Research article - Peer-reviewed, 2007
Potyvirus-induced gene silencing: the dynamic process of systemic silencing and silencing suppression
Gammelgard E, Mohan M, Valkonen JPTAbstract
Potato virus A (PVA; genus Potyvirus) was used for virus-induced gene silencing in a model system that included transgenic Nicotiana benthamiana (line 16c) expressing the gfp transgene for green fluorescent protein (GFP) and chimeric PVA (PVA-GFP) carrying gfp in the P1 -encoding region. Infection of the 16c plants with PVA-GFP in five experiments resulted in a reproducible pattern of systemic gfp transgene silencing, despite the presence of the strong silencing-suppressor protein, HC-Pro, produced by the virus. PVA-GFP was also targeted by silencing, and virus-specific short interfering RNA accumulated from the length of the viral genome. Viral deletion mutants lacking the gfp insert appeared in systemically infected leaves and reversed silencing of the gfp transgene in limited areas. However, systemic gfp silencing continued in newly emerging leaves in the absence of the gfp-carrying virus, which implicated a systemic silencing signal that moved from lower leaves without interference by HC-Pro. Use of GFP as a visual marker revealed a novel, mosaic-like recovery phenotype in the top leaves. The leaf areas appearing red or purple under UV light (no GFP expression) contained little PVA and gfp mRNA, and corresponded to the dark-green islands observed under visible light. The surrounding green fluorescent tissues contained actively replicating viral deletion mutants that suppressed GFP silencing. Taken together, systemic progression of gene silencing and antiviral defence (RNA silencing) and circumvention of the silencing by the virus could be visualized and analysed in a novel mannerPublished in
Journal of General Virology2007, volume: 88, pages: 2337-2346
Publisher: SOC GENERAL MICROBIOLOGY
Authors' information
Gammelgård, Elin
Swedish University of Agricultural Sciences, Department of Plant Biology
Valkonen, Jari
Swedish University of Agricultural Sciences, Department of Plant Biology
Mohan, Maradumane
Swedish University of Agricultural Sciences, Department of Plant Biology
UKÄ Subject classification
Agricultural Science
Publication Identifiers
DOI: https://doi.org/10.1099/vir.0.82928-0
URI (permanent link to this page)
https://res.slu.se/id/publ/15991