Stability of gene silencing-based resistance to Plum pox virus in transgenic plum (Prunus domestica L.) under field conditions

Abstract

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.

Cassava brown streak disease: a threat to food security in Africa

“…RNAi-mediated field resistance has also been demonstrated for papaya (Fuchs & Gonsalves, 2007), squash (Tricoli et al, 1995) and plum (Hily et al, 2004), which are approved and commercially cultivated by farmers. However, the major concern in using RNAi technology to control plant viruses is that point mutations or recombinations in the target virus could 'break' the engineered resistance.…”

Genetic Transformation Strategies in Fruit Crops

“…Obtained by transformation of ´Bluebyrd´ explants, C5 was derived from transformation events using A. tumefaciens strain C58/Z707 containing a binary plasmid with the coat protein (CP) PPV gene plus the 3' non-translated region of the viral genome (EMBL Accession No X16415, Teycheney et al, 1989). The high degree of resistance observed has been stable in more than 10 years of evaluations in greenhouses and in the field (Hily et al, 2004;Malinowski et al, 2006;Polák et al;. In C5, the clone has exhibited resistance associated to RNA interference (RNAi), i.e.…”

Gene silencing: concepts, applications, and perspectives in woody plants

“…(Domínguez et al, 2002b;Fagoaga et al, 2006), Prunus sp. (Ravelonandro et al, 2000;Hily et al, 2004;2005;Di Nicola-Negri et al, 2005;Zhang et al, 2006), Populus sp. (Jouanin et al, 2000;Kumar & Fladung, 2001;Hawkins et al, 2003), Solanum dulcamara L. (Curtis et al, 2000), Malus domestica Borkh.…”