Stability of gene silencing-based resistance to Plum pox virus in transgenic plum (Prunus domestica L.) under field conditions.
Plum pox virus (PPV) is one of the most devastating diseases of Prunus species. Since few sources of resistance to PPV have been identified, transgene-based resistance offers a complementary approach to developing PPV-resistant stone fruit cultivars. C5, a transgenic clone of Prunus domestica L., containing the PPV coat protein (CP) gene, has been described as highly resistant to PPV in greenhouse tests, displaying characteristics typical of post-transcriptional gene silencing (PTGS). We show in this report that C5 trees exposed to natural aphid vectors in the field remained uninfected after 4 years while susceptible transgenic and untransformed trees developed severe symptoms within the first year. C5 trees inoculated by chip budding showed only very mild symptoms and PPV could be detected in these trees by IC-RT-PCR. The PPV-CP transgene in C5 was specifically hyper-methylated with no detectable expression. These results indicate both stability and efficiency of PTGS-based PPV resistance in plum under field conditions.
Hily
Jean-Michel
JM
USDA-ARS Appalachian Fruit Research Station, 2217 Wiltshire Rd., Kearneysville, West Virginia 25430, USA.
Scorza
Ralph
R
Malinowski
Tadeusz
T
Zawadzka
Barbara
B
Ravelonandro
Michel
M
D000818:Animals; D001042:Aphids / Q000235:genetics; D036022:Capsid Proteins / Q000235:genetics*; D019175:DNA Methylation; D017931:DNA Primers / Q000235:genetics; D020868:Gene Silencing; D018515:Plant Leaves / Q000235:genetics / Q000821:virology; D030821:Plants, Genetically Modified / Q000235:genetics* / Q000821:virology; D017801:Plum Pox Virus / Q000235:genetics* / Q000378:metabolism; D027861:Prunus / Q000235:genetics* / Q000821:virology
D036022:Capsid Proteins; D017931:DNA Primers