Submitted to: Acta Horticulturae
Publication Type: Proceedings
Publication Acceptance Date: 6/5/2005
Publication Date: N/A
Citation: Interpretive Summary: We have shown that genetically engineered plum trees are highly resistant to plum pox virus (PPV) and have remained so for over six years in the field. One potential threat to this resistance is the infection of trees with other stone fruit viruses which may have the potential of breaking the resistance to PPV. In order to test this possibility, we inoculated the resistant plums with Prunus necrotic ringspot virus (PNRSV), a virus that commonly infects stone fruits. We found that although the genetically engineered plum trees were not resistant to PNRSV, the infection of this virus did not break down resistance to PPV, and genetically engineered plums remained highly resistant to PPV. This shows both the effectiveness and the specificity of genetically engineered virus resistance.
Technical Abstract: The reaction of the transgenic plum pox virus (PPV) resistant C-5 plum was studied under conditions of co-infection with Prunus necrotic ringspot virus (PNRSV) and PPV, as may be encountered in the field. C-5 and controls were inoculated with PPV and PNRSV following several co-infection schemes. The results of this preliminary study showed that, as expected, the transgenic clones including C-5 were not resistant to PNRSV. Further, no PPV resistance breaking effects of the two viruses co-existing in C-5 were observed. In the susceptible clones, the data suggest that PNRSV might induce some masking effects of sharka disease (PPV). These synergistic effects are under investigation.