Faculty Opinions recommendation of A multifunctional protein encoded by turkey herpesvirus suppresses RNA silencing in Nicotiana benthamiana.

RNA silencing suppressor genes derived from six virus genera were transformed into Nicotiana benthamiana and N. tabacum plants. These suppressors were P1 of Rice yellow mottle virus (RYMV), P1 of Cocksfoot mottle virus, P19 of Tomato bushy stunt virus, P25 of Potato virus X, HcPro of Potato virus Y (strain N), 2b of Cucumber mosaic virus (strain Kin), and AC2 of African cassava mosaic virus (ACMV). HcPro caused the most severe phenotypes in both Nicotiana spp. AC2 also produced severe effects in N. tabacum but a much milder phenotype in N. benthamiana, although both HcPro and AC2 affected the leaf tissues of the two Nicotiana spp. in similar ways, causing hyperplasia and hypoplasia, respectively. P1-RYMV caused high lethality in the N. benthamiana plants but only mild effects in the N. tabacum plants. Phenotypic alterations produced by the other transgenes were minor in both species. Interestingly, the suppressors had very different effects on crucifer-infecting Tobamovirus (crTMV) infections. AC2 enhanced both spread and brightness of the crTMV-green fluorescent protein (GFP) lesions, whereas 2b and both P1 suppressors enhanced spread but not brightness of these lesions. P19 promoted spread of the infection into new foci within the infiltrated leaf, whereas HcPro and P25 suppressed the spread of crTMV-GFP lesions.

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The Consensus N-Myristoylation Motif of a Geminivirus AC4 Protein Is Required for Membrane Binding and Pathogenicity

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-20-4-0380 ◽

2007 ◽

Vol 20 (4) ◽

pp. 380-391 ◽

Cited By ~ 50

Author(s):

Vincent N. Fondong ◽

R. V. Chowda Reddy ◽

Cheng Lu ◽

Bertrand Hankoua ◽

Christian Felton ◽

...

Keyword(s):

Plasma Membrane ◽

Membrane Protein ◽

Nicotiana Benthamiana ◽

Rna Silencing ◽

Membrane Binding ◽

Confocal Imaging ◽

East African ◽

Intrinsic Signals ◽

Pathogenicity Determinant ◽

Silencing Suppression

Some geminiviruses encode a small protein, AC4, whose role in pathogenesis has only recently attracted attention. A few studies have shown that this protein is involved in pathogenesis and suppresses RNA silencing. Here, using Nicotiana benthamiana, we show that East African cassava mosaic Cameroon virus (EACMCV) AC4 is a pathogenicity determinant and that it suppresses the systemic phase of RNA silencing. Furthermore, confocal imaging analyses show that it binds preferentially to the plasma membrane as well as to cytosolic membranes including the perinucleus but is excluded from the nucleus. A computational examination of the AC4 protein encoded by the EACMCV, a bipartite geminivirus, shows that it encodes a consensus N-myristoylation motif and is likely posttranslationally myristoylated and palmitoylated. Replacement of Gly-2 and Cys-3 (sites of posttranslational attachment of myristic and palmatic acids, respectively) with alanine affected AC4 membrane binding and pathogenesis. Furthermore, replacement of Ile-5, a nonessential myristoylation residue, with alanine did not affect AC4 function. Together, these data indicate that EACMCV AC4 is likely dually acylated at Gly-2 and Cys-3 and that these modifications are intrinsic signals for membrane targeting and pathogenesis. This is the first report of a membrane protein to be involved in pathogenesis and RNA silencing suppression.

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Involvement of RDR6 in short-range intercellular RNA silencing in Nicotiana benthamiana

Scientific Reports ◽

10.1038/srep00467 ◽

2012 ◽

Vol 2 (1) ◽

Cited By ~ 15

Author(s):

Cheng Qin ◽

Nongnong Shi ◽

Mei Gu ◽

Hang Zhang ◽

Bin Li ◽

...

Keyword(s):

Nicotiana Benthamiana ◽

Rna Silencing ◽

Short Range

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Evidence That RNA Silencing-Mediated Resistance to Beet necrotic yellow vein virus Is Less Effective in Roots Than in Leaves

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-18-0194 ◽

2005 ◽

Vol 18 (3) ◽

pp. 194-204 ◽

Cited By ~ 71

Author(s):

Ida Bagus Andika ◽

Hideki Kondo ◽

Tetsuo Tamada

Keyword(s):

Nicotiana Benthamiana ◽

Rna Silencing ◽

Defense Mechanism ◽

Virus Titer ◽

Virus Multiplication ◽

Open Reading Frame ◽

Yellow Vein ◽

Polymyxa Betae ◽

Small Interfering Rnas ◽

Reading Frame

In plants, RNA silencing is part of a defense mechanism against virus infection but there is little information as to whether RNA silencing-mediated resistance functions similarly in roots and leaves. We have obtained transgenic Nicotiana benthamiana plants encoding the coat protein readthrough domain open reading frame (54 kDa) of Beet necrotic yellow vein virus (BNYVV), which either showed a highly resistant or a recovery phenotype following foliar rub-inoculation with BNYVV. These phenotypes were associated with an RNA silencing mechanism. Roots of the resistant plants that were immune to foliar rub-inoculation with BNYVV could be infected by viruliferous zoospores of the vector fungus Polymyxa betae, although virus multiplication was greatly limited. In addition, virus titer was reduced in symptomless leaves of the plants showing the recovery phenotype, but it was high in roots of the same plants. Compared with leaves of silenced plants, higher levels of transgene mRNAs and lower levels of transgene-derived small interfering RNAs (siRNAs) accumulated in roots. Similarly, in nontransgenic plants inoculated with BNYVV, accumulation level of viral RNA-derived siRNAs in roots was lower than in leaves. These results indicate that the RNA silencing-mediated resistance to BNYVV is less effective in roots than in leaves.

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Inhibition of long-distance movement of RNA silencing signals in Nicotiana benthamiana by Apple chlorotic leaf spot virus 50 kDa movement protein

Virology ◽

10.1016/j.virol.2008.09.024 ◽

2008 ◽

Vol 382 (2) ◽

pp. 199-206 ◽

Cited By ~ 15

Author(s):

Hajime Yaegashi ◽

Akihiro Tamura ◽

Masamichi Isogai ◽

Nobuyuki Yoshikawa

Keyword(s):

Leaf Spot ◽

Nicotiana Benthamiana ◽

Rna Silencing ◽

Movement Protein ◽

Long Distance ◽

Spot Virus ◽

Chlorotic Leaf ◽

Long Distance Movement

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The NLR helper protein NRC3 but not NRC1 is required for Pto-mediated cell death in Nicotiana benthamiana

10.1101/015479 ◽

2015 ◽

Author(s):

Chih-Hang Wu ◽

Khaoula Belhaj ◽

Tolga O. Bozkurt ◽

Sophien Kamoun

Keyword(s):

Cell Death ◽

Nicotiana Benthamiana ◽

Rna Silencing ◽

Genetic Complementation ◽

Hypersensitive Cell Death ◽

Immune Receptors ◽

Disease Resistance Protein ◽

Resistance Protein ◽

Solanaceous Plants ◽

Lrr Protein

Intracellular immune receptors of the nucleotide-binding leucine-rich repeat (NB-LRR or NLR) proteins often function in pairs, with "helper" proteins required for the activity of "sensors" that mediate pathogen recognition. The NLR helper NRC1 (NB-LRR protein required for HR-associated cell death 1) has been described as a signalling hub required for the cell death mediated by both cell surface and intracellular immune receptors in the model plant Nicotiana benthamiana. However, this work predates the availability of the N. benthamiana genome and whether NRC1 is indeed required for the reported phenotypes has not been confirmed. Here, we investigated the NRC family of solanaceous plants using a combination of genome annotation, phylogenetics, gene silencing and genetic complementation experiments. We discovered that a paralog of NRC1, we termed NRC3, is required for the hypersensitive cell death triggered by the disease resistance protein Pto but not Rx and Mi-1.2. NRC3 may also contribute to the hypersensitive cell death triggered by the receptor-like protein Cf-4. Our results highlight the importance of applying genetic complementation to validate gene function in RNA silencing experiments.

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