Résumé
Viruses rely totally on the host to achieve every step of the infection cycle. Much is known about how viruses interfere with cellular processes to put them at their use and it is clear that they intercept intracellular and intra-host communication and processes to optimise interaction with the host. Here we unprecedentedly that show viruses are also able to use the host sensorial system to very rapidly perceive and react on cues from the world outside the host, in a way disconnected from the reaction of the host itself. Cauliflower mosaic virus (CaMV) is transmitted from plant-to-plant by aphids, and previous work has shown that the virus-aphid interaction is not an accidental process but depends on the presence of the virusinduced Transmission Bodies (TBs) in infected cells, containing the CaMV transmissible complexes. Our results demonstrate that TBs react on the presence and feeding of the insect vector by rapidly and reversibly dispersing their contents on cortical microtubules throughout the cell. If this TB reaction is perturbed, transmission rates drop; if this reaction is artificially enhanced, transmission rates rise. This shows that CaMV intercepts the host's perception of the aphid and immediately translates it in an appropriate response that optimises its chances of acquisition, everything going back to normal standby state a few minutes later.