文章来源：管理员
作者：Admin
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发布时间：2017-03-21
Abstract
The
sesquiterpene (E)-b-farnesene (EBF) is the alarm pheromone for many species of
aphids [1]. When released from aphids attacked by parasitoids or predators, it
alerts nearby conspecifics to escape by
walking away and dropping off the
host plant [2, 3]. The reception of alarm pheromone in aphids is accomplished
through a highly sensitive chemosensory system. Although olfaction-related gene
families including odorant receptors (ORs) and odorant-binding proteins (OBPs)
have recently been identified from aphid genomes [4–6], the cellular and
molecular mechanisms of EBF reception are still largely unknown.
Herewedemonstrate thatApisOR5, amember of the large superfamily of odorant
receptors, is expressedinlargeplacoidsensillumneuronsonthe sixth antennal
segment and confers response to EBF when co-expressed with Orco, an obligate
odorant receptor co-receptor, in parallel heterologous expression systems. In
addition, the repellent behavior of Acyrthosiphon pisum to EBF disappears after
knocking down ApisOR5 by RNAi as well as two A. pisum odorantbinding proteins
known to bind EBF (ApisOBP3 and ApisOBP7). Furthermore, other odorants that can
also activate ApisOR5, such as geranyl acetate, significantly repel A. pisum, as
does EBF. Taken together, thesedata allowus to concludethatApisOR5 is essential
to EBF reception in A. pisum. The characterization of the EBF receptor allows
high-throughput screening of aphid repellents, providing the necessary
information to develop new strategies for aphid control.
