Coordinative mediation of the response to alarm pheromones by three odorant binding proteins in the green peach aphid Myzus persicae.

Abstract Odorant binding proteins (OBPs) play an essential role for insect chemosensation in insect peripheral nervous systems of antennae. Each antennal sensilla contains more than one OBP at high concentrations but the interactions and cooperation between co-localized OBPs are rarely reported. In present study, we cloned, expressed and purified eight OBPs of the green peach aphid Myzus persicae. The effects of knocking down the expression of these OBP genes by RNAi on the electrophysiological and behavioural responses of M. persicae to the aphid alarm pheromone, (E)-β-farnesene (EβF) were investigated. The results showed that the aphids could still be repelled by EβF when the expression of each of three OBP genes was individually knocked down. However, the simultaneous knockdown of MperOBP3/7/9 expression significantly reduced the electrophysiological response and the repellent behaviours of M. persicae to EβF than the single OBP gene knockdown (P