scholarly journals Suppressor activity of potyviral and cucumoviral infections in potyvirus-induced transgene silencing

2003 ◽  
Vol 84 (10) ◽  
pp. 2877-2883 ◽  
Author(s):  
Carmen Simón-Mateo ◽  
Juan José López-Moya ◽  
Hui Shan Guo ◽  
Elena González ◽  
Juan Antonio García
Keyword(s):  
Virus Resistance ◽  
Rna Silencing ◽  
Infected Plant ◽  
Transgene Silencing ◽  
Plum Pox Virus ◽  
Silencing Suppressor ◽  
Suppressor Activity ◽  
Interesting Phenomenon ◽  
Resistance Phenotype ◽  
Tobacco Vein Mottling Virus

The process known as ‘recovery’ by which virus-infected plants become resistant to the infection is an interesting phenomenon where both RNA silencing and virus resistance fully converge. In a previous study, we showed that transgenic Nicotiana benthamiana NIbV3 plants, transformed with a mutated NIb coding sequence from Plum pox virus (PPV), showed a delayed, very specific, resistance phenotype, which was induced by the initial infection. This recovery was the consequence of the activation of an RNA silencing mechanism in the PPV-infected plant, which took place even though PPV encodes a silencing suppressor (HCPro). Making use of plants regenerated from the recovered tissue, which maintained the transgene silencing/virus resistance phenotype, we have demonstrated that both Cucumber mosaic virus (CMV) and Tobacco vein mottling virus (TVMV), expressing the silencing suppressor 2b and HCPro, respectively, were able to reactivate transgene expression. Surprisingly, only the silencing suppression caused by CMV, but not that originating from TVMV, was able to revert the recovered NIbV3 plants to a PPV-susceptible phenotype.

scholarly journals A critical domain of theCucumber mosaic virus2b protein for RNA silencing suppressor activity

FEBS Letters ◽  
2008 ◽  
Vol 583 (1) ◽  
pp. 101-106 ◽  
Author(s):  
Jian Ye ◽  
Jing Qu ◽  
Jian-Feng Zhang ◽  
Yun-Feng Geng ◽  
Rong-Xiang Fang
Keyword(s):  
Rna Silencing ◽  
Silencing Suppressor ◽  
Suppressor Activity ◽  
Critical Domain ◽  
Rna Silencing Suppressor

scholarly journals The Cucumber vein yellowing virus Silencing Suppressor P1b Can Functionally Replace HCPro in Plum pox virus Infection in a Host-Specific Manner

2012 ◽  
Vol 25 (2) ◽  
pp. 151-164 ◽  
Author(s):  
Alberto Carbonell ◽  
Gabriela Dujovny ◽  
Juan Antonio García ◽  
Adrian Valli
Keyword(s):  
Rna Silencing ◽  
Deleterious Effect ◽  
Prunus Persica ◽  
Plant Viruses ◽  
Natural Host ◽  
Plum Pox Virus ◽  
Silencing Suppressor ◽  
Specific Manner ◽  
Silencing Suppression ◽  
Yellowing Virus

Plant viruses of the genera Potyvirus and Ipomovirus (Potyviridae family) use unrelated RNA silencing suppressors (RSS) to counteract antiviral RNA silencing responses. HCPro is the RSS of Potyvirus spp., and its activity is enhanced by the upstream P1 protein. Distinctively, the ipomovirus Cucumber vein yellowing virus (CVYV) lacks HCPro but contains two P1 copies in tandem (P1aP1b), the second of which functions as RSS. Using chimeras based on the potyvirus Plum pox virus (PPV), we found that P1b can functionally replace HCPro in potyviral infections of Nicotiana plants. Interestingly, P1a, the CVYV protein homologous to potyviral P1, disrupted the silencing suppression activity of P1b and reduced the infection efficiency of PPV in Nicotiana benthamiana. Testing the influence of RSS in host specificity, we found that a P1b-expressing chimera poorly infected PPV's natural host, Prunus persica. Conversely, P1b conferred on PPV chimeras the ability to replicate locally in cucumber, CVYV's natural host. The deleterious effect of P1a on PPV infection is host dependent, because the P1aP1b-expressing PPV chimera accumulated in cucumber to higher levels than PPV expressing P1b alone. These results demonstrate that a potyvirus can use different RSS, and that particular RSS and upstream P1-like proteins contribute to defining the virus host range.

scholarly journals Short interfering RNAs are Associated with Virus Resistance in a Woody Perennial Fruit Tree (Prunus domestica)

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 862D-862
Author(s):  
Jean-Michel Hily ◽  
Ralph Scorza* ◽  
Michel Ravelonandro
Keyword(s):  
Virus Resistance ◽  
Rna Silencing ◽  
Transcriptional Gene Silencing ◽  
Marker Genes ◽  
Plum Pox Virus ◽  
Woody Perennials ◽  
Woody Perennial ◽  
Post Transcriptional Gene Silencing ◽  
High Level ◽  
Interfering Rna

We have shown that high-level resistance to plum pox virus (PPV) in transgenic plum clone C5 is based on post-transcriptional gene silencing (PTGS), otherwise termed RNA silencing (Scorza et al. Transgenic Res. 10:201-209, 2001). In order to more fully characterize RNA silencing in woody perennial crops, we investigated the production of short interfering RNA (siRNA) in transgenic plum clones C3 and C5, both of which harbor the capsid protein (CP) gene of PPV. We used as a control, plum PT-23, a clone only transformed with the two marker genes, NPTII and GUS. We show in the current report that C5 constitutively produces two classes of siRNA, the short (21-22 nucleotides) and long (≈27 nucleotides) species in the absence of PPV inoculation. Transgenic susceptible clone C3 and the control clone PT-23, when healthy, produce no siRNA. Upon infection, these clones produce only the short siRNA (21-22 nt). This siRNA production suggests that plum trees naturally respond to virus infection by initiating PTGS or PTGS-like mechanisms. This study also suggests that high-level virus resistance in woody perennials may require the production of both the short and long size classes of siRNA, as are produced by the resistant C5 plum clone.

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