UMR1131, Santé de la vigne et qualité du vin, Inra, Université Louis Pasteur de Strasbourg. Laboratoire de Virologie et Vection, 28 rue de Herrlisheim, 68021 Colmar
Transmission of plant viruses in nature often involves vectors which are usually plant pests. A class of soil borne invertebrates acts in this way. Ectoparasitic nematodes belonging to the Longidoridae family are responsible for the transmission of viruses from the Nepovirus genus using a semipersistant, non circulative mechanism. This passive transmission occurs during the feeding process of the nematodes on actively growing roots. However, only a few longidorid nematodes are able to acquire and subsequently transmit 12 of the 32 known Nepovirus. This singularity reflects a highly specific and strong association between the virus and the vector likely via a putative receptor on the cuticular lining of the oesophageal tract. Using a reverse genetics approach, investigations on the Grapevine fanleaf virus/Xiphinema index virus-vector association showed that the transmission specificity is solely determined by the coat protein.