THE ABILITY OF A MILD ISOLATE OF PLUM POX VIRUS TO CROSS-PROTECT AGAINST SHARKA VIRUS

Plant viruses remain so far refractory to any chemical treatment or anything similar. When virus is incoming there is no cure neither treatment available. Our strategy consists of find out an appropriate approach to fight against Plum pox potyvirus. Plant pathologists identified a basic strategy similar to the “vaccine” concept, which is designated as cross-protection. Many examples are applied to solve some agronomical problems caused by plant viruses: Citrus tristeza virus (CTV), Zucchini yellow mosaic virus (ZYMV), Papaya ringspot virus (PRSV)... For this reason, our challenge was to adapt cross-protection approach to control sharka disease. Taking PPV-Bor3 as a model, we have isolated a few virus variants with whose the designated PPV-T12 has been selected. Since the availability of different monoclonal antibodies raised specifically to PPV-D and PPV-M types, we have proven that PPV-T12 provided the opportunity to protect plants against an undesired PPV strain. Thus we have explored the potential of cross-protection by transferring PPV-T12 in woody natural hosts. The preliminary results of the challenging assays with a severe isolate of PPV D isolate in GF305 peach have permitted to demonstrate that cross-protection is effective.