Résumé
Aphids are the only known vectors of stylet-borne non-circulative viruses comprising hundreds of species in the genera Caulimovirus, Potyvirus and Cucumovirus. These viruses can be acquired and inoculated from one plant to another within seconds when aphids feed. They are retained on receptors located at the surface of the stylets cuticle. The acrostyle is an organ at the tip of aphid stylets that binds the Cauliflower mosaic virus (CaMV) and that is suspected to contain receptors of other viruses. Some receptor candidates have been identified at the surface of the acrostyle. Among these, Stylin-01, a cuticular protein from the CPR family, was shown to play an important role in CaMV transmission through RNAi mediated knockdown experiments. CRISPR-Cas9 technology is an efficient functional analysis tool that has been successfully achieved to edit the genome of the pea aphid, Acyrthosiphon pisum. Several Stylin-01 mutant lineages have been generated to confirm the role of this protein in virus transmission. In our work, we focus on four mutant lineages that are altered to varying degrees, among which one lineage is totally knocked out. We are currently characterizing their virus binding capacity and their ability to transmit two non-circulative viruses, a Caulimovirus, the CaMV, and a Potyvirus, the Turnip mosaic virus (TuMV). Our ongoing data indicate that the lowest transmission rates for both viruses were obtained with the Stylin-01 KO lineage, although the differences observed for TuMV between wild type and mutant lineages were less important. These results will be presented and discussed.