Vector manipulation by viruses: The pathosystem Brassicaceae-aphids-phytoviruses, a study case
Résumé
Introduction: Vector-borne viruses can induce changes in the phenotype of their host plants that influence the frequency and nature of host–vector interactions. Insect-vectored phytoviruses that differ in their modes of transmission (persistent, semi-persistent and non-persistent) benefit from different patterns of interaction among host plants and vectors. Manipulation of vector behavior by phytovirus facilitates its propagation and seems to converge according to the virus transmission mode. However, this convergence has barely been studied in viruses infecting Brassicaceae. Methods: The present study has tested the effects of infection of the Brassicaceae plant Camelina sativa with the persistent Turnip Yellows Virus and the semi-persistent Cauliflower Mosaic Virus on (i) arrestment and dispersal, (ii) feeding behavior by electropenetrography and (iii) physiology of two aphid species: the polyphagous Myzus persicae and the Brassicaceae specialist Brevicoryne brassicae. Results/Conclusion: Results showed no evidence of evolutionary convergence in vector behavior within persistent and semi-persistent phytovirus-infected camelina. Indeed, whatever the virus species considered, infected camelina had opposite effects (i.e. negative and positive) on the feeding behavior and physiology of the two aphid species. In conclusion, viral manipulation of vector behavior could therefore depend not only on the virus mode of transmission, which is generally considered as a common assumption, but also on the aphid species. Indeed, aphid species with dissimilar dietary specialization differed in their response to the same virus infection.