|Ravelonandro, M - INRA, FRANCE|
|Malinowski, T - RES INST/POMOLOGY, POLAND|
|Levy, L - APHIS|
Submitted to: International Biotechnology Congress
Publication Type: Abstract Only
Publication Acceptance Date: March 1, 2002
Publication Date: June 23, 2002
Citation: Scorza, R., Ravelonandro, M., Callahan, A.M., Malinowski, T., Damsteegt, V.D., Levy, L. 2002. Studies of plum pox virus resistance in transgenic plum C5 and its progeny. International Biotechnology Congress, 10th IAPTC&B Congress Proceedings, June 2002, P-1033, p 41. Technical Abstract: Plum pox virus (PPV) is one of the most devastating diseases of Prunus (stone fruit) species. Since the first report of PPV in Bulgaria in the early 1900's PPV has spread throughout Europe, into parts of Asia and Northern Africa, and more recently to Chile, the U.S. and Canada, where eradication efforts are currently underway. Breeding for resistance is an nimportant control strategy but few sources of high level resistance have been identified, and these are multigenic, requiring long-term breeding efforts for their incorporation into commercial cultivars. Transgene-based resistance offers a complementary approach to developing PPV-resistant stone fruit cultivars. Transgenic plum clone C5 carrying the PPV coat protein (CP) gene, found to be highly resistant to PPV in greenhouse graft- inoculation tests, also displayed high levels of resistance in field tests in Poland, Romania, and Spain. These field tests have also suggested that C5 is immune to aphid inoculation under conditions of natural aphid- vectored infection. C5 has been shown to be resistant to all of the major PPV strains. Resistance appears to be mediated through post- transcriptional gene silencing. The transgene, which appears to be a complex multicopy repeat and rearrangement of the original gene cassette, is inherited in crosses to Prunus domestic and P. spinosa as a single dominant locus with all progeny carrying the insert resistant to PPV. Our work with clone C5 indicates the usefulness of transgene-mediated resistance to PPV, the efficiency of gene-silencing in a woody perennial tree crop, and provides new and useful transgenic germplasm for developing new PPV-resistant lines through hybridization.