VPg of Potato virus A alone does not suppress RNA silencing but affects virulence of a heterologous virus

Anna Germundsson, Eugene I Savenkov, Marjo Ala-Poikela, Jari P. T Valkonen, Jari Valkonen

Tutkimustuotos: ArtikkelijulkaisuArtikkeliTieteellinenvertaisarvioitu

Abstrakti

The viral genome-linked protein (VPg) is a well-known virulence factor in potyviruses (genus Potyvirus), including Potato virus A (PVA). Its ability to suppress onset and signalling of transgene-mediated RNA silencing and accumulation of small interfering RNA (siRNA) was studied using cross-protection and Agrobacterium infiltration assays and green fluorescent protein (GFP) and PVA VPg protein-expressing transgenic Nicotiana benthamiana plants. N. benthamiana plants were also transformed with a transgene comprising the cylindrical inclusion protein (CI), nuclear inclusion protein a (NIa) and coat protein (CP) encoding regions of PVA. This transgene mRNA was expressed in the T1 progeny of the transgenic lines but all were susceptible to PVA. This result contrasted the plants transformed with the PVA P1, VPg (N-proximal part of NIa) or CP encoding regions that expressed various forms of resistance. There was little evidence for direct involvement of VPg in suppression of silencing, while other mechanisms by which VPg might interfere with transgenic resistance could not be excluded. Expression of the wild-type PVA VPg from the genome of Potato virus X (PVX, genus Potexvirus) increased symptom severity in N. benthamiana, whereas a single point mutation introduced to the VPg enhanced accumulation of the PVX chimera. These data demonstrated previously unknown virulence functions controlled by the VPg of a potyvirus.
Alkuperäiskielienglanti
LehtiVirus Genes
Vuosikerta34
Sivut387-399
Sivumäärä13
ISSN0920-8569
DOI - pysyväislinkit
TilaJulkaistu - 2007
OKM-julkaisutyyppiA1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä, vertaisarvioitu

Tieteenalat

  • 414 Maatalouden bioteknologia
  • 411 Maatalous ja metsätieteet

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