The acrostyle within aphid stylets : role in plant virus transmission and plant-aphid interaction

BGPI : équipe 2International audienceIntroduction: Aphids are sap-feeding insects with piercing-sucking mouthparts. Their reknown as major pests in agriculture relies mainly on their formidable capacity to transmit countless plant viruses to most important crops worldwide. The primary mode of virus transmission is the non-circulative manner where the virus is retained on specific receptors, yet unidentified, located in the aphids’ stylets. Viruses are transported on the stylet’s surface while the aphid moves from plant to plant. They are inoculated to healthy plants often within a single puncture lasting a few seconds, thereby promoting viral outbreaks. Highly specific interactions between viruses and their vectors are involved in this reversible attachment process. Over the last decade, we have discovered the acrostyle, an organ located at the tip of aphids’ maxillary stylets, which bears the receptors of Cauliflower mosaic virus (CaMV), and likely those of all agronomically important non-circulatively transmitted viruses. Using an antibodies library, we identified very recently the first protein of the acrostyle. We aim to determine the role it plays in plant virus transmission. Moreover, the physiological function of the acrostyle remains totally unknown. Methods: Antibodies library and immunolabelling were used to identify proteins located on the acrostyle. Results/Conclusion: We propose that the acrostyle, conserved across many aphid species, could be involved in the retention and release of other compounds, originating either from the plant or from the saliva, and thereby play a role in aphid/plant compatibility. The most recent advances will be presented and discussed