ARS | Publication request: HoneySweet: a hope for stone-fruit growers

Submitted to: International Symposium on the Biosafety of Genetically Modified Organisms
Publication Type: Abstract Only
Publication Acceptance Date: April 24, 2008
Publication Date: November 16, 2008
Citation: Ravelonandro, M., Scorza, R. 2008. HoneySweet: a hope for stone-fruit growers. International Symposium on the Biosafety of Genetically Modified Organisms. p. 49.

Technical Abstract: Prunus species are among the important domesticated fruit crops, and they have been spread worldwide. Since its identification in the early 1900’s, Plum pox virus (PPV), one of the most damaging pathogens of stone fruit trees, has also been spreading worldwide, and the pace of its movement has accelerated. PPV or sharka disease has become endemic in extensive areas of stone fruit production including Central Europe, the Mediterranean Basin, and the Balkans. Limited areas of infection are found in Western Europe, and more recently, outbreaks have been reported in countries such as the USA, Canada, and many others. Efforts to combat PPV started 93 years ago, but due to the paucity of natural resistance, few resistant cultivars have been produced. Using transgenic technology, we identified the C5 plum clone named 'HoneySweet' which is highly resistant to PPV infection. Greenhouse experiments, phytopathological and molecular studies, and field tests have confirmed the stability and the durability of PPV resistance in this variety. No PPV strain has broken the genetically engineered resistance. Reflecting upon the 10 years of field and laboratory research conducted on 'HoneySweet', we have found it to be: 1) an important tool to better understand the gene silencing (si-miRNA) resistance mechanism, 2) an important demonstration of the successful deployment of biotechnology against a quarantine pest, and 3) a safe and useful strategy for avoiding the use of pesticides to control natural aphid vectors of PPV. The deregulation of 'HoneySweet' in the USA by USDA/APHIS corroborates the utility of these findings. 'HoneySweet' is useful to plant pathologists particularly for studying the key factors involved in virus resistance in plants, and for fruit tree breeders and growers as an important genetic resource for PPV resistance.