Résumé
Plant viruses transmitted by aphids cause tremendous losses in most important crops around the world. The majority of these viruses are transmitted in a noncirculative manner and transported on the surface of the stylets while the aphids move from plant to plant. They are reversibly attached to specific receptors located on the cuticle of the feeding apparatus, and can be efficiently inoculated within seconds, thereby promoting viral outbreaks. The identification of receptors of viruses within their insect vectors is a key challenge to understanding the mechanisms of transmission, because they are promising targets for alternative control strategies to limit viral spread. Ten years ago, we discovered the acrostyle, an organ at the distal tip of aphid maxillary stylets that displays the receptors of Cauliflower mosaic virus all over its surface, and likely those of other noncirculative viruses (1,2). Since then, we developed complementary approaches to characterize this organ and identify virus receptors in aphid stylets. We have recently determined the first proteome of insect stylets and identified several cuticular proteins in the acrostyle, named Stylins, all candidate receptors of plant viruses. The role of Stylins in virus transmission is being evaluated. Stylin-01 has already been shown to play a key role in Cauliflower mosaic virus transmission (3). Our current data indicate that the acrostyle is a multifaceted organ with various binding properties and functions.