCL2s and SlDCL4 in line 72E decreased to about a half that of the empty cassette line, EC. When challenged with potato spindle tuber viroid (PSTVd), line 72E showed significantly higher levels of PSTVd accumulation early in the course of the infection and lethal systemic necrosis late in the infection. The size distribution of PSTVd-derived small RNAs was significantly different with the number of RNAs of 21 and 22 nucleotides (nt) in line 72E, at approximately 66.7% and 5% of those in line EC, respectively. Conversely, the numbers of 24 nt species increased by 1100%. Furthermore, expression of the stress-responsive microRNA species miR398 and miR398a-3p increased 770% and 868% in the PSTVd-infected line 72E compared with the PSTVd-infected EC. At the same time, the expression of cytosolic and chloroplast-localized Cu/Zn-superoxide dismutase 1 and 2 (SOD1 and SOD2) and the copper chaperon for SOD (CCS1) mRNAs, potential targets of miR398 or 398a-3p, decreased significantly in the PSTVd-infected line 72E leaves, showing necrosis. In concert with miR398 and 398a-3p, SODs control the detoxification of reactive oxygen species (ROS) generated in cells. Since high levels of ROS production were observed in PSTVd-infected line 72E plants, it is likely that the lack of full dicer-likes (DCL) activity in these plants made them unable to control excessive ROS production after PSTVd infection, as disruption in the ability of miR398 and miR398a-3p to regulate SODs resulted in the development of lethal systemic necrosis.

An investigation of the role of the adiponectin variable domain on the stability of the collagen-like domain

Biopolymers ◽  
2014 ◽  
Vol 102 (4) ◽  
pp. 313-321 ◽  
Author(s):  
Paul W. R. Harris ◽  
Lutz Hampe ◽  
Mazdak Radjainia ◽  
Margaret A. Brimble ◽  
Alok K. Mitra
Keyword(s):  
Variable Domain ◽  
The Stability

scholarly journals Virp1 Is a Host Protein with a Major Role in Potato Spindle Tuber Viroid Infection in Nicotiana Plants

2007 ◽  
Vol 81 (23) ◽  
pp. 12872-12880 ◽  
Author(s):  
K. Kalantidis ◽  
M. A. Denti ◽  
S. Tzortzakaki ◽  
E. Marinou ◽  
M. Tabler ◽  
...  
Keyword(s):  
Rna Binding ◽  
Potato Spindle Tuber Viroid ◽  
Plant Diseases ◽  
Host Protein ◽  
Rna Molecules ◽  
Viroid Infection ◽  
Transgenic Lines ◽  
Localization Signal ◽  
Positive Strand Rna

ABSTRACT Viroids are small, circular, single-stranded RNA molecules that, while not coding for any protein, cause several plant diseases. Viroids rely for their infectious cycle on host proteins, most of which are likely to be involved in endogenous RNA-mediated phenomena. Therefore, characterization of host factors interacting with the viroid may contribute to the elucidation of RNA-related pathways of the hosts. Potato spindle tuber viroid (PSTVd) infects several members of the Solanaceae family. In an RNA ligand screening we have previously isolated the tomato protein Virp1 by its ability to specifically interact with PSTVd positive-strand RNA. Virp1 is a bromodomain-containing protein with an atypical RNA binding domain and a nuclear localization signal. Here we investigate the role of Virp1 in the viroid infection cycle by the use of transgenic lines of Nicotiana tabacum and Nicotiana benthamiana that either overexpress the tomato Virp1 RNA or suppress the orthologous Nicotiana genes through RNA silencing. Plants of the Virp1-suppressed lines were not infected by PSTVd or Citrus exocortis viroid through mechanical inoculation, indicating a major role of Virp1 in viroid infection. On the other hand, overexpression of tomato Virp1 in N. tabacum and N. benthamiana plants did not affect PSTVd KF 440-2 infectivity or symptomatology in these species. Transfection experiments with isolated protoplasts revealed that Virp1-suppressed cells were unable to sustain viroid replication, suggesting that resistance to viroid infection in Virp1-suppressed plants is likely the result of cell-autonomous events.

scholarly journals Tomato RNA polymerase II interacts with the rod-like conformation of the left terminal domain of the potato spindle tuber viroid positive RNA genome

2012 ◽  
Vol 93 (7) ◽  
pp. 1591-1600 ◽  
Author(s):  
Teodora Bojić ◽  
Yasnee Beeharry ◽  
Da Jiang Zhang ◽  
Martin Pelchat
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Potato Spindle Tuber Viroid ◽  
Site Directed Mutagenesis ◽  
Terminal Domain ◽  
Non Coding Rna ◽  
Rna Genome ◽  
Rnap Ii ◽  
Carboxy Terminal

Potato spindle tuber viroid (PSTVd) is a small, single-stranded, circular, non-coding RNA pathogen. Host DNA-dependent RNA polymerase II (RNAP II) was proposed to be critical for its replication, but no interaction site for RNAP II on the PSTVd RNA genome was identified. Using a co-immunoprecipitation strategy involving a mAb specific for the conserved heptapeptide (i.e. YSPTSPS) located at the carboxy-terminal domain of the largest subunit of RNAP II, we established the interaction of tomato RNAP II with PSTVd RNA and showed that RNAP II associates with the left terminal domain of PSTVd (+) RNA. RNAP II did not interact with any of several PSTVd (−) RNAs tested. Deletion and site-directed mutagenesis of a shortened model PSTVd (+) RNA fragment were used to identify the role of specific nucleotides and structural motifs in this interaction. Our results provide evidence for the interaction of a RNAP II complex from a natural host with the rod-like conformation of the left terminal domain of PSTVd (+) RNA.

scholarly journals RNAi-Mediated Down-Regulation of Dicer-Like 2 and 4 Changes the Response of “Moneymaker” Tomato to Potato Spindle Tuber Viroid Infection from Tolerance to Lethal Systemic Necrosis, Accompanied by Up-Regulation of miR398a-3p and Reactive Oxygen Species

2018 ◽  
Author(s):  
Takairo Suzuki ◽  
Sho Ikeda ◽  
Atsushi Kasai ◽  
Akito Taneda ◽  
Kohei Sugawara ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Rna Silencing ◽  
Reactive Oxygen ◽  
Potato Spindle Tuber Viroid ◽  
Ros Production ◽  
Oxygen Species ◽  
Systemic Necrosis ◽  
Tomato Line ◽  
Viroid Infection

To examine the role of RNA silencing in defense against viroid, a Dicer-like 2 and 4 (DCL2&4)—double knockdown transgenic tomato line 72E was created. The expression of endogenous DCL2 and DCL4 in line 72E decreased to about a half of the empty cassette line EC. When challenged with potato spindle tuber viroid (PSTVd), 72E allowed significantly higher level of PSTVd accumulation early in infection and showed lethal systemic necrosis. The size distribution of PSTVd-derived small RNA was significantly changed: the numbers of 21 and 22 nucleotides (nt) species in line 72E was approximately 66.7% and 5% of those in line EC, respectively. Conversely, the numbers of 24-nt species increased by 1100%. Furthermore, expression of miR398a-3p and miR398 increased 770–868% in the PSTVd-infected 72E, compared to the PSTVd-infected EC. In parallel, superoxide dismutase (SOD1) in PSTVd-infected 72E showed higher expression levels. In concert with miR398a-3p, SOD1 controls detoxification of reactive oxygen species (ROS) generated in cells. Since high levels of ROS production and its scavenging activity were observed in PSTVd-infected 72E, the lack of full-activity of DCLs was thought to have made the plant incapable to control excessive ROS production and thus resulted in to develop lethal systemic necrosis.

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